基于TCAD的绝缘体上硅器件总剂量效应仿真技术研究

Research on Total Ionizing Dose Effect Simulation Technology of Silicon-on-Insulator Device Based on TCAD

绝缘体上硅(Silicon-on-Insulator,SOI)器件的全介质隔离结构改善了其抗单粒子效应性能,但也使其对总剂量效应更加敏感.为了评估SOI器件的总剂量效应敏感性,本文提出了一种基于TCAD(Technology Computer Aided Design)的总剂量效应仿真技术.通过对SOI器件三维结构进行建模,利用TCAD内置的辐射模型开展瞬态仿真,模拟氧化层中辐射感应电荷的产生、输运和俘获过程,从而分别评估绝缘埋层(Buried Oxide,BOX)和浅沟槽隔离(Shallow Trench Isolation,STI)氧化层中辐射感应陷阱电荷对器件电学性能的影响.基于该仿真技术,本文分别研究了不同偏置、沟道长度、体区掺杂浓度以及STI形貌对SOI MOSFET器件总剂量辐射效应的影响.仿真结果表明高浓度的体区掺杂、较小的STI凹槽深度和更陡峭的STI侧壁将有助于改善SOI器件的抗总剂量效应性能.

The fully dielectric isolation structure of Silicon-on-Insulator(SOI)devices improves their immunity to single event effects,but also makes them more sensitive to total ionizing dose(TID)effects.In order to evaluate the sensitivity of SOI devices to TID effects,a simulation method based on TCAD(Technology Computer Aided Design)was proposed.By modeling the three-dimensional structure of SOI devices and using the TCAD built-in radiation model to simulate the generation,transport and capture of radiation-induced charges in oxide layer,the effects of radiation-induced trap charges in buried oxide(BOX)and shallow trench isolation(STI)oxide on the electrical properties of SOI devices are evaluated respectively.Based on this simulation technique,the effects of radiation bias,channel length,body doping concentration and STI morphology on TID effect of SOI MOSFET were investigated.The simulation results show that higher body doping concentration,smaller STI divot depth and steeper STI sidewall will be helpful to improve the TID hardness performance of SOI devices.