Methods for predicting polishing parameters of polishing pads and methods and machines for planarizing microelectronic substrate assemblies in mechanical or chemical-mechanical planarization

Abstract

Methods for predicting polishing characteristics of polishing pads in mechanical or chemical-mechanical planarization of microelectronic substrate assemblies, and methods and machines for planarizing microelectronic substrate assemblies. One embodiment of a method in accordance with the invention includes ascertaining a surface parameter of a bearing surface of at least one raised feature projecting from a base portion of a raised feature polishing pad. The raised feature, for example, can be a pyramidal structure having a first cross-sectional area at the base portion of the pad and a second cross-sectional area at the bearing surface. The first cross-sectional area is generally greater than the second cross-sectional area. To ascertain the surface parameter of the bearing surface, one particular embodiment of the invention involves determining an indication of the surface area of the bearing surface. The surface area of the bearing surface can be estimated by illuminating the bearing surface with a light source and detecting an intensity of the light reflected from the bearing surface. The intensity of the reflected light is proportional to the surface area of the bearing surface, and thus the surface area of the bearing surface can be estimated by correlating the detected intensity of the reflected light with a predetermined relationship between the surface area and the light intensity. The actual surface area of selected bearing surfaces can also be measured by viewing the bearing surfaces through a confocal microscope or another type of optical device.