3300V SiC SBD嵌入式MOSFET研制

R&D of 3300V SiC MOSFET With Embedded SBD

研制了一种3300 V碳化硅(silicon carbide,SiC)肖特基二极管(schottky barrier diodes,SBD)嵌入式金属-氧化物半导体场效应晶体管(metal-oxide-semiconductor field effect transistors,MOSFET),即在传统MOSFET结构中集成一个由钛形成的肖特基接触。在芯片制造过程中,通过增加Ni退火后的表面处理工艺,使得栅源短路失效率降低约58%。研究发现,当二极管电流密度J_(SD)=100 A/cm^(2)时,嵌入式二极管电压降V_(SD)(SBD)=2.1 V,寄生二极管的开启电压约为8 V,这说明嵌入式SBD可以抑制MOSFET寄生二极管开启,降低碳化硅MOSFET"双极退化"风险。另外,该芯片的阈值电压为3.05 V,比导通电阻和阻断电压分别为18.9 mΩ·cm^(2)和3955 V,在高压轨交市场具有广阔的应用前景。

In this paper,a 3300 V silicon carbide(SiC)metal-oxide-semiconductor field effect transistors(MOSFET)with embedded schottky barrier diodes(SBD)is developed,where the traditional MOSFET structure is integrated with a titanium-formed Schottky contact.The optimized surface treatment procedure after nickel annealing is adopted to improve the leakage performance of gatesource in the chip manufacturing process,which contributes to a 58%reduction in gate-source short circuit failure rate.It is found that the switch-on voltage of parasitic diode is about 8V,when the diode current density(J_(SD))reaches 100 A/cm^(2),the voltage drop of SBD(V_(SD(SBD)))is 2.1V,which indicates the effectiveness of the embedded SBD in suppressing the parasitic diode turn-on and reducing the bipolar degradation risk of MOSFET.In addition,the threshold voltage of the chip is 3.05V,and the specific onresistance and blocking voltage are 18mΩ·cm^(2) and 3955V respectively,suggesting a broad application prospect in the high-voltage rail transit market.