半导体照明课件 第8章 AlGaInP 发光二极管1

gas control unit
reactor with heated susceptor
control unit
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vacuum system scrubbing system
Simplified Presentation of a Crystal Growth Process
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Compound semiconductors III-Vs: GaAs, AlGaAs,
GalnP, AlGaInP, GaN, InGaN…
Speciality: SiC Enabling technology for:
How MOCVD Works
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Components of a Low Pressure (LP) MOCVD System
第 8 章 AlGaInP 发光二极管
AlGaInP
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Introduction to MOCVD/MOVPE/OMVPE
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MOCVD/MOVPE/OMVPE
▪ MOCVD: Metal Organic Chemical Vapor Deposition
▪ MOVPE: Metal Organic Vapor Phase Epitaxy ▪ OMVPE: Organo Metallic Vapor Phase Epitaxy
Basic Principle of the MOVPE Process
▪ A gas mixture containing the precursors needed for growth, and if necessary for doping, is passed over a heated substrate.
▪ Desirable properties of precursors:
▪ Low toxicity ▪ Liquid at room temperature ▪ Suitable vapor pressure at room temperature ▪ Low carbon contamination in grown layer (avoid CH3 radicals),
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Group III MO Precursors
Precursor Symbol
TMGa
(CH3)3Ga
TEGa
(C2H5)3Ga
TMIn TEIn TMAl TEAl
(CH3)3In (C2H5)3In (CH3)3Al (C2H5)3Al
Advantages
liquid, high vapor pressure
三、LED外延片的制作
The World of Semiconductors
III IV V
Traditional semiconductors Si: DRAMs, processors
Advantages of compound semiconductors: • faster, higher frequencies • visible light, infrared • high efficient photovoltaics • heat and high power resistant
▪ The precursor molecules pyrolyze(使裂解) leaving the atoms, e.g., Ga and As atoms on the substrate surface.
▪ The atoms bond to the substrate surface and a new crystalline layer is grown, in this case GaAs.
however, for some applications C doping is desired (though rarely achieved by autodoping techniques. ▪ No parasitic reactions with other sources ▪ Good long term stability (should not decompose in bubbler) ▪ Pyrolysis temperature should match the ideal growth temperature ▪ Inexpensive for industrial mass production
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▪ MOCVD已经成为工业界主要使用的镀膜技术。 ▪ 使用MOCVD这种镀膜技术制作LED的外延片，即
在衬底上镀多层膜。 ▪ 外延片是LED生产的上游产业，在光电产业中扮
演重要的角色。 ▪ 有些专家经常用一个国家或地区拥有MOCVD外延
炉的数量来衡量这个国家或地区的光电行业的发 展规模。
liquid, low carbon contamination, decomposes by -hydride elimination reaction, used in LP MOVPE systems
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Precursors
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8.11 源材料（Precursors）
Sample: Precursor Molecules AsH3
DMZn - (CH3)2Zn
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TMGa - (CH3)3Ga
H C As Zn Ga
MOCVD Precursors
▪ Often all three expressions are used interchangeably
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二、LED外延片的制作
MOCVD实例
三、LED外延片的制作
二、LED外延片的制作
系统简介 本系统为英国Thomas Swan公司制造，具有世 界先进水平的商用金属有机源气相外延(MOCVD) 材料生长系统，可用于制备GaAs和InP、GaN为代 表的第二、三代半导体材料。在高亮度的蓝光发 光二极管(LED)、激光器(LD)、日盲紫外光电探测 器、高效率太阳能电池、高频大功率电子器件领 域中具有广泛的应用。