Patent ID: 7413969
Filing Date: 2008-08-19
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device having a substrate with an active area defined by an isolation layer, the method comprising: forming: an oxide layer or an insulation layer; a poly-silicon layer; and a reflection-proof layer on the active area of the semiconductor substrate; forming a mask pattern defining an expected substrate recess area on the reflection-proof layer; etching the reflection-proof layer, the poly-silicon layer, and the oxide layer or the insulation layer to expose the expected substrate recess area; first etching the substrate of the expected recess area to form a first recess having a first recess width and a first recess depth; removing the mask pattern and the reflection-proof layer; second etching the substrate at the bottom surface of the first recess by using the etched poly-silicon layer as an etching mask to form a second recess having a second recess width and a second recess depth, wherein the first recess width is wider than the second recess width; removing the poly-silicon layer and the oxide layer or the insulation layer; and forming a gate in the first and second recesses.