The effect of base doping on the performance of Si bipolar transistors at low temperatures
The effect of base doping on the performance of Si bipolar transistors at low temperatures
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基极掺杂对Si双极晶体管低温性能的影响
DOI：
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发表时间：
1981
影响因子：
3.1
通讯作者：
W. Dumke
中科院分区：
文献类型：
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作者：
W. Dumke
研究了在低温（77 ~ 200 K）下使用硅双极晶体管的可能性。从有效带隙随发射极区杂质浓度的变化和输运性质随基极中杂质浓度的变化的结果中可以估计出去电流增益β和开关性能。低温下β的减少不能通过在掺杂As的晶体管中使用最佳As浓度来消除。然而，从发射极区消除补偿受体，在低温方面有显著的改善。在低温下减少基区补偿施主陷阱的数量也很重要。利用Morin和Maita的Si数据计算了不同碱掺杂对Si的影响，并重新绘制了与杂质浓度的依赖关系。开关速度最大可达150k。在更低的温度下，大多数载流子的冻结会导致性能下降。在低温下，可以通过减少碱掺杂来增加去电流增益。结果表明，与室温相比，性能的下降幅度较小，而β的改善幅度更大，因为在低温下，较轻的掺杂减少了杂质散射，显著提高了基区电子和空穴的迁移率。
The possibility of using Si bipolar transistors at low temperatures (77 to 200 K) is examined. Estimates of the de-current gain β and the switching performance are obtained from results on the variation of the effective band gap with the concentration of impurities in the emitter region and from the variation of the transport properties with the impurity concentration in the base. The reduction in β at low temperatures cannot be eliminated by using an optimum As concentration in transistors with As doped emitters. There is, however, a significant improvement in the low-temperature from eliminating the compensating acceptors from the emitter region. It is important to also reduce the number of compensating donor traps from the base region at low temperatures. The effect of varying the base doping is calculated using the data on Si of Morin and Maita, replotted to obtain the dependence on impurity concentration. The switching speed goes through a maximum close to 150 K. At even lower temperatures majority-carrier freeze out is responsible for a decreased performance. At low temperatures, the de-current gain can be increased by reducing the base doping. The resulting performance decrease is less than at room temperature and the improvement in β is greater, because, at low temperatures, the decreased impurity scattering at a lighter doping significantly improves the electron and hole mobilities in the base region.