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Providing Wafers with Chamfered Edges

IP.com Disclosure Number: IPCOM000085647D
Original Publication Date: 1976-May-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Pearson, JB: AUTHOR

Abstract

A chamfered edge which acts to reduce damage to semiconductor wafers is produced by chemical means.

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Providing Wafers with Chamfered Edges

A chamfered edge which acts to reduce damage to semiconductor wafers is produced by chemical means.

As illustrated in Fig. 1, the wafer is provided with HF resistant masking layers, such as a photoresist, on each side except at the edge. The masked wafer is then subjected to an electrolyte consisting of a dilute solution of HF acid and water, where the concentration of HF can range from 1049%. This produces porous areas in the wafer material at the edge as shown in Fig. 2.

The porous areas are readily etched so that a dip etch using a diluted silicon etch, such as 5:2:1 composed of 5 parts nitric, 2 parts acetic and 1 part by volume of HF acid removes the porous portion leaving the desired chamfered profile of Fig. 3. The final step is the removal of the masking layers to provide a wafer with a rounded edge which is resistant to edge chipping, as shown in Fig.
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