A novel 700 V triple REduced SURface Field (RESURF) lateral double-diffused MOSFETs (LDMOS) with a variable high- ${K}$ (VHK) dielectric trench for smart power applications is proposed and studied by TCAD simulations. Compared with conventional triple RESURF (CTR) LDMOS, the new structure features a composite high- ${K}$ (HK) dielectric trench embedded in the drain edge. First, a higher HK dielectric layer is in the upper trench to suppress the high electric field ( ${E}$ -field) under the drain by dielectric RESURF. Second, a lower HK dielectric is at the bottom of the trench to promote the depletion of the ${N}$ -buffer layer and ${P}$ -substrate, which increases the ${N}$ -buffer doping concentration and thus reduces ON-resistance. The overall vertical bulk ${E}$ -field distribution is modulated by the ${E}$ -field peak generated at the position of varying ${K}$ dielectric, which greatly improves breakdown voltage (BV). An analytical model of BV and vertical ${E}$ -field taking account of the influence of the VHK dielectric trench is presented. Simulation results show that the proposed VHK TR LDMOS is able to obtain a 30.2% higher BV and a lower 15.4% ${R}_{ \mathrm{\scriptscriptstyle ON}, \text {sp}}$ than the CTR LDMOS. Moreover, the figure of merit (BV ² / ${R}_{ \mathrm{\scriptscriptstyle ON}, \text {sp}}$ ) of VHK TR LDMOS has doubled further breaking the lateral silicon limit.

中文翻译：

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高可变700 V三重RESURF LDMOS的分析研究ķ 介电沟槽

一种新颖的700 V三重减小SURface场（RESURF）横向双扩散MOSFET（LDMOS），具有可变的高 $ {K} $ 通过TCAD仿真，提出并研究了用于智能电源应用的（VHK）电介质沟槽。与传统的三重RESURF（CTR）LDMOS相比，新结构的特点是采用了 $ {K} $ （HK）介电沟槽嵌入漏极边缘。首先，较高的HK电介质层位于上部沟槽中，以抑制高电场（ $ {E} $ 场）通过电介质RESURF在漏极下方。其次，较低的HK电介质位于沟槽的底部，以促进沟道的耗尽。 $ {N} $ -缓冲层和 $ {P} $ -底物，增加了 $ {N} $ -缓冲掺杂浓度，因此降低了导通电阻。整体垂直散装 $ {E} $ 场分布由 $ {E} $ 场峰值在变化的位置产生 $ {K} $ 电介质，可大大提高击穿电压（BV）。BV和垂直的分析模型 $ {E} $ 提出了考虑VHK介质沟槽影响的磁场。仿真结果表明，所提出的VHK TR LDMOS能够获得30.2％的较高BV和15.4％的较低BV。 $ {R} _ {\ mathrm {\ scriptscriptstyle ON}，\ text {sp}} $ 比点击率LDMOS高。此外，品质因数（BV ² / $ {R} _ {\ mathrm {\ scriptscriptstyle ON}，\ text {sp}} $ VHK TR LDMOS的）已加倍，进一步突破了横向硅限制。