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半导体制造工艺

参考教材
1、《集成电路工艺基础》，王阳元等编著，高等教育出版社。 2、《微电子制造科学原理与工程技术》，Stephen A. Campbell
著，国外电子与通信教材系列，电子工业出版社。 3、《集成电路制造技术—原理与实践》，庄同曾编，电子工业出
版社。
先修课程
半导体物理微电子器件
—— 课程内容 ——
学时：32学时
第一章概论第二章器件技术基础第三章硅和硅片制备简述第四章集成电路制造工艺概况第五章氧化
—— 课程内容 ——
第六章淀积第七章金属化第八章光刻原理和技术第九章刻蚀第十章扩散和离子注入第十一章化学机械平坦化
1
第一章概论
§ 1.1 半导体产业介绍
晶体管的发明（1947年）集成电路的发明（1959年）
体积大笨重功耗高可靠性差
The First Transistor from Bell Labs
体积小重量轻功耗低可靠性好
Inventors: Willian Schockley, Tohn Bardeen, Walter brattain
因此发明获得诺贝尔奖
Jack Kilby’s First Integrated Circuit
nMOSFET
VDD
G
S
DDLeabharlann GSVSS
n+
p+
p+
n+
n+
p+
p-well
n-type silicon substrate
Field oxide
7
第三章硅和硅片制备
3.1 半导体级硅
（1）半导体级硅

新一代宽禁带4H_SiC功率半导体外延材料的产业化进展

使用量产型10×100mm暖壁行星式外延生长系
37 2013 6 军民两用技术与产品
专家观点
表1 自2001年起由不同外延生长系统所获得的 4H-SiC外延晶片的性能指标
50mm
75mm
100mm
系统容量
7× 5× 7× 50mm 75mm 75mm
8× 100mm
10× 100mm
出现时间总晶片面积
使用高分辨X射线衍射谱仪（XRD）对外延晶片的晶体质量进行表征。外延晶片的厚度和掺杂浓度分别使用傅立叶变换红外光谱仪（FTIR）和C-V 汞探针进行表征。使用原子力显微镜（AFM）对晶片表面粗糙度进行测量。使用Candela光学表面分析仪对外延晶片的表面缺陷进行分析。
3 结果与讨论
图1为使用10×100mm暖壁行星式外延生长系统所获得的4H-SiC外延晶片的XRD图，其中，最强峰出现在35.57°，对应4H-SiC晶体的（0004）晶面。图1中的插图为外延晶片（0004）晶面的摇摆曲线，其半高宽（FWHM）为26.74″，说明整个外延晶片的结晶质量良好。
图4为该外延晶片的Candela缺陷扫描结果图，其总缺陷密度为0.75cm-2。所统计的外延层表面缺陷主要包括微管缺陷、三角形缺陷、掉落物缺陷和胡萝卜缺陷等常见形貌缺陷。
图5为10×100mm暖壁行星式外延生长系统全片生长时的片间厚度和掺杂均匀性测试结果。测试结果为：外延晶片的平均厚度为11.43μm，片间均匀性为0.5%；平均掺杂浓度为5.4×1015cm-3，片间均匀性为3.4%。这表明，尽管10×100mm暖壁行星式外延生长系统的容量高达10×100mm，但各外延晶片在厚度与掺杂方面具有良好的一致性。
专家观点
新一代宽禁带4H-SiC功率半导体外延材料的产业化进展

The_Fundamentals_of_Digital_Semiconductor_Testing_(chinese)

目录第一章.认识半导体和测试设备 (3)一、晶圆、晶片和封装 (3)二、自动测试设备 (6)三、半导体技术 (7)四、数字和模拟电路 (7)五、测试系统的种类 (8)六、测试负载板(LoadBoard) (11)七、探针卡（ProbeCard） (12)第二章.半导体测试基础 (13)一、基础术语 (13)二、正确的测试方法 (14)三、测试系统 (16)四、PMU (18)五、管脚电路 (21)第三章.基于PMU的开短路测试 (25)一、测试目的 (25)二、测试方法 (25)第四章.DC参数测试 (29)一、基本术语 (29)二、Binning (29)三、Program Flow (30)四、Test Summary (31)五、DC测试与隐藏电阻 (32)六、VOH/IOH (33)七、VOL/IOL (36)八、IDD Gross Current (39)九、IDD Static Current (42)十、IDDQ (44)十一、IDD Dynamic Current (45)十二、入电流（IIL/IIH）测试 (48)十三、输入结构－高阻/上拉/下拉 (54)十四、输出扇出 (55)十五、高阻电流（High Impedance Currents, IOZH/IOZL） (57)十六、输出短路电流（output short circuit current） (60)第五章．功能测试 (63)一、基础术语 (64)二、功能测试 (64)三、测试周期 (65)四、输入数据 (65)五、输出数据 (68)六、功能测试参数定义 (72)七、总功能测试（Gross Function Test） (73)八、功能测试实例 (77)九、标准功能测试 (80)第六章.AC参数测试 (91)第一章.认识半导体和测试设备本章节包括以下内容，●晶圆（Wafers）、晶片（Dice）和封装（Packages）●自动测试设备（ATE）的总体认识●模拟、数字和存储器测试等系统的介绍●负载板（Loadboards）、探测机（Probers）、机械手（Handlers）和温度控制单元（Temperature units）一、晶圆、晶片和封装1947年，第一只晶体管的诞生标志着半导体工业的开始，从那时起，半导体生产和制造技术变得越来越重要。

压电薄膜特性参数的测量方法_王青萍

收稿日期:2009-01-19基金项目:国家高技术/八六三0计划基金资助项目(2007AA03Z120);国家自然科学基金资助项目(60777043) 作者简介:王青萍(1980-),女,陕西绥德人,硕士生,主要从事压电薄膜的性能研究。

文章编号:1004-2474(2009)04-0608-05压电薄膜特性参数的测量方法王青萍1,3,范跃农2,3,姜胜林3(1.湖北第二师范学院物理与电子工程系,湖北武汉430205;2.景德镇陶瓷学院机械电子工程系,江西景德镇333403;3.华中科技大学电子科学与技术系教育部敏感陶瓷工程研究中心,湖北武汉430074)摘要:随着电子元器件向微型、高灵敏、集成等方向发展,薄膜材料及器件在微机电(M EM S)系统中得到广泛应用,而测量压电薄膜特性参数的方法与体材料相比有很大的不同。

介绍了当前测量压电薄膜特性参数的两大类方法:直接测量法(包括气腔压力法、悬臂梁法、激光干涉法和激光多普勒振动法)和间接测量法(传统阻抗分析法),详细分析了这些方法的基本原理、测试表征、应用状况及存在的问题,比较了这些方法的优缺点,并对未来压电薄膜特性参数的测试表征作了展望。

关键词:压电薄膜;压电参数;测量方法中图分类号:T N30;T M 282 文献标识码:AMeasurement Methods for Piezoelectric Coefficient of Piezoelectric Thin FilmsWANG Qing -ping 1,3,FAN Yue -nong 2,3,JIANG Sheng -lin 3(1.H ub ei University of E ducation ,Physics &Electronics Dept.Wuhan 430205,Ch ina; 2.Jingdezhen Ceramic Institute,M ech anis m &Electronics Dept.,Jingdezhen 333403,China; 3.Dept.of Electronic Science and T ech nology,Engin eering Research Centre for Function al Ceramics M OE H uazhong University of Science and T ech nology,W uhan 430074,Chin a)Abstract:F ilm mater ials and dev ices have been widely used in micr o -electr omechanical sy stem (M EM S)system wit h the develo pment o f micromation,hig h sensit ivity and integr ation of electr onic devices.But the measurement met ho ds for piezo electric pr operties o f piezoelect ric thin films ar e ver y differ ent fro m those of bulk materials.T wo categ or ies of measur ing piezoelectric pro per ties o f piezoelect ric thin films wer e intr oduced in this paper:direct meas -urement(including pneumatic pr essure r ig,cant ilev er method,laser interfer ometer method and laser Do ppler vibr o -meter met ho d)and indirect measur ement(conventional impedance analy zer ).T he basic pr inciple,measurement char -acter izat ion,applicatio n status and problems wer e all illustrated in this paper,t he adv antag es/disadv antag es o f these techniques wer e co mpar ed fo r piezoelectr ic applicatio ns and the futur e dev elo pment of measurement characterization of piezo electr ic thin f ilms w ere predicted.Key words:piezoelect ric thin film;piezoelectr ic coefficient;measurement methods压电薄膜作为一种很有前景的材料被广泛应用在微机电系统(MEM S)中,比如微致动器、微泵、化学传感器及移动通信中的射频滤波器[1-4]等。

