高耐压横向SJ器件等效衬底模型与新结构研究

The concept of "equivalent substrate (ES)" of the high voltage lateral super junction(SJ) device has been proposed. With our innovative research on the fundamental theory and technology of this concept, the essence of the substrate assistant depletion(SAD) is revealed. The "silicon limit"of the lateral high voltage device can be broken through the application of this concept. There are three innovations in this study. 1 the ES model of the high voltage lateral SJ device is developed. Based of the interaction mechanism of the fields between the SJ and the ES layers, the essense of the SAD effect is the modulation of the ES field to the SJ field.Then the optimized substrate conditions are obtained. 2 A novel high voltage lateral SJ device structure with optimized charge compensation layer(CCL) is proposed, which has superior breakdown characteristic than the reported SJ devices. The electric field expression of the aribitrary doped CCL is driven from the Green function. The experimental resuls of the new device will be researched and the BV of the device is over 1000V. 3 A novel "silicon limit" model for the lateral SJ device is proposed. The BV of the device in the model is normalized to obtain the general design expressio. The doping concentration of the drift region is increased with the reduction of the breadth length ratio of the N and P region of the SJ layer.This study is of great significance, which can provide fundamental theory for application and advanced research.

针对现存疑义提出高压横向SJ器件等效衬底（ES）概念，揭示其机理和衬底辅助耗尽（SAD）效应本质，突破横向器件耐压"硅极限"。含三个创新点：1、提出横向SJ器件等效衬底（ES）模型。基于SJ和ES层场互作用机理，求解三维泊松方程，导出包含ES的SJ器件三维电场分布。揭示SAD的本质系ES场对SJ场的调制，消除途径是产生附加补偿场，从而获得优化ES条件；2、提出满足ES条件的无SAD效应器件新结构即电荷补偿层（CCL）结构，突破现有横向SJ耐压值，导出任意浓度分布下电场的Green函数解，进行实验研究；3、建立横向SJ器件"硅极限"理论。采用耐压归一化思想，发现漂移区掺杂浓度随N、P区宽长比减小而增加，获得普适设计公式。该理论用于纵向SJ器件，突破经典耐压比导1.33次方关系。本研究系与国际水平同步的应用基础性和超前性研究，意义重大。

横向SJ器件打破常规器件“硅极限”，实现器件耐压与比导通电阻折中，是功率器件与集成电路领域中极具发展潜力的重要器件。横向SJ器件耐压的瓶颈是SAD效应的作用。因此本项目的研究在于揭示横向SJ耐压机理和SAD效应物理本质，为实现无SAD效应的新器件结构作理论依据。本研究建立了横向SJ器件等效衬底（ES）概念，提出横向SJ器件的ES模型。ES概念就是将耗尽P型衬底与电荷补偿层（CCL）看成一个整体ES进行研究。而ES模型就是研究包括CCL层在内的ES层电场与SJ电场相互作用，即是三维场相互作用模型或简称场补偿模型。借助泰勒级数与傅里叶级数展开方法求解三维泊松方程，分析横向SJ和ES电场相互作用机理，发现SAD效应的本质系ES场对SJ场的调制，消除SAD效应的途径是增加附加补偿场。本研究提出了具有优化电荷补偿层（CCL）横向SJ器件新结构，突破现有SJ器件耐压值并进行了实验研究。根据电荷补偿原理，借助Green函数 获得补偿层场，用误差调整函数计算其掺杂浓度，并求解扩散方程获得其杂质浓度分布。作者提出的T-SJ LDMOS器件新结构，经过流片实验实现了977V的高VB，且Ron,sp比“硅极限”低18.1％的优异性能。仿真结果还证实了所提出的器件可以达到超过1000 V的VB。本研究还建立了横向SJ器件“硅极限”理论，基于耐压归一化思想，获得横向SJ普适设计公式，该公式突破现有经典耐压比导的1.32次方关系，为该类器件的发展提供了理论和技术基础。本研究发表相关学术论文11篇，其中SCI收录8篇，包括IEEE顶级期刊T-PE 1篇，IEEE T-ED和IEEE E.D.L. 7篇，EI论文2篇，申请中国发明专利16项，获得四川省科技进步一等奖1项。