Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Patent
1989-02-13
1990-12-11
Nelms, David C.
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
2504922, 356381, G01N 2186
Patent
active
049773305
ABSTRACT:
An in-line photoresist thickness measuring device wherein a plurality of projection optical fibers are disposed over a wafer processing track for illuminating portions of a wafer as the wafer proceeds along the track. The light scattered back from each illuminated portion is detected by a corresponding plurality of pickup optical fibers and communicated to an optical fiber multiplexer. The multiplexer sequentially selects the optical signal from each pickup optical fiber and communicates the light from the selected pickup optical fiber to a spectrometer. The spectrometer simultaneously diffuses the scattered light into a plurality of light bands, each light band having a different wavelength. The plurality of light bands are projected in parallel onto a pin diode array which acts as a photodetector. The electrical signals generated by each pin diode in response to the incident light bands are communicated to a processor which calculates resist thickness for each illuminated portion of the wafer. The average and standard deviation values for the thickness data may be calculated as well.
REFERENCES:
patent: 3492491 (1970-01-01), Beeh
patent: 4151008 (1979-04-01), Kirkpatrick
patent: 4450358 (1984-05-01), Reynolds
patent: 4498009 (1985-02-01), Reynolds
patent: 4647172 (1987-03-01), Batchelder et al.
patent: 4732473 (1988-03-01), Bille et al.
"Automated Process Monitoring Techniques for Photoresist Handling Systems," Kenneth M. Sautter et al., presented at the Semicom East Technical Symposiums, Sep. 23, 1987.
"Automated Process Monitoring Techniques for Photoresist Handling Systems", Kenneth M. Sautter et al.; Microelectronics Mfg. and Test, Sep. 1987.
"In-Line Automatic Photoresist Process Control", L. Lauchlan, et al., Proceedings of SPI-The International Society for Optical Engineering, vol. 539, Mar. 1985.
"Resist Characterization Using a Multichannel Development Rate Monitor", A. W. McCullough and S. P. Grindle, based on material presented at Sixth International Technical Conference on Photopolymers, Ellenville, N.Y., Nov. 1982.
"Determination of Exposure Dose Via PDR", James A. Bruce et al., Semiconductor International, Jun. 1988.
"Automatic Process Control for VLSI Linewidth", L. Lauchlan, et al., reprinted from Solid State Technology, Apr. 1985.
"Development Rate Monitor (DRM) for Characterization of Photoresist", Perkin-Elmer advertisement.
"In-Process Thickness Monitor for Polycrystalline Silicon Deposition", Research and Development Laboratory, T. I. Kamins and C. J. Dell'Oca, vol. 119, No. 1, Jan. 1972.
"Ellipsometry for Semiconductor Process Control", R. J. Kutko, Solid State Technology, Feb. 1978.
Batchelder Tom W.
Memovich Gary H.
Sautter Kenneth M.
Allen Stephone B.
Nelms David C.
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