US3849136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Masking of deposited thin films by use of a masking layer photoresist composite
Assignee: International Business Machines Corp
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Filing: 1973-07-31
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Granted: 1974-11-19
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Expires: 1993-07-31
Abstract
Abstract A method and structure for use in depositing thin films which avoids edge-tearing of the films. The structure is a composite comprising a photosensitive layer (photoresist) on the substrate onto which deposition is to occur, and an overlaying masking layer (which is conveniently a metal such as aluminum). Apertures in the photoresist layer and the masking layer expose portions of the substrate. The masking layer acts as a deposition mask which is spaced away from the substrate at a distance equal to the thickness of the underlying photoresist layer. The photoresist layer acts to keep the masking layer in close proximity to the substrate and is patterned through the use of the overlying masking layer as an exposure mask. Recession of the edges of the photoresist layer is achieved by overexposure and subsequent development. In this manner, the masking layer overhangs the photoresist layer, thereby providing an undercut in order to prevent edge-tearing of deposited films.
Inventors
- 👤 K Grebe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:27
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/02; H05K3/04; H05K3/046; H05K3/048; G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/095; H10; H10N; H10N97/00; H10P; H10P95/00
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
104 words
A METHOD OF DEPOSITING PATTERNED THIN FILMS ON A SUBSTRATE, COMPRISING: FORMING A FIRST LAYER OF PHOTOSENSITIVE MATERIAL WHICH CAN BE PATTERNED ON SAID SUBSTRATE, FORMING A MASKING LAYER ON SAID FIRST LAYER, PATTERNING SAID MASKING LAYER TO FORM OPENINGS THEREIN WHICH EXTEND TO SAID FIRST PHOTOSENSITIVE LAYER, PATTERNING SAID FIRST PHOTOSENSITIVE LAYER TO FORM OPENINGS THEREIN WHICH EXTEND TO SAID SUBSTRATE AND WHICH ARE ALIGNED WITH SAID OPENINGS IN SAID MASKING LAYER AND OF LARGER SIZE THAN SAID OPENINGS IN SAID MASKING LAYER, AND DEPOSITING SAID THIN FILMS ONTO SAID SUBSTRATE THROUGH SAID ALIGNED OPENINGS USING SAID MASKING LAYER AS A DEPOSITION MASK.
Claim 2
Independent Claim
104 words
A METHOD OF DEPOSITING PATTERNED THIN FILMS ON A SUBSTRATE, COMPRISING: FORMING A FIRST LAYER OF PHOTOSENSITIVE MATERIAL WHICH CAN BE PATTERNED ON SAID SUBSTRATE, FORMING A MASKING LAYER ON SAID FIRST LAYER, PATTERNING SAID MASKING LAYER TO FORM OPENINGS THEREIN WHICH EXTEND TO SAID FIRST PHOTOSENSITIVE LAYER, PATTERNING SAID FIRST PHOTOSENSITIVE LAYER TO FORM OPENINGS THEREIN WHICH EXTEND TO SAID SUBSTRATE AND WHICH ARE ALIGNED WITH SAID OPENINGS IN SAID MASKING LAYER AND OF LARGER SIZE THAN SAID OPENINGS IN SAID MASKING LAYER, AND DEPOSITING SAID THIN FILMS ONTO SAID SUBSTRATE THROUGH SAID ALIGNED OPENINGS USING SAID MASKING LAYER AS A DEPOSITION MASK.
Claim 3
Dependent Claim
26 words
The method of claim 1, where said masking layer is comprised of an etchable material and said first layer is comprised of positive acting photoresist material.
Claim 4
Dependent Claim
25 words
The method of claim 1, where said masking layer is approximately one micron in thickness and said first layer is approximately 1.5 microns in thickness.
Claim 5
Dependent Claim
27 words
The method of claim 1, including the further step of removing said first layer and said masking layer after deposition of said thin films on said substrate.
Claim 6
Dependent Claim
46 words
The method of claim 1, where said masking layer is patterned by forming a second photosensitive layer of patternable material on said masking layer, patterning said second layer to expose portions of said underlying masking layer, and selectively removing said exposed portions of said masking layer.
Claim 7
Dependent Claim
20 words
The method of claim 1, where the openings in said masking layer are about 0.5 - 5 mils in width.
Claim 8
Dependent Claim
16 words
The method of claim 1, where said masking layer is vacuum deposited on said first layer.
