【摘要】 通过在Si面p型4 H-SiC外延层上使用P+离子注入来形成n阱.Ti和Ni依次淀积在有源区的表面,金属化退火后的XRD分析结果表明Ni2Si是主要的合金相.XEDS的结果表明在Ni2Si/SiC界面处存在一层无定型C.去除Ni2Si合金相与无定型C之后重新淀积金属,不经退火即可形成欧姆接触.同时,注入层的方块电阻Rsh从975下降到438Ω/□.结果表明,合金化退火过程中形成了起施主作用的C空位(VC) .C空位提高了有效载流子浓度并对最终形成欧姆接触起到了重要作用.更多还原

【Abstract】 N-wells are created by P⁺ ion implantation into Si-faced p-type 4H-SiC epilayer.Ti and Ni are deposited in sequence on the surface of the active regions.Ni₂Si is identified as the dominant phase by X-ray diffraction （XRD） analysis after metallization annealing.An amorphous C film at the Ni₂Si/SiC interface is confirmed by an X-ray energy-dispersive spectrometer （XEDS）.The Ni₂Si and amorphous C film are etched away selectively,followed by deposition of new metal films without annealing.Measurement of the current-voltage characteristics shows that the contacts are still ohmic after the Ni₂Si and amorphous C film are replaced by new metal films.The sheet resistance R sh of the implanted layers decreases from 975 to 438Ω/,because carbon vacancies （V_C） appeared during annealing,which act as donors for electrons in SiC.更多还原