SILICON CORNER ROUNDING BY ION IMPLANTATION FOR SHALLOW TRENCH ISOLATION

摘要

A method for rounding corners of a silicon substrate, in accordance with the present invention, includes forming a plateau on a silicon substrate having corners at edges of the plateau. A mask is formed on a top surface of the plateau, which is recessed back from vertical edges of the plateau to provide exposed horizontal portions. Fluorine or Argon dopants are implanted at the corners and on the exposed portions, and the substrate is oxidized such that the corners become rounded providing a gradual transition at the edges of the plateau.