半导体一些术语的中英文对照

半导体一些术语的中英文对照离子注入机ion implanterLSS理论Lindhand Scharff and Schiott theory 又称“林汉德-斯卡夫—斯高特理论”.沟道效应channeling effect射程分布range distribution深度分布depth distribution投影射程projected range阻止距离stopping distance阻止本领stopping power标准阻止截面standard stopping cross section退火annealing激活能activation energy等温退火isothermal annealing激光退火laser annealing应力感生缺陷stress-induced defect择优取向preferred orientation制版工艺mask—making technology图形畸变pattern distortion初缩first minification精缩final minification母版master mask铬版chromium plate干版dry plate乳胶版emulsion plate透明版see-through plate高分辨率版high resolution plate, HRP超微粒干版plate for ultra—microminiaturization 掩模mask掩模对准mask alignment对准精度alignment precision光刻胶photoresist又称“光致抗蚀剂”。

负性光刻胶negative photoresist正性光刻胶positive photoresist无机光刻胶inorganic resist多层光刻胶multilevel resist电子束光刻胶electron beam resistX射线光刻胶X-ray resist刷洗scrubbing甩胶spinning涂胶photoresist coating后烘postbaking光刻photolithographyX射线光刻X—ray lithography电子束光刻electron beam lithography离子束光刻ion beam lithography深紫外光刻deep-UV lithography光刻机mask aligner投影光刻机projection mask aligner曝光exposure接触式曝光法contact exposure method接近式曝光法proximity exposure method光学投影曝光法optical projection exposure method 电子束曝光系统electron beam exposure system分步重复系统step-and-repeat system显影development线宽linewidth去胶stripping of photoresist氧化去胶removing of photoresist by oxidation等离子［体]去胶removing of photoresist by plasma 刻蚀etching干法刻蚀dry etching反应离子刻蚀reactive ion etching，RIE各向同性刻蚀isotropic etching各向异性刻蚀anisotropic etching反应溅射刻蚀reactive sputter etching离子铣ion beam milling又称“离子磨削”。

高可靠性微电子装备国产焊膏研制工程

2021年3月电子工艺技术Electronics Process Technology第42卷第2期113作者简介：樊融融，男，研究员，中兴通讯股份有限公司终身荣誉专家。

摘　要：针对当前国内高可靠性微电子装备用焊膏完全受制于国外，国内尚无一品牌产品可以替代的问题，分析了这一隐患的严重性，对高可靠性微电子装备国产焊膏研制工程的立项背景、实施路线和研制工程试验大纲等进行了详实介绍。

研制工程团队历时两年多先后完成了摸底试验和定型认证试验，积累了海量数据，并进行了归纳处理。

对近千幅分析图像判读和比较，不断浓缩迭代，最终获得受试的１１种焊膏（有铅焊膏国内３种，国外２种；无铅焊膏国内和国外各３种）的全部测试数据项（有铅焊膏５７项、无铅焊膏６３项），并逐项按其性能的优劣进行排序，最后再按获得优项的次数和权重，对受测试的公司再排序，从而获得了对高可靠性微电子装备国产焊膏研制工程成果的评价结论。

关键词：焊膏；互连可靠性；应用工艺性；成果评价；微电子装备中图分类号：ＴＮ６０４　文献标识码：Ａ　文章编号：１００１－３４７４（２０２１）０２－０１１３－０７Abstract: In view of the problem that the domestic solder paste for high reliability microelectronic equipment is completely controlled by foreign countries, and there is no domestic brand product to replace, the seriousness of this hidden danger is analyzed, and the project background, implementation route and test program of domestic solder paste for high reliability microelectronic equipment is introduced in detail. It took more than two years for the research and development and engineering team to complete the thorough test高可靠性微电子装备国产焊膏研制工程Research and Development of Domestic Solder Paste with High Reliability forMicroelectronic Equipment樊融融FAN Rongrong（中兴通讯股份有限公司，广东　深圳　５１８０５７）( Zhongxing Telecommunication Equipment Corporation, Shenzhen 518057, China )高可靠性微电子装备国产焊膏研制工程ｄｏｉ：　１０．１４１７６／ｊ．ｉｓｓｎ．１００１－３４７４．２０２１．０２．０１５【编者按】　当前国内高可靠性微电子装备用焊膏完全受制于国外，国内尚无一品牌产品可以替代。

中国光刻机英语作文范文

中国光刻机英语作文范文Lithography, also known as photolithography, is a crucial process in the manufacturing of semiconductors and microchips. It involves the use of a device called a photolithography machine, commonly known as a wafer stepper or a lithography tool, to transfer a pattern onto a substrate, typically a silicon wafer. This pattern is crucial as it determines the layout of the integrated circuits on the wafer, and therefore it plays a critical role in the overall functionality of the microchip.The lithography process begins with the design of the circuit pattern using specialized software. This pattern is then transferred onto a photomask, which is a high-precision quartz plate that contains the circuit pattern in the form of opaque and transparent regions. The photomask is then loadedinto the lithography machine, along with the silicon wafer coated with a light-sensitive material known as photoresist.During operation, the photomask is illuminated with ultraviolet light, and the pattern is projected onto the wafer. The light-sensitive photoresist undergoes a chemical reaction when exposed to the light, and the pattern is transferred onto the wafer. This process is repeated multiple times to create the desired circuit layout on the entire surface of the wafer.The precision and accuracy of the lithography machine are crucial, as any deviation or error in the pattern transfer can result in defective or non-functional microchips. Therefore, lithography machines are equipped with advanced optical systems, high-precision stages, and sophisticated control algorithms to ensure the highest level of accuracy and consistency in the pattern transfer process.In recent years, the semiconductor industry has witnessed a rapid evolution in lithography technology, driven by the demand for smaller and more complex microchips. This has led to the development of new generation lithography machines, such as extreme ultraviolet (EUV) lithography, which use shorter wavelength light sources to achieve even finercircuit patterns.In conclusion, the role of lithography machines in semiconductor manufacturing cannot be overstated. These high-precision, state-of-the-art devices are instrumental in shaping the future of microelectronics, enabling the production of smaller, faster, and more powerful microchips that drive innovation in various industries.。

第三、四代半导体晶圆超精密加工粉末-概述说明以及解释

第三、四代半导体晶圆超精密加工粉末-概述说明以及解释1.引言1.1 概述概述部分的内容可以描述第三、四代半导体晶圆超精密加工粉末的背景和意义。

以下是一个示例：在当今信息技术迅速发展的背景下，第三、四代半导体材料如氮化镓和碳化硅材料逐渐成为半导体行业的研究热点。

与传统硅材料相比，第三、四代半导体材料具有更高的耐电压和导热性能，使其成为高频高功率电子器件的理想选择。

然而，要将这些半导体材料应用于实际生产中，需要对晶圆进行超精密加工。

而超精密加工粉末作为加工过程中的重要材料，具有直接影响加工质量和成本的关键作用。

本文主要讨论第三、四代半导体晶圆超精密加工粉末的相关问题和研究进展。

在第二章中，将重点介绍第三代半导体晶圆超精密加工粉末的要点，包括粉末特性、制备方法和应用领域等方面的内容。

第三章将进一步探讨第四代半导体晶圆超精密加工粉末的要点，包括粉末的纳米特性、制备技术的改进和未来发展趋势等内容。

通过对第三、四代半导体晶圆超精密加工粉末的综述，我们可以更加全面地了解这一领域的最新进展和未来发展趋势。

这对于推动半导体材料和工艺的创新，提高器件性能和制造质量，具有重要的理论和实践意义。

本文的结论部分将总结目前的研究成果，并展望未来可能的研究方向和应用前景。

1.2文章结构文章结构是指文章的整体框架和组织方式，它有助于读者理解文章的逻辑结构和内容安排。

本文的结构可以按照以下方式组织：1. 引言1.1 概述引言部分将对第三、四代半导体晶圆超精密加工粉末的研究领域进行介绍，并指出该领域的重要性和应用前景。

1.2 文章结构本文将按照以下结构进行组织和论述：2. 正文2.1 第三代半导体晶圆超精密加工粉末的要点1在此部分，将详细阐述第三代半导体晶圆超精密加工粉末的特点、加工工艺和应用领域，以及相关的研究成果和进展。

2.2 第三代半导体晶圆超精密加工粉末的要点2本部分将进一步介绍第三代半导体晶圆超精密加工粉末的关键技术和具体实验方法，以及相关的研究成果和应用案例。

TC4钛合金激光选区熔化制件与传统锻铸件的对比

工业技术科技创新导报 Science and Technology Innovation Herald91DOI：10.16660/ki.1674-098X.2009-5640-3744TC4钛合金激光选区熔化制件与传统锻铸件的对比①张婷陈素明刘焕文(西安飞机工业（集团）有限责任公司陕西西安 710089)摘要：本文通过探讨激光选区熔化的成形原理及应用现状，从TC4成形工艺、成形组织、力学性能、质量等级等方面，将激光选区熔化TC4制件与传统锻铸件间的区别进行了简单分析。

结果表明，相较于传统锻件、铸件而言，激光选区熔化制件材料利用率更高，制造周期更短；静态力学性能高于钛合金铸件性能，达到甚至超过锻件性能；激光选区熔化制件质量级别处于中等，比锻件质量级别低，但高于铸件质量级别。

关键词：激光选区熔化锻件铸件对比中图分类号：AAa 文献标识码：A 文章编号：1674-098X(2020)12(c)-0091-03Comparison of Laser Selective Melting Parts of TC4 TitaniumAlloy and Traditional Forging CastingsZHANG Ting CHEN Suming LIU Huanwen(Xi'an Aircraft Industry (Group) Co., Ltd.,Xi'an,Shaanxi Province,710089 China)Abstract: By discussing the forming principle and application status of laser selective melting, the difference between laser selective melting TC4 parts and traditional forging castings is brief ly analyzed from the aspects of TC4 forming process, forming structure, mechanical properties and quality grade. The results show that, compared with traditional forgings and castings, the material utilization rate of laser selective melting parts is higher and the manufacturing cycle is shorter; the static mechanical properties are higher than the performance of titanium alloy castings, reaching or even exceeding the performance of forging parts; laser selective melting parts The quality level is medium, lower than the forging quality level, but higher than the casting quality level.Key Words: Laser selective melting; Forgings; Castings; Comparison①作者简介：张婷（1988—），女，汉族，陕西西安人，硕士，工程师，研究方向为3D打印及锻铸技术。

SMT英文

SMT英文缩写词汇解析AI :Auto-Insertion 自动插件AQL :acceptable quality level 允收水准ATE :automatic test equipment 自动测试ATM :atmosphere 气压BGA :ball grid array 球形矩阵CCD :charge coupled device 监视连接组件(摄影机)CLCC :Ceramic leadless chip carrier 陶瓷引脚载具COB :chip-on-board 芯片直接贴附在电路板上cps :centipoises(黏度单位) 百分之一CSB :chip scale ball grid array 芯片尺寸BGACSP :chip scale package 芯片尺寸构装CTE :coefficient of thermal expansion 热膨胀系数DIP :dual in-line package 双内线包装(泛指手插组件)FPT :fine pitch technology 微间距技术FR-4 :flame-retardant substrate 玻璃纤维胶片(用来制作PCB材质) IC :integrate circuit 集成电路IR :infra-red 红外线Kpa :kilopascals(压力单位)LCC :leadless chip carrier 引脚式芯片承载器MCM :multi-chip module 多层芯片模块MELF :metal electrode face 二极管MQFP :metalized QFP 金属四方扁平封装NEPCON :National Electronic Package andProduction Conference 国际电子包装及生产会议PBGA:plastic ball grid array 塑料球形矩阵PCB:printed circuit board 印刷电路板PFC :polymer flip chipPLCC:plastic leadless chip carrier 塑料式有引脚芯片承载器Polyurethane 聚亚胺酯(刮刀材质)ppm:parts per million 指每百万PAD(点)有多少个不良PAD(点) psi :pounds/inch2 磅/英吋2PWB :printed wiring board 电路板QFP :quad flat package 四边平坦封装SIP :single in-line packageSIR :surface insulation resistance 绝缘阻抗SMC :Surface Mount Component 表面黏着组件SMD :Surface Mount Device 表面黏着组件SMEMA :Surface Mount EquipmentManufacturers Association 表面黏着设备制造协会SMT :surface mount technology 表面黏着技术SOIC :small outline integrated circuitSOJ :small out-line j-leaded packageSOP :small out-line package 小外型封装SOT :small outline transistor 晶体管SPC :statistical process control 统计过程控制SSOP :shrink small outline package 收缩型小外形封装TAB :tape automaticed bonding 带状自动结合TCE :thermal coefficient of expansion 膨胀(因热)系数Tg :glass transition temperature 玻璃转换温度THD :Through hole device 须穿过洞之组件(贯穿孔)TQFP :tape quad flat package 带状四方平坦封装UV :ultraviolet 紫外线uBGA :micro BGA 微小球型矩阵cBGA :ceramic BGA 陶瓷球型矩阵PTH :Plated Thru Hole 导通孔IA Information Appliance 信息家电产品MESH 网目OXIDE 氧化物FLUX 助焊剂LGA (Land Grid Arry)封装技术LGA封装不需植球，适合轻薄短小产品应用。

中国芯片产业的崛起英语介绍

中国芯片产业的崛起英语介绍In recent years, the rise of China's chip industry has been a remarkable trend in the global technology landscape. From being a latecomer in the semiconductor race, China has rapidly transformed into a major player, investing billions of dollars in research and development, building manufacturing facilities, and attracting top talent from around the world. This transformation is not just about numbers; it's about the shift in technological paradigms and the emergence of a new era in chip design and manufacturing.**Innovation Drivers**The driving force behind China's chip industry rise is its unwavering commitment to innovation. The country has established a robust ecosystem of research institutions, universities, and private sector companies that are focused on pushing the boundaries of semiconductor technology. This commitment is reflected in the number of patents filed by Chinese companies in the field of semiconductors, which has been growing at a rapid pace.Moreover, China has been aggressive in attracting global talent, offering competitive salaries and research funds to top scientists and engineers. This strategy has been successful in bringing many of the world's brightest minds to China, who are now contributing to the country's chip industry in areas such as advanced packaging, chip design, and materials research.**Manufacturing Capabilities**Another key aspect of China's chip industry rise is its manufacturing capabilities. The country has invested heavily in building state-of-the-art chip fabs that can produce chips with advanced features and high yields. These fabs are not just located in traditional manufacturing hubs like Shanghai and Beijing but are also being set up in emerging tech cities like Chengdu and Wuhan.This widespread distribution of manufacturingfacilities ensures that China has the capacity to meet the growing demand for chips across various industries, from consumer electronics to automotive and healthcare. Additionally, China is also making strides in areas likewafer manufacturing and chip packaging, which are crucial for the production of advanced chips.**Challenges and Opportunities**However, the rise of China's chip industry is not without its challenges. One of the main obstacles is the dependence on foreign technology and equipment, as many of the key components and materials used in chip manufacturing are still imported from abroad. This dependence limits China's ability to fully control its chip supply chain and can pose significant risks in times of geopolitical tensions.To overcome these challenges, China is actively investing in research and development to develop its own technologies and materials. It is also promoting domestic production of key components and equipment to reduce its dependence on imports. These efforts are expected to payoff in the long run, making China's chip industry more resilient and competitive.Despite these challenges, the opportunities for China's chip industry are immense. The global demand for chips is growing rapidly, driven by the increasing digitization ofeconomies and the emergence of new applications like artificial intelligence, 5G, and the Internet of Things. By leveraging its manufacturing capabilities, research strength, and vast market, China has the potential to capture a significant share of this growing market.**Conclusion**In conclusion, the rise of China's chip industry represents a significant milestone in the global technology landscape. Through innovation, investment, and strategic planning, China has transformed itself into a major player in the semiconductor industry, challenging the established order. While there are still challenges to overcome, the opportunities for growth and development are immense. As we move into the future, it will be fascinating to watch how China's chip industry continues to evolve and shape the global technology landscape.**中国芯片产业的崛起：创新与挑战并存的新时代** 近年来，中国芯片产业的崛起已成为全球科技领域的一个显著趋势。

