Forming three dimensional isolation structures

摘要

A three dimensional shallow trench isolation structure including sets of parallel trenches extending in two perpendicular directions may be formed by depositing a conformal deposition in a first set of parallel trenches, oxidizing the second set of trenches to enable selective deposition in said second set of trenches and then conformally depositing in said second set of trenches. In some embodiments, only one wet anneal, one etch back, and one high density plasma chemical vapor deposition step may be used to fill both sets of trenches.

主权项

1. A method comprising:
forming a first plurality of parallel trenches extending in a first direction; conformally depositing a dielectric in said first plurality of parallel trenches; forming a second plurality of generally parallel trenches in a second direction perpendicular to said first direction; treating said second plurality of generally parallel trenches, after said conformally depositing a dielectric in said first plurality of parallel trenches, to encourage selective deposition in said second plurality of generally parallel trenches; and conformally and selectively depositing a dielectric material in said second plurality of generally parallel trenches after said treating the second plurality of generally parallel trenches.