Atmospheric pressure CVD-grown SiGe base HBT with the highest value of current gain-Early voltage product

A low thermal-budget SiGe base heterojunction bipolar transistor (HBT) with a record current gain-Early voltage product (/spl beta//spl middot/Va) has been fabricated using atmospheric pressure (AP) CVD. After growing the SiGe layer on the wafer patterned by local oxidation of silicon (LOCOS), the HBT received thermal annealing only one time for drive-in and activation of arsenic (As) dopant in the polysilicon-emitter. For the 1/spl times/4 /spl mu/m/sup 2/ emitter, typical value of /spl beta//spl middot/Va is 200,000 V (/spl beta/=2,000 and Va=100 V) at the collector current of 0.9 mA.