US4396458A
Expired / Lapsed
US
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Method for forming planar metal/insulator structures
Assignee: International Business Machines Corp
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Filing: 1981-12-21
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Granted: 1983-08-02
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Expires: 2001-12-21
Abstract
Abstract Formation of planar conductor/insulator semiconductor devices utilizing hafnium coated aluminum based metallization with a magnesium oxide mask for dry etching of the metallization and deposition of planar insulation. The hafnium coating is used to protect the aluminum metallization during mask removal, and as a registration enhancer for subsequent electron-beam processing.
Inventors
- 👤 Valeria Platter
- 👤 Laura B. Rothman
- 👤 Paul M. Schaible
- 👤 Geraldine C. Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:49
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/425; H10W20/01; H10W20/031; H10W20/056; H10W20/058; H10W20/064; H10W20/071; H10W70/00; H10W70/01; H10W70/05; H10W70/60; H10W70/62; H10W70/66; H05; H05K; H05K3/00; H05K3/46; H05K3/4644; H05K3/4647; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/951
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
85 words
A method for the formation of a planar dielectric coating over a surface of a substrate having a conductive pattern of an aluminum based metal thereon exposing complementary portions of said substrate, comprising: forming a hafnium coating over a portion of said pattern, forming a magnesium oxide coating on said hafnium coating, depositing a dielectric coating over said substrate inclusive of said magnesium oxide coating, and wet etching said magnesium oxide coating for removal thereof together with the overlying portions of said dielectric coating thereon.
Claim 2
Independent Claim
85 words
A method for the formation of a planar dielectric coating over a surface of a substrate having a conductive pattern of an aluminum based metal thereon exposing complementary portions of said substrate, comprising: forming a hafnium coating over a portion of said pattern, forming a magnesium oxide coating on said hafnium coating, depositing a dielectric coating over said substrate inclusive of said magnesium oxide coating, and wet etching said magnesium oxide coating for removal thereof together with the overlying portions of said dielectric coating thereon.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein said substrate surface comprises a passivating coating on a semiconductor device having at least one integrated circuit therein.
Claim 4
Dependent Claim
25 words
The method of claim 2 wherein said coating has at least one via opening for interconnection of an element of said device to said pattern.
Claim 5
Dependent Claim
11 words
The method of claim 1 wherein said substrate comprises a ceramic.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein said substrate is a glass ceramic.
Claim 7
Independent Claim
109 words
A method for formation of a planar dielectric coating over a surface of a substrate comprising: (A) forming on said surface a lift-off mask having a pattern of openings exposing complementary portions of said surface to define a desired metallization pattern, (B) sequentially depositing over said surface inclusive of said mask films of an aluminum based metal, hafnium and magnesium oxide, (C) removing said mask with the overlying layers of said sequential films thereon, (D) sputter depositing a layer of a dielectric over said substrate, and (E) selectively wet etching said substrate to remove remaining portions of said magnesium oxide film and overlying portions of the dielectric layer thereon.
Claim 8
Independent Claim
109 words
A method for formation of a planar dielectric coating over a surface of a substrate comprising: (A) forming on said surface a lift-off mask having a pattern of openings exposing complementary portions of said surface to define a desired metallization pattern, (B) sequentially depositing over said surface inclusive of said mask films of an aluminum based metal, hafnium and magnesium oxide, (C) removing said mask with the overlying layers of said sequential films thereon, (D) sputter depositing a layer of a dielectric over said substrate, and (E) selectively wet etching said substrate to remove remaining portions of said magnesium oxide film and overlying portions of the dielectric layer thereon.
Claim 9
Dependent Claim
23 words
The method of claim 6 wherein said substrate surface comprises a coating on a semiconductor device having at least one integrated circuit therein.
Claim 10
Dependent Claim
25 words
The method of claim 7 wherein said coating has at least one via opening for interconnection of an element of said device to said pattern.
Claim 11
Dependent Claim
11 words
The method of claim 6 wherein said substrate comprises a ceramic.
Claim 12
Dependent Claim
12 words
The method of claim 6 wherein said substrate is a glass ceramic.
Claim 13
Dependent Claim
114 words
The method of claim 6 including the additional steps of (A) forming over the substrate of Step E of claim 6 a second lift-off mask having a pattern of openings defining at least one point of interconnection to said first metallization pattern; (B) sequentially depositing over the surface of said substrate inclusive of said second mask, a second combination of films of an aluminum based metal, hafnium, and magnesium oxide, (C) removing said mask with the overlying layers of said second combination of films thereon, (D) sputter depositing a second layer of a dielectric over said substrate, and (E) selectively etching said magnesium oxide for removal thereof together with overlying portions of dielectric thereon.
