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Design and Optimization of 4.5 kV 4H-SiC MOSFET with Current Spreading Layer

Current Spreading Layer를 도입한 4.5 kV 4H-SiC MOSFET의 설계 및 최적화

  • Young-Hun, Cho (Dept. of Electronic materials Engineering, Kwangwoon University) ;
  • Hyung-Jin, Lee (Dept. of Electronic materials Engineering, Kwangwoon University) ;
  • Hee-Jae, Lee (Dept. of Electronic materials Engineering, Kwangwoon University) ;
  • Geon-Hee, Lee (Dept. of Electronic materials Engineering, Kwangwoon University) ;
  • Sang-Mo, Koo (Dept. of Electronic materials Engineering, Kwangwoon University)
  • Received : 2022.12.13
  • Accepted : 2022.12.26
  • Published : 2022.12.31

Abstract

In this work, we investigated a high-voltage (~4.5 kV) 4H-SiC power DMOSFET with modifications of current spreading layer (CSL), which was introduced below the p-well region for low on-resistance. These include the following: 1) a thickness of CSL (TCSL) from 0 um to 0.9 um; 2) a doping concentration of CSL (NCSL) from 1×1016 cm-3 to 5×1016 cm-3. The design is optimized using TCAD 2D-simulation, and we found that CSL helps to reduce specific on-resistance but also breakdown voltage. The resulting structures exhibit a specific on-resistance (Ron,sp) of 59.61 mΩ·cm2, a breakdown voltage (VB) of 5 kV, and a Baliga's Figure of Merit (BFOM) of 0.43 GW/cm2.

이번 연구에서 우리는 낮은 온 저항을 위해 p-well 영역 아래에 도입된 전류 확산층을 변화시켜 고전압 4H-SiC 전력 Diffused MOSFET(DMOSFET)에 대해 연구했다. Current Spreading Layer(CSL)의 두께(TCSL)를 0~0.9 um, CSL의 도핑 농도(NCSL)를 1~5×1016 cm-3으로 변화시키면서 소자의 전기적 특성을 분석하였다. TCAD 2D-simulation을 통해 최적화되었으며 CSL이 온 저항을 낮추는 것뿐만 아니라 항복전압도 낮춤으로써 CSL의 최적화의 중요성을 확인하였다. 최적화된 구조는 59.61 mΩ·cm2의 온저항, 5 kV의 항복전압, 0.43 GW/cm2의 Baliga's Figure of Merit(BFOM)을 보여주었다.

Keywords

Acknowledgement

This work was supported by the Technology Innovation Program Development of next-generation power semiconductor based on Si-on-SiC structure(RS-2022-00154720) Ministry of Trade, Industry & Energy(MOTIE, Korea), Korea Institute for Advancement of Technology(KIAT) grant funded by the Korea Government(MOTIE) (P0012451). The present research has been conducted by the Excellent researcher support project of Kwangwoon University in 2022.

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