Method of forming micro-trench isolation regions in the fabrication of semiconductor devices

Abstract

Abstract A method of forming micro-trench isolation regions with a separation of 0.20 mu m to 0.35 mu m in the fabrication of semiconductor devices involves forming an silicon dioxide layer on select locations of a semiconductor substrate and depositing a polysilicon layer onto the silicon dioxide layer. A layer of photoresist is then deposited over select areas of the polysilicon layer and patterned to form micro-trench isolation regions of widths between about 0.2 mu m to about 0.5 mu m and aspect ratio of between about 2:1 to about 7:1. Thereafter, the isolation regions are etched for a time and pressure sufficient to form micro-trenches in the substrate surface. The micro-trenches will generally have a width ranging from about 1000 ANGSTROM to about 3500 ANGSTROM and depth ranging from about 500 ANGSTROM to about 5000 ANGSTROM . The layer of photoresist is then removed to expose the polysilicon layer and a channel stop implant is deposited and aligned with the micro-trenches. A thermal silicon dioxide layer is formed in the micro-trenches and an undoped silicon dioxide layer is deposited onto the polysilicon layer to fill the micro-trenches. A planar silicon dioxide layer is then deposited onto the undoped silicon dioxide layer and the undoped and planar silicon dioxide layers are then etched back to expose the polysilicon layer. After etchback, the polysilicon layer is stripped to provide the micro-trench isolation regions.

Inventors

• 👤 Stephen W. Swan
• 👤 Ellen G. Piccioli

Bibliographic Details