Method of forming a semiconductor structure having laterally merged body layer
First Claim
1. A method of forming a semiconductor structure, comprising the steps of:
- (a) providing a semiconductor substrate having a major surface;
(b) disposing a masking layer having at least two openings above said major surface;
(c) depositing material in said substrate through said at least two openings;
(d) diffusing said material in said substrate downwardly and sidewardly so as to merge the material under each of said at least two openings together;
(e) etching said substrate through said openings by using an etchant which does not significantly etch said masking layer to form at least two cavities in said substrate under said at least two openings;
(f) lining said cavities with insulating material; and
(g) filling said cavities with conductive material.
5 Assignments
0 Petitions
Accused Products
Abstract
A trenched gate MOSFET (metal oxide semiconductor field effect transistor) structure is fabricated via a novel process which includes the step of using a common mask serving the dual role as a mask for the body layer formation and as a mask for trench etching. The common mask defines an patterned oxide layer which includes a plurality of openings at a predetermined distance away from the scribe line of the MOSFET structure. During fabrication, material of the body layer is implanted through the openings of the patterned oxide layer. Thereafter, the implanted material is side-diffused and merged together under a drive-in cycle as one continuous body layer. Using the same patterned oxide layer as a shield, trenches are anisotropically etched in the substrate. The MOSFET structure as formed requires no separate mask for delineating the active body region away from the scribe line, resulting reduction of fabrication steps. The consequential benefits are lower manufacturing costs and higher production yields.
23 Citations
11 Claims
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1. A method of forming a semiconductor structure, comprising the steps of:
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(a) providing a semiconductor substrate having a major surface; (b) disposing a masking layer having at least two openings above said major surface; (c) depositing material in said substrate through said at least two openings; (d) diffusing said material in said substrate downwardly and sidewardly so as to merge the material under each of said at least two openings together; (e) etching said substrate through said openings by using an etchant which does not significantly etch said masking layer to form at least two cavities in said substrate under said at least two openings; (f) lining said cavities with insulating material; and (g) filling said cavities with conductive material. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of forming a semiconductor cell array, comprising the steps of:
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(a) providing a semiconductor substrate of a first conductivity type, said substrate having a major surface; (b) disposing a masking layer having a plurality of openings above said major surface; (c) depositing material of a second conductivity type through said plurality of openings; (d) diffusing material of said second conductivity type in said substrate sidewardly and downwardly so as to merge the material of said second conductivity type under each of said openings together; (e) etching said substrate through the openings of said masking layer to form a plurality of trenches in said substrate; (f) lining said trenches with insulating material; and (g) filling said trenches with conductive material. - View Dependent Claims (8, 9, 10, 11)
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Specification