摘要
对在76.2 mm 4H-SiC半绝缘衬底上研制的SiC MESFET进行了高温工作寿命试验,试验结果表明采用Au/Ti/欧姆接触结构的器件在结温275℃条件下工作500 h后,饱和电流下降幅度超过了29%,器件均发生失效。分析表明器件失效的主要原因是Ti层扩散使欧姆接触性能下降。改进工艺采用WTi作为扩散阻挡层后,扩散现象得到了有效抑制,试验前后器件的饱和电流下降幅度在16%以内。三温加速寿命试验表明,器件在150℃结温下平均失效时间(MTTF)达4.1×106h。
A high temperature operation life tes of SiC MESFET with 76.2 mm wafer processt was carried out.After 500 hours operating under 275℃ junction temperature,the saturation current of the device with Au/Ti/Ohmic contact structure decreased by more than 29%.Failure analysis showed that the Ohmic contact degradation resulting from the diffusion of Ti was responsible for the device failure.A diffusion barrier layer of WTi was introduced in the SiC MESFET process to prevent the diffusion.Saturation current of the improved devices decreased less than 16% after the same reliability test.The improved devices showed a mean time to failure（MTTF） of 4.1E6 hours at a junction temperature of 150℃.
出处
《固体电子学研究与进展》
CAS
CSCD
北大核心
2011年第4期331-334,共4页
Research & Progress of SSE
