Ge组分对SiGe HBT直流特性的影响

Effect of Ge Content on DC Characteristics of SiGe HBT

制作了基区Ge组分分别为0.20和0.23的多发射极指数双台面结构SiGe异质结双极型晶体管(HBT)。实验结果表明,基区Ge组分的微小增加,引起了较大的基极复合电流,但减小了总的基极电流,提高了发射结的注入效率,电流增益成倍地提高。Ge组分从0.20增加到0.23,HBT的最大直流电流增益从60增加到158,提高了约2.6倍。

Multi-finger double-mesa SiGe heterojunction bipolar transistors （HBT） with Ge content of 0.20 and 0. 23 have been fabricated. With a little increase of Ge content from 0. 20 to 0. 23, the current gain increases as much as 2.6 times. Although the ratio of recombination current increases with increase of Ge content in base, due to high injection of minor carriers from the emitter to base, the total base current decreases and the collector current increases with increase of Ge content.