低温、小电流、高增益硅双极晶体管的研究与设计

介绍了一种用于低温、小注入电流条件下工作的新型多晶硅发射区双极晶体管,并给出了晶体管电流增益的低温模型。该模型考虑了低温下多子和少子的冻析效应、禁带变窄效应、Auger复合、多晶硅发射效率增强效应等。在此基础上,通过用SUPREM-Ⅲ和PISCES-Ⅱ进行了工艺模拟和器件模拟,最后完成了实际版图制作和工艺流水。对管子的测试表明,该晶体管具有极好的小电流特性,在0.5μA的注入电流下其共射电流放大倍数可高达1000,在低温(77K)下其β仍可达70左右,能够正常工作。

Investigation and Design on Si Bipolar Transistors with Low Temperature, Low Injection Current, and High Gain

The bipolar transistors with poly-silicon emitter suitable for low temperature and low injection current operation are presented. Low temperature models of current gain of the transistor are given, which include apparent bandgap narrowing, enhancement of emitter efficiency of poly-Si, Auger recombination, carrier freezing-out, etc. Base on these, processing simulation and device characteristics simulation are practised using SUPREM-Ⅲ and PISCES-Ⅱ. Finally, experimental bipolar transistors are fabricated. The devices show an excellent characteristics at low injection current with β=1000 and I_R= 0. 5μA, and can work normally with β=70 at 77K.