Browse Prior Art Database

Rounding of Square Shape Holes in Silicon Wafers

IP.com Disclosure Number: IPCOM000087357D
Original Publication Date: 1977-Jan-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Aboaf, JA: AUTHOR [+2]

Abstract

The following method rounds the corners of the holes in silicon wafers and prepares the wafer for porous silicon oxide processing:

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Rounding of Square Shape Holes in Silicon Wafers

The following method rounds the corners of the holes in silicon wafers and prepares the wafer for porous silicon oxide processing:

1. Use porous silicon conditions so that electropolishing occurs. This is obtained for P+ type wafers using a current density of 60 to 80 mA/cm/2/. The concentration of the HF electrolyte is 5 to 10%. During electropolishing, the silicon at the corners of the holes is etched off, which results in rounding of the corners. At the same time, silicon is removed on both sides of the wafers, thereby cleaning and smoothing the wafers for the formation of porous silicon.

2. Form porous silicon using 10% HF electrolyte and current density of 40 mA/cm/2. The resulting thick layer is made with little resulting stress.

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