Optical thin film coater
AssigneeTexas Instruments Incorporated
InventorDale E. Morton
Life of this patent
Estimating the term…
Abstract
Disclosed is an improved optical thin film coating system comprising all essential elements of resistive and electron beam evaporation systems, chemical vapor deposition systems and reactive plasma deposition systems. Sequences of cleaning and deposition processes which previously required moving substrates through several chambers are performed in a single vacuum chamber. The evaporative sources also efficiently vaporize solid materials to provide reactive gases for reactive plasma and chemical vapor deposition processes, which were previously difficult or impossible to perform. Substrate movement, masking, and monitoring means previously used with evaporative sources are used to control thickness and uniformity of films deposited by chemical vapor and reactive plasma processes, to provide optical quality films.
Claims8
An optical thin film deposition system comprising a vacuum chamber, evaporative deposition means within said chamber, reactive plasma deposition means within said chamber, chemical vapor deposition means within said chamber, a movable substrate support means within said chamber, and means for selectively activating the evaporative deposition means, the reactive plasma deposition means, and the chemical vapor deposition means whereby thin films are deposited upon a substrate by evaporative deposition, RPD, and CVD in any sequence or in combination without removal of the substrate between deposition of layers.
An optical thin film deposition system comprising:
- a vacuum chamber including at least one vacuum pump connected to said chamber for providing a preselected level of vacuum within said chamber;
- a resistive evaporation source within said chamber including a pair of electrodes extending through a wall of said chamber in sealing relationship for connection to a source of electrical power and a resistive heating element connected between said electrodes within said chamber, said heating element being shaped to hold materials to be vaporized,
- an electron beam evaporation source within said chamber including an electron gun for providing an electron beam, support means for holding material to be vaporized by said beam, and control means coupled to said gun for activating said gun and for directing said beam onto the surface of material to be vaporized,
- a movable substrate support within said chamber for holding substrates to be coated in the path of particles generated by said resistive and electron beam evaporation sources and for moving said substrates to improve uniformity of deposition,
- reactive gas inlet means within said chamber including a baffle for directing a primary flow of inlet gases across the surface of said substrate support, said inlet means coupled in sealing relationship through a wall of said chamber to a source of reactive gases,
- reactive gas exhaust means within said chamber for removing gases from the chamber after they have flowed across the surface of the substrate support, said exhaust means coupled through a wall of said chamber to a vacuum pump,
- an antenna within said chamber spaced from the surface of said substrate support, said antenna coupled through a wall of said chamber to a source of radio frequency power for generating a radio frequency electrical field at the surface of said substrate support, and
- heating means within said chamber for heating the surface of the substrate support, said heating means coupled through a wall of said chamber to a source of electrical power.
In an optical thin film deposition system of the class having resistive and electron beam evaporative sources, a movable substrate support for holding substrates to be coated in a path of vaporized materials, source masking means for blocking the path of vaporized material in response to a monitor signal indicating a preselected deposition thickness, and substrate heating means for maintaining substrates at an elevated temperature during deposition, said sources, supports, masks, monitor, and heating means mounted in an evacuable chamber which is maintained at low pressure during deposition, the improvement comprising gas inlet means within said chamber and coupled to a source of gases outside said chamber, gas exhaust means within said chamber and coupled to a vacuum pump outside said chamber, said gas inlet and gas exhaust means being positioned to provide a flow of gases across the surface of the substrate support, and an antenna mounted in said chamber spaced from said substrate support and coupled to a source of radio frequency energy outside said chamber for providing an RF field at the surface of said support.
Dependencies are inferred from the claim text.