Investigation of Gate Oxide Integrity and mechanism forGate Oxide pre-clean process

• 1、Shanghai Huali Microelectronics Corporation, Shanghai201203, China

Abstract：With the development of science and technology, the size of devices becomes smaller and smaller, and the gate oxide integrity (GOI) problem becomes more and more critical. In this paper, the failure of gate oxide process due to gate oxide pre-clean process was studied.Standard cleansolution (SC1) at different temperatures has a great influence on the morphology of in the active area(AA) cornerduring gate oxide pre-clean process.The use of hot SC1 cleansolution would cause sharp corner at AA corner, which was mainly caused by the high etching amount of hot SC1 on the silicon substrate. However, due to the small contact area between AA Corner and clean solution, hot SC1 would cause less silicon loss on AA Corner.Finally, the thickness of AA Corner gate oxide layer was relatively thin, which eventually leaded to the reliability failure of gate oxide.The use of cold SC1 cleanmethod could eliminate the sharp corner anomaly of AA Corner, and the reliability failure point of gate oxide could be completely eliminated.)

Keywords： Gate Oxide integrity SC1 GOI failure reliability Gate Oxide breakdown.