氢氟酸刻蚀对Ni/6H-SiC接触性质的作用  

Effect of hydrofluoric acid etching time on Ni/6H-SiC contacts

作　　者：黄维[1,2] 陈之战[1] 陈博源[1,2] 张静玉[2,3] 严成锋[1] 肖兵[1] 施尔畏[1] 

机构地区：[1]中国科学院上海硅酸盐研究所宽禁带半导体材料课题组,上海200050 [2]中国科学院研究生院,北京100049 [3]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《物理学报》2009年第5期3443-3447,共5页Acta Physica Sinica

基　　金：国家高技术研究发展计划(863)(批准号:2006AA03A146);中国科学院知识创新项目(批准号:KGCX2-YW-206);上海自然科学基金(批准号:06ZR14096);高性能陶瓷和超微结构国家重点实验室开放基金(批准号:SKL200810SIC)资助的课题~~

摘　　要：采用浓度为10%的氢氟酸(HF)刻蚀6H-SiC单晶片,研究了HF刻蚀时间对Ni/6H-SiC接触性质的影响.经24h刻蚀的SiC基片在溅射Ni层后,其接触表现良好线性的电流-电压(I-V)曲线.低于这个腐蚀时间的接触具有明显的势垒,但在大于1000℃快速退火后,也得到了良好线性的I-V曲线.X射线衍射(XRD)和俄歇能谱(AES)深度元素分析表明Ni2Si和C是快速退火后的主要产物.XRD和低能反射电子能量损失谱表明表层的C元素是以非晶态存在.通过研究高温快速退火下元素的互扩散及HF与SiC表层反应机理,发现SiC表面富碳层是这两种方法形成欧姆接触的关键因素.The effect of hydrofluoric acid （HF） etching time on Ni/6H-SiC ohmic contacts was investigated. The as-deposited Ni/6H- SiC contacts prepared by 6H-SiC substrates which have been subjected to different HF etching time have different I-V characteristics. For SiC substrates etched for less than 12 hours, the contacts were rectifying, and excellent linear curves were observed after high temperature thermal annealing. X-ray diffraction, Auger electronic spectroscopy and low-energy reflection electron energy loss spectroscopy showed that Ni2 Si and amorphous C were the main reaction products after annealing. For SiC substrate etched for 24 hours, the as-deposited Ni/6H-SiC contact was ohmic. The carbon-enriched layer （CEL） on the SiC surface plays an important role in the formation of ohmic contact.

关 键 词：欧姆接触 SIC 富碳层 互扩散 

分 类 号：TN304[电子电信—物理电子学]