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JOURNAL OF SYNTHETIC CRYSTALS ›› 2024, Vol. 53 ›› Issue (12): 2027-2042.

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Research Progress on High-k Gate Dielectrics Materials for 4H-SiC Based Power Devices

LIU Shuai1,2, SONG Lihui1,2, YANG Deren1,2, PI Xiaodong1,2   

  1. 1. State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China;
    2. Institute of Advanced Semiconductors & Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, China
  • Received:2024-05-20 Online:2024-12-15 Published:2024-12-20

Abstract: Metal-oxide-semiconductor field effect transistor (MOSFET) as a typical device of silicon carbide insulate gate sturcture is one of the most widely applied devices for 4H-SiC. However, the low dielectric constant of gate oxide (SiO2) and poor interface characteristics of SiO2/4H-SiC limits further application of 4H-SiC insulated gate structures (metal-insulator-semiconductor, MIS). Therefore, the research on high-k gate dielectrics which is able to substitute or compensate for SiO2 has attracted extensive attention. This paper reports several key areas on this issue to obtain a better understanding of potential high-k gate dielectrics. Firstly, an ideal gate dielectric materials for 4H-SiC would have large bandgap, high dielectric constant, good interface with 4H-SiC and favorable thermal stability. And the several methods are summarized to evaluate the structural, electrical and interface properties of gate dielectric materials. Furthermore, this paper assesses the current status of these dielectrics and their processing in terms of gate preparation, deposition temperature, interfacial propertiesand electrical performance, including HfO2, Al2O3, AlN, Y2O3, CeO2, ZrO2, La2O3, Ta2O5, BaTiO3, Ho2O3 and gate dielectric stacks composed of them. Finaly, based on an extensive survey on high-k gate dielectrics for 4H-SiC devices, a future perspective is provided with regards to gate leakage current mechanism, more efforts on varied materials and device viability in harsh environment.

Key words: 4H-SiC MOS capacitor, high-k gate dielectric material, gate dielectric stack, interfacial property, electrical performance

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