4H-SiC LDMOSFET沟道迁移率影响因素的研究  

Study of the Affect Factors of 4H-SiC LDMOSFET Channel Mobility

作　　者：高秀秀 邱乐山 戴小平 李诚瞻 GAO Xiu-xiu;QIU Le-shan;DAI Xiao-ping;LI Cheng-zhan(R&D,Coresing Semiconductor Technology Co.,Ltd.,Zhuzhou 412001,China;不详)

机构地区：[1]湖南国芯半导体科技有限公司,湖南株洲412001 [2]株洲中车时代半导体有限公司,湖南株洲412001

出　　处：《电力电子技术》2022年第3期136-140,共5页Power Electronics

基　　金：长株潭国家自主创新示范区专项(2018XK2202)。

摘　　要：为了研究4H-SiC金属氧化物半导体场效应晶体管(MOSFET)沟道迁移率和界面态密度的影响因素,通过在N型4H-SiC(0001)外延片上制备不同沟道长度和宽度的横向扩散MOSFET(LDMOSFET),其干氧氧化的栅极氧化层在不同温度和时间的NO和/或N2气氛中退火,测试了其输出和转移曲线,提取了有效迁移率和场效应迁移率,利用亚阈值摆幅法提取了界面态密度,并探讨了漏源电压、晶圆位置、温度对迁移率和界面态密度的影响。结果显示,LDMOSFET的沟道尺寸对沟道迁移率和界面态密度有显著的影响,增加NO的退火温度和时间可以提高沟道迁移率,1250℃40 min NO退火和1200℃70 min NO退火的LDMOSFET的常温峰值迁移率均约为45 cm^(2)·V^(-1)·s^(-1),沟道迁移率随测试温度的增加而增加,且高栅压下栅压比测试温度对迁移率的影响更大。It is important to research affect factors of 4 H-SiC metal-oxide-semiconductor field-effect transistors(MOSFET)channel mobility and interface traps density.Lateral diffused MOSFET(LDMOSFET)with various channel dimension are fabricated on 4 H-SiC(0001)face,gate oxidation followed by niridation with various NO and/or N_(2) temperature and time.The output and transfer curves are tested,the effective mobility and field-effect mobility are extracted,and the interface traps density is extracted by subthreshold swing method,the effect of drain-source voltage,position on wafer and temperature on the channel mobility and interface traps density are discussed.The results show that LDMOSFET’s channel size has significant influence on channel mobility and interface traps density,channel mobility can be increased by increasing the annealing temperature and time of NO,the peak effective moblility 1250℃40 min NO annealing and 1200℃70 min NO annealing LDMOSFET are about 45 cm^(2)·V^(-1)·s^(-1),the channel mobility increases with the increase of the test temperature,and the effect of gate voltage is greater than that of the test temperature on the channel mobility at high gate voltage.

关 键 词：金属氧化物半导体场效应晶体管 界面态密度 沟道迁移率 

分 类 号：TN32[电子电信—物理电子学]