SILICON DIOXIDE SPACER FOR LOCOS OR RECESSED LOCOS

摘要

A local oxidation of silicon process directed toward reducing lateral encroachment by use of silicon dioxide spacers. A barrier oxide (120) is formed on a silicon substrate (110) and a masking layer (130) is formed over the barrier oxide layer (120). The masking layers are removed to form windows in the masking layer having sidewalls (135) against which silicon dioxide sidewall spacers (175) are formed. The structure is exposed to an ambient oxidant to form fieldoxide regions (140). The silicon dioxide sidewall spacers (175) effectively slow the oxidation of the underlying substrate thereby reducing encroachment.