THICKER OXIDE FORMATION AT THE TRENCH BOTTOM BY SELECTIVE OXIDE DEPOSITION
First Claim
1. A method of fabricating a trench MOSFET, the method comprising:
- providing a semiconductor substrate;
forming a trench in the substrate, the trench comprising a side wall and a bottom;
forming a barrier layer on at least a portion of the side wall; and
depositing a thick insulating layer overlying the bottom of the trench;
wherein the barrier layer is selected such that the thick insulating layer deposits on the semiconductor substrate at a faster rate than the thick insulating layer deposits on the barrier layer.
7 Assignments
0 Petitions
Accused Products
Abstract
A trench MOSFET is formed by creating a trench in a semiconductor substrate, then forming a barrier layer over a portion of the side wall of the trench. A thick insulating layer is deposited in the bottom of the trench. The barrier layer is selected such that the thick insulating layer deposits in the bottom of the trench at a faster rate than the thick insulating layer deposits on the barrier layer. Embodiments of the present invention avoid stress and reliability problems associated with thermal growth of insulating layers, and avoid problems with control of the shape and thickness of the thick insulating layer encountered when a thick insulating layer is deposited, then etched to the proper shape and thickness.
-
Citations
13 Claims
-
1. A method of fabricating a trench MOSFET, the method comprising:
-
providing a semiconductor substrate;
forming a trench in the substrate, the trench comprising a side wall and a bottom;
forming a barrier layer on at least a portion of the side wall; and
depositing a thick insulating layer overlying the bottom of the trench;
wherein the barrier layer is selected such that the thick insulating layer deposits on the semiconductor substrate at a faster rate than the thick insulating layer deposits on the barrier layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification