In-situ reflectometry for real-time process control

A method of calibrating a substrate film thickness monitoring system, comprising:

• generating a reference spectra, comprising:
• rotating a susceptor;
• causing a light source to emit light;
• reflecting the light off a substrate, wherein a spectrometer receives light reflected off of the substrate;
• and
• recording an initial data set associated with the light reflected off of the substrate;
• determining a thickness of a film deposited on the substrate, comprising:
• rotating the susceptor;
• causing the light source to emit light;
• reflecting the light off of a reference surface, wherein the spectrometer receives light reflected off of the reference surface;
• recording a new data set associated with the light reflected off of the reference surface;
• and
• comparing the initial data set against the new data set to determine a film thickness.

A method of mitigating signal variations due to rotation in film thickness monitoring system, comprising:

• generating a reference spectra, comprising:
• rotating a susceptor;
• causing a light source to emit light;
• reflecting the light off a substrate, wherein a spectrometer receives light reflected off of the substrate;
• and
• recording an initial data set associated with the light reflected off of the substrate;
• determining a thickness of a film deposited on the substrate, comprising:
• rotating the susceptor;
• causing the light source to emit light;
• reflecting the light off of a reference surface, wherein the spectrometer receives the light reflected off of the reference surface;
• syncing the light reflected off of the substrate with an angular position of the substrate during rotation;
• performing a deposition process, wherein a new data set is created from reflecting the light off of a reference surface and the substrate;
• and
• comparing the initial data set against the new data set to determine a film thickness.