一、为什么要用砷(As)代替磷(P)扩散超高频硅n—p—n 平面晶体管需要有良好的高频特性,要提高晶体管的特征频率f_T,在设计中一般都采用减少发射极面积和采用窄的发射极条宽以降低发射结电容,另一方面是采用浅结薄基区以降低基区渡越时间。制版和光刻技术的发展使得管子发 First, why should we use arsenic (As) instead of phosphorus (P) diffusion of ultra-high frequency silicon n-p-n planar transistors need good high-frequency characteristics, to improve the transistor’s characteristic frequency f_T, in the design are generally used to reduce emissions Polar area and the use of narrow emitter width to reduce the launch junction capacitance, the other is the use of shallow junction base region to reduce the base transit time. The development of plate making and photolithography made tube hair