Dog Bone栅型MOS场效应晶体管的等效宽长比计算

Equivalent aspect ratio calculation of MOS field effect transistor with Dog Bone gate

Dog Bone栅型MOS场效应晶体管是一种对称性的、防辐射总剂量效应的版图结构。为了计算其等效宽长比,把它划分为常规结构的主MOS晶体管和非常规结构的边缘MOS晶体管2种类型的并联。借助Silvaco TCAD工艺与器件仿真工具构建了它的模型,分析了主MOS晶体管的宽度、长度和边缘MOS晶体管的多晶硅与有源区的交叠宽度对边缘MOS等效宽长比的影响,得到拟合的Dog Bone栅型MOS晶体管等效宽长比的计算公式。采用CSMC 0.5μm DPTMCMOS混合信号工艺制作了样管,对实验测量值和公式计算值进行比较,Dog Bone栅型MOS场效应晶体管的等效宽长比的计算公式与实验能够较好地吻合。

MOS field effect transistor（FET） with Dog Bone shape gate is a symmetric layout structure with hardened radiation-total-dose effect（RTDE）.In order to calculate its equivalent aspect ratio,it is divided into a regular MOS FET（host MOS） and two parasitic MOS FETs（edge MOS） in parallel.The model of this device is constructed in Silvaco TCAD software,then a fitted formula of the equivalent aspect ratio is derived based on the simulation of drain current with respect to the width and length of host MOS,and overlap width between polysilicon and active area of edge MOS.The comparison between the fitted formula and measurements of sample transistors taped out in CSMC 0.5 μm DPTM CMOS mixed-signal process indicates the fitted formula for equivalent aspect ratio of Dog Bone Gate MOS FET matches the measurement.