On the reliability of SiGe microwave power heterojunction bipolar transistor

Although the performance of SiGe heterojunction bipolar transistor has been improved much with the development of epitaxy technology, the reliability is a concern for practical application due to its large mismatch. We have carried out accelerated life test on the SiGe microwave power heterojunction bipolar transistor, and found that the performance of the SiGe microwave power HBT does not change after the HBT is addressed at peak junction temperature of 200/spl deg/C for 168 hrs by forward DC bias. This clearly indicates that the SiGe HBT has the same reliability as Si bipolar transistor.