低温退火制备Ti/4H-SiC欧姆接触  

Fabrication of Ti/4H-SiC Ohmic Contact by Annealing at Low Temperature

作　　者：陈素华[1] 王海波[1] 赵亮[1] 马继开[1] 

机构地区：[1]大连理工大学电信学院电子系,辽宁大连116023

出　　处：《半导体技术》2008年第2期147-150,共4页Semiconductor Technology

基　　金：国家973项目(2005CCA00100)

摘　　要：实现SiC器件欧姆接触常规工艺需要800—1200℃的高温退火。研究了n型4H-SiC低温制备Ti欧姆电极的工艺及其基本电学特性。通过氢等离子体处理4H-SiC的表面，沉积Ti后可直接形成欧姆接触，室温下比接触电阻率ρc为2．25×10^-3Ω·cm^2（ρc由圆形传输线模型CTLM测得），随着合金温度的升高，其欧姆特性逐渐增强，400℃合金后获得最低的比接触电阻率ρc为2．07×10^-4Ω·cm^2。采用X射线衍射（XRD）确定金属／n-SiC界面反应时形成的相，以分析电学性质与微观结构间的联系。最后讨论了低温欧姆接触的形成机制。Annealing at 800 - 1 200 ℃ is required in traditional fabrication of ohmic contact on SiC devices. Low temperature preparing process and basic electrical characters of Ti ohmic electrodes on n type 4H-SiC substmtes were studied. Ohmic contact was formed by depositing Ti after 4H-SiC surface was cleaned by hydrogen plasma. At room temperature ρc was 2.25 × 10^-3Ω· cm^2 （measured by circular transmission line model （CTLM））. With the annealing temperature increasing, ohmic behavior of the contacts improved gradually. After annealing at 400℃, the lowest Pc was 2.07 × 10^-4·cm^2. XRD was used to determine the intermetallic compound formed at the metal/n-SiC interfaces for analyzing the correlation between electrical properties and the microstructure. Ohmic contact formation mechanism at low temperatures was also discussed.

关 键 词：碳化硅 氢等离子体 欧姆接触 比接触电阻率 

分 类 号：TN305.93[电子电信—物理电子学] TN304