SiGe HBT发射极台面湿法腐蚀技术研究

Research on wet etching technique for SiGe HBT emitter mesa for mation

在SiGeHBT的制造工艺中,为了防止干法刻蚀发射极台面对外基区表面造成损伤,从而导致SiGeHBT小电流下较大漏电问题,对SiGeHBT发射极台面的湿法腐蚀技术进行了研究。通过改变超声功率、腐蚀液温度,从中获得了较为理想的腐蚀条件。

In the double-mesa SiGe HBT technology,extrinsic base surface would be damaged during emitter mesa formation with RIE.This would lead to high junction leakage current ,conse-quently degrading the characteristics of SiGe HBT.This paper investigates wet etching technique for SiGe HBT emitter mesa formation.By comparing different ultrasonic power and different solu-tion temperature,the suitable etching condition is obtained to improve SiGe HBT leakage current characteristics.