Method to create a measurement recipe

摘要

Fabrication of electronic chips is a highly advanced process which involves several type of tools, such as an lithographic tool, metrology tools, etching tools, etc.Although this equipment is highly advanced, each of said tools has a residual of errors which manifest in errors in fabricating the electronic devices.In order to deal with such wealth of possible errors, the metrology step comprises a stage where the metrology tool is calibrated to provide the best metrology measurement conditions such that accurate metrology parameters are measured, a step known as recipe selection.Despite the continuous efforts to improve such recipe selection of the metrology tool, the small errors of the other tools used in the fabrication process may affect the reliability of the metrology recipe selection step.Such errors may be due to intrinsic optical aberrations of the lithographic tools.Such lithographic tool error may be manifested as different aberrations due to the different architecture of the lithographic tool, for example tool using deep ultraviolet light and tools using soft x-ray light.Or such lithographic tool error may be manifested as variability of the optical wavetront depending on the position in the slit of said lithographic tool.