Workpiece characterization system

摘要

A workpiece characterization system for obtaining simultaneous measurement of layer and photoluminescence properties of a workpiece. The workpiece characterization system includes an excitation light and an illumination light each impinging upon a surface of a workpiece whereby the workpiece emits photoluminescent light and encodes light from said illumination source with layer information. The excitation light and the illumination light are generated from a single light source. The light from the single light source is filtered to remove wavelengths of light that correlate to light wavelengths emitted from the workpiece as a result of excitation. Wavelengths that correlate to light reflected from the workpiece that may contain encoded information are not filtered.

主权项

1. An optical characterization system for evaluating photoluminescence and property characteristics of a workpiece, said workpiece having workpiece material characteristics comprising an excitation region of high absorption wavelengths between a first wavelength and a second wavelength and photoluminescence emission region between a third wavelength and a fourth wavelength, wherein the said second wavelength is longer than said first wavelength, said third and fourth wavelength are longer than said first and second wavelengths and said fourth wavelength is longer than said third wavelength, the optical characterization system comprising:
a broadband excitation light source for generating an excitation light across an excitation source region of wavelengths between a fifth wavelength and a sixth wavelength for exciting the workpiece material, wherein said second wavelength is longer than said fifth wavelength and said sixth wavelength is longer than said fourth wavelength, wherein the excitation source region of wavelengths encompasses the photoluminescence emission region of the workpiece material; a light filter optically coupled to said broadband excitation light source for spectral filtering a band of wavelengths of the excitation light encompassing the photoluminescence emission region of the excitation source region of wavelengths between a seventh wavelength and an eighth wavelength, wherein said seventh wavelength is longer than said second wavelength and shorter than said third wavelength, and said eighth wavelength is longer than said fourth wavelength; a light analyzer; first optical components optically coupled between the broadband excitation light source and the light analyzer for receiving the filtered excitation light and directing the filtered light to a measurement point on the workpiece; and second optical components optically coupled between the broadband excitation light source and the light analyzer for receiving light from the measurement point on the workpiece and directing the light from the measurement point on the workpiece to the light analyzer.