Process system health index and method of using the same
First Claim
1. A method of monitoring a processing system for processing a substrate during the course of semiconductor manufacturing comprising:
- acquiring data from said processing system for a plurality of observations, said data comprising a plurality of data variables;
determining one or more principal components of said data for said plurality of observations using principal components analysis;
applying a first weighting factor to a first one of said plurality of data variables and a second weighting factor to a second one of said plurality of data variables during said principal components analysis;
acquiring additional data from said processing system;
determining at least one statistical quantity from one or more scores calculated from a projection of said additional data onto said one or more principal components determined by using said first weighting factor and said second weighting factor;
determining a control limit for said at least one statistical quantity; and
comparing said at least one statistical quantity to said control limit,wherein the first weighting factor is based on a first relative importance of the first one of said plurality of data variables, the second weighting factor is based on a second relative importance of the second one of said plurality of data variables, and the first relative importance is different from the second relative importance.
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Abstract
A method of monitoring a processing system for processing a substrate during the course of semiconductor manufacturing is described. The method comprises acquiring data from the processing system for a plurality of observations. It further comprises constructing a principal components analysis (PCA) model from the data, wherein a weighting factor is applied to at least one of the data variables in the acquired data. The PCA mode is utilized in conjunction with the acquisition of additional data, and at least one statistical quantity is determined for each additional observation. Upon setting a control limit for the processing system, the at least one statistical quantity is compared with the control limit for each additional observation. When, for example, the at least one statistical quantity exceeds the control limit, a fault for the processing system is detected.
23 Citations
11 Claims
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1. A method of monitoring a processing system for processing a substrate during the course of semiconductor manufacturing comprising:
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acquiring data from said processing system for a plurality of observations, said data comprising a plurality of data variables; determining one or more principal components of said data for said plurality of observations using principal components analysis; applying a first weighting factor to a first one of said plurality of data variables and a second weighting factor to a second one of said plurality of data variables during said principal components analysis; acquiring additional data from said processing system; determining at least one statistical quantity from one or more scores calculated from a projection of said additional data onto said one or more principal components determined by using said first weighting factor and said second weighting factor; determining a control limit for said at least one statistical quantity; and comparing said at least one statistical quantity to said control limit, wherein the first weighting factor is based on a first relative importance of the first one of said plurality of data variables, the second weighting factor is based on a second relative importance of the second one of said plurality of data variables, and the first relative importance is different from the second relative importance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification