Patent EP0139165A2 successfully refreshed from Google Patents.
EP0139165A2
Expired / Lapsed
EP
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Method of making a trench isolated integrated circuit device
Assignee: International Business Machines Corp
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Filing: 1984-08-23
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Granted: —
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Expires: 2004-08-23
Abstract
Abstract A method is provided for making a semiconductor device which includes the steps of forming a first insulating layer (20,20',22) on the surface of a semiconductor layer (14) having a given conductivity type, forming an opening (24,26) in the insulating layer and forming a diffusion region (28,30) of a conductivity type opposite to that of the given conductivity type at the surface of the semiconductor layer to provide a P-N junction (52) below the surface of the semiconductor layer. A trench (34,36) is then formed along a given axis in the semiconductor layer having a sidewall passing through the opening and through the P-N junction. A second layer of insulation (42,44) is formed on the sidewall of the trench, on the first insulating layer and though the opening over the diffusion region. The second layer of insulation is etched in the direction of the given axis to remove from the opening at least a portion of said second layer of insulation, and an electrical contact is formed on the diffusion region within the opening. In a preferred embodiment the second layer is a dual insulating layer.
Inventors
- 👤 Donald George Chesebro
- 👤 Francis John Soychak
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 15:56
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/021; H10D; H10D10/00; H10D10/40; H10D10/441; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0145; H10W10/10; H10W10/17
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
177 words
A method of making a semiconductor device which includes the steps of: forming a first layer of insulation (20, 20', 22) on the surface of a semiconductor layer (14) having a given conductivity type, forming an opening (24, 26) in said first layer of insulation, forming a doped region (28, 30) of a conductivity type opposite to that of said given conductivity type at the surface of said semiconductor layer through said opening to provide a P-N junction below the surface of said semiconductor layer, forming in said semiconductor layer a trench (34, 36) having a sidewall located along a given plane through said opening and through said P-N junction, said method further comprising the steps of: forming a second layer of insulation (42, 44) on the sidewall of said trench, on said first layer of insulation and through said opening over said doped region (28, 30), etching said second layer of insulation substantially only in the direction of said given plane to remove from said opening at least a portion of said second layer of insulation.
Claim 2
Independent Claim
177 words
A method of making a semiconductor device which includes the steps of: forming a first layer of insulation (20, 20', 22) on the surface of a semiconductor layer (14) having a given conductivity type, forming an opening (24, 26) in said first layer of insulation, forming a doped region (28, 30) of a conductivity type opposite to that of said given conductivity type at the surface of said semiconductor layer through said opening to provide a P-N junction below the surface of said semiconductor layer, forming in said semiconductor layer a trench (34, 36) having a sidewall located along a given plane through said opening and through said P-N junction, said method further comprising the steps of: forming a second layer of insulation (42, 44) on the sidewall of said trench, on said first layer of insulation and through said opening over said doped region (28, 30), etching said second layer of insulation substantially only in the direction of said given plane to remove from said opening at least a portion of said second layer of insulation.
Claim 3
Dependent Claim
44 words
A method as set forth in claim 1 wherein all of said second layer of insulation within said opening is removed to expose said doped region and further including the step of forming an ohmic contact (54, 56) on said doped region (28, 30).
Claim 4
Independent Claim
31 words
A method as set forth in claims 1 or 2 wherein each of said first and second layers of insulation is a dual insulating layer including silicon dioxide and silicon nitride.
Claim 5
Independent Claim
27 words
A method as set forth in one of the preceding claims wherein said etching is performed with an etchant that preferentially etches said second layer of insulation.
Claim 6
Independent Claim
29 words
A method as set forth in one of the preceding claims further including the step of filling said trench with polyimide (46) after forming said second layer of insulation.
Claim 7
Independent Claim
26 words
A method as set forth in one of the preceding claims wherein said etching is performed with a dry etching process, preferably by reactive ion etching.
Claim 8
Independent Claim
212 words
A method of making a semiconductor device which includes the steps of: forming a given layer of insulation (20, 20', 22) on the surface of a semiconductor layer (14) having a given conductivity type, forming an opening (24, 26) in said given layer of insulation, forming a doped region (28, 30) of a conductivity type opposite to that of said given conductivity type through said opening to provide a P-N junction below the surface of said semiconductor layer, forming in said semiconductor layer a trench (34, 36) having a sidewall passing through said opening and through said P-N junction, said method comprising the steps of: forming a first layer of insulation (42) and a subsequent second layer of insulation (44) on the sidewall of said trench, on said given layer of insulation (20, 20', 22, 32') and through said opening on said doped region, etching said second layer of insulation substantially only in a direction parallel to the sidewall of said trench until all of said second layer of insulation is removed from said opening area overlying said doped region, etching said first layer of insulation (32') until the surface of said doped region (28, 30) is at least partially exposed and forming an ohmic contact (54, 56) on said doped region.
Claim 9
Independent Claim
212 words
A method of making a semiconductor device which includes the steps of: forming a given layer of insulation (20, 20', 22) on the surface of a semiconductor layer (14) having a given conductivity type, forming an opening (24, 26) in said given layer of insulation, forming a doped region (28, 30) of a conductivity type opposite to that of said given conductivity type through said opening to provide a P-N junction below the surface of said semiconductor layer, forming in said semiconductor layer a trench (34, 36) having a sidewall passing through said opening and through said P-N junction, said method comprising the steps of: forming a first layer of insulation (42) and a subsequent second layer of insulation (44) on the sidewall of said trench, on said given layer of insulation (20, 20', 22, 32') and through said opening on said doped region, etching said second layer of insulation substantially only in a direction parallel to the sidewall of said trench until all of said second layer of insulation is removed from said opening area overlying said doped region, etching said first layer of insulation (32') until the surface of said doped region (28, 30) is at least partially exposed and forming an ohmic contact (54, 56) on said doped region.
Claim 10
Dependent Claim
27 words
A method as set forth in claim 7 wherein said first layer of insulation (32', 42) is silicon dioxide and said second layer (44) is silicon nitride.
Claim 11
Independent Claim
30 words
A method as set forth in claims 7 or 8 wherein the etching of said first layer is performed with an etchant that preferentially etches said first layer of insulation.
Claim 12
Independent Claim
31 words
A method as set forth in one of the preceding claims further including a step of filling said trench (34, 36) with polyimide (46) after forming said second layer of insulation.
Claim 13
Independent Claim
26 words
A method as set forth in one of the preceding claims wherein said etching is performed with a dry etching process, preferably by reactive ion etching.
Claim 14
Independent Claim
32 words
A method as set forth in one of the preceding claims wherein said first layer of insulation (32') is etched by a wet etching process after said directional etching process is completed.
Claim 15
Independent Claim
33 words
A method as set forth in one of the preceding claims wherein said given layer of insulation is a dual layer including a layer of silicon dioxide and a layer of silicon nitride.
Claim 16
Dependent Claim
42 words
A method as set forth in claim 11 wherein said first insulation layer of silicon dioxide is formed on the sidewall of said trench and said second insulation layer of silicon nitride is formed on said first insulation layer of silicon dioxide.
Claim 17
Independent Claim
51 words
A method as set forth in one of the preceding claims wherein said first insulation layer of silicon dioxide is formed by growing a layer of silicon dioxide on the sidewall of said trench and then, preferably pyrolytically, depositing a layer of silicon dioxide on said grown layer of silicon dioxide.
Claim 18
Dependent Claim
29 words
A method as set forth in claim 15 wherein said layer of silicon dioxide grown on the sidewalls of said trench is of a thickness of approximately 250 angstroms.
References Cited (Backward Citations)
No citation records indexed.
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