期末复习-2015剖析

幻灯片1期末复习专业外语幻灯片2考试题型●一、汉译英（20分） 10个词，每个词2分●二、英译汉（20分） 10个词，每个词2分●三、翻译句子（40分） 10个句子，每个句子4分●四、翻译（20分）一整段或者几个句子幻灯片3考试注意事项●一、考试时间：2个小时● 7月9日9：00-11：00 经信F1●二、不允许带词典（包括电子词典）●三、手机关机（用手表看时间）●四、不允许上厕所●五、交卷要在一个小时十分钟之后！！！幻灯片4复习题幻灯片5一、掌握（给出汉语可以写成英文）●semiconductor：半导体●photoconductivity：光电导性（率）●rectification ：整流●intrinsic properties：本征特性●Hall effect ：霍尔效应●current carriers ：载流子●carrier mobility ：载流子迁移率●silicon ：硅（Si）●germanium：锗（Ge）●solar cell ：太阳电池幻灯片6一、掌握（给出汉语可以写成英文）●quantum theory ：量子理论●photo-voltage：光电压、光生电动势●solid-state laser ：固体激光器●optical fiber：光纤●quantum mechanics：量子力学●conductivity：电导率●periodic lattice ：周期点阵●Hall coefficient：霍尔系数●electron-hole pairs：电子、空穴对●single crystal：单晶体幻灯片7一、掌握（给出汉语可以写成英文）●Wet chemical etching：湿法化学刻蚀●diffraction effect：衍射效应●index of refraction：折射率●focal length：焦距●donor levels：施主能级●acceptor levels：受主能级●electric circuit ：电路●long-range order：长程有序●photoelectric effect：光电效应幻灯片8一、掌握（给出汉语可以写成英文）●periodic table：元素周期表●energy levels：能级●chemical binding：化学键●conduction band：导带●crystalline solids：结晶固体、晶体●etching：刻蚀●periodic field：周期势场●energy level ：能级●diode rectifiers ：二极管整流器幻灯片9一、掌握（给出汉语可以写成英文）●filled band ：满带●empty band：空带●wave length：波长●valence electron：价电子●photovoltaic effect：光伏效应●Liquid phase epitaxy(LPE)：液相外延●Integrated circuit(IC)：集成电路●Light-emitting diode(LED)：发光二极管幻灯片10一、掌握（给出汉语可以写成英文）●numerical apertures (NA)：数值孔径●Field effect-transistor(FET)：场效应晶体管●Metal-Oxide-Semicondutor(MOS)：金属氧化物半导体；●physical vapor deposition(PVD)：物理气相沉积；chemical vapor deposition(CVD)：化学气相沉积幻灯片11二、认识（给出英语能翻译成汉语）●negative temperature coefficient of resistance:电阻的负温度系数●silver sulphidel : 硫化银●poly-crystalline ingots : 多晶块●titanium : 钛（Ti）●zirconium：锆（Zr）●tellurium：碲（Te)●lead sulphide : 硫化铅●iron pyrites ：黄铁矿●selenium：硒（Se）幻灯片12二、认识（给出英语能翻译成汉语）●Transmission polarized light microscopy：透射偏光显微术●galena：方铅矿●photocell：光电管、光电池●copper oxide：氧化铜●crystal detector：晶体检波器●infrared detector ：红外探测器●fields of force：力场●polarize：偏振片、起偏器幻灯片13二、认识（给出英语能翻译成汉语）●N-fold degenerate ：N度简并●oscillator：振子●Pauli principle：泡利不相容原理●excited states：激发态●magnesium：镁●thermally excited：热激发●intrinsic conduction：本征导电●prism：棱镜●Cr：chromium：铬幻灯片14二、认识（给出英语能翻译成汉语）X-ray topography： X射线形貌学Optical Microscopy ：光学显微术（镜）stacking fault ：层错crystallography ：结晶学polishing etch ：抛光腐蚀selective etch ：选择腐蚀avalanche：雪崩anodic：阳极的cathodic：阴极的infrared spectroscopy：红外光谱学幻灯片15二、认识（给出英语能翻译成汉语）depth of field：景深，视场深度resolution：分辨率compound microscope：复显微镜useful magnification：有效倍率reflection microscopy：反射显微技术Czochralski growth：提（直）拉法生长thermo-electric power : 温差电动势，热电势alkali halide：碱金属卤化物electron volts ：电子伏特幻灯片16二、认识（给出英语能翻译成汉语）amorphous semiconductors：非晶态半导体，无定型半导体selenide：硒化物telluride：碲化物optical communication：光通信Gallium arsenide：砷化镓arsenide of gallium and aluminium ：镓铝砷aurum ：元素金幻灯片17二、认识（给出英语能翻译成汉语）semiconductor technology ：半导体工艺wave-mechanic：波动力学specific heat :比热metallic contact ：金属接触dislocations ：位错ion implantation ：离子注入epilayer：外延层bipolar transistors：双极型晶体管photo detectors：光探测器幻灯片18二、认识（给出英语能翻译成汉语）●acetic acid ：乙酸、醋酸●diluents ：稀释剂●oxidation-reduction reactions：氧化-还原反应●oxidant：氧化剂●complexer：络合剂●apochromat：复消色差●image plane：像平面●birefringent：双折射的幻灯片19二、认识（给出英语能翻译成汉语）●differential interference contrast method：微分干涉相称方法●in phase：位相相同●angle of divergence：发散角●analyzer：检偏器●elliptically polarized beam：椭圆偏振光●out of phase：（物理）异相●interferometer：干涉仪●melting point : 熔点幻灯片20二、认识（给出英语能翻译成汉语）●magnetic field ：磁场●radar detector ：雷达探测器●lattice points ：晶格格点●lattice spacing ：晶格间距●infrared radiation：红外辐射幻灯片21三、句子●1、It is, nevertheless, a high tribute to the skill and care of many experimentersthat, in spite of this, semiconductors had been recognized as a distinct class of substances and their main properties appreciated long before a comprehensive theory was available to account for them.●2、These effects are now known to be due to oxide films or actual gaps separatingthe individual crystals but led to the metals titanium and zirconium once being listed as semiconductors.●3、It must be admitted, however, that no infallible criterion was availabletill the quantum theory of solids gave an understanding of the reasons for the various properties observed.幻灯片22●4、A review of this early work has been given by K. Lark-Horowitz together witha very extensive bibliography containing over 350 references. Earlier reviewsby B' Gudden also deal extensively with this phase and discuss in some detail the problems of identifying semiconductors.●5、The various methods of distinguishing between ionic and electronic conductionhave been discussed by K. Lark-Horowitz (loc.cit.) in some detail and also the difficulties of interpretation caused by failure to make the distinction.●6、The latter, which is generally known as the carrier mobility, and which weshall define more precisely later generally tends to decrease as the temperatureis raised, especially at the higher temperatures, and this accounts for the decrease in conductivity of metals with increasing temperature.●7、The substances concerned were mainly metallic oxides and sulphides and the‘defect’ semiconductors were those with a metallic content less than that corresponding to stoichiometric composition, i.c. oxidized compounds.幻灯片23●8、The importance of this work was in showing the vital part played by smalldeviations from stoichiometric composition in determining the properties of compound semiconductors.● 9、Although they are not strictly semiconductors but insulators, mention mustbe made of the large amount of research carried out by R. W. Pohl and his collaborators on the alkali halides, since this helped greatly to clarify many of the properties of semiconductors.●10、Much of the uncertainty of the early work on semiconductors arose througha failure to differentiate between effects, which arise in the bulk of thematerial, and those, which are characteristic of the surface or of the interface between two different materials.●11、The use of single crystals has enabled not only the separation of the bulkand surface properties but has also enabled the surface and the interface between two types of semiconductor, or between a semiconductor and a metal, to be studied in much greater detail.幻灯片24●12、More recently the study of amorphous semiconductors has led to a fullerappreciation of those properties, such as high carrier mobility, that depend principally on the quality of the crystals being studied and those more fundamental properties which do not depend on long-range order.●13、 The photoconductive properties of selenium, and of copper oxide, have beenused to provide exposure meters for photography and photocells, which are used in the film industry for transforming the markings on the sound track into electric currents for implication and reproduction by loud-speakers.●14、The discovery that a fine wire, or ‘cat’s whisker, in contact with a crystalof semiconducting material made an excellent rectifier for high-frequency currents led to a great increase in the sensitivity of radio receivers, and this type of device was widely used in the early days of broadcasting.幻灯片25●15、The use of solar cells to provide power for satellites and even theirpossibilities for wide scale power generation, now being actively examined, are based on the photoelectric effect in semiconductors.●16、The modern successor to the transistor is the integrated circuit (IC.) inwhich many transistors and their associated components such as resistors, capacitors etc. are produced by controlled diffusion of impurities into a small‘chip’ of silicon.●17、Here these forces are supposed to attract the electron strongly if it movesoutside the boundary, and in the simplest form of the theory it is assumed that they set up an impenetrable potential barrier which holds the electrons in the solid.●18、In Summerfield’s theory, the allowed energy levels for the valence electronsof a crystal of macroscopic dimensions lie very close together and their values extend from nearly the bottom of the potential trough in which the electrons move to indefinitely high values.幻灯片26●19、Each band consists of many closely spaced levels and for many purposes maybe regarded as a continuum, when we come to allocate electrons to these levels, however, we must remember that they are discrete and that there exists a definite number of them.●20、If now we have N atoms in a crystal, and we assume the crystal to be expandedso that the lattice spacing becomes very great, then the allowed energy levels will be just the atomic energy levels which, for the moment, we shall assume to be non-degenerate, i.e. each has a separate energy.●21、 Thus we see that electrons can only contribute appreciably to conductionif there are available neighboring empty levels into which they can go: completely filled bands do not contribute to conduction.●22、This not only explains why ‘inner’ electrons do not contribute to conductionbut it gave Wilson the clue to the essential deference between metals on the one hand and insulators and semiconductors on the other.幻灯片27●23、Most of the substances with which we shall be concerned have such a structure,but may not always consist of large single crystals but of aggregates of very small crystals with random orientation.●24、It turns out that the packing of the atoms in actual solids is so closethat an electron in any particular atom, particularly a valance electron, would easily escape from the potential hole confining it to that particular atom into that of a neighboring atom.●25、The number of excited electrons would increase with temperature in a mannergoverned by a process having an ‘activation energy’, of the order of ΔE and we should expect a rapid increase of the conductivity with temperature.●26、As we shall also see later the effect of very small amounts of impuritycan have a marked effect on this activation energy so that materials which have considerably greater values of ΔE may behave as semiconductors when they contain certain ‘active’ impurities.幻灯片2827、If the densities of free electrons and holes n, p are both small compared withN, the density of atoms in the crystal, which is thus nearly equal to the number of unexcited states (eh), we have from the thermo dynamical theory of chemical reactions:np/N2=K(T),where K(T) is a function of the temperature only.28、If we assume that the variation with T of the mobility of electrons and holes in an electric field is small compared with the variation in the exponential factor in (4) then we have for the conductivity σ, which is then simply proportional to the number of carriers, a variation of the form. P1529、In many instances, it is found that the energy required to excite an electron into the conduction band from a donor level is so small that the electrons from all, the available donor levels are excited and are in the conduction band at room temperature.幻灯片29●30、Hence, for a semiconductor in this condition the resistance will increasewith increasing temperature, till a temperature is reached at which the intrinsic electrons begin to predominate, when it will begin to fall exponentially in the manner once thought to be characteristic if semiconductors.●31、When light frequency is high enough so that a quantum absorbed by a valenceelectron has sufficient energy to raise it from the top of the full band to the conduction band, extra carriers are created and these lead to increased conductivity.●32、It will be clear from the above calculation that if germanium is to beintrinsic at room temperature it must be free from impurities giving levels near the conduction band to better than one part in 10-9.●33、The purpose of this chapter is to acquaint the scientist who is not aspecialist in defect analysis with some of the etching, optical and X-ray microscopy techniques normally used to characterize defects in crystalline semiconductors.幻灯片30●34、It is anticipated that the reader will have a "hands-on" involvement withetching and optical microscopy, but it is expected that with X-ray topography, the appropriate specialist will perform the work and help interpret the results.●35、It turns out, however, that the minority carriers are nevertheless, of greatimportance, as many electronic processes in semiconductor technology are controlled by the minority carriers, the density of which, being small, may be more readily varied.●36、One to one correlations between dislocations and emitter to collector shortsin bipolar transistors, as well as avalanche sites in photo detectors have been made, whereas process induced stacking faults are known to reduce the storage time in MOS memory devices.●37、If defect characterization is worthy of a philosophy, then it must be "donot use overkill", or in other words use the simplest technique possible toobtain the necessary information and it first.幻灯片31●38、When a new etchant is needed, it is almost always formulated by utilizingthe experience gained from the prior etching of similar materials and additional trial and error experimentation, rather than the application of chemical theory.●39、It should be understood, however, that a selective etch can become apolishing etch if the temperature is raised and the surface reaction rate exceeds the diffusion rate, or if one essential ingredient in the etch is reduced to the point where its diffusion rate to the surface limits the reaction.●40、Carrier concentration differences as low as 1016/cm3 at a total doping levelof 1017/cm3 can produce etch rate differences resulting in surface variations.幻灯片32●41、Since the NA governs the resolution, obtaining greater magnification throughuse of high power coulars with lenses of low NA will not produce more detail.●42、If the prism is moved far enough, eventually the rays become so out of phasethat the shortest visible wavelengths (dark blus) begin to interfere destructively.●43、As long as all observations are made using the same side of the null point,all features with the same contrast as the known feature, a pit for example, will be depressions and all features with reversed contrast will be mounds.幻灯片33预祝同学们取得理想的成绩！。