Backing pad and method of forming the backing pad by precision surface machining

Assignee: Shin-Etsu Handotai Co Ltd

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Filing: 1991-04-18

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Granted: —

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Expires: 2011-04-18

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Abstract

Abstract A backing pad be used in a holding jig for holding a semiconductor wafer in the step of mirror polishing comprises a hydrophobic foam, possessed rigidity such that the defference between the thickness, T₁, thereof under a load of 300 gf/cm² and the thickness, T₂, thereof under a load of 1,800 gf/cm² (T₁ - T₂) is in the range of from 1 to 100 µ m, and has holes formed therein in a diameter in the range of 10 to 30 µ m through the wafer-holding surface thereof. The polishing of a semiconductor is effected by a method which comprises preparing a finished backing pad by the precision surface machining operation, setting the semiconductor wafer on a wafer holding jig having a template containing at least one wafer-positioning hole fixed on a carrier plate in such a manner that the backing pad enters the positioning hole , and polishing the semiconductor wafer.

Inventors

👤 Hiromasa Hashimoto

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-11-05 13:25

CPC Classifications

H; H10; H10P; H10P90/00; H10P90/12; H10P90/129; B; B24; B24B; B24B37/00; B24B37/27; B24B37/30; B24B41/00; B24B41/06; B24B41/068

Claims Analysis

Total Claims: 5

Claim 1

Independent Claim 94 words

(1) A backing pad for use in a holding jig for holding a semiconductor wafer in the step of mirror polishing the semiconductor wafer, which backing pad is characterized by comprising a hydrophobic foam, possessing rigidity such that the difference between the thickness, T₁, thereof under a load of 300 gf/cm² and the thickness, T₂, thereof under a load of 1,800 gf/cm² (T₁ -T₂) is in the range from 1 to 100 µ m, having pores formed therein in a diameter in the range of 10 to 30µ m through the wafer-holding surface thereof.

Claim 2

Dependent Claim 75 words

(2) A backing pad according to claim 1, wherein the difference between the maximum and the minimum, TV₅, of thickness of said backing pad measured at a total of five points, i.e. one point at the center thereof and four points at an inward distance of 5 mm from the terminals of two perpendicularly intersecting diameters thereof, after one minute's exertion thereto of a load of 300 gf/cm² is not more than 1 µ m.

Claim 3

Dependent Claim 139 words

(3) A method for precision surface machining of a backing pad for use in a holding jig for holding a semiconductor wafer in the step of mirror polishing the semiconductor wafer, which method comprises fixing a backing pad blank on a carrier plate with the wafer-holding surface thereof laid upwards and surface grinding the wafer-holding surface of said backing pad blank with a precision surface grinder until the flatness thereof reaches a level such that difference between the miximum and the minimum of, TV₅, of thickness of said backing pad measured at a total of five points, i.e. one point at the center thereof and four points at an inward distance of 5 mm from the terminals of two perpendicularlyintersecting diameters thereof, after one minute's exertion thereto of a load of 300 gf/cm² is not more than 1µ m.

Claim 4

Dependent Claim 66 words

(4) A method for polishing a semiconductor wafer, characterized by preparing a finished backing pad by the precision surface machining operation set forth in claim 3, placing said semiconductor wafer on a wafer holding jig having a template containing at least one wafer-positioning hole fixed on a carrier plate in such a manner that said backing pad enters said positioning hole, and polishing said semiconductor wafer.

Claim 5

Dependent Claim 39 words

(5) A mehtod according to claim 4, wherein a gap in the range of from 0.5 to 1.5 mm is interposed between the inner edge of said wafer-positioning hole of said templateand the outer edge of said backing pad.

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