US4975386A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process enhancement using molybdenum plugs in fabricating integrated circuits
Assignee: Micro Power Systems Inc
•
Filing: 1989-12-22
•
Granted: 1990-12-04
•
Expires: 2009-12-22
Abstract
Abstract A method of interconnecting circuit components in a semiconductor integrated circuit including component elements formed in the substrate and thin-film resistors and capacitors formed on a surface of the substrate, a molybdenum plug is utilized to facilitate stable, uniform low resistance contacts to circuit elements, molybdenum (moly) plugs are utilized as a barrier between interconnect metallization and the circuit components. A CLAD moly/aluminum metallization interconnect can be fabricated in a standard process in which the moly plugs are formed. The accuracy and stability of thin-film resistors is facilitated during wafer processing, laser trimming, temperature cycling, and assembly processing thereby providing repeatable matching by eliminating contact resistance as a process variable.
Inventors
- 👤 Raman K. Rao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:54
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/40; H10D1/47; H10D1/474; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; Y; Y10; Y10S; Y10S148/00; Y10S148/136
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
123 words
In the fabrication of an integrated circuit having at least one thin-film resistor, a method of interconnecting the thin-film resistor with other circuit components comprising the steps of: providing a semiconductor substrate with circuit components formed therein, forming a thin-film resistor on a major surface of said substrate, depositing an insulation layer on said thin-film resistor, annealing said thin-film resistor, forming contact openings through said insulation layer to said thin-film resistor, depositing molybdenum on said semiconductor substrate and on said thin-film resistor, selectively etching said molybdenum to define molybdenum plugs in said contact openings, depositing interconnect metallization on said semiconductor substrate, said insulation layer, and said molybdenum plugs, selectively etching said interconnect metallization to define an interconnect pattern, and alloying said semiconductor substrate.
Claim 2
Dependent Claim
123 words
In the fabrication of an integrated circuit having at least one thin-film resistor, a method of interconnecting the thin-film resistor with other circuit components comprising the steps of: providing a semiconductor substrate with circuit components formed therein, forming a thin-film resistor on a major surface of said substrate, depositing an insulation layer on said thin-film resistor, annealing said thin-film resistor, forming contact openings through said insulation layer to said thin-film resistor, depositing molybdenum on said semiconductor substrate and on said thin-film resistor, selectively etching said molybdenum to define molybdenum plugs in said contact openings, depositing interconnect metallization on said semiconductor substrate, said insulation layer, and said molybdenum plugs, selectively etching said interconnect metallization to define an interconnect pattern, and alloying said semiconductor substrate.
Claim 3
Dependent Claim
22 words
The method as defined by claim 1 and including the steps of depositing and selectively etching a passivation layer over said substrate.
Claim 4
Dependent Claim
24 words
The method as defined by claim 1 and including the step of annealing said molybdenum after deposition thereof and before selectively etching said molybdenum.
Claim 5
Dependent Claim
20 words
The method as defined by claim 1 and including the step of annealing said molybdenum after selectively etching said molybdenum.
Claim 6
Dependent Claim
38 words
The method as defined by claim 1 and including the step of forming additional contact openings to circuit components formed in said substrate prior to depositing interconnect metallization whereby said circuit components are connected to said interconnect pattern.
Claim 7
Dependent Claim
147 words
In the fabrication of an integrated circuit having at least one thin-film resistor and at least one capacitor, a method of interconnecting the thin-film resistor and capacitor with other circuit components comprising the steps of: providing a semiconductor substrate with circuit components formed therein and at least one capacitor element formed thereon, forming a thin-film resistor on a major surface of said substrate, depositing an insulation layer on said major surface and over said thin-film resistor and said capacitor, annealing said thin-film resistor, forming contact openings to said resistor, said components in said substrate, and to said capacitor, depositing molybdenum on said semiconductor substrate and in said contact openings, selectively etching said molybdenum to define molybdenum plugs in said contact openings, depositing interconnect metallization over said insulation and on said molybdenum plugs, selectively etching said interconnect metallization to define an interconnect pattern, and alloying said semiconductor substrate.
Claim 8
Dependent Claim
147 words
In the fabrication of an integrated circuit having at least one thin-film resistor and at least one capacitor, a method of interconnecting the thin-film resistor and capacitor with other circuit components comprising the steps of: providing a semiconductor substrate with circuit components formed therein and at least one capacitor element formed thereon, forming a thin-film resistor on a major surface of said substrate, depositing an insulation layer on said major surface and over said thin-film resistor and said capacitor, annealing said thin-film resistor, forming contact openings to said resistor, said components in said substrate, and to said capacitor, depositing molybdenum on said semiconductor substrate and in said contact openings, selectively etching said molybdenum to define molybdenum plugs in said contact openings, depositing interconnect metallization over said insulation and on said molybdenum plugs, selectively etching said interconnect metallization to define an interconnect pattern, and alloying said semiconductor substrate.
Claim 9
Dependent Claim
23 words
The method as defined by claim 6 and further including the steps of depositing and selectively etching a passivation layer over said substrate.
Claim 10
Dependent Claim
24 words
The method as defined by claim 6 and further including the step of annealing said molybdenum after deposition and before selectively etching said molybdenum.
Claim 11
Dependent Claim
20 words
The method as defined by claim 6 and including the step of annealing said molybdenum after selectively etching said molybdenum.
Claim 12
Dependent Claim
99 words
In the fabrication of an integrated circuit having at least one thin-film resistor, a method of interconnecting the thin-film resistor with other circuit components comprising the steps of: providing a semiconductor substrate with circuit components formed therein, forming a thin-film resistor on a major surface substrate, depositing an insulation layer on said thin-film resistor, performing contact openings through said insulation layer to said thin-film resistor, depositing molybdenum on said semiconductor substrate and on said insulation, depositing interconnect metallization on said molybdenum, selectively etching said metallization and said molybdenum thereby defining an interconnect pattern, and alloying said metallization and molybdenum.
Claim 13
Dependent Claim
99 words
In the fabrication of an integrated circuit having at least one thin-film resistor, a method of interconnecting the thin-film resistor with other circuit components comprising the steps of: providing a semiconductor substrate with circuit components formed therein, forming a thin-film resistor on a major surface substrate, depositing an insulation layer on said thin-film resistor, performing contact openings through said insulation layer to said thin-film resistor, depositing molybdenum on said semiconductor substrate and on said insulation, depositing interconnect metallization on said molybdenum, selectively etching said metallization and said molybdenum thereby defining an interconnect pattern, and alloying said metallization and molybdenum.
Claim 14
Dependent Claim
95 words
In the fabrication of an integrated circuit, a method of interconnecting circuit components comprising the steps of: providing a semiconductor substrate with circuit components formed therein, including at least one thin-film resistor element formed, providing an insulation layer over the surface of said semiconductor substrate, performing contact openings through said insulation layer to said circuit components, depositing a layer of molybdenum on said insulation layer and in said contact openings, annealing said molybdenum, depositing a metallization layer over said molybdenum, etching said metallization and molybdenum thereby forming an interconnect pattern, and alloying said interconnect pattern.
Claim 15
Dependent Claim
95 words
In the fabrication of an integrated circuit, a method of interconnecting circuit components comprising the steps of: providing a semiconductor substrate with circuit components formed therein, including at least one thin-film resistor element formed, providing an insulation layer over the surface of said semiconductor substrate, performing contact openings through said insulation layer to said circuit components, depositing a layer of molybdenum on said insulation layer and in said contact openings, annealing said molybdenum, depositing a metallization layer over said molybdenum, etching said metallization and molybdenum thereby forming an interconnect pattern, and alloying said interconnect pattern.
References Cited (Backward Citations)
US3649945A
Cited
US3996551A
Cited
JPS59121925A
Cited
US4569122A
Cited
EP0137701A1
Cited
EP0145926A2
Cited
US4582563A
Cited
US4581815A
Cited
US4906593A
Cited
JPS61220441A
Cited
US4898838A
Cited
EP0226549A1
Cited
US4755480A
Cited
US4884123A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |