N型高压DDDMOS热载流子损伤研究

Study on the Damage of N Type High Pressure DDDMOS Hot Carrier

高压场效应管是BCD工艺中的核心器件,常用有LDMOS(Lateral-Double-Diffused MOS,横向双扩散场效应晶体管)和DDDMOS(Double-Diffuse-Drain MOS,双扩散漏场效应晶体管)两种。由于DDDMOS实现结构简单且工艺流程与传统CMOS工艺兼容,被大量应用于LCD驱动电路,电源芯片管理电路等对耐压要求不高的高压电路。随着DDDMOS器件尺寸的不断缩小和集成度的不断提高,其热载流子注入(HCI)损伤却变得越来越严重。分析N型高压双扩散漏MOSFET的热载流子注入效应,有针对性地对轻掺杂区的工艺条件进行优化,并分析其对N型DDDMOS HCI可靠性的影响,重点研究了在保持晶体管性能不变且不增加工艺成本的条件下如何改善N型HV DDDMOS的HCI,延长器件的HCI寿命使之达到业界的实用标准,为高压DDDMOS器件可靠性优化提供重要参考。

High voltage field effect tube （HFET） is the core device in BCD process, which is commonly used in two kinds of LDMOS （Lateral-Double-Diffused MOS, transverse double diffusion field effect transistor） and DDDMOS （Double-Diffuse-Drain MOS, double diffusion leakage field effect transistor）. Because of its simple structure and compatible with the traditional CMOS process, DDDMOS is widely used in LCD drive circuit, power chip management circuit and so on. However, with the shrinking of DDDMOS devices and the improvement of integration, the hot carrier injection （HCI） damage is becoming more and more serious. The hot carrier injection effect of N type high pressure double diffusion leakage MOSFET is analyzed. The process conditions for the light doping area are optimized and its influence on the reliability of N type DDDMOS HCI is analyzed. How to improve the HCI and extender of N HV DDDMOS under the condition that the performance of the transistor is kept constant and the process cost is not increased The HCI life of the device makes it meet the practical standards of the industry, providing important reference for the reliability optimization of high voltage DDDMOS devices.