提出非均匀厚度漂移区SOI高压器件新结构及其优化设计方法.非均匀厚度漂移区调制SOI层的电场并增强埋层电场,从而提高器件击穿电压.考虑到这种调制效应,提出解析模型用以优化设计该新器件的结构参数.借助解析模型,研究了电场分布和器件击穿电压与结构参数的关系.数值仿真证实了解析模型的正确性.具有3阶梯的非均匀厚度漂移区SOI器件耐压为常规结构SOI器件的2倍,且保持较低的导通电阻. A new structure of SOI high voltage device with non-uniform thickness drift region and its optimal design method are proposed. The non-uniform thickness drift region modulates the electric field of SOI layer and enhances the buried electric field to increase the device breakdown voltage. Considering this modulation effect, Which is used to optimize the structural parameters of the new device.The analytical model is used to study the distribution of electric field and the relationship between the device breakdown voltage and the structural parameters.The numerical simulation confirms the correctness of the analytical model.The SOI The device withstands twice the voltage of conventional SOI devices and maintains a low on-resistance.