Reactive ion etch loading measurement technique
First Claim
Patent Images
1. A process for estimating a critical dimension of a trench formed by etching a substrate, said process comprising the steps of:
- (a) constructing a regression model for estimating said critical dimension, wherein during construction of said regression model principal component loadings and principal component scores are calculated;
(b) etching said substrate and simultaneously collecting spectral data of said etching;
(c) calculating a new principal component score from said spectral data and said principal component loadings; and
(d) estimating said critical dimension by applying said new principal component score to said regression model;
wherein said step (a) of constructing a regression model comprises;
(i) etching a first substrate to form a desired critical dimension and simultaneously collecting spectral data of said etching;
(ii) etching a second substrate to form a differing critical dimension and simultaneously collecting spectral data of said etching;
(iii) calculating principal component loadings and principal component scores by analyzing the spectral data collected in (i) and (ii) using principal component analysis; and
(iv) forming a regression model using said principal component scores such that said regression model correlates said desired critical dimension to said principal component scores.
1 Assignment
0 Petitions
Accused Products
Abstract
A process for estimating a critical dimension of a trench formed by etching a substrate. First, a regression model is constructed for estimating the critical dimension, in which principal component loadings and principal component scores are also calculated. Next, a substrate is etched and spectral data of the etching are collected. A new principal component score is then calculated using the spectral data and the principal component loadings. Finally, the critical dimension of the trench is estimated by applying the new principal component score to the regression model.
42 Citations
19 Claims
-
1. A process for estimating a critical dimension of a trench formed by etching a substrate, said process comprising the steps of:
-
(a) constructing a regression model for estimating said critical dimension, wherein during construction of said regression model principal component loadings and principal component scores are calculated;
(b) etching said substrate and simultaneously collecting spectral data of said etching;
(c) calculating a new principal component score from said spectral data and said principal component loadings; and
(d) estimating said critical dimension by applying said new principal component score to said regression model;
wherein said step (a) of constructing a regression model comprises;
(i) etching a first substrate to form a desired critical dimension and simultaneously collecting spectral data of said etching;
(ii) etching a second substrate to form a differing critical dimension and simultaneously collecting spectral data of said etching;
(iii) calculating principal component loadings and principal component scores by analyzing the spectral data collected in (i) and (ii) using principal component analysis; and
(iv) forming a regression model using said principal component scores such that said regression model correlates said desired critical dimension to said principal component scores. - View Dependent Claims (2, 3, 4, 7, 9, 11, 13, 15, 17, 19)
-
-
5. A process for estimating a critical dimension of a trench formed by etching a substrate, said process comprising the steps of:
-
(a) constructing a regression model for estimating said critical dimension, wherein during construction of said regression model principal component loadings and principal component scores are calculated;
(b) etching said substrate and simultaneously collecting spectral data of said etching;
(c) calculating a new principal component score from said spectral data and said principal component loadings, and calculating said new principal component score from said spectral data comprises multiplying said principal component loadings times said spectral data to calculate said new principal component score, and (d) estimating said critical dimension by applying said new principal component score to said regression model. - View Dependent Claims (6, 8, 10, 12, 14, 16, 18)
-
Specification