Thin film temperature measurement using optical absorption edge wavelength

A method for determining temperature of a semiconductor film having a measurable optical absorption edge deposited on an optically transparent substrate material having no measurable optical absorption edge, said method comprising the steps of:

• a) providing an optically transparent substrate of material having no measurable optical absorption edge,
• b) depositing a film of a semiconductor material having a measurable optical absorption edge and a measurable thickness on the substrate,
• c) interacting light with the film deposited on the substrate to produce diffusely scattered light,
• d) collecting the diffusely scattered light from the film,
• e) producing a spectra indicating optical absorption of the film based on the diffusely scattered light from the film,
• f) determining a thickness of the film,
• g) determining the optical absorption edge wavelength of the film based on the spectra, and
• h) determining a temperature of the film at the film thickness as a function of the film thickness and the optical absorption edge wavelength.