LOW ENCROACHMENT SELECTIVE PLANARIZATION PROCESS FOR TRENCH ISOLATION
Original Publication Date: 2000-Jan-01
Included in the Prior Art Database: 2002-Sep-05
Deep trench isolation on submicron BiCMOS process results in oxide encroachment and defectivi- ty issues related to surface topography. Poor surface topography in trenches following cap oxidation causes a yield degrading stringer problems. Oxide encroachment limits cap oxide thickness forcing the use of an additional masking step to protect the cap oxide during stringer removal. Resulting integration is marginal. A new approach with deep trench side- wall nitride and high pressure argon sputter etch to smooth surface topography results in a low encroachment selective planarization process that alleviates both of these issues.