Ohmic Contact Properties of Multi-Metal Films on n-Type 4H-SiC  

多层金属-n型4H-SiC的欧姆接触(英文)

作　　者：韩茹[1] 杨银堂[1] 王平[1] 崔占东[2] 李亮[2] 

机构地区：[1]西安电子科技大学宽禁带半导体材料与器件教育部重点实验室,西安710071 [2]中国电子科技集团公司第13研究所,石家庄050051

出　　处：《Journal of Semiconductors》2007年第2期149-153,共5页半导体学报（英文版）

基　　金：教育部重点科技项目(批准号:02074);国家部委预研计划(批准号:41308060105)资助项目~~

摘　　要：An investigation of Au/Ti/Ni and Au/Ti/Pt ohmic contacts to n-type 4H-SiC and the behavior of metal films on SiC with thermal anneals is reported. Specific contact resistance as low as 2. 765 x 10^-6Ω·cm^2 was achieved after rapid thermal annealing in N2 for 2min at 950℃. SIMS analysis shows that the formation of Ni silicide after annealing supported a number of carbon atoms＇ outdiffusion from the SiC to form interstitial compound TiC. This process can create abundant C vacancies near the interface. It is the carbon defect layer that enhances the defect-assisted tunneling. The interface band structure within the defect level could make it clear why the metal-SiC contacts become ohmic during annealing.研究了热退火条件下Au/Ti/Ni-4H-SiC欧姆接触形成机制.通过950℃下的快速热退火形成的最低欧姆接触电阻为2.765×10-6Ω.cm2.SIMS分析表明退火过程中NiSi化合物的形成会带来SiC内部多余C原子的溢出,并在接触面上与Ti形成间隙化合物TiC.这一过程造成接触表面存在由大量C空位形成的缺陷层从而增强了表面间接隧穿.通过界面能带结构图直观地解释了欧姆接触在热退火条件下的形成机制.

关 键 词：silicon carbide ohmic contact carbon vacancy interface band structure 

分 类 号：TN304[电子电信—物理电子学]