Chinese Vinegar and its Solid-State Fermentation Process

FOOD REVIEWS INTERNATIONALVol.20,No.4,pp.407–424,2004Chinese Vinegar and its Solid-StateFermentation ProcessDengru Liu,1,*Yang Zhu,2Rik Beeftink,1Lydia Ooijkaas,1Arjen Rinzema,1Jian Chen,3and Johannes Tramper11Food and Bioprocess Engineering,Wageningen University and Research Centre,Wageningen,The Netherlands2Applied Plant Research,Wageningen University and Research Centre,Horst,The Netherlands3Southern Yangtze University,School of Biotechnology,Wuxi,ChinaABSTRACTChina uses solid-state fermentation(SSF)processes on a large scale for productssuch as vinegar,Chinese distilled spirit,soy sauce,Furu,and other national foodsthat are consumed around the world.In this article,the typical SSF process isdiscussed,with a focus on Chinese vinegars,especially those that are preparedthrough solid-state fermentation.Six well-known types are discussed in detail.Finally,possible ways to improve the traditional vinegar production process arediscussed.The article discloses Chinese information about solid-state vinegarfermentation that otherwise would be inaccessible to Western scientists due tolanguage barriers.Key Words:Chinese vinegar;Solid-state fermentation;Mixed culture;Anaerobic and aerobic fermentation.*Correspondence:Dengru Liu,Food and Bioprocess Engineering,Wageningen University and Research Centre,P.O.Box8129,6700,EV Wageningen,The Netherlands;E-mail: dengru.liu@wur.nl.407DOI:10.1081/LFRI-2000334608755-9129(Print);1525-6103(Online) Copyright&2004by Marcel Dekker,408Liu et al.INTRODUCTIONSolid-state fermentation(SSF)refers to the growth of microorganisms on moist solid substrate in the absence of free-flowing water(Moo-Yong et al.,1983).SSF may be more suitable and practical than submerged fermentation(SmF)for low-technology applications because(1)cheap unrefined agricultural products are used as substrates;(2)capital investment and operating cost are moderate;and(3)aseptic processing is less stringent.Other advantages and disadvantages of SSF over SmF have been discussed extensively(Mitchell and Lonsane,1992;Murthy et al.,1993; Robinson et al.,2001).During the last two decades,SSF has attracted interest from scientists and industries due to its potential for the production of food and pharmaceuticals,but large-scale application of SSF in Western countries is still limited because of scale-up problems(Nagel,2002).In Asian countries,however,SSF has been playing an important role in food and beverage preparation for thousands of years.In China alone,annual amounts of4.0Â109kg of Chinese soy sauce,of 2.0Â109kg of Chinese vinegar,and of8.0Â109kg of Chinese distilled spirits were produced;more than80%of these materials were produced by SSF(Wei,2001).Other important SSF products include Chinese sufu,lobster sauce,Chinese distilled spirit,and mushrooms.Vinegar is consumed worldwide as a food condiment and preservative,especially in the Chinese diet.Chinese vinegar has a history of more than3000years(Shi,1999). There are at least14main types on the market,including Zhenjiang aromatic vinegar,Shanxi old mature vinegar,Jiangzhe Rose vinegar,and Sichuan bran vinegar,whereas are all produced by SSF(Huang,1998).Traditional Chinese vinegar is made from different sorts of cereals,where as in more recent years many vinegars prepared from fruits have appeared on the market.This article does not discuss fruit vinegars because these are usually prepared by liquid fermentation.The SSF process for Chinese vinegar comprises four successive stages,namely koji preparation,saccharification of starch and alcohol fermentation,acetic-acid fermentation,and maturation(Huang and Yin,2000a).Figure1is a general flowchart of Chinese vinegar SSF.Saccharification and alcohol fermentation may either be SSF or SmF;other stages are always SSF(Huang and Yin,2000a).The entire process includes two aerobic fermentations(koji preparation and acetic-acid fermentation)and an anaerobic fermentation(alcohol fermentation).Fungi,yeasts, and bacteria are involved in the process;traditionally,all these microorganisms come from the environment or from the substrate and more or less spontaneously evolve throughout the process(Lei,2000).Although vinegar is produced and consumed worldwide,no publications in English on vinegar production by SSF processes have appeared in the last20years.A large number of Chinese publications are inaccessible to Western scientists due to language barriers.Hubert(1976)reviewed vinegar history,but did not include Chinese and Japanese SSF processes.The Japanese SSF processes are rooted in and similar to relevant processes in China(Bao,1988).This article reviews Chinese vinegar production through SSF.First,the history of Chinese vinegar production is presented briefly and general characteristics of the process are discussed,followed by the raw materials and composition of ChineseChinese Vinegar409Figure1.General flowchart of SSF for Chinese vinegar depicting the four steps. vinegar.Then,six major types of SSF-prepared Chinese vinegars are reviewed. Finally,opportunities to improve the traditional SSF processes and the possible implementation of such innovations are discussed.HISTORYChina probably has the oldest historical records about cereal vinegar in the world.The book Ceremony Notes(about800b.c.)(Xiao,2000)recorded that vinegar played an important ceremonial role during the Zhou dynasty(1000b.c.–256b.c.).Also,in The Analects of Confucius(450b.c.),there are many records on vinegar(Xiao,2000).In Techniques of Qinese(533–544a.d.),23methods for vinegar preparation are described in detail,among which the SSF method with cereals,a repeated successive fermentation process,was a unique technique for vinegar preparation(Bao,1985).Until the late Qing Dynasty(1644–1911a.d.),when industrial-scale vinegar production appeared(Zhang,2000),Chinese vinegar was only domestically produced on a small scale.It is generally believed that the production process of Shanxi old mature vinegar was invented by Wang Laifu during the Qing Dynasty, between1644and1661a.d.(Yan,1997).The fuming technique that characterizes this process is still used widely by all old mature vinegar manufacturers(Yan,1997). The Zhenjiang Henshun vinegar plant was established in1840a.d.and still is a major producer of aromatic rice vinegar,with an annual yield of60million kilograms (Ren and Jian,2000).RAW MATERIALS AND COMPOSITION OF CHINESE VINEGARSRaw MaterialThe main raw materials for production of traditional Chinese vinegars are cereals and their bran (i.e.,the outside layers of grains,containing about 50%starch).In more recent years,however,many other starch and sugar-containing materials,such as sweet potato and fruits,have found their way into vinegar production,resulting in new types of vinegar.Table 1lists the main raw materials that are used for Chinese vinegars.The type of raw material is the basis for the specific characteristics of different vinegar types (Zhu,1991a).Wheat bran is the main carrier of microorganisms in the SSF system;besides being a source of starch,it also provides other nutrients,such as proteins,to microorganisms.Rice hull has less nutritional value.It merely acts as a carrier of microorganisms and spacer to increase porosity of the substrate mixture (Liu and Li,1992).MicroorganismsMicroorganisms involved in Chinese vinegar fermentation include fungi,yeasts,and bacteria.Although the SSF process for Chinese vinegar is not aseptic,specific fungi,yeasts,and bacteria dominate the koji,alcohol,and acetic-acid fermentations due to the highly selective materials and operational conditions.Nowadays,some manufacturers add pure cultures of yeast and acetic acid bacteria,but traditional Chinese vinegar fermentation is still a spontaneous mixed-culture fermentation (Lin,1985).Aspergillus ,Rhizopus ,and Monascus are the main fungi in koji preparation;Saccharomyces cerevisiae and Hansenula anomala are the main yeasts in alcoholTable 1.Major raw materials for Chinese vinegar production.aName Carbohydrate (%)Protein(%)Lipid (%)Ash (%)Example Sticky rice 72.18.53.20.9Zhenjiang vinegar,Shanghai vinegar Japonica rice 73.48.82.2 1.3Jiangzhe vinegar Nonsticky rice 74.58.22.3 1.3Beijing vinegar Oat 66.715.63.2 1.7Highland barley 70.310.11.8 3.4Sorghum 70.08.35.0 3.0Shanxi vinegar Foxtail millet 76.09.73.3 1.4Corn 67.29.55.0 1.3Sweet potato 76.7 6.10.5 2.4Wheat bran55.014.0 4.0 5.0Sichuan vinegar a Data adapted from Huang and Cai (1999).410Liu et al.fermentation (Huang and Yin,2000a).In almost every Chinese vinegar SSF process,several species of acetic-acid bacteria are present:Acetobacter pasteurianus is the predominant species in Zhenjiang vinegar,due to the high initial ethanol concentration (Huang and Cai,1999).A.aceti dominates in Sichuan bran vinegar production,whereas in Jiangzhe and Fujian vinegars, A.xylinum is the main bacterium.A.xylinum forms a pellicle on the surface of the static liquid (Lei,2000),which is different from traditional wine vinegar production methods (e.g.,the Orleans method and the Balsamic method)where a foam rather than a pellicle forms at the surface (Adams,1985).Other bacteria,such as Gluconobacter and lactic-acid bacteria,are commonly found as well and their metabolites contribute to the