Integrated circuit with self-aligned isolation

A method of integrated circuit manufacture comprising the steps of:

• forming layers of oxide and a material on a substrate, said substrate having a semiconductor surface and buried oxide and silicide layers, said layers of oxide and material on the semiconductor surface and being closer to said silicide layer than to said buried oxide layer;
• first patterning to form isolation regions in said semiconductor;
• second patterning to form trenches which expose portions of said oxide layer;
• depositing an oxide in said isolation regions and in said trenches;
• and completing said integrated circuit fabrication.