4H-SiC基功率器件的high-k栅介质材料研究进展  

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

作　　者：刘帅[1,2] 宋立辉 杨德仁 皮孝东[1,2] LIU Shuai;SONG Lihui;YANG Deren;PI Xiaodong(State Key Laboratory of Silicon and Advanced Semiconductor Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China;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)

机构地区：[1]浙江大学材料科学与工程学院,硅及先进半导体材料全国重点实验室,杭州310027 [2]浙江大学杭州国际科创中心,先进半导体研究院和浙江省宽禁带功率半导体材料与器件重点实验室,杭州311200

出　　处：《人工晶体学报》2024年第12期2027-2042,共16页Journal of Synthetic Crystals

基　　金：浙江大学杭州国际科创中心人才专项(02010600-K02013005)。

摘　　要：金属氧化物半导体场效应晶体管(MOSFET)作为碳化硅绝缘栅结构的典型器件被广泛使用,然而SiO_(2)介电常数低的缺点和SiO_(2)/4H-SiC界面特性差的问题一直制约着4H-SiC绝缘栅结构(金属-绝缘体-半导体,MIS)器件更大规模商业化应用,因此科研工作者一直致力于寻找能够替代或弥补SiO_(2)的high-k栅介质材料。本文对该科学问题的研究现状进行综述,首先指出合适的high-k栅介质材料应该拥有较宽的禁带宽度、较高的介电常数、良好的界面特性和热稳定性。然后,主要从栅薄膜制备工艺、沉积温度、栅介质界面特性和电学性能等方面对典型high-k栅介质材料的研究结果进行评价,包括氧化铪(HfO_(2))、氧化铝(Al_(2)O_(3))、氮化铝(AlN)、氧化钇(Y_(2)O_(3))、氧化铈(CeO_(2))、氧化锆(ZrO_(2))、氧化镧(La_(2)O_(3))、五氧化二钽(Ta_(2)O_(5))、钛酸钡(BaTiO_(3))、氧化钬(Ho_(2)O_(3))和由它们组合而成的堆栈栅介质。最后,对未来该领域的研究方向进行了展望和建议,例如对栅漏电流机理的研究、对新材料的更多尝试、器件在极端环境下的可靠性问题等。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(SiO_(2))and poor interface characteristics of SiO_(2)/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 SiO_(2) 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 properties and electrical performance,including HfO_(2),Al_(2)O_(3),AlN,Y_(2)O_(3),CeO_(2),ZrO_(2),La_(2)O_(3),Ta_(2)O_(5),BaTiO_(3),Ho_(2)O_(3) 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.

关 键 词：4H-SiC MOS电容器 high-k栅介质材料 堆栈栅介质 界面特性 电学性能 

分 类 号：O487[理学—固体物理] TN386[理学—物理]