characteristic flavor and aroma (Lei,2000).CompositionThe composition of Chinese vinegar has been investigated and reviewed extensively (Cui,1986;Huang and Yin,2000b).A large number of substances are present in Chinese vinegar,including organic acids,free amino acids,carbohydrates,alcohols,esters,and various microconstituents.Table 2outlines the general composition of seven Chinese vinegars;more detailed data were presented by Cui (1986).The complicated composition of Chinese vinegars is a reflection of their raw materials and production processes.Some components (e.g.,carbohydrates)were already present in raw materials,whereas others emerge during the production process,either (bio-)chemically or microbially.Because of differences in composition,each type of Chinese vinegar has its own distinct sensory characteristics.Traditional Chinese vinegar usually has a higher concentration of organic acids (up to 12%,of which more than 99%is acetic acid)Table 2.General composition of main Chinese vinegars (g/100mL).ComponentsRice vinegar Fumed vinegar Zhenjiang vinegar Shanxi vinegar Sichuan vinegar Jiangzhe vinegar Density107.2105.6108.6119.4111.4106.0Acids5.18.06.810.97.2 3.6Solid12.89.711.930.521.47.0Salt0.020.8 3.2 3.4 1.57.0Total carbohydrate3.90.8 1.812.87.3 3.7Reduced sugar2.00.6 1.511.3 4.5 2.5Total nitrogen0.30.60.7 1.2 1.30.2Amino acids0.7 1.7 1.1 2.3 2.60.4Total aromavolatile substance0.50.60.7 1.10.70.4Main aromacomponents Propyl acetate i -BuOH,furfural i -PrOH 2,3-BuDiOH Furfural i -BuOHData adapted from Cui (1986)and Tang (1985).i -PrOH,iso-propanol;i -BuOH,iso-butanol;2,3-BuDiOH,2,3-butanediol.Chinese Vinegar 411412Liu et al. than common vinegar.Xia et al.(1985)made a dynamic analysis of the formation of main components in Chinese vinegar during SSF or traditional SmF.They showed that during SSF,different components are formed continuously and simultaneously, whereas in SmF,components are formed more sequentially.The traditional SmF,however,is very different from modern SmF,as it uses mixed cultures like in SSF;the quality of the traditional product is regarded as superior to modern SmF vinegar(Liu,1982).Similar traditional SmF processes are used in Europe to produce high-quality wine vinegar(Tesfaye et al.,2002).SOLID-STATE FERMENTATION OF CHINESE VINEGAR Traditional production processes of Chinese vinegar are typically empirical and craftlike,rather than scientific.Generally,SSF for Chinese vinegar includes four stages:koji preparation,saccharification and alcohol fermentation,acetic-acid formation,and maturation(Huang and Yin,2000b).In the past,processes were developed by trial and error,and handed down by mouth and hands of the veterans in the plants.A great body of experience and practical knowledge accumulated over time,but the underlying microbiological and biochemical mechanisms were not investigated systematically.Consequently,many different production processes exist and significant improvements have been scarce.There are two basic SSF processes in Chinese vinegar production,based on the treatment method of the raw material,namely the‘‘cook method’’and the‘‘steam method’’(Huang and Cai,1999).In the‘‘cook method,’’saccharification and alcohol fermentation occur in the liquid state(i.e.,SmF;Fig.2a),whereas the acetic-acid fermentation is SSF.In the‘‘steam method,’’the whole process takes place in the solid state(SSF;Fig.2b),where rice hull and part of the wheat bran are mixed with the main raw material(grain)immediately after soaking and are steamed together.Koji PreparationKoji may be regarded as an enzyme-containing starch material for starch hydrolysis.Its preparation method is ancient and originated in ter,it found its way to Japan and other Southeast Asian countries(Fukashima,1989).In China, koji is widely used in the production of traditional distilled spirit(Bai Jiu,in Chinese),soy sauce,and vinegar.Historically,koji is a solid fermentative mixture of substrate and microbial metabolites,especially saccharolytic enzymes.Generally, koji is classified according to its preparation method:great koji,mini koji,bran koji, wheat koji,herb koji,and red-rice koji.Herb koji is a special koji only used in Sichuan vinegar production(see‘‘Major Types of Chinese Vinegar’’).The dominant microorganisms in koji are various moulds,such as Aspergillus,Rhizopus,Mucor, and Penicillium(Huang and Yin,2000a).Different types of koji have a different microbial flora.The microorganisms in great koji,mini koji,herb koji,and red-rice koji spontaneously originate from the natural environment,whereas bran koji and wheat koji are usually based on cultures of Aspergillus or Rhizopus.Chinese Vinegar413ABFigure 2.Flowchart of solid-state fermentation of Chinese vinegar.A,Cook method (Zhenjiang aromatic vinegar);B,steam method(Shanxi old mature vinegar).(Data from Huang and Cai(1999).)Great koji (Da Qu,in Chinese)and mini koji (Xiao Qu)are the most traditional koji.Figure 3is a chart of the typical preparation of Chinese great koji,which was used to produce traditionally distilled spirit and vinegar (Huang and Cai,1999).Every step of the process schematized in Fig.3must be carried out carefully to ensure high-quality koji (Wang,1999),and practical experience and hands-on knowledge are very important.The fermentation actually consists of three stages,each at a different temperature.As a result,specific fungi proliferate (Wang,1997).These different temperatures are obtained by controlling the heat transfer among the cakes (by adjusting the spacing)and the heat transfer from the koji room to the environment (by closing or opening the windows).The important processes are metabolic heat production,heat convection,and water evaporation.Finally,most of the water in the great koji evaporates and most microorganisms lose viability.Only temperature-tolerant fungal enzymes remain and play an important role in the subsequent saccharification (Wang,1995).The preparation of mini koji is similar to that of great koji,with the dominant microorganism being Rhizopus rather than Aspergillus (Huang and Yin,2000a).Other kinds of koji are much simpler to prepare.Instead of great koji,more and more companies use wheat koji,which is prepared from a pure culture of Aspergillus sp.and wheat.Bran koji is another pure-culture product.The preparation of pure-culture koji and the relevant reactors have been described elsewhere (Kitamoto,2002).The preparation of koji is laborious and time consuming.Some manufacturers tried to replace the saccharifying action of koji with enzyme mixtures,but found that the quality of their products was negatively affected (Hou et al.,1996).Grind & mixBlend &configurate Water Koji cakes Pile in line Get moldy(2–4 d)(12 h)Fermentation Maturation(2 d)(12–15 d)Figure 3.Typical flowchart of preparation of Chinese great koji.Koji cakes are piled in line in the ‘‘koji house.’’At different stages,temperature is controlled by adjusting the spacing among the cakes and opening or closing windows.The period indicated in the bracket may vary a little between winter and summer.For more details,see text.414Liu et al.Chinese Vinegar415 Saccharification and Alcohol FermentationIn traditional processes,alcohol fermentation starts as soon as liquefaction and saccharification of starch are under way(Hou et al.,1996).The process is initiated by addition of koji and cultured yeast to the starch material.Many manufacturers do not use cultured yeast,but rely on yeast that comes spontaneously from the environment or is indigenous to the koji(Lei,2000).Some manufacturers also use fermented broth from a previous successful batch as inoculum to initiate alcohol fermentation(repeated fermentation or‘‘back slopping’’).However,a few manufacturers,such as the Shanghai rice vinegar plant,replace koji with enzyme mixtures.As a result,the starch material is liquefied and then saccharified completely before alcohol fermentation is initiated by yeast addition (Chen and Chen,1996).In both the cook method and the steam method,the temperature during alcohol fermentation must be kept below28 C to minimize evaporation of ethanol. The average duration of saccharification and alcohol fermentation is10days (Huang and Cai,1999).Acetic-Acid FermentationIn the cook method,the fermented broth or solids from the alcohol fermentation are mixed with wheat bran and vinegar seeds(i.e.,parent vinegar Pei from the last batch of acetic-acid fermentation or,as an alternative,an inoculum of acetic-acid-producing bacteria such as Acetobacter).For the steam method,wheat bran and rice hull are mixed with the main starch materials before alcohol fermentation,so only vinegar seeds need to be added after alcohol fermentation.Wheat bran is used as a substrate and as a carrier for the bacteria,whereas rice hull is used both as a carrier of the bacteria and a spacer increasing porosity,thus increasing the exchange area and promoting oxygen uptake and heat discharge.The ratio of the main substrate to the bran and rice hull is generally1:1.2:1.4(Liu and Li,1992).The manufacturers of Sichuan bran vinegar use pure wheat bran as the only solid substrate.The traditional acid fermentor is a clay jar(about0.5m3capacity).Nowadays, many manufacturers replace it with a concrete basin(about8m3),which