A flux monitor system includes a light source and a sensor.
1. An in-situ flux monitor system for in-line deposition process with plurality of separate rollers and plurality of moving substrates comprising:
a first light source to generate a measuring light beam including a wavelength that can be absorbed by a vapor flux of deposition along a measuring channel;
an optic device to create a reference signal by splitting a portion of the measuring light beam, wherein the portion of the light beam, the reference light beam, is directed along a reference channel without passing through the vapor flux;
a plurality of optic fibers to direct the measuring channel under a plurality of separate rollers and plurality of moving substrates, wherein the flux pass through the gap between the rollers to the measuring channel;
a mounting backbone, wherein the entire system is mounted on the backbone and the backbone is made from material with a very small coefficient of thermal expansion to minimize the possible misalignment due to thermal expansion;
a first sensor to measure the attenuation of the measuring light beam;
a second sensor to measure the attenuation of the reference light beam; and
a measurement module configured to calculate vapor flux density by comparing the attenuation of the measuring light beam and the attenuation of the reference light beam to eliminate the effect of fluctuation of the light source, calculating the absorption from the attenuation, and correlating the absorption to vapor flux density.
2. The system of claim 1 , wherein the system further comprises:
a second light source to generate a calibration light beam, wherein the calibration light beam is directed along the same measuring channel and through the vapor flux, and its attenuation is detected by the same first sensor;
a first sensor mask comprising a top slit and bottom slit to split the calibration light and the measuring light, wherein one of the slits can be used for the calibration light, the other one of the slits can be used for the measuring light;
a configuration to use the moving substrates to shutter the flux on and off, wherein the shutter-off position is used to calibrate the measurement; and
a calibration module configured to read the first sensor, subtract the contribution from optical coating via the calibration light beam in the measuring channel, and correlate absorption to vapor flux density from calibration.
3. The system of claim 2 , wherein the configuration further comprises:
an additional flux and radiation shield to protect the first sensor and second sensor, wherein the shield comprises a window transparent in the measuring wavelength range in the measuring channel;
an aperture on the additional flux and radiation shield to allow the vapor flux to pass the measuring channel, wherein the dimension of the aperture is significantly bigger than the measuring light beam diameter.
4. The system of claim 1 , wherein the first light source comprises a hollow cathode lamp.
5. The system of claim 1 , wherein the first light source comprises a monochromatic light source.
6. The system of claim 1 , wherein the mounting backbone comprises ceramics.
7. The system of claim 1 , wherein the mounting backbone comprises graphite.
8. The system of claim 2 , wherein the second light source comprises a monochromatic light source.
9. The system of claim 1 , wherein the measurement module is further configured to use the signal change caused by the moving substrates to count the number of substrates, check distances between the substrates, and compute the moving speed of substrates, wherein the moving substrates shutter the flux on and off and the spacing between the moving substrates determines the length of signal change cycle.
10. The system of claim 1 , wherein the optic fiber comprises sapphire.
11. The system of claim 1 , wherein the optic fiber comprises quartz.