Simulation study on radiation hardness for total ionizing dose effect of ultra-thin shielding layer 300 V SOI LDMOS

Shu-Hao Zhang,Ming Qiao, ,Zhang-Yi-An Yuan,Bo Zhang

doi:10.7498/aps.71.20220041

Abstract

In this work, the linear current degradation mechanism of 300 V silicon-on-insulator laterally double-diffused metal-oxide-semiconductor field effect transistor under total ionizing effect is studied, and a method in radiation-hardness for linear current by introducing an ultra-thin shielding layer is proposed. This new structure is realized with P-type ultra-thin shielding layer implantation under field oxide, in order to prevent the P-type layer from complete surface inversion, thereby truncating the surface current route and mitigating the current degradation effectively. For a laterally double-diffused metal-oxide-semiconductor field effect transistor, linear current degradation can be attributed mainly to holes introduced in the field oxide. In this work, the influence of introduced holes on electrical properties in the transistor oxides under harsh environment is simulated based on device and process simulation software, with optimized layer length, implantation energy, lateral distance and dose window, and the goal of linear current hardness (linear current increment decreasing from 447% in conventional structure to less than 10% in proposed structure) is achieved while maintaining pre-rad and post-rad breakdown voltages above 300 V under total dose of 0–500 krad(Si).

Highlights

本文研究了 300V 绝缘体上硅横向双扩散金属氧化物半导体场效应管在电离辐射总剂量效应下的线性电流退化机理,提出了一种具有超薄屏蔽层的抗辐射结构实现线性电流加固。超薄屏蔽层位于器件场氧化层的部分下方,旨在阻止 P 型掺杂层表面发生反型,从而截断表面电流路径, 有效抑制线性电流的退化。对于横向双扩散金属氧化物半导体场效应管, 漂移区上的场氧化层中引入的空穴对线性电流的退化起着主导作用。本文基于器件工艺仿真软件,模拟器件在辐射环境下引入氧化物空穴后的电学特性,对超薄屏蔽层的长度、注入能量、横向间距进行优化,给出相应的剂量窗口,在电离辐射总剂量为 0-500krad(Si)的条件下,将最大线性电流增量从传统结构的 447%缩减至 10%以内,且辐照前后击穿电压均维持在 300V 以上。.
电流(linear drain current, Idlin)、关态漏电流增加等。横向双扩散金属氧化物半导体场效应管(laterally double-diffused metal-oxide-semiconductor field effect transistor, LDMOS)以其工艺简单、与低压器件兼容度高的优势, 在集成电路中应用广泛,辐射环境下的 LDMOS 器件需要进行抗辐射加固设计。相较于体硅 LDMOS,绝缘体上硅(silicon on insulator, SOI)LDMOS 因引入额外的埋氧层,其在抗单粒子能力上表现出优势,但在总剂量效应(total dose ionizing effect, TID effect)下发生的性能退化更为严重。
对Idlin的影响: Not = g0 ∙ fot ∙ fy ∙ tox ∙ D, (1)

Summary

Introduction

本文研究了 300V 绝缘体上硅横向双扩散金属氧化物半导体场效应管在电离辐射总剂量效应下的线性电流退化机理,提出了一种具有超薄屏蔽层的抗辐射结构实现线性电流加固。超薄屏蔽层位于器件场氧化层的部分下方,旨在阻止 P 型掺杂层表面发生反型,从而截断表面电流路径, 有效抑制线性电流的退化。对于横向双扩散金属氧化物半导体场效应管, 漂移区上的场氧化层中引入的空穴对线性电流的退化起着主导作用。本文基于器件工艺仿真软件,模拟器件在辐射环境下引入氧化物空穴后的电学特性,对超薄屏蔽层的长度、注入能量、横向间距进行优化,给出相应的剂量窗口,在电离辐射总剂量为 0-500krad(Si)的条件下,将最大线性电流增量从传统结构的 447%缩减至 10%以内,且辐照前后击穿电压均维持在 300V 以上。. 电流(linear drain current, Idlin)、关态漏电流增加等。横向双扩散金属氧化物半导体场效应管(laterally double-diffused metal-oxide-semiconductor field effect transistor, LDMOS)以其工艺简单、与低压器件兼容度高的优势, 在集成电路中应用广泛,辐射环境下的 LDMOS 器件需要进行抗辐射加固设计。相较于体硅 LDMOS,绝缘体上硅(silicon on insulator, SOI)LDMOS 因引入额外的埋氧层,其在抗单粒子能力上表现出优势,但在总剂量效应(total dose ionizing effect, TID effect)下发生的性能退化更为严重。对Idlin的影响: Not = g0 ∙ fot ∙ fy ∙ tox ∙ D, (1)

Results

Conclusion