Patent ID: 6987572
Filing Date: 2006-01-17
Classification: G01N,G03F,H01L,Y10S

Abstract:
1. A wafer measurement system for use within a wafer process tool, comprising: a wafer handler associated with the wafer process tool for feeding wafers between a cassette and any one or more of a plurality of stations of the wafer process tool; a wafer measurement station forming one of the stations of the wafer process tool, the measurement station having a wafer support in communication with the wafer handler, the measurement station also having therein an optical measurement system forming a scatterometry instrument that is moveable by a stage to specified locations over the wafer support, the optical measurement system optically coupled to a light source to direct a light beam as a spot onto patterned features of a wafer surface on the wafer support, wherein the light beam is characterized by a spot size that is larger at the wafer surface than a periodicity of the patterned features, the optical measurement system also having a light collector associated with a detector whereby illuminated features on the wafer surface yield characteristic optical signatures with independent optical parameters in the signatures including one or more of wavelength, incidence angle, and altitude and azimuthal collection angles; and a data processor analyzing the characteristic signatures of a wafer using a scattering model for possible periodic strictures on the wafer to obtain a measure of the patterned features on the wafer so that a process carried out by the wafer process tool can be analyzed, and altering at least one parameter of at least one of the plurality of the stations in response to the measure of the patterned features such that a first portion of the wafer is processed with a first set of process conditions during a step of the process and such that a second portion of the wafer is processed with a second set of process conditions during the step, wherein the first set is different than the second set.