Patent ID: 6129613
Filing Date: 2000-10-10
Classification: B24B,G01L

Abstract:
An apparatus for measuring a local pressure on a surface of a wafer while the wafer is subjected to a chemical mechanical polishing process, the apparatus comprising:a wafer having a front side provided with a surface to be subjected to the local pressure, a back side provided with a substrate, a pressure sensing structure between the surface and the substrate for generating information related to the local pressure on the surface, and conductive vias extending from the structure through the substrate to the back side;a chemical mechanical polishing unit for applying pressure to the surface of the wafer at the front side of the wafer;conductive pads connected to the conductive vias for collecting the information related to the local pressure from the pressure sensing structure; andsensor circuitry effective during operation of the chemical mechanical polishing unit for determining the magnitude of the local pressure from the information related to the local pressure.