Method for determining planarization endpoint during chemical-mechanical polishing

摘要

A moat is preferably created in a region of an insulation layer on a wafer that will be destroyed when the wafer is cut. The integrated circuit includes a first metal pattern in an active region and a second metal pattern on the moat island. An insulating layer is conformally deposited and chemical-mechanical polishing is performed thereon. The polish rate above the second metal pattern is significantly higher than above the first metal pattern. Polishing is monitored and ended when the second metal pattern is exposed, achieving planarization of the top surface in the active region of the integrated circuit. Monitoring may be visual or electrical. For visual monitoring, the second metal pattern preferably comprises a visually noticeable metal in relation to the insulating layer.