METHOD OF MANUFACTURING THE TRENCH OF U-SHAPE

摘要

The present invention relates to the manufacture of CMOS semiconductor device. This invention includes: Step S1, a layer of silicon oxide is deposited covering the surface of the polysilicon gates and the exposed upper surface of the silicon substrate, the silicon oxide layer is removed on the upper surface of the exposed silicon substrate, and then the barrier layer is formed at the surface of the polysilicon gates; Step S2, the ions are implanted into the exposed substrate, and then several doped silicon regions are formed in the silicon substrate; Step S3, the doped silicon regions are etched to form the trench of U-shape, then the barrier layer is removed. The present invention protects the polysilicon gate and the substrate during the process of forming the trench. The rate of etching is increased and the productivity is improved and it is possible to control the depth of the U-shaped trench.

主权项

1. A method for forming a U-shaped trench in a semiconductor structure with polysilicon gates, the structure having a silicon substrate and one or more polysilicon gates, the polysilicon gates being disposed at an upper surface of the silicon substrate, the method comprises:
depositing a layer of silicon oxide covering a surface of the polysilicon gates and the upper surface of the exposed silicon substrate, the silicon oxide layer on the upper surface of the exposed silicon substrate being removed to form a barrier layer at the surface of the polysilicon gates; implanting ions into the exposed substrate, and forming one or more doped silicon regions in the silicon substrate; etching the doped silicon areas to form a U-shaped trench and forming a barrier layer.