Alignment index forecasting method based on integration of quotient spaces and knowledge sources for photoetching process

Abstract

An alignment index forecasting method based on the integration of quotient spaces and knowledge sources for a photoetching process belongs to the field of advanced manufacturing, automation and information. The characteristic of the invention lies in that the alignment index forecasting method based on the integration of the quotient spaces and the knowledge sources for the photoetching process is proposed for the problem of product rework caused by alignment inaccuracy of a photoetching device in a micro-electronics production line. The method comprises the following steps of: firstly, using historical data of a plurality of alignment indexes of a wafer as different knowledge sources, and integrating the different knowledge sources to obtain a knowledge source integration model to be optimized, wherein the output of the model is the plurality of alignment indexes; secondly, carrying out polar decomposition on the above model to obtain three low-rank factors, and carrying out symmetrical transformation on each low-rank factor to obtain an equivalent-class factor; and finally, optimizing each equivalent-class factor by using an alternative-direction optimal strategy in the quotient spaces, and achieving synergic modeling on the plurality of alignment indexes by the optimization process of the knowledge source integration model. The method proposed by the invention can be used for combined forecasting of the plurality of alignment indexes.

Description

technical field [0001] The invention belongs to the fields of advanced manufacturing, automation and information, and in particular relates to a forecasting method for overlaying process indexes in a microelectronics production line. Background technique [0002] In the process of microelectronics production, the photolithographic overlay in the photolithography area is a key process index that affects the qualified rate of microelectronics products. Due to the influence of the mechanical properties of the equipment and the expansion and contraction of the mask, the horizontal axis offset of the product, Overlay indicators such as vertical axis offset, orthogonal offset and rotational offset often do not meet the process specifications, which eventually lead to product rework. In order to improve the overlay accuracy, it is necessary to predict the overlay index in the photolithography area to guide the optimal setting of the operating parameters in the overlay process, so a...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem of product rework caused by inaccurate overlay of lithography equipment in the overlay process of microelectronics production line, a method for predicting overlay index of microelectronics production line based on the integration of quotient space and knowledge source is proposed

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