Wafer edge cleaning

Abstract

In a first aspect, an apparatus for cleaning a thin disk is provided. The apparatus includes (1) a plurality of support rollers adapted to support an edge of the thin disk as the thin disk rotates within a first plane; and (2) an edge-cleaning roller adapted to rotate within a second plane oriented at a first non-zero angle to the first plane, so as to contact an edge bevel of the thin disk while so rotating. Numerous other aspects are provided.

Description

[0001] This application claims priority to U.S. Provisional Application Ser. No. 60 / 514,938, filed Oct. 28, 2003 and entitled “Wafer Edge Cleaning,” which is hereby incorporated by reference herein in its entirety for all purposes.FIELD OF THE INVENTION [0002] The present invention relates generally to cleaning thin disks, such as semiconductor wafers, compact disks, glass substrates and the like. More particularly, the invention relates to scrubbing devices for simultaneously scrubbing the entire surface of a thin disk, including the edges thereof. BACKGROUND OF THE INVENTION [0003] To manufacture a thin disk such as a semiconductor wafer, an elongated billet of semiconductor material is cut into very thin slices or disks, about ½ mm in thickness. The slices or wafers of semiconductor material are then lapped and polished by a process that applies an abrasive slurry to the wafer's surfaces. After polishing, slurry residue conventionally is cleaned or scrubbed from wafer surfaces vi...

AI Technical Summary

Benefits of technology

[0017] In a second aspect of the invention, a support roller is provided for supporting a vertically rotating wafer. The support roller includes (1) a guide portion, for receiving an edge of a wafer, having an inclined surface comprising a low-friction material and adapted to allow the wafer edge to slide thereagainst; and (2) an edge-trap portion for retaining the edge of the wafer and having a transverse surface comprising a high-friction material and adapted, when in communication with the edge of the wafer, to resist sliding thereagainst.

[0018] In a third aspect of the invention, a side-contact roller is provided for contacting one or more major surfaces of a rotating wafer. The side-contacting roller includes (1) a guide portion, for receiving an edge of a wafer, having an inclined surface comprising a low-friction material and adapted to allow the wafer edge to slide thereagainst; and (2) an edge-trap portion for retaining the edge of the wafer and having a planar surface comprising a high-friction material and adapted, when in communication with a major surface of the wafer, to resist sliding thereagainst. Numerous other aspects, as are methods in accordance with these and other aspects of the invention.

Problems solved by technology

Although these conventional cleaning devices remove a substantial portion of the slurry residue which adheres to wafer edges, slurry particles nonetheless may remain and produce defects during subsequent processing.

However, research shows that slurry induced defects still occur, and are caused by slurry residue remaining along the edges of the wafer despite cleaning with apparatuses such as that described above.

Specifically, subsequent processing has been found to redistribute slurry residue from the wafer edges to the front of the wafer, causing defects.

Although the edge-cleaning roller 21 addresses the need to clean slurry residue from wafer edges, it can be subject to quick wear, such wear typically being concentrated at locations where it contacts the wafer W.

Other rollers that may rotate in a common plane with a wafer W while contacting a portion of the wafer edge, but that perform additional or separate functions such as rotating the wafer W (e.g., drive rollers, such as the spinning mechanism 17a-c of FIG. 1) or guiding the rotating wafer W so as to limit or prevent tilting of the same (e.g., idling guide rollers (not separately shown)), are typically also subject to rapid wear where contact is made with the wafer W. The cost of maintaining proper operation of such parts and / or conducting frequent replacement of the same can mount quickly.

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