沟槽肖特基器件Si深槽刻蚀工艺  

Silicon Deep-Trench Etching for Trench Schottky Device

作　　者：李志栓[1] 汤光洪[1] 於广军 杨新刚[1] 杨富宝[1] Li Zhishuan Tang Guanghong Yu Guangjun Yang Xingang Yang Fubao(Hangzhou Silan Integrated Circuit Co., Ltd. , Hangzhou 310083, China)

机构地区：[1]杭州士兰集成电路有限公司,杭州310083

出　　处：《半导体技术》2016年第12期933-938,共6页Semiconductor Technology

摘　　要：深硅刻蚀工艺是制造沟槽肖特基器件的关键技术。Si深槽的深度影响肖特基反向击穿电压,深槽的垂直度影响多晶Si回填效果,侧壁平滑度及深槽底部长草现象对器件的耐压性能影响显著。采用SF6/O2常温刻蚀工艺刻蚀Si深槽。研究了工艺压力、线圈功率、SF6/O2比例以及下电极功率等参数对沟槽深度均匀性和垂直度的影响。得到了使Si深槽形貌为槽口宽度略大于槽底,侧壁光滑,且沟槽深度均匀性为2.3%左右的工艺条件。利用该刻蚀工艺可实现沟槽多晶Si无缝回填。该工艺条件成功应用于沟槽肖特基器件制作中,反向击穿电压达到58 V,反向电压通48 V,漏电流为11.2μA,良率达到97.55%。Si deep-trench etching technique is the key technology to manufacture trench Schottky devices. Trench depth affects the reverse breakdown voltage of the Schottky device; trench verticality affects poly silicon backfill; sidewall smoothness and micro-grass phenomenon on the silicon bottom surface have a significant effect on breakdown resistant characteristic of the device. Si deep-trench was etched by SF_6/O_2 mixture gases at room temperature. Effects of process parameters such as process pressure,coil power,SF_6/O_2 ratio and chuck power on trench depth uniformity and verticality was discussed,and the process conditions was got,which was made the top of Si deep-trench size slightly wider than the bottom,side wall was smooth and trench depth uniformity was about 2. 3%. Utilizing the optimized etching process can realize the trench poly silicon void-free backfill. The process is successfully applied to the production of the trench Schottky device, in which the reverse breakdown voltage is 58 V,the reverse voltage through 48 V,the leakage current is 11. 2 μA,and the yield is 97. 55%.

关 键 词：沟槽肖特基器件 Si深槽刻蚀 常温刻蚀 无缝回填 SF6/O2比例 

分 类 号：TN305.7[电子电信—物理电子学]