纳米CMOS器件中源/漏串联电阻栅长相关性研究

本文利用恒定迁移率、直接I_d-V_gs和Y函数三种方法对纳米CMOS器件中提取的源/漏串联电阻(R_sd)与器件栅长(L)相关性进行了研究。结果表明,采用恒迁移率方法得到的R_sd具有与栅长无关的特性,纳米小尺寸CMOS器件的R_sd值在14.3Ω～10.9Ω之间。直接I_d-V_gs和Y函数方法都得到了与L相关的R_sd值,误差分析发现从直接I_d-V_gs和Y函数两种方法中提取的R_sd对L依赖性与提取过程中的栅极电压导致有效沟道迁移率(μ_eff)降低有关,推导过程中忽略了这种影响,R_sd值叠加了一个与栅长相关的量。本文计算了这个叠加的误差值,并得到消除此误差值之后各个栅长器件的R_sd值。

Study on the Gate Length Dependence of Source/Drain Series Resistance in Nanoscale CMOS devices

The dependence on gate length of the source/drain series resistance extracted from nanoscale CMOS devices is studied by constant-mobility method,direct Id-Vgs method and y-function method.The results show that the Rsd obtained by the method of constant-mobility is independent of channel gate length,and the Rsd of nanometer deeply CMOS devices is between 14.3Ωand 10.9Ω.Both the direct Id-Vgs and the y-function methods obtained the gate length dependent Rsd values.Error analysis shows that the dependence of Rsd on gate length extracted from direct Id-Vgs and y-function methods is related to the decrease of effective channel mobility caused by gate voltage in the extraction process,which is ignored in the derivation process.The Rsd value adds a quantity relative to the gate length.In this paper,the error of the superposition is calculated,and the Rsd value of each gate length CMOS devices after eliminating the error value is obtained.