Polishing pad having a sealed pressure relief channel

Abstract

The present invention provides a chemical mechanical polishing pad comprising a window formed in the polishing pad, the window having a void provided on a side thereof. The invention further provides a pressure relief channel provided in the polishing pad from the void to a periphery of the polishing pad. In addition, a membrane is provided in the channel to prevent contamination of the void.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60 / 706,873 filed Aug. 10, 2005.BACKGROUND OF THE INVENTION [0002] The present invention relates to polishing pads for chemical mechanical planarization (CMP), and in particular, relates to polishing pads having reduced stress windows formed therein for performing optical end-point detection. Further, the present invention relates to polishing pads having a sealed pressure relief channel to reduce stress on the windows and prevent contamination of the window area. [0003] In the fabrication of integrated circuits and other electronic devices, multiple layers of conducting, semiconducting and dielectric materials are deposited on or removed from a surface of a semiconductor wafer. Thin layers of conducting, semiconducting, and dielectric materials may be deposited by a number of deposition techniques. Common deposition techniques in modem processing include physica...

AI Technical Summary

Benefits of technology

[0009] In a first aspect of the present invention, there is provided a chemical mechanical polishing pad comprising: a window formed in the polishing pad, the window having a void provided on a side thereof; a pressure relief channel provided in the polishing pad from the void to a periphery of the polishing pad; and a membrane provided in the channel to prevent contamination of the void.

[0010] In another aspect of the present invention, there is provided a chemical mechanical polishing pad comprising: a polishing layer having a window formed therein, the window being exposed to a void on a side thereof; a pressure relief channel provided in the polishing layer from a portion of the void-exposed side of the window to a periphery of the polishing layer; and a membrane provided in the channel to prevent contamination of the void.

[0011] In another aspect of the present invention, there is provided a chemical mechanical polishing pad comprising: a polishing layer overlying a bottom layer, and an adhesive layer disposed between the polishing layer and the bottom layer; a window formed in the polishing layer, the window being exposed to a void on a side thereof; a pressure relief channel provided in the adhesive layer from the void to a periphery of the adhesive layer; and a membrane provided in the channel to prevent contamination of the void.

[0012] In another aspect of the present invention, there is provided a chemical mechanical polishing pad comprising: a polishing layer overlying a bottom layer, and an adhesive layer disposed between the polishing layer and the bottom layer; a window formed in the polishing layer, the window being exposed to a void on a side thereof; a pressure relief channel provided in the bottom layer from the void to a periphery of the bottom layer; and a membrane provided in the channel to prevent contamination of the void.

Problems solved by technology

Unfortunately, during polishing, undue stress is applied to the window from the pressure that is generated in the void and may cause unwanted residual stress deformations (e.g., “bulges” or “caving-in”) in the window.

These stress deformations may result in non-planar windows and cause poor end-point detection, defectivity and wafer slippage.

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