Kink效应对低温CMOS读出电路的影响

Impact of Kink Effect on CMOS Readout Circuits for Cryogenic Operation

在深低温下(T<50K),CMOS器件会出现Kink效应,即I-V特性曲线会发生扭曲。当漏源电压较大时(Vds>4V),漏电流突然加大,电流曲线偏离正常的平方关系。本文通过实验表明,Kink效应对CMOS读出电路中的一些电路结构产生较严重的影响,Kink效应会导致源跟随器输出产生严重的非线性;对于共源放大器和两级运放,Kink效应会使其增益产生非线性。最后,针对影响低温读出电路性能的Kink效应进行分析和研究,提出在低温CMOS读出集成电路设计中如何解决这些问题的方案。

The Kink phenomenon presented in the Ⅰ - Ⅴ output characteristics of CMOS devices at low temperature （ T 〈 50K） is studied. The impact of Kink effect on CMOS readout integrated circuits for cryogenic operation is examined. The output characteristic of source follower, the gain characteristic of common - source amplifier and two - stage amplifier all exhibit severe nonlinearity resulted from the Kink effect. Based on the analysis of Kink effect problems, several solutions are proposed for the design of CMOS readout integrated circuit operated at low temperature. The improvement is verified through the simulation.