Vertical p-n-p for complementary bipolar technology

A process to fabricate high-performance vertical p-n-p devices has been developed. The use of a high-dose boron-implanted poly-Si layer to form the emitter is essential to obtain shallow emitters with high emitter gradient. The devices exhibit very high current gain (>200) and a calculated cutoff frequency of 3.6 GHz. The process as developed is compatible with the n-p-n process and, thus, suitable for fabrication of complementary bipolar devices.