in fact is a deep-bed tray system with intermittent mixing.Rice hull is fed to the fermentor during pared with the thin-layer tray system,the surface area per unit volume in deep-bed tray system is reduced and consequently,evaporation of ethanol is reduced.At the same time,intermittent mixing and rice-hull feeding facilitate oxygen diffusion.The most important variable at this stage is the temperature,which is controlled by stirring and turning the substrate(Liu,1982;Zhu,1991b).If there is sufficient oxygen,bacteria will propagate and metabolize rapidly and produce a large amount of metabolic heat.When the temperature becomes too high,the operator will‘‘turn up’’or mix,the substrate to disperse heat,and then press the surface to reduce oxygen supply,thereby decreasing the rate of ethanol consumption and heat production(Yu,1985).The temperature is usually kept at38 C to40 C. Generally,stirring and turning up the substrate is carried out once per day (Guo,2000).Some manufacturers use concrete basins with two bottoms(the upper416Liu et al. bottom is perforated,a so-called‘‘false bottom’’)to collect the vinegar liquid, which is then intermittently recycled onto the top surface of the solid substrate to regulate the temperature(Xing,1991).The recycled broth is used as a cooling agent (in summer)or heating agent(in winter).Even so,the solid substrate needs to be stirred and turned up at least three times during the whole period because the substrate tends to agglomerate and clog after being showered with the recycling broth.MaturationMost of the traditional production processes of Chinese vinegar feature a maturation period(Zhu,1992b)in which many flavor substances,such as esters,are formed by chemical reactions.Its length varies with the type of vinegar.During maturation,microbial activity comes to a halt.Salt is usually added to the maturing vinegar to prevent microbial overoxidation of acetic acid to carbon dioxide.Storage is common for maturation,but the exact method varies.For example, manufacturers of Zhenjiang aromatic vinegar usually mature their vinegar by adding salt and sealing the surface of the fermented solid substrate with clay;thus,the maturation process is anaerobic(Guo,2000).The manufacturers of Shanxi old mature vinegar,however,use solarization(in the summer)and ice removal(in the winter)to mature and to concentrate the vinegar broth;thus,the course is mainly aerobic.In addition,this method brings about a concentration of the acetic acid because water is removed as ice and water vapor.MAJOR TYPES OF CHINESE VINEGARIn the former National Industrial Standard of Vinegar,vinegar is classified into three grades,depending on its concentration of acetic acid(3.5–4.5%,4.5–6%,and >6%,respectively)(Wei,2001).More recently,a new National Standard Code of Condiments was issued by the Chinese State Administration Bureau for Quality and Technology,in which vinegar is classified as either brewed or formulated(acetic-acid blended with other ingredients,such as flavors)(Qiao,1999).Besides,each major vinegar also has its own local quality criteria and grading system.Generally,brewed vinegars are more popular on the Chinese market,especially those that are prepared by SSF.In this article,only brewed vinegar is referred to as Chinese vinegar (Table3).Chinese vinegars have specific local features.Every region has its own manufac-turers,who produce vinegar in specific processes,using particular raw materials. Consequently,each vinegar has its own taste,flavor characteristic,and market. There are at least14types of traditional Chinese vinegar on the market.Most of them are produced by SSF,but published data are quite scarce(Huang,1998).Here, we only discuss six well-known types of brewed vinegar.Shanxi Old Mature VinegarShanxi old mature vinegar is the most famous vinegar in northern China.It hasa history of more than 300years.In the province of Shanxi,there are more than 1000vinegar manufacturers that produce mature vinegar,fumed vinegar,and old maturevinegar.Only 120producers sell their products outside the province (Wang,1997).Shanxi old vinegars use sorghum as the main raw material with a very largedosage of great koji (about 60%of the raw materials)(Huang and Cai,1999).Production of Shanxi old mature vinegar takes about 18months,although the acidproduction itself takes less than 10days.The most time-consuming stage is thematuration process.Upon fermentation,half of the solid Pei is ‘‘fumed’’(heated in ajar with a lid at 70 C for 4days)and then mixed with the remaining half and leached.Flavor compounds are formed chemically during fuming.The filtrate is transferredto a big jar and is exposed to the sun (solarized);in winter,surface ice is removed.Solarization and ice removal entail a concentration increase of acetic acid and flavorsubstances formed by chemical and enzymatic reactions.Preparation of great koji is also lengthy,taking more than 1month.One of themajor challenges is to improve the process in such a way that the total productiontime is significantly reduced while preserving the typical flavor style of old maturevinegar (Yan,1997).Replacing part of the great koji with wheat bran and applyingnew maturation methods (e.g.,infrared vacuum concentration instead of naturalevaporation and maturation),together with modern formulation methods,mightincrease productivity and consistency of quality greatly (Wang,1997).Zhenjiang Aromatic VinegarZhenjiang aromatic vinegar is most famous in Southern China.Its main rawmaterials are sticky rice and wheat koji.Henshun Group Co.,Ltd.,is the largestmanufacturer and its product,Kingsan Õvinegar,is sold in more than 43countriesTable 3.The main types of Chinese vinegar.Main materials Sticky rice Sticky rice Sticky rice Sorghum Wheat branRiceSaccharifying agentEnzyme Red koji Wheat koji Great koji Herb koji NoProcess type SSF LSF SSF SSF SSF LSFProduction period (days)100>100060>500>400160Annual yield (kg)3.0Â105 6.0Â107 2.1Â108Refs.Hang and Cai,1999Huang and Yin,2000a;Liu,1982Hang and Cai,1999;Ren and Jian,2000Huang and Yin,2000a;Wang,1997Hang and Cai,1999;Li,1999Hang andCai,1999Chinese Vinegar417418Liu et al. (Ren and Jian,2000).Zhenjiang aromatic vinegar is a typical example of the so-called‘‘cook method’’for ethanol production.However,the acetic-acid stage is a unique multilayer SSF with a fed-batch fermentation process in a series of two open containers(big jar or basin).First,a certain amount of rice wine(about14% ethanol,v/v)is mixed with wheat bran,rice hull,and so-called vinegar seeds(i.e., starter culture)to form a semi-solid substrate in the first container(half volume). The substrate is divided in10layers;every24h,the top layer is mixed with fresh rice hull to increase porosity and transferred to the second container;after10days,the first container is thus empty and the second one full(Chen and Chen,1996).This process is called‘‘fed-batch fermentation by layers’’(Guo,2000).Ethanol oxidation and acetic-acid formation mainly take place in the top layer of the second container, which is exposed to the air.In the old days,feeding and mixing was done manually. In more recent years,technicians of the Henshun plant modified the process by introducing a concrete basin with mechanical mixing,thus reducing manual labor input.As a result,productivity was greatly increased and the vinegar quality remained unaffected(Zhou,1990).These changes made Henshun the largest vinegar producer in China;they changed the view that a traditional process could not be altered without affecting the quality of the product.Sichuan Bran VinegarSichuan is a hilly province in Southwest China.Its climate,mild all year round and misty in autumn and winter,is favorable for specific microorganisms that are a basis of traditional SSF.Chinese spirit(Bai Jiu,in Chinese)and bran vinegar are the main fermentation products in Sichuan.Both are produced by SSF,and both are based on mixed cultures of natural origin.BaoningÕvinegar and ZigengÕsun vinegar are the most famous Sichuan bran vinegars(Feng et al., 2000).The raw materials for Sichuan bran vinegar production process are herb koji (including as many as108medicinal herbs),which is the liquid extract of smartweed leaves(a marsh plant,Polygonum hydropiper,Laliao in Chinese)used to initiate vinegar fermentation;and wheat bran,used both as carrier and substrate in the fermentation process.Production of herb koji is rather selective for specific microorganisms.Unlike most other processes,rice hull is not used in bran vinegar production and neither is parent Pei(fermented bran as vinegar seed)(Li,1999). Instead,a special‘‘vinegar mother’’is prepared from steamed rice,herb koji,and a liquid extract of the special smartweed.This mixture is fermented for7days,with intermittent mixing of the semi-liquid broth to provide oxygen for propagation (Huang and Yin,2000a).The‘‘vinegar mother’’is then mixed with wheat bran to finish the acetic acid fermentation.Enzymes,yeast,and bacteria from the‘‘vinegar mother’’convert the bran starch into ethanol,and finally,acetic-acid.The14-day fermentation is a combined alcohol and acetic-acid fermentation.When the fermentations finished,the vinegar Pei is stored in a closed jar for maturation (about1year)before extraction.。

高迁移率金属氧化物半导体薄膜晶体管的研究进展

第 39 卷第 4 期2024 年 4 月Vol.39 No.4Apr. 2024液晶与显示Chinese Journal of Liquid Crystals and Displays高迁移率金属氧化物半导体薄膜晶体管的研究进展李强，葛春桥*，陈露，钟威平，梁齐莹，柳春锡，丁金铎（中山智隆新材料科技有限公司，广东中山 528459）摘要：基于金属氧化物半导体（MOS）的薄膜晶体管（TFT）由于较高的场效应迁移率（μFE）、极低的关断漏电流和大面积电性均匀等特点，已成为助推平板显示或柔性显示产业发展的一项关键技术。

经过30余年的研究，非晶铟镓锌氧化物（a-IGZO）率先替代非晶硅（a-Si）在TFT中得到推广应用。

然而，为了同时满足显示产业对更高生产效益、更佳显示性能（如高分辨率、高刷新率等）和更低功耗等多元升级要求，需要迁移率更高的MOS TFTs技术。

本文从固体物理学的角度，系统综述了MOS TFTs通过多元MOS材料实现高迁移率特性的研究进展，并讨论了迁移率与器件稳定性之间的关系。

最后，总结展望了MOS TFTs的现状和发展趋势。

关键词：金属氧化物半导体；薄膜晶体管；场效应迁移率；偏压稳定性中图分类号：TN321+.5 文献标识码：A doi：10.37188/CJLCD.2024-0032Research progress of high mobility metal oxide semiconductorthin film transistorsLI Qiang，GE Chunqiao*，CHEN Lu，ZHONG Weiping，LIANG Qiying，LIU Chunxi，DING Jinduo （Zhongshan Zhilong New Material Technology Co. Ltd.， Zhongshan 528459， China）Abstract：Thin-film transistor （TFT）based on metal oxide semiconductor （MOS）has become a key technology to boost the development of the flat panel display or flexible display industry due to their high field-effect mobility （μFE）， extremely low cut-off leakage current and good large-area electrical uniformity. After more than 30 years of research，amorphous indium gallium zinc oxide （a-IGZO）is the first to be popularized in TFT by replacing the amorphous silicon （a-Si）. However， in order to simultaneously meet the multiple upgrade requirements of the display industry for higher productivity，better display performance （such as high resolution， high refresh rate，etc.） and lower power consumption， MOS TFTs technology with higher mobility is required.From the perspective of solid-state physics，this paper reviews the research progress of MOS TFTs to achieve high mobility characteristics through multi-component MOS materials， and discusses the relationship between mobility and device stability. Finally， the status quo and development trend of MOS TFTs are summarized and prospected.文章编号：1007-2780（2024）04-0447-19收稿日期：2024-01-23；修订日期：2024-02-14.基金项目：中山市科技计划（No.LJ2021006，No.CXTD2022005，No.2022A1009）Supported by Zhongshan Science and Technology Development Plan（No.LJ2021006，No.CXTD2022005，No.2022A1009）*通信联系人，E-mail：gechunqiao@zhilong.pro第 39 卷液晶与显示Key words： metal oxide semiconductor； thin-film transistor； field-effect mobility； bias stability1 引言在各类消费电子和工业设备显示中，薄膜晶体管（TFT）驱动背板是保障显示屏幕稳定运行的核心部件。

半导体封装工艺介绍

IC Package （IC的封装形式）
按与PCB板的连接方式划分为：
PTH
PTH-Pin Through Hole, 通孔式； SMT-Surface Mount Technology，表面贴装式。目前市面上大部分IC均采为SMT式的
SMT
IC Package （IC的封装形式）按封装外型可分为： SOT 、QFN 、SOIC、TSSOP、QFP、BGA、CSP等；决定封装形式的两个关键因素: 封装效率。芯片面积/封装面积，尽量接近1:1；引脚数。引脚数越多，越高级，但是工艺难度也相应增加；其中，CSP由于采用了Flip Chip技术和裸片封装，达到了芯片面积/封装面积=1:1，为目前最高级的技术；封装形式和工艺逐步高级和复杂
存放条件：零下5°保存，常温下需回温24小时；
主要成分为：环氧树脂及各种添加剂（固化剂，改性剂，脱
Raw Material in Assembly(封装原材料) 【Epoxy】银浆成分为环氧树脂填充金属粉末（Ag）；有三个作用：将Die固定在Die Pad上；散热作用，导电作用； 50°以下存放，使用之前回温24小时；
Cavity
L/F
L/F
EOL– Molding（注塑）
Molding Cycle -L/F置于模具中，每个Die位于Cavity中，模具合模。 -块状EMC放入模具孔中 -高温下，EMC开始熔化，顺着轨道流向Cavity中 -从底部开始，逐渐覆盖芯片 -完全覆盖包裹完毕，成型固化
EOL– Laser Mark（激光打字）在产品（Package）的正面或者背面激光刻字。内容有：产品名称，生产日期，生产批次等； Before After
FOL– Wire Bonding 引线焊接陶瓷的Capillary 内穿金线，并且在EFO的作用下，高温烧球；金线在Cap施加的一定压力和超声的作用下，形成Bond Ball；金线在Cap施加的一定压力作用下，形成Wedge；

晶圆制造工艺流程英文版9个步骤

晶圆制造工艺流程英文版9个步骤The manufacturing process of semiconductor wafers involves several crucial steps to produce high-quality chips. The following nine steps outline the typical process used in semiconductor wafer manufacturing:Step 1: Wafer Ingot GrowthThe process begins with the growth of a silicon ingot, which serves as the starting material for the wafers. The ingot is carefully grown using the Czochralski method, where a seed crystal is dipped into molten silicon and slowly drawn out to form a cylindrical ingot.Step 2: Ingot CuttingOnce the ingot has been grown to the desired size, it is then cut into thin wafers using a diamond wire saw. This step requires precision to ensure the wafers are of uniform thickness and free from defects.Step 3: Surface PolishingAfter cutting, the wafers undergo a series of chemical and mechanical processes to remove any surface imperfections and create a mirror-like finish. This step is critical to ensure the wafers are pristine and ready for the next stages of processing.Step 4: PhotolithographyIn this step, a light-sensitive photoresist is coated onto the wafer's surface, followed by exposure to UV light through a photomask. This process transfers the pattern of the photomask onto the wafer, defining the circuit layout for the chips.Step 5: EtchingThe exposed areas of the wafer are selectively etched away using chemical or plasma etching processes, leavingbehind the desired pattern in the wafer. This step is crucial for defining the circuitry and features of the chips.Step 6: DopingDopants such as phosphorus or boron are implanted into the wafer to modify its electrical properties and create the necessary regions for transistor formation. This step is essential for controlling the conductivity of the semiconductor material.Step 7: Thermal ProcessingThe doped wafers undergo high-temperature annealing processes to activate the dopants and repair any damage caused during doping and etching. This step is critical for ensuring the proper functioning of the semiconductor devices.Step 8: MetallizationThin films of metal are deposited onto the wafer's surface to create interconnections and contacts for thesemiconductor devices. This step involves sputtering or evaporation of metal layers followed by patterning through photolithography and etching.Step 9: PackagingThe individual wafers are diced into separate chips and assembled into packages, along with wire bonding and encapsulation processes to protect the chips. This final step prepares the chips for testing and integration intoelectronic devices.In conclusion, the manufacturing process of semiconductor wafers involves a series of intricate steps, each of which plays a crucial role in producing high-performance chips for electronic applications. From ingot growth to packaging, careful control and precision are essential to ensure the quality and reliability of the semiconductor devices.。

中国高科技产品英语作文

中国高科技产品英语作文In recent years, China has made significant strides in the field of technology, emerging as a global leader in high-tech product development and innovation. This essay will explore the factors contributing to this rise, the impact on the global market, and the future prospects of Chinese high-tech products.Firstly, the Chinese government's strong support and investment in research and development have been instrumental in fostering a conducive environment for technological advancements. Initiatives such as "Made in China 2025" have focused on upgrading the country's manufacturing capabilities to include more high-tech sectors.Secondly, the growth of a highly skilled workforce and the emphasis on science and technology education in China have led to a pool of talent that is driving innovation. Many Chinese universities are now ranked among the best in the world, producing graduates who are well-equipped tocontribute to the tech industry.Thirdly, the rapid expansion of China's domestic market has provided a vast testing ground for new technologies. With a population of over 1.4 billion, the demand for advanced consumer electronics, smartphones, and other tech products is insatiable, allowing Chinese companies to refine their products and compete on a global scale.The impact of China's high-tech products on the global market has been profound. Chinese companies like Huawei, Xiaomi, and DJI have become household names, offering competitive products that often rival those of established international brands in terms of quality and features. This has led to increased competition, driving down prices and encouraging innovation across the industry.Moreover, China's high-tech exports have grown exponentially, contributing to the country's trade surplus and economic growth. Products ranging from telecommunications equipment to surveillance technology are now exported worldwide, often at competitive prices that make them attractive to cost-conscious consumers.Looking to the future, the prospects for Chinese high-tech products remain promising. As the country continues to invest in research and development and nurture its talent pool, itis likely that we will see even more innovative products emerging from China. Additionally, the Chinese government's push for global connectivity through initiatives like the Belt and Road will further integrate Chinese tech products into international markets.However, challenges also lie ahead. Concerns overintellectual property theft and cybersecurity have led to increased scrutiny of Chinese tech products. To maintain its position as a global tech leader, China will need to address these issues and continue to build trust with international consumers and partners.In conclusion, the rise of China's high-tech products has been a transformative force in the global market. With continued support from the government, a growing workforce of tech-savvy individuals, and a massive domestic market to fuel demand, China is well-positioned to maintain its lead in the high-tech sector. As the world becomes increasingly interconnected, the role of Chinese high-tech products is set to become even more prominent, shaping the future of technology and innovation worldwide.。

国内芯片制造工艺流程

国内芯片制造工艺流程英文回答：The manufacturing process of semiconductor chips involves several steps that are crucial for the production of high-quality chips. Here is a brief overview of the typical chip manufacturing process:1. Design and Layout:The chip design is created by engineers using computer-aided design (CAD) software. The layout of the chip, including the arrangement of transistors, interconnections, and other components, is also determined during this stage.设计和布局：芯片设计是由工程师使用计算机辅助设计（CAD）软件创建的。

在此阶段还确定了芯片的布局，包括晶体管、互连和其他组件的排列。

2. Photolithography:In this step, a photosensitive material called photoresist is applied to the surface of a silicon wafer. A mask, containing the desired circuit pattern, is then placed on top of the wafer. Ultraviolet light is used to expose the photoresist through the mask, creating a pattern on the wafer.光刻：在这一步骤中，将一种称为光刻胶的感光材料涂在硅晶圆的表面上。

半导体中集成的层次和环节

集成的层次和环节2022-03-16 14:35导读集成，integration，是指将不同的功能单元汇聚到一起，并能实现其特定功能的过程，集成多指人类的活动，集成电路、系统集成是比较常见的名词。

前面一篇文章，集成的尺度和维度，我们从尺度和维度两个方面对集成进行了解析。

这篇文章，我们从层次-Level和环节-Step两个方面来剖析现代电子集成技术。

Integration1集成的层次电子系统的集成主要分为三个层次（Level）：芯片上的集成，封装内的集成，PCB板级集成，如下图所示：芯片上集成的基本单元是晶体管Transistor，我们称之为功能细胞 (Function Cell)，大量的功能细胞集成在一起形成了芯片。

封装内集成的基本单元是上一步完成的裸芯片或者小芯片Chiplet，我们称之为功能单元 (Function Unit)，这些功能单元在封装内集成形成了SiP。

PCB上集成的基本单元是上一步完成的封装或SiP，我们称之为微系统(MicroSystem)，这些微系统在PCB上集成为尺度更大的系统。

可以看出，集成的层次是一步步进行的，每一个层次的集成，其功能在上一个层次的基础上不断地完善，尺度在也不断地放大。

到了PCB这一层次，电子系统的功能已经比较完备，尺度也已经放大适合人类操控的地步，加上其他的部件，就构成了人们最常用的系统——常系统 (Common System)，例如我们每天接触的手机或电脑。

芯片上的集成芯片上的晶体管之所以被称作功能细胞，因为它是不可再分的最小功能单位。

功能细胞的数量也成为系统先进性的重要标志，人体的细胞数量为40~60万亿，系统如果要想真正成为像人一样智能的系统，其包含的功能细胞或许也要达到相同的量级。

为了集成更多的功能细胞，晶体管只能越做越小。

现在的晶体管尺寸可能只有最初晶体管刚发明时尺寸的亿万分之一，而其基本功能却是没有变化的。

芯片上的集成，首先要制造出功能细胞，并将它们集成在一起，这些作为功能细胞的晶体管是怎么制造出来并集成在一起的呢？从极简的视角来说，我们需要了解三类材料和三类工艺。