基于SOI的可变电容的特性分析

提出了一种利用二维器件与电路模拟器ISE中的AC分析提取可变电容主要参数的方法,利用它对一种基于SOI的三端可变电容(栅控二极管)进行了模拟研究,并分析了几个主要结构参数对SOI变容管性能的影响.结果显示,栅氧厚度、硅膜掺杂、硅膜厚度等结构参数会对SOI变容管的调节范围和灵敏度有直接影响.在模拟中,还观察到了当栅氧厚度很薄时,多晶硅栅耗尽导致的可调电容的变化范围不规则变化的现象.该研究结果可为SOI可变电容的进一步实验设计和优化以及建模工作提供指导方向和依据.

Characteristic Analysis of Varactors Based on SOI

A method to extract the primary parameters of varactor according to the AC analysis results of ISE, 2D device and circuit simulator, is presented. By using this method, a three terminal SOI varactor (gated diode) is simulated, and several parameters' influences on the performance of the varactor are analyzed. It can be seen that the tuning range and the sensitivity of SOI varactor are influenced by gate oxide thickness, silicon film doping and silicon film thickness directly. Especially, with the decrease of the thickness of the gate oxide, an irregular change of the varactor's tuning range is observed, which is due to the gate depletion of polysilicon. The work can serve as a guideline to the further design and optimization of varactor.