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Forming an antireflective coating for VLSI metallization

Assignee: Texas Instruments Inc
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Filing: 1986-11-06
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Granted: 1989-06-13
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Expires: 2006-11-06
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Abstract

Abstract Method of forming an antireflective coating on a face of a semiconductor which includes forming a metal oxide layer on the face, heating the oxide layer to a temperature sufficiently high to cause the migration of free metal atoms over the surface of the metal oxide and then sputtering a thin layer of aluminum or aluminum alloy on the oxide layer of a thickness such that bumps are formed which reduce the specularity of the surface. The aluminum atoms form bumps which reduce the specularity of the surface.

Inventors

  • 👤 Cloves R. Cleavelin
  • 👤 Danny Phillips

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 15:40
CPC Classifications
H; H10; H10P; H10P95/00; C; C23; C23C; C23C14/00; C23C14/02; C23C14/024; C23C14/06; C23C14/14; C23C14/18; C23C14/185; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/952

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 82 words
A method of forming an antireflective coating on a face of a semiconductor, comprising: (a) forming an oxide layer of a metal on said face; (b) heating the metal oxide layer to an elevated temperature; and (c) sputtering a metal layer selected from the group consisting of aluminum alloys over said metal oxide layer of a thickness such that the sputtered metal atoms migrate over the oxide surface forming bumps which reduce the specularity of the surface of the said sputtered metal.
Claim 2
Independent Claim 82 words
A method of forming an antireflective coating on a face of a semiconductor, comprising: (a) forming an oxide layer of a metal on said face; (b) heating the metal oxide layer to an elevated temperature; and (c) sputtering a metal layer selected from the group consisting of aluminum alloys over said metal oxide layer of a thickness such that the sputtered metal atoms migrate over the oxide surface forming bumps which reduce the specularity of the surface of the said sputtered metal.
Claim 3
Dependent Claim 16 words
A method as in claim 1, wherein the metal deposited on said oxide layer is aluminum.
Claim 4
Dependent Claim 28 words
A method as in claim 2, wherein an underlying layer of aluminum is formed over said face and a surface thereof oxidized to form said metal oxide layer.
Claim 5
Dependent Claim 24 words
A method as in claim 3, wherein the heating step raises the temperature to be in the range of 325° C. to 375° C.
Claim 6
Dependent Claim 19 words
A method as in claim 4, wherein the thickness of said metal layer is less than about 3 microinches.
Claim 7
Dependent Claim 21 words
A method as in claim 1, wherein said metal layer sputtered on said metal oxide layer is an alloy of aluminum.
Claim 8
Dependent Claim 26 words
A method as in claim 6, wherein the thickness of the said metal layer sputtered on said metal oxide layer is less than about 3 microinches.
Claim 9
Independent Claim 94 words
A method of forming an antireflective coating on a face of a semiconductor, comprising: (a) depositing a first metal layer on said face; (b) forming a metal oxide layer on said first metal layer; (c) heating the metal oxide layer to a temperature in the range of 325° C. to 375° C.; and (d) sputtering a second layer of metal selected from the group consisting of aluminum and aluminum alloys over the oxide layer of a sufficient thickness such that bumps are formed which reduce the specularity of a surface of the second layer.
Claim 10
Independent Claim 94 words
A method of forming an antireflective coating on a face of a semiconductor, comprising: (a) depositing a first metal layer on said face; (b) forming a metal oxide layer on said first metal layer; (c) heating the metal oxide layer to a temperature in the range of 325° C. to 375° C.; and (d) sputtering a second layer of metal selected from the group consisting of aluminum and aluminum alloys over the oxide layer of a sufficient thickness such that bumps are formed which reduce the specularity of a surface of the second layer.
Claim 11
Dependent Claim 14 words
A method as in claim 8, wherein said second layer of metal is aluminum.
Claim 12
Dependent Claim 20 words
A method as in claim 9, wherein the thickness of said second layer metal is less than about 3 microinches.
Claim 13
Dependent Claim 16 words
A method as in claim 8, wherein said second layer of metal is an aluminum alloy.
Claim 14
Dependent Claim 21 words
A method as in claim 11, wherein the thickness of said second layer of metal is less than about 3 microinches.

References Cited (Backward Citations)

US3884698A Cited
US4307132A Cited
US4490184A Cited
US4462884A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-06-12 1992-12-12 1993-06-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-06-12 1996-12-12 1997-06-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-06-12 2000-12-12 2001-06-13 $7700.00 Window Closed / Lapsed

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