根据泊松方程和热扩散方程提出了新型PB-PSOI 器件漂移区的二维表面电场分布模型和温度分布模型，模型计算结果与Medici模拟结果相一致。根据所提出的模型，重点研究了埋氧化层厚度及长度对漂移区表面电场分布和温度分布的影响，最后给出了PB-PSOI 器件的埋氧化层厚度和长度的优化设计方法。

In this paper, the 2-D analytical models for the surface electrical field and temperature distributions of PB-PSOI devices in terms of Poisson's solution and thermal diffusion solution have been suggested. The analytical results of the presented models show a good agreement with the numerical simulation results obtained by Medici. The dependences of the surface electrical field and temperature on the thickness and the length of the buried oxide have also been discussed in detail. Finally, the methods to optimize the thickness and the length of the buried oxide have been proposed to achieve the high performance of PB-PSOI devices.