Method for forming a low barrier height oxide layer on a silicon substrate

摘要

This invention relates to a method for forming a low barrier height oxide layer on the surface of a crystalline silicon substrate, comprising: (A) forming spaced field oxide regions on the surface of said crystalline silicon substrate, the space between said field oxide regions comprising a tunnel region; (B) vapor depositing a layer of amorphous silicon on the surface of said field oxide regions and on the surface of said substrate in said tunnel region, the thickness of said layer of amorphous silicon being in the range of about 50 ANGSTROM to about 100 ANGSTROM ; and (C) oxidizing said layer of amorphous silicon. The oxidized amorphous silicon layer in said tunnel region is a tunnel oxide layer and, in one embodiment, the inventive method includes the step of (D) forming a floating gate over said tunnel oxide layer, said tunnel oxide layer having a barrier height of about 1.6 to about 2.0 eV.