电子温度对SiGe HBT基区渡越时间的影响

Effects of Electron Temperature Distribution on Base Transit Time of SiGe HBT

讨论了采用能量传输模型时的SiGe HBT基区电子温度分布,以及电子温度对基区渡越时间的影响.计算结果表明:基区电子温度呈现明显的不均匀分布,从发射极侧到集电极侧逐渐增大;电子温度分布主要由基区Ge分布决定,而基区掺杂对电子温度的影响不大.考虑基区电子温度分布时基区渡越时间减小,在较大的Ge分布梯度下,电子温度对基区渡越时间的影响不可忽略.

The electron temperature distribution in the base of SiGe HBT and its effects on the base transit time are studied. Results show that the electron temperature distribution in the base is uneven, increasing from emitter to collector. Ge profile has a great effect on the electron temperature, and the effect of the base doping profile is rather small. Moreover, the base transit time decreases if the electron temperature distribution is considered, and the effect of electron temperature distribution on base transit time cannot be neglected if Ge profile has a large slope.