Improvement Research of Round Convex Residue in Dual Gate Layer

With the development of integrated circuit technology, the application of new materials and new process in integrated circuit process also brings new challenges. This paper reported some improvement research for round convex residue (oxide residue) in dual gate layer which may result in low yield. Improvement research include change wet clean process condition before thick gate oxidation, add wet clean process post thick gate oxidation, change lithography process conditions and change thick gate growth mode. The results show that oxide residue can be effectively removed by these methods, and which can improve yield about 20%.