Patent EP0232508A2 successfully refreshed from Google Patents.
EP0232508A2
Expired / Lapsed
EP
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Dual glass reflow process for forming contacts
Assignee: International Business Machines Corp
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Filing: 1986-12-09
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Granted: —
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Expires: 2006-12-09
Abstract
Abstract A method for forming contact openings (19) in semiconductor devices. A borosilicate glass layer (13) is deposited over the gate and drain area (14, 11) of a device, followed by a borophosphosilicate glass layer (15). After masking with photoresist (16) and defining openings (17) the borophosphosilicate glass (15) is isotropically etched to undercut the resist layer (16). A plasma etch is utilized to anisotropically etch the borosilicate glass layer (13) and expose the surface of the drain area (11). After the photoresist (16) is stripped away, a reflow step is employed to reduce the sharp edges of the glass layer and result in a sloped contact opening profile. Good metal coverage is achieved while maintaining isolation of the gate (14).
Inventors
- 👤 Stephen T. Chambers
- 👤 Stephen E. Luce
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 18:24
CPC Classifications
H; H10; H10P; H10P95/00; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6921; H10P14/6922; H10P14/6923; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/082
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
155 words
A method of forming contacts (19) on a semiconductor body comprising the steps of: forming a first dielectric layer (13) on said body, said first dielectric layer having a first reflow temperature; forming a second dielectric layer (15) on said first dielectric layer (13), said second dielectric layer (15) having a second reflow temperature, said second reflow temperature lower than said first reflow temperature; heating said body to said second reflow temperature; forming a mask layer (16) on said second dielectric layer (15) ; defining openings (17) in said mask layer (16) to expose said second dielectric layer (15); removing said exposed portions of said second dielectric layer (15) to expose said first dielectric layer (13); removing said exposed portions of said first dielectric layer (13) to expose said body; heating said body to said second reflow temperature; forming a conductive layer on said exposed portions of said body; whereby an improved contact is realized.
Claim 2
Independent Claim
155 words
A method of forming contacts (19) on a semiconductor body comprising the steps of: forming a first dielectric layer (13) on said body, said first dielectric layer having a first reflow temperature; forming a second dielectric layer (15) on said first dielectric layer (13), said second dielectric layer (15) having a second reflow temperature, said second reflow temperature lower than said first reflow temperature; heating said body to said second reflow temperature; forming a mask layer (16) on said second dielectric layer (15) ; defining openings (17) in said mask layer (16) to expose said second dielectric layer (15); removing said exposed portions of said second dielectric layer (15) to expose said first dielectric layer (13); removing said exposed portions of said first dielectric layer (13) to expose said body; heating said body to said second reflow temperature; forming a conductive layer on said exposed portions of said body; whereby an improved contact is realized.
Claim 3
Dependent Claim
29 words
The method as defined by claim 1 wherein said second dielectric layer (15) has an etch rate being higher than the etch rate of the first dielectric layer (13).
Claim 4
Dependent Claim
27 words
The mehtod as defined by claims 1 or 2 wherein said exposed portions of said second dielectric layer (15) are removed by means of an isotropic etch.
Claim 5
Independent Claim
27 words
The method as defined by claims 2 or 3 wherein said exposed portions of said first dielectric layer (13) are removed by means of an anisotropic etch.
Claim 6
Independent Claim
16 words
The method as defined by claims 1 to 4 wherein said mask layer (16) comprises photoresist.
Claim 7
Independent Claim
21 words
The method as defined by claims 1 to 5 wherein said second dielectric layer (15) is removed by a wt etch.
Claim 8
Independent Claim
21 words
The method as defined by claims 1 to 6 wherein said first dielectric layer (13) is removed by a plasma etch.
Claim 9
Independent Claim
22 words
The method as defined by claims 1 to 7 wherein said first and second dielectric layers (13, 15) are permeable by hydrogen.
Claim 10
Independent Claim
27 words
The method as defined by claims 1 to 8 wherein said first dielectric layer (13) comprises borosilicate glass, and said second dielectric layer (15) comprises borophosphosilicate glass.
Claim 11
Independent Claim
17 words
The method as defined by claims 8 and 9 wherein said second reflow temperature is approximately 920°C.
References Cited (Backward Citations)
No citation records indexed.
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