Method for etching source contact hole of groove type SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor)

The invention discloses a method for etching a source contact hole of a groove type SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), which belongs to the technical field of semiconductor manufacturing, and is characterized in that the prior art is improved, a cleaning liquid after two-step etching is replaced, a Clean-A cleaning liquid is used to eliminate defects caused after an insulating layer is etched, and the problem of poor morphology of BPSG is solved; in addition, one step of deposition of silicon oxynitride SION is added after etching of the oxide layer is finished, and the added deposition of the SION can avoid the problem of gate source short circuit caused by Over ETCH in the etching process due to photoetching alignment errors. 本发明公开了一种沟槽型SiC MOSFET源接触孔的刻蚀方法，属于半导体制造技术领域，该方法对现有技术进行了改进，更换了两步刻蚀过后的清洗液体，使用Clean-A清洗液消除了刻蚀绝缘层过后的引来的缺陷，解决了BPSG形貌不好的问题；此外在氧化层刻蚀结束后又增加了一步氮氧化硅SION的沉积，增加的SION的沉积，可以避免由于光刻对准误差引来刻蚀过程中Over ETCH导致栅源短路的问题。