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EP0121707A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method for polishing amorphous aluminum oxide

Assignee: International Business Machines Corp
•
Filing: 1984-02-22
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Granted: —
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Expires: 2004-02-22
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Abstract

Abstract The method comprises the chemical-mechanical polishing of amorphous aluminum oxide surfaces to a high degree of perfection. The aluminum oxide surfaces are continuously wetted with a water-citric acid slurry containing a soft abrasive material. The continuously wiping of the aluminum oxide surface is accomplished with a firm surface (16) using pressure while maintaining a relative movement between the aluminum oxide surface and the firm surface (16) to remove the water reacted aluminum oxide product from the high points of the aluminum oxide surface. This method is continued until a high degree of perfection of the surface is accomplished. The slurry is typically composed of colloidal silicon dioxide dispersed in water containing citric acid.

Inventors

  • 👤 Jagtar Singh Basi
  • 👤 Eric Mendel

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-01 22:54
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/04

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 100 words
A method of chemical-mechanical polishing of an amorphous aluminum oxide surface providing a substrate (8) having a surface layer (9) of said aluminum oxide of a thickness in the order of µm's; maintaining said aluminum oxide surface continuously wetted with an excess quantity of an aqueous dispersion containing citric acid and a soft abrasive material; continuously wiping the aluminum oxide surface with a firm surface (16) using pressure while maintaining relative movement between the aluminum oxide surface and the firm surface (16) to remove the citric acid reacted aluminum oxide product from the high points of the aluminum oxide surface.
Claim 2
Independent Claim 100 words
A method of chemical-mechanical polishing of an amorphous aluminum oxide surface providing a substrate (8) having a surface layer (9) of said aluminum oxide of a thickness in the order of µm's; maintaining said aluminum oxide surface continuously wetted with an excess quantity of an aqueous dispersion containing citric acid and a soft abrasive material; continuously wiping the aluminum oxide surface with a firm surface (16) using pressure while maintaining relative movement between the aluminum oxide surface and the firm surface (16) to remove the citric acid reacted aluminum oxide product from the high points of the aluminum oxide surface.
Claim 3
Dependent Claim 18 words
The method of claim 1 wherein the pH of said aqueous dispersion is between about 7 to 9.
Claim 4
Dependent Claim 25 words
The method of claim 1 or 2 wherein the said aluminum oxide surface layer is a sputtering layer of 5 to 8 µm in thickness.
Claim 5
Independent Claim 22 words
The method of any one of claims 1 to 3 wherein after polishing the aluminum oxide surface is rinsed with deionized water.
Claim 6
Independent Claim 36 words
The method of any one of claims 1 to 4 wherein said aluminum oxide surface layer is located on the surface of a body comprised of a fine grain mixture of aluminum oxide and titanium carbide.
Claim 7
Independent Claim 19 words
The method of any one of claims 1 to 5 wherein said soft abrasive material is colloidal silicon dioxide.
Claim 8
Dependent Claim 21 words
The method of claim 6 wherein the silicon dioxide portion of the dispersion is between about 60 to 16 weight percent.
Claim 9
Independent Claim 39 words
The method of any one of claims I to 7 wherein the removal rate is between about 1.5 to 3 µm per hour at a pressure of less than 4.25 x 10 4 Pa (about 425 gm/cm 2 ).

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