应变p型Si1-xGex层中载流子冻析

本文用解析的方法研究了应变Ｐ型Ｓｉ１－ｘＧｅｘ层中载流子冻析现象，研究发现，用Ｓｉ归一化的Ｓｉ１－ｘＧｅｘ价带有效态密度、随ｘ的增加而减小，而且温度Ｔ越低，随Ｇｅ组份ｘ的增加而减少的速度越快，与Ｓｉ相比，常温下Ｇｅ组份ｘ几乎对电离 杂质浓度没有什么影响，而在低温下，随Ｇｅ组份ｘ的增加，电离杂质浓度随之增加，载流子冻析减弱，这对低温工作的Ｓｉ１－ｘＧｅｘ器件有利。

Carrier Freeze-Out in Strained p-Si1-xGex Layers

The caaccer freeze-out in strained p-Si1--Gex layers is studied analytically. It is found that as the Ge fraction increases, the valences effective densities of states(Nv)SiGe/(Nv)Si normlized bythat in Si decreases, furthermore, as the temperature beecomes lower, the decrease in (Nv)SiGe/(Nv)Si becomes more rapid. It is also shown that as the Ge fraction increases, although it has little effect on theionized doping concentration at room temperature, the ionias doping concentration inereases at low temperatures compared with that in Si. This implies that caaccer freeze-out is mitigated at low temperatures,which is beneficial to the operation of Sil-Gex-based devices at low temperatures.