Deposition monitor and control system
AssigneeInficon Leybold-Heraeus Inc.
InventorsCarl A. Gogol, Jr., Eric T. Prince
Life of this patent
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Abstract
Method and apparatus for monitoring the deposition of a material or materials upon a substrate using atomic absorption techniques. Radiant energy is directed through a flow of evaporant during a deposition process. The radiation contains spectral emission lines absorbable by the evaporant as well as emission lines not absorbable by the evaporant. Changes in the transmission of one or more non-absorbable lines are used to compensate for changes in the absorption of absorbable lines of interest that are caused by misalignment or displacement of the optical elements during the deposition process.
Claims8
The method of correcting flow indication measurements in a vacuum deposition system of the type wherein a single atom evaporant is flowed onto a substrate in a vacuum, the steps including
- passing radiation containing a first emission line at a wavelength that is absorbable in the single atom evaporant and a second emission line at a wavelength that is not absorbable in said single evaporant through the flow maintained in the chamber along a common optical path,
- measuring the intensity of the radiation at the first and second emission lines after said radiation has passed through the flow, and
- correcting the intensity measurement of the first emission line for changes in the intensity of the second emission line to compensate for errors produced by the realignment in the measuring equipment during the measurement period.
In a vacuum deposition system wherein a single atom evaporant is flowed onto a substrate in a vacuum apparatus for monitoring said flow that includes
- source means for directing radiation along an optical path through said single atom evaporant flow, said radiation containing a first emission line at a wavelength that is absorbable by the evaporant and a second emission line at a wavelength that is not absorbable by the evaporant,
- means for measuring the intensity of the radiation at the first and the second emission line wavelengths after it has passed through the evaporant flow, and
- means for correcting the measured intensity of the radiation at the first emission line in response for changes in the intensity of the radiation at the second emission line to compensate for errors produced by the realignment of the measuring equipment as the evaporant is being flowed onto the substrate.
Dependencies are inferred from the claim text.