Raytheon Company

Eco-Snow Systems, Inc.

Hughes Electronics Corporation

Michael R Borden

Thomas J Kosic

Charles W Bowers

Christopher D Taylor

Jeanette Lurier

Herbert C Bitting

Clarke T Wellman

Apparatus and methods for removing particles from a surface of a semiconductor wafer or optical component using a carbon dioxide snow spray directed at the wafer or component while simultaneously irradiating the surface with a laser beam. The apparatus comprises a carbon dioxide jet spray cleaning system disposed within an environmental cleaning station of a processing system that processes the wafer or component. The processing system is a conveyorized system wherein a conveyor belt or web transports wafers or components from processing station to processing station. The cleaning station includes a recirculating blower system, a laminar flow screen, a high efficiency particulate air filter, and a ducting system for recirculating purified air or inert gas. The cleaning station contains a jet spray nozzle that produces a carbon dioxide snow spray. The jet spray nozzle is coupled by way of a manifold to a liquid carbon dioxide tank that supplies liquid carbon dioxide to the jet spray nozzle. The wafer or component is grounded to prevent static charge buildup. A carbon dioxide laser, operating at 10.6 microns, produces a laser beam that is generally aligned with the carbon dioxide snow spray so that the beam and spray overlap. The laser beam heats the surface of the wafer or component to compensate for the cooling effects of the carbon dioxide snow.

Wafer cleaning using a laser and carbon dioxide snow

A window structure includes a first window layer having a zinc sulfide substrate coated on each side with an antireflective coating, and a second window layer having a bulk silicon substrate coated on each side with an antireflective coating. The two window layers are bonded together in a facing-but-spaced-apart relation by an infrared-transparent adhesive layer, preferably a silicone rubber. A targeting/sensor system using the window structure includes a targeting laser and a sensor within a housing having the window structure in its wall.

Infrared-transparent window structure

A window structure includes a first window layer including a zinc sulfide substrate coated on each side with an antireflective coating, and a second window layer including a sapphire substrate coated on each side with an antireflective coating. The two window layers are bonded together in a facing-but-spaced-apart relation by an infrared-transparent adhesive layer, preferably a silicone rubber. The window is placed into the wall of a sensor housing that contains an infrared sensor.

Environmentally resistant, infrared-transparent window structure

Low-cost composite infrared windows that are transparent to long wave infrared radiation (8-12 microns) that provide sufficient strength and impact resistance for automotive-type environments, and the like. The windows may be used with night vision systems for automobiles, surveillance imaging systems, and other applications requiring low cost, long wave infrared windows. In one embodiment, the composite infrared window is a sandwich comprised of a polyethylene plastic film bonded with an acrylic adhesive to a relatively thin (0.015-0.040 inch) silicon substrate. The thin silicon substrate is mechanically stiff and low cost, and transmits in the 8-12 micron bandpass. The thin (0.001-0.007 inch) plastic film provides an exterior particle impact absorbing layer sufficient to enable the use of the window in automotive applications. In another embodiment, the infrared window is a dual pane, long wave infrared transmitting window comprising a thin, antireflection coated, silicon window and a plain or reinforced, embossed, plastic window that may be mounted in a frame.

Composite infrared windows using silicon and plastic

Detection apparatus for use with a carbon dioxide jet spray cleaning system that determines whether liquid carbon dioxide is flowing between a storage tank and a jet spray nozzle. The detection apparatus determines whether carbon dioxide snow is generated by the jet spray nozzle, which is produced by expansion of liquid carbon dioxide through the jet spray nozzle. The apparatus comprises a transfer tube coupled between the storage tank and the jet spray nozzle that has transparent input and output windows and which permits liquid carbon dioxide to flow from the storage tank to the jet spray nozzle. A light source produces light that is focused on a pinhole in an aperture stop. A collimating lens images collimated light on the input window of the transfer tube, and a light detector detects light that is refracted by liquid carbon dioxide in the transfer tube that exits through the output window and is incident thereon, and generates an output signal indicating light detection. The output signal indicates that liquid carbon dioxide is flowing between the storage tank and the jet spray nozzle, and thus that snow is generated.

Carbon dioxide liquid and gas sensor apparatus for use with jet spray

An optical device comprising an electrode (&lt;200 ohms/square) that is transparent to infrared radiation through and beyond the mid-wavelength infrared (3-5 micrometers), and long wavelength infrared (8-12 micrometers), out to 30 micrometers. The optical device is comprised of a sandwich of a thin (.ltoreq.0.001') conductive silicon wafer optically contacted or bonded to an optically transparent substrate. Typical substrates that may be employed are cadmium telluride, zinc sulfide or zinc selenide substrates. The substrate provides the rigidity necessary to prevent optical distortion which can result from bowing caused by mounting stresses. The optical device provides an electrode having high infrared transmission without the optical diffraction effects produced by a conductive grid. Unlike conductive coatings, the optical device does not incur transmission degradation caused by temperature increases. The optical device provides an optical window for use with liquid crystal light valves, and the like, or where heating and/or electromagnetic shielding is required together with long wavelength infrared transmittance.

Growing community of inventors

Redondo Beach, CA, United States of America

Michael R Borden