关键词: 光电晶体管, 反向击穿, 掺杂浓度, 放大倍数

Abstract: Phototransistors are extremely different from ordinary transistors in performance parameters and structural designs due to their special application scenarios, and the influence of each parameter should be taken into account during device design. Through theoretical and simulation calculations combined with experimental tape-out, several factors affecting the reverse breakdown voltage of NPN phototransistors are summarized, including doping concentration, junction depth, and amplification, etc. Process improvement methods are then proposed to enhance the withstand voltage of phototransistors, achieving an increase in emitter-base reverse breakdown voltage of approximately 20% and a collector-emitter reverse breakdown voltage of 400 V or more.

Key words: phototransistors, reverse breakdown voltage, doping concentration, amplification