硅低温双极型晶体管电流增益的分析

Analysis of Current Gain of Siikon Bipolar Transistors for Low Temperature Operation

从理论和实验两方面研究了硅晶体管电流增益的低温特性,建立了电流增益的温度模型,阐明了电流增益低温下降的机理,在此基础上探讨了获得具有良好电性能的硅低温晶体管的方法,结论如下:电流增益由发射效率决定时,具有正温度系数,且随温度下降而下降,下降程度随工作电流的减小而增强.发射区采用轻掺杂技术以减小禁带变窄量,并考虑载流子冻析效应,可获得适于低温工作的硅双极晶体管.

The low temperature characteristics of current gain in silicon bipo- lar transistors is investigated.The temperature model of current gain is pres- ented and the mechanism of the decrease of current gain at love temperature clarified.It indicates that the current gain has positive temperature coefficient when it is determined by the emitter efficiency,and it falls as the temper- ature decreases,especially at low current.Using the lightly doped emitter technology for reducing the energy gap narrowing and taking the carrier free- ze-out effect into account,we can obtain the silicon bipolar transistors with good electrical characteristics for low temperature operation.