全耗尽型浮空埋层LDMOS的耐压特性

Breakdown Voltage Characteristics of LDMOS with a Full Depletion Floating Buried Layer

提出了一种新的全耗尽型浮空埋层LDMOS(FB-LDMOS)结构.全耗尽n型埋层在器件的体内产生新的电场,该电场调制了漂移区电场,使得在降低漂移区漏端电场的同时提高了源侧和中部电场REBULF效应.分析了埋层的浓度、厚度、长度等对器件击穿电压的影响.借助二维仿真软件MEDICI,该新结构的击穿电压由传统LDMOS的585.8V提高到886.9V,提高了51.4%.

A new LDMOS with a full depletion floating buried layer is proposed. Because of the buried layer, a new electric field peak is induced and this new field modulates the field in the drift region. The modulation reduces the field of the drain side, and mean- while,the fields of the source side and the middle of the drift are improved （the REBULF effect）. The influence of the doping, thickness,and length of bury on the breakdown voltage is discussed. 2D numerical simulations using MEDICI show that the breakdown voltage increases from 585.8 to 886.9V.