本文提出了一种新型结构的Npn砷化镓双极型微波晶体管,该结构用一个两层的镓铝砷(Ga_(0.4)Al_(0.6)As/Ga_(0.7)Al_(0.3)As)来代替正常的单层作宽发射极用的镓铝砷(Ga_(0.7)Al_(0.3)As)。双发射极结构中的低铝(30％)层紧靠着基区,起宽发射极作用,保持了发射极异质结的良好匹配,并使管子的开启电压Von较小。高铝(60％)层和n~+GaAs顶层相配合,成为一个工艺上易控的选择性腐蚀系统,形成了自掩蔽结构。该结构使晶体管的结面减小,工艺简化,且取得良好的性能。 In this paper, we propose a new type of Npn GaAs bipolar transistor with a two-layer GaAs (0.4) Al_ (0.6) As / Ga_ (0.7) Al_ (0.3) As Instead of the normal monolayer for gallium arsenide (Ga_ (0.7) Al_ (0.3) As) for wide emitters. The low aluminum (30%) layer in the dual emitter structure abuts the base region, acts as a wide emitter, maintains a good match for the emitter heterojunction and provides a small open-tube voltage Von. High aluminum (60%) layer and top layer of n ~ + GaAs cooperate to become a process-controlled selective corrosion system, forming a self-masking structure. This structure reduces the junction area of ​​the transistor, simplifies the process, and achieves good performance.