USA as Represented by Secretary of the Navy

Euclid Techlabs, LLC

James E Butler

Pehr E Pehrsson

Francis J Kub

Karl D Hobart

Michael W Geis

Marko J Tadjer

Michael Anthony Mastro

Robert Wright, Jr

Joshua D Caldwell

Tatyana I Feygelson

Daniel J Vestyck

Kendrick X Liu

Donald D Flechtner

John L Giuliani, Jr

Vasgen A Shamamian

Kathleen Doverspike

A method of preparing a diamond crystal substrate for epitaxial deposition thereupon of a delta doping layer includes preparing an atomically smooth, undamaged diamond crystal substrate surface, which can be in the (100) plane, by polishing the surface and then etching the surface to remove subsurface damage caused by the polishing. The polishing can include a rough polish, for example in the (010) direction, followed by a fine polish, for example in the (011) direction, that removes the polishing tracks from the rough polishing. After etching the polished face can have a roughness Sa of less than 0.3 nm. An inductively coupled reactive ion etcher can apply the etching at a homogeneous etch rate using an appropriate gas mixture such as using argon and chlorine to remove between 0.1 and 10 microns of material from the polished surface.

Method of preparing diamond substrates for CVD nanometric delta doping

An apparatus and method for creating