PLATEN ENDPOINT WINDOW WITH PRESSURE RELIEF

摘要

A polish pad (40, 42) and platen (50) assembly for use in chemical mechanical polishing of semiconductor devices includes a platen (50) having a vented endpoint window (62, 72, 82) with one or more venting passageways (e.g., 64, 66) and/or a grooved or channeled platen surface (176) to prevent air pressure buildup in the air gap (46) by discharging or venting air through one or more vent pathways (52) formed in the platen to provide a pathway to ambient or sub-ambient environment. The air permeable construction of the vented endpoint window (72) provides pressure relief for the air gap (46) between the pad endpoint window (44) and the vented endpoint window (72), but may also include passages (75, 76) that are filled with an air permeable hydrophobic material which protects the underlying endpoint detection system (30, 32) from contamination during cleaning of the platen endpoint window (72).