IN-SITU SPECTROSCOPY FOR MONITORING FABRICATION OF INTEGRATED COMPUTATIONAL ELEMENTS

摘要

Technologies are described for monitoring characteristics of layers of integrated computational elements (ICEs) during fabrication using an in-situ spectrometer operated in step-scan mode in combination with lock-in or time-gated detection. As part of the step-scan mode, a wavelength selecting element of the spectrometer is discretely scanned to provide spectrally different instances of probe-light, such that each of the spectrally different instances of the probe-light is provided for a finite time interval. Additionally, an instance of the probe-light interacted during the finite time interval with the ICE layers includes a modulation that is being detected by the lock-in or time-gated detection over the finite time interval.

主权项

1. A method comprising:
receiving, by a fabrication system, a design of an integrated computational element (ICE), the ICE design comprising specification of a substrate and a plurality of layers, their respective target thicknesses and complex refractive indices, wherein complex refractive indices of adjacent layers are different from each other, and wherein a notional ICE fabricated in accordance with the ICE design is related to a characteristic of a sample; forming, by the fabrication system, at least some of the layers of a plurality of ICEs in accordance with the ICE design; sequentially illuminating, by a measurement system associated with the fabrication system, the formed layers with instances of probe-light provided by the measurement system, the instances being spectrally different from each other within a measurement spectral range, such that each of the instances of the probe-light illuminates the formed layers for a finite time interval; detecting, by the measurement system for each of the instances of the probe-light, a modulation of probe-light that interacts with the formed layers; generating, by the measurement system, a spectrum of the probe-light interacted with the formed layers over the measurement spectral range from a set of values of the detected modulations corresponding to the instances of the probe-light; and adjusting, by the fabrication system, said forming based on the generated spectrum.