H_2表面处理形成Al/n型6H-SiC欧姆接触及其退化机制

Study of H_2-treatment to Form Al/n-type 6H-SiC Ohmic Contacts and the Annealing Mechanism of the Contacts

作者通过氢气表面热处理,获得了具有较好特性的Al/n 6H SiC欧姆接触.在这种H2处理后的SiC表面,可以直接通过蒸铝(Al)形成欧姆接触,而无须进行退火处理.该方法也适用于低掺杂外延层上的欧姆接触.XPS测试表明,这种欧姆接触是在400℃以上的退化时,由Al及6H SiC中的Si元素互扩散所致.

Al/n6HSiC ohmic contact was obtained on thermalH2treated surface. The experiments showed this method was also suitable for ohmic contacts on the lightly doped epilayer and there was no postannealing needed to form the ohmic contacts. The XPS study shows the mechanism that ohmic properties of the contacts become worse is commutative diffusion between aluminum and silicon in 6HSiC.