Claim 14
Dependent Claim
102 words
The method of claim 11 including the additional steps of (A) forming over the substrate of Step E of claim 11 a third lift-off mask having a pattern of openings defining a second conductive pattern including portions thereof over said points of interconnection, (B) sequentially depositing over said substrate, inclusive of said third mask films of an aluminum based metal, hafnium, and magnesium oxide, (C) removing said mask with overlying film portions thereon, (D) sputter depositing a third layer of a dielectric over said substrate, and (E) selectively etching said magnesium oxide for removal thereof together with overlying portions of dielectric thereon.
Claim 15
Dependent Claim
25 words
The method of claim 12 including the sequential repetition of the steps of claims 11 and 12 until the desired level of metallization is obtained.
Claim 16
Independent Claim
132 words
A method for formation of planar dielectric coatings over a surface of a substrate comprising: (A) depositing a first film of an aluminum based metal over said surface; (B) forming over said first film a lift-off mask having a pattern of openings defining a corresponding metallization pattern of said first film, (C) sequentially depositing over said surface inclusive of said mask, films of hafnium, to form a part of said metallization pattern, and magnesium oxide, (D) removing said mask with the overlying portions of said hafnium and magnesium oxide films, (E) dry etching the exposed portions of said first metal film to removal thereof, (F) depositing a layer of a dielectric over said substrate, and (G) selectively etching said magnesium oxide for removal thereof together with overlying portions of the dielectric thereon.
Claim 17
Independent Claim
132 words
A method for formation of planar dielectric coatings over a surface of a substrate comprising: (A) depositing a first film of an aluminum based metal over said surface; (B) forming over said first film a lift-off mask having a pattern of openings defining a corresponding metallization pattern of said first film, (C) sequentially depositing over said surface inclusive of said mask, films of hafnium, to form a part of said metallization pattern, and magnesium oxide, (D) removing said mask with the overlying portions of said hafnium and magnesium oxide films, (E) dry etching the exposed portions of said first metal film to removal thereof, (F) depositing a layer of a dielectric over said substrate, and (G) selectively etching said magnesium oxide for removal thereof together with overlying portions of the dielectric thereon.
Claim 18
Dependent Claim
23 words
The method of claim 14 wherein said substrate surface comprises a coating on a semiconductor device having at least one integrated circuit therein.
Claim 19
Dependent Claim
25 words
The method of claim 15 wherein said coating has at least one via opening for interconnection of an element of said device to said pattern.
Claim 20
Dependent Claim
11 words
The method of claim 14 wherein said substrate comprises a ceramic.
Claim 21
Dependent Claim
12 words
The method of claim 14 wherein said substrate is a glass ceramic.
Claim 22
Dependent Claim
132 words
The method of claim 14 including the additional steps of (A) depositing a second film of an aluminum based metal over the substrate of Step G of claim 14, (B) forming over said first film a second lift-off mask having a pattern of opening defining at least one point of interconnection to said metallization pattern, (C) sequentially depositing over said substrate, inclusive of said second mask, a second combination of films of hafnium and magnesium oxide, (D) removing said mask with overlying portion of the hafnium and magnesium oxide films thereon, (E) dry etching the exposed portions of said second aluminum film to removal thereof, (F) depositing a layer of a dielectric over said substrate, and (G) selectively etching said magnesium oxide for removal thereof together with overlying portions of dielectric thereon.
Claim 23
Dependent Claim
131 words
The method of claim 19 including the additional steps of (A) depositing a third film of an aluminum based metal over the substrate of Step G, in claim 19, (B) forming over said third metal film a third lift-off mask having a pattern of openings defining a second conductive pattern including portions thereof over said points of interconnection, (C) sequentially depositing over said substrate inclusive of said third mask and exposed portion of said third metal film, films of hafnium and magnesium oxide, (D) removing said third mask with overlying film portions, (E) dry etching the exposed portions of said third metal film to removal thereof, (F) depositing a layer of a dielectric over said substrate, and (G) selectively etching said magnesium oxide to removal thereof together with overlying dielectric portions.
Claim 24
Dependent Claim
25 words
The method of claim 20 including the sequential repetition of the steps of claims 19 and 20 until the desired levels of metallization are obtained.
Claim 25
Independent Claim
139 words
A method for deposition of a dielectric coating over a surface of a substrate comprising: (A) sequentially depositing a first film of an aluminum based metal and a second metal film of hafnium over said surface, (B) forming over said second metal film a lift-off mask having a pattern of openings defining a desired corresponding metallization pattern of said first and second films, (C) depositing over said substrate, inclusive of said mask and the exposed portions of said second film, a layer of magnesium oxide, (D) removing said mask and portions of said oxide layer thereon, (E) sequentially dry etching the exposed portions of said second and first films to removal thereof, (F) depositing a layer of a dielectric over said substrate, and (G) selectively etching said oxide for removal thereof together with overlying portions of the dielectric thereon.
Claim 26
Independent Claim
139 words
A method for deposition of a dielectric coating over a surface of a substrate comprising: (A) sequentially depositing a first film of an aluminum based metal and a second metal film of hafnium over said surface, (B) forming over said second metal film a lift-off mask having a pattern of openings defining a desired corresponding metallization pattern of said first and second films, (C) depositing over said substrate, inclusive of said mask and the exposed portions of said second film, a layer of magnesium oxide, (D) removing said mask and portions of said oxide layer thereon, (E) sequentially dry etching the exposed portions of said second and first films to removal thereof, (F) depositing a layer of a dielectric over said substrate, and (G) selectively etching said oxide for removal thereof together with overlying portions of the dielectric thereon.
Claim 27
Dependent Claim
23 words
The method of claim 22 wherein said substrate surface comprises a coating on a semiconductor device having at least one integrated circuit therein.
Claim 28
Dependent Claim
11 words
The method of claim 22 wherein said substrate comprises a ceramic.
Claim 29
Dependent Claim
12 words
The method of claim 22 wherein said substrate is a glass ceramic.
Claim 30
Dependent Claim
136 words
The method of claim 22 including the additional steps of (A) sequentially depositing a third film of an aluminum based metal and a fourth film of hafnium over the substrate of Step G of claim 22, (B) forming over said fourth film a second lift-off mask having a pattern of openings defining at least one point of interconnection to said metallization pattern, (C) depositing over said mask and exposed portions of said fourth film, a layer of magnesium oxide, (D) removing said mask and portions of said oxide thereon, (E) sequentially dry etching the exposed portions of said fourth and third films to removal thereof, (F) depositing a layer of a dielectric over said substrate inclusive of said oxide, and (G) selectively etching said oxide to removal thereof together with overlying portions of the dielectric thereon.
Claim 31
Dependent Claim
132 words
The method of claim 26 including the additional steps of (A) sequentially depositing a fifth film of an aluminum based metal and a sixth film of hafnium over the substrate of Step G in claim 26, (B) forming over said sixth film a third lift-off mask having a pattern of openings defining a second conductive pattern including portions thereof over said points of interconnection, (C) depositing over said mask and exposed metal portions, a layer of magnesium oxide, (D) removing said third mask together with portions of said oxide thereon, (E) sequentially dry etching the exposed metal portions to removal thereof, (F) depositing a layer of a dielectric over said substrate inclusive of said oxide, and (G) selectively etching said oxide to removal thereof together with overlying portions of the dielectric thereof.
Claim 32
Dependent Claim
25 words
The method of claim 27 including the sequential repetition of the steps of claim 26 and 27 until the desired levels of metallization are obtained.
Claim 33
Dependent Claim
57 words
A process for selective removal of material from an aluminum based metal lamina of a substrate, comprising coating said lamina with a film of hafnium, forming a superimposed mask of magnesium oxide on said film exposing discrete areas thereof, sequential etching exposed portions of said film and said lamina, and removing said mask with an etchant thereof.
Claim 34
Dependent Claim
57 words
A process for selective removal of material from an aluminum based metal lamina of a substrate, comprising coating said lamina with a film of hafnium, forming a superimposed mask of magnesium oxide on said film exposing discrete areas thereof, sequential etching exposed portions of said film and said lamina, and removing said mask with an etchant thereof.
Claim 35
Dependent Claim
26 words
The process of claim 29 including the step of depositing an insulator on said substrate after the etching step and prior to removal of said mask.
Claim 36
Dependent Claim
86 words
In a process for fabrication of semiconductor devices comprised of an aluminum based layer on an insulating layer over a semiconductor substrate containing at least one integrated circuit therein, the steps comprising depositing a layer of hafnium over said aluminum based layer, defining a desired metallization pattern to be formed in said hafnium and aluminum based layers by a mask of magnesium oxide, dry etching exposed portions of said hafnium and aluminum based metal layers to said insulating layer, and removing said mask with an etchant.
Claim 37
Dependent Claim
86 words
In a process for fabrication of semiconductor devices comprised of an aluminum based layer on an insulating layer over a semiconductor substrate containing at least one integrated circuit therein, the steps comprising depositing a layer of hafnium over said aluminum based layer, defining a desired metallization pattern to be formed in said hafnium and aluminum based layers by a mask of magnesium oxide, dry etching exposed portions of said hafnium and aluminum based metal layers to said insulating layer, and removing said mask with an etchant.
Claim 38
Dependent Claim
26 words
The process of claim 31 including the step of depositing an insulating layer over said substrate after said etching step and before removal of said mask.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |