Method for measuring thermo-optically induced material phase-change response in a multiple layer thin film structure using visible and ultraviolet spectroscopy

1. A method for in-line film monitoring, comprising:

inducing a material phase change with radiant exposure using a pulsed laser;

measuring a material phase change response;

fitting measured spectra with a spectroscopic model;

determining at least one of refractive index dispersion or film layer thickness; and

correlating a thermo-optically induced change in a refractive index measurement with an electro-thermally induced change in electrical response.

2. The method in claim 1 , wherein the inducing a material phase change with radiant exposure using a pulsed laser comprises:

inducing an amorphous phase to crystalline phase change.

3. The method in claim 1 , wherein the inducing a material phase change with radiant exposure using a pulsed laser comprises:

inducing a material phase change in a chalcogenide glass.

4. The method in claim 3 , wherein the inducing a material phase change in a chalcogenide glass comprises:

inducing a material phase change in Ge 22 Sb 22 Te 56 .

5. The method in claim 1 , wherein the inducing a material phase change with radiant exposure using a pulsed laser comprises:

controlling a sequence of measurement spot exposure to the pulsed laser.

6. The method in claim 1 , wherein the inducing a material phase change with radiant exposure using a pulsed laser comprises:

adjusting at least one of power and time duration of the pulsed laser.

7. The method in claim 1 , wherein the inducing a material phase change with radiant exposure using a pulsed laser comprises:

specifying at least one of a wavelength or time duration of a spectroscopic exposure.

8. The method in claim 1 , wherein the measuring a material phase change response comprises:

measuring a change in refractive index (RI).

9. The method in claim 8 , wherein the measuring a change in refractive index (RI) comprises:

measuring a change in refractive index (RI) at a specified wavelength.

10. The method in claim 8 , wherein the measuring a change in refractive index (RI) comprises:

measuring refractive index (RI) model parameters.

11. The method in claim 1 , wherein the measuring a change in refractive index (RI) comprises:

specifying a structural state.

12. The method in claim 1 , wherein the fitting measured spectra with a spectroscopic model comprises:

utilizing a regression algorithm.

13. The method in claim 1 , wherein the fitting measured spectra with a spectroscopic model comprises:

fitting measured spectra with a spectroscopic model including a refractive index (RI) model for a phase change material.

14. The method in claim 13 , wherein the fitting measured spectra with a spectroscopic model including a refractive index (RI) model for a phase change material comprises:

fitting measured spectra with a spectroscopic model including a refractive index (RI) model for layers other than the phase change material.

15. The method in claim 1 , wherein the fitting measured spectra with a spectroscopic model comprises:

fitting measured spectra with at least one of surface roughness measurement or haze level.

16. The method in claim 1 , wherein the fitting measured spectra with a spectroscopic model comprises:

fitting measured spectra with a spectroscopic model including at least one patterned film structure having at least one of a one dimensional grating or a two dimensional grating.

17. A device for in-line film monitoring, comprising:

a measurement system platform configured to measure a phase change material;

at least one electrical resistor configured to provide electro-thermal energy for inducing a phase change in the phase change material;

at least one external electric probe configured to measure the phase change material; and

ohmic contact circuitry configured to couple with the at least one external probe.

18. The device in claim 17 , wherein the measurement system platform configured to measure a phase change material comprises:

a measurement system platform configured to measure a chalcogenide glass.

19. The device in claim 18 , wherein the measurement system platform configured to measure a chalcogenide glass comprises:

a measurement system platform configured to measure Ge22Sb22Te56.

20. The device in claim 17 , wherein the measurement system platform configured to measure a phase change material comprises:

a measurement system platform configured to measure a phase change material during a manufacturing process of a thin film structure.