REDUCING NOISE IN SPECTRAL DATA FROM POLISHING SUBSTRATES

摘要

Among other things, a machine based method comprises representing a plurality of spectra reflected from one or more substrates at a plurality of different positions on the one or more substrates in the form of a first matrix; decomposing, by one or more computers, the first matrix into products of at least two component matrixes of a first set of component matrixes; reducing dimensions of each of the at least two component matrixes to produce a second set of component matrixes containing the at least two matrixes with reduced dimensions; and generating, by the one or more computers, a second matrix by taking a product of the matrixes of the second set of component matrixes.

主权项

1. A machine-based method comprising:
representing a plurality of spectra reflected from one or more substrates at a plurality of different positions on the one or more substrates in the form of a first matrix, each spectrum being represented by a dataset arranged in a single row or a single column of the first matrix, and the spectra being reflected when an outer layer of the one or more substrates has substantially the same thickness at the plurality of positions; decomposing, by one or more computers, the first matrix into products of at least two component matrixes of a first set of component matrixes; reducing dimensions of each of the at least two component matrixes to produce a second set of component matrixes containing the at least two matrixes with reduced dimensions; and generating, by the one or more computers, a second matrix by taking a product of the matrixes of the second set of component matrixes, the second matrix having the same dimensions as the first matrix, and each single row or each single column of the second matrix comprising a modified dataset representing a modified spectrum corresponding to the spectrum represented by a respective single row or single column of the first matrix.