Emulsion-free chemical-mechanical polishing unit for semiconductor wafers has rotary wafer holder and fixed table which is supplied with aqueous medium of variable pH

摘要

This chemical-mechanical polishing (CMP) unit includes a polishing table holding a fixed polishing cushion, used without polishing emulsion. A rotary holder (101) presses the wafer (103) against the fixed polishing cushion (107). A system supplying aqueous solution to the fixed cushion is able to change the pH during the polishing process. An independent claim is included for the corresponding process, which takes place in two stages supplying a medium of differing pH.