研究了Si/Si_(1-x)Ge_x/Si n-p-n异质结双极晶体管(HBT)的结界面处基区杂质外扩散与标定的未掺杂Si_(1-x)Ge_x隔离层的影响。发现,来自重掺杂基区或非突变界面处少量硼的外扩散会在导带中形成寄生势垒,它严重地影响了HBT中集电极电流的提高。未掺杂界面隔离层能消除这些寄生势垒从而极大地提高了集电极电流。 The influence of out-diffusion of base impurity and calibration of undoped Si_ (1-x) Ge_x isolation layer at the interface of Si / Si_ (1-x) Ge_x / Si n-p-n heterojunction bipolar transistor (HBT) It has been found that the extra diffusion of a small amount of boron from the heavily doped base or non-abrupt interface creates a parasitic barrier in the conduction band that severely affects the collector current increase in the HBT. The undoped interface isolation layer can eliminate these parasitic barrier and thus greatly improve the collector current.