Claim 9
Dependent Claim
32 words
The method of claim 1, where said masking alyer overhangs said first layer at the edges of its opening therein by an amount which is approximately the thickness of said masking layer.
Claim 10
Dependent Claim
77 words
A structure for deposition of patterned layers on a substrate, comprising: a substrate having formed thereon a layer of photosensitive material, there being a layer of masking material vacuum deposited on said photosensitive material, said photosensitive material and said masking layer having at least one aperture therein which exposes a portion of the surface of said substrate, wherein said aperture in said masking layer is smaller than said aperture in said photosensitive layer and substantially aligned therewith.
Claim 11
Dependent Claim
77 words
A structure for deposition of patterned layers on a substrate, comprising: a substrate having formed thereon a layer of photosensitive material, there being a layer of masking material vacuum deposited on said photosensitive material, said photosensitive material and said masking layer having at least one aperture therein which exposes a portion of the surface of said substrate, wherein said aperture in said masking layer is smaller than said aperture in said photosensitive layer and substantially aligned therewith.
Claim 12
Dependent Claim
15 words
The structure of claim 9, where said masking layer is comprised of an etchable material.
Claim 13
Independent Claim
171 words
A method for depositing thin films, comprising the steps of: forming a first layer of photosensitive material on a substrate, depositing a masking layer on said first layer, forming a second layer of photosensitive material on said masking layer, exposing and developing said second layer of photosensitive material to pattern said second layer, there being openings in said second layer which expose portions of the surface of said masking layer, removing said exposed portions of said masking layer to create openings therein which expose portions of said first photosensitive layer, exposing and developing the remaining portions of said second photosensitive layer and said first photosensitive layer through said openings in said masking layer to remove said portions of said first photosensitive layer, said first photosensitive layer being overexposed to provide openings therein which are larger than the openings in said masking layer, depositing said thin film onto said substrate through said openings in said masking layer and said first photosensitive layer, and removing said first photosensitive layer and said masking layer.
Claim 14
Independent Claim
171 words
A method for depositing thin films, comprising the steps of: forming a first layer of photosensitive material on a substrate, depositing a masking layer on said first layer, forming a second layer of photosensitive material on said masking layer, exposing and developing said second layer of photosensitive material to pattern said second layer, there being openings in said second layer which expose portions of the surface of said masking layer, removing said exposed portions of said masking layer to create openings therein which expose portions of said first photosensitive layer, exposing and developing the remaining portions of said second photosensitive layer and said first photosensitive layer through said openings in said masking layer to remove said portions of said first photosensitive layer, said first photosensitive layer being overexposed to provide openings therein which are larger than the openings in said masking layer, depositing said thin film onto said substrate through said openings in said masking layer and said first photosensitive layer, and removing said first photosensitive layer and said masking layer.
Claim 15
Dependent Claim
14 words
The method of claim 11, where said masking layer is comprised of a metal.
Claim 16
Dependent Claim
18 words
The method of claim 11, where said masking layer is of the order of a micron in thickness.
Claim 17
Dependent Claim
14 words
The method of claim 11, where said deposited thin film is a metallic film.
Claim 18
Dependent Claim
13 words
The method of claim 11, where said deposited thin film is an insulator.
Claim 19
Dependent Claim
16 words
The method of claiM 11, where said masking layer and said thin film are vacuum deposited.
Claim 20
Dependent Claim
79 words
A structure for deposition of patterned layers on a substrate, comprising: a substrate having formed thereon a layer of organic material, there being a layer of masking material vacuum deposited on said layer of organic material, said organic layer and said masking layer having at least one aperture therein which exposes a portion of the surface of said substrate, wherein said aperture in said masking layer is smaller than said aperture in said organic layer and substantially aligned therewith.
Claim 21
Dependent Claim
79 words
A structure for deposition of patterned layers on a substrate, comprising: a substrate having formed thereon a layer of organic material, there being a layer of masking material vacuum deposited on said layer of organic material, said organic layer and said masking layer having at least one aperture therein which exposes a portion of the surface of said substrate, wherein said aperture in said masking layer is smaller than said aperture in said organic layer and substantially aligned therewith.
Claim 22
Dependent Claim
38 words
The structure of claim 17, wherein the width of said aperture in said organic layer exceeds the width of the aperture in said masking layer by an amount which is about twice the thickness of said masking layer.
References Cited (Backward Citations)
US3228794A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |