Browse Prior Art Database

Single Step Wafer Processing

IP.com Disclosure Number: IPCOM000051574D
Original Publication Date: 1981-Feb-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Burdick, RD: AUTHOR [+3]

Abstract

Sliced semiconductor wafer are polished directly without any intermedi damage removal steps.

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This is the abbreviated version, containing approximately 100% of the total text.

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Single Step Wafer Processing

Sliced semiconductor wafer are polished directly without any intermedi damage removal steps.

The grown, single crystal of silicon is ground to a cylindrical shape to within ten mils of the final diameter. The crystal grinding damage, which may penetrate to a depth of 5 mils, is removed by a chemical etch in hydrofluoric-nitric-acetic acid solution to the final required diameter. The fiducial notch and flat are ground, and the crystal is sliced into wafers. The edges of the wafers are chamfered, and the wafers are free polished in a 40-minute free-polishing cycle with removal rates of 5 mils per hour using a colloidal silicon dioxide-based polishing slurry. Polishing cycle time can be further reduced by: (1) increasing polishing pressure, (2) using faster polishing pads and a two-step cycle, (3) increasing process temperature, (4) increasing polishing slurry solids content, (5) reducing slicing damage, and (6) using a high pH slurry containing colloidal silicon dioxide, a metal carbonate, sodium hypochlorite and an alkali metal hydroxide to adjust the pH to a range of 11 to 12.

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