Kla Tencor Corporation

Heyin Li

Qiang Zhao

Lie-Quan Lee

Meng Cao

Mengmeng Ye

Methods and systems for optimizing a set of measurement library control parameters for a particular metrology application are presented herein. Measurement signals are collected from one or more metrology targets by a target measurement system. Values of user selected parameters of interest are resolved by fitting a pre-computed measurement library function to the measurement signals for a given set of library control parameters. Values of one or more library control parameters are optimized such that differences between the values of the parameters of interest estimated by the library based measurement and reference values associated with trusted measurements of the parameters of interest are minimized. The optimization of the library control parameter values is performed without recalculating the pre-computed measurement library. Subsequent library based measurements are performed by the target measurement system using the optimized set of measurement library control parameters with improved measurement performance.

Measurement library optimization in semiconductor metrology

Methods and systems for evaluating and ranking the measurement efficacy of multiple sets of measurement system combinations and recipes for a particular metrology application are presented herein. Measurement efficacy is based on estimates of measurement precision, measurement accuracy, correlation to a reference measurement, measurement time, or any combination thereof. The automated the selection of measurement system combinations and recipes reduces time to measurement and improves measurement results. Measurement efficacy is quantified by a set of measurement performance metrics associated with each measurement system and recipe. In one example, the sets of measurement system combinations and recipes most capable of measuring the desired parameter of interest are presented to the user in rank order based on corresponding values of one or more measurement performance metrics. A user is able to select the appropriate measurement system combination in an objective, quantitative manner.

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Shanghai, China

Heyin Li