USA As Represented by Secretary of the Navy

Wadad B Dubbelday

Stephen Douglas Russell

Randy L Shimabukuro

Paul R De La Houssaye

Larry D Flesner

Shannon D Kasa

Andrew S Katz

Diane M Szaflarski

Robert C Dynes

George P Imthurn

Isaac Lagnado

Debra M Gookin

Stephen A Miller

A single crystal silicon film nanostructure capable of optical emission is aterally disposed on an insulating transparent substrate of sapphire. By laterally disposing the nanostructure, adequate support for the structure is provided, and the option of fabricating efficient electrical contact structures to the nanostructure is made possible. The method of the invention begins with the deposition of ultrathin layers of silicon on the substrate. A Solid Phase Epitaxy improvement process is then used to remove crystalline defects formed during the deposition. The silicon is then annealed and thinned using thermal oxidation steps to reduce its thickness to be on the order of five nanometers in height. The width and length of the nanostructure are defined by lithography. The nanometer dimensioned silicon is then spin-coated with a resist with width and length definition in the resist being performed by way of electron beam exposure. The photoresist is developed and the e-beam written pattern is transferred to the silicon by etching. Oxidations and etchings may subsequently be employed to further thin the width of the nanostructure to be on the order of two to three nanometers. The single crystal, silicon-based nanostructures can be made an integral part of silicon-based photo, electroluminescent, and quantum-effect devices all of which are compatible with current silicon manufacturing techniques and with other silicon-based microelectronics.

Laterally disposed nanostructures of silicon on an insulating substrate

A light emitting photonic structure has a transparent substrate, such as sapphire, supporting a layer of group IV semiconductor material, such as silicon, having at least one porous region from which light is emitted as a response to an electrical or optical stimulus. Optionally, the group IV semiconductor material may be germanium, carbon, tin, silicon-germanium, silicon carbide, single crystal structures, polycrystalline structures, or amorphous structures and the transparent substrate may be glass, quartz, fused silica, diamond, ruby, yttria alumina garnet, yttria stabilized zirconium, magnesium fluoride or magnesium oxide. When the stimulus is electrical, the response is electroluminescence or cathodoluminescence and when the stimulus is optical, the response is photoluminescence. The method includes providing a transparent substrate, forming a layer of a group IV semiconductor material on the transparent substrate, and fabricating at least one region in the layer of the group IV semiconductor material from which light is emitted as a response to a electro- or photo-stimulus. The fabricating of the region is by a photochemical etch by an etching solution and a means to catalyze an etching reaction and may further include an illuminating of the region with light or an other suitable wavelength to provide for a photo-initiated photo-chemical stain etch of the region.

Photonic silicon on a transparent substrate

A single crystal silicon film nanostructure capable of optical emission is laterally disposed on an insulating transparent substrate of sapphire. By laterally disposing the nanostructure, adequate support for the structure is provided, and the option of fabricating efficient electrical contact structures to the nanostructure is made possible. The method of the invention begins with the deposition of ultrathin layers of silicon on the substrate. A Solid Phase Epitaxy improvement process is then used to remove crystalline defects formed during the deposition. The silicon is then annealed and thinned using thermal oxidation steps to reduce its thickness to be on the order of five nanometers in height. The width and length of the nanostructure are defined by lithography. The nanometer dimensioned silicon is then spin-coated with a resist with width and length definition in the resist being performed by way of electron beam exposure. The photoresist is developed and the e-beam written pattern is transferred to the silicon by etching. Oxidations and etchings may subsequently be employed to further thin the width of the nanostructure to be on the order of two to three nanometers. The single crystal, silicon-based nanostructures can be made an integral part of silicon-based photo, electroluminescent, and quantum-effect devices all of which are compatible with current silicon manufacturing techniques and with other silicon-based microelectronics.

A method for fabricating silicon-germanium alloy on a sapphire substrate of the present invention comprises the steps of passivating a surface of a sapphire substrate, maintaining a deposition temperature of about 900 degrees C., exposing the passivated surface to a flow of about 1 slm of about 2 percent silane in a hydrogen carrier and a flow of at least 200 sccm of about 10 percent germane in a hydrogen carrier to form a layer of single crystal silicon germanium alloy on the passivated surface of the sapphire substrate, and ramping the temperature down to about 650 degrees C. during the step of exposing the passivated surface to the germane gas.

Method for making silicon germanium alloy and electric device structures

A light emitting photonic structure has a transparent substrate, such as sapphire, supporting a layer of group IV semiconductor material, such as silicon, having at least one porous region from which light is emitted as a response to a stimulus. An example of such a photonic structure is described in U.S. patent application Ser. No. 08/118,900. The photonic structure can be used to assess the presence of various fluids. The photonic structure is disposed to be contacted by the fluid to be sensed should it be present. The light emitting region of the photonic structure is stimulated by an appropriate source, and the light emitted by the photonic source is detected by a detector. The light emitting region of the photonic structure will emit a certain luminescence in air and should the light emitting region be contacted by other fluid or fluids, this luminescence can be affected and the corresponding change in luminescence can be detected thus the presence of these fluids can be sensed. Because the photonic structure has a light emitting region is formed on a transparent substrate, the light emitting region can be both excited and interrogated through the transparent substrate and outside of the presence of the fluid to be sensed. Hence absorption of the excitation radiation used as well as the luminescence emitted by the fluid to be sensed is eliminated.

Liquid level sensor and detector

A method for manufacturing an optical RF bandpass filter comprises the st of: (1) mounting an optical fiber having first and second ends in a fiber support structure having first and second surfaces so that the first end is exposed at the first surface and the second end is exposed at the second surface; (2) forming a first layered mirror structure on a first substrate to create a first mirror wafer structure having a first reflective surface; (3) forming a second layered mirror structure on a second substrate to create a second mirror wafer structure having a second reflective surface; (4) affixing the first reflective surface of the first mirror wafer structure to the first surface of the fiber support structure; and (5) affixing the second reflective surface of the second mirror wafer structure to the second surface of the fiber support structure.

Optical RF bandpass filter and method for manufacturing same

Electroluminescent devices are formed on a transparent sapphire substrate follows. Crystalline silicon is formed on the sapphire substrate and patterned into a mesa. An electrode of, for example, titanium silicide, is formed in the silicon around the mesa, and an electrically insulating layer is formed over the electrode. The crystalline silicon is exposed on the mesa, and a porous silicon layer is formed on the crystalline silicon. An electrode made of aluminum, for example, is formed on the porous silicon layer. This electrode need not be transparent. An outer insulating layer may be formed on the aluminum electrode and additional electrodes may be formed on and through the outer insulating layer to make electrical contact with the titanium silicide and aluminum electrodes, respectively. A voltage source may be connected to the electrodes to pass a current through the porous silicon to cause light to be emitted from the porous silicon through the sapphire substrate.

Electroluminescent device in silicon on sapphire

This invention describes a method of controlling light emission from porous silicon and porous silicon devices using ion implantation. The emitted light intensity can be either selectively increased or decreased by suitable processing of the silicon prior to the fabrication of the porous layer. Amorphizing the silicon prior to the fabrication of the porous layer quenches the light emission. Ion implantation with doses below the amorphization level enhances the intensity of the emitted light of the subsequently fabricated porous layer.

Method of controlling photoemission from porous silicon using ion

A method is provided for forming a multi-cell photovoltaic circuit on an insulating substrate, comprising the steps of: forming a photovoltaic junction between p-type and n-type layers in a silicon wafer; bonding the silicon wafer to an insulating substrate after forming the photovoltaic junction; patterning the silicon wafer to produce isolated photovoltaic cells; and electrically interconnecting the photovoltaic cells.

Method of forming a high voltage silicon-on-sapphire photocell array

A light energized high voltage direct current power supply comprises a li source including solid-state laser diodes powered by electrical current at a voltage level, V.sub.1, for generating light; a photocell array positioned to receive the light and fabricated with silicon-on-sapphire for providing electrical power having an output voltage V.sub.2, where V.sub.2 &gt;V.sub.1, where the photocell array includes serially connected photovoltaic cells; and a voltage regulator operably coupled to the light source and the photocell array for controlling the output of the power supply to a predetermined voltage level.

Laser energized high voltage direct current power supply

An optically powered photomultiplier tube is provided, comprising a vacuum chamber having a window for incident optical radiation which is to be detected; a photocathode to receive the optical radiation; an electron multiplier system within the chamber to amplify the electron current from the photocathode; an anode to receive the amplified electron current; a high voltage photocell array positioned within the chamber for generating high voltage electrical power that is provided to the electron multiplier system; a system for delivering optical power to the photocell array; a first electrical contact penetrating the container in a vacuum tight manner and operably coupled to the anode; and a second electrical contact penetrating the container in a vacuum tight manner and operably coupled to the photocell array.

Growing community of inventors

Spring Valley, CA, United States of America

Wadad B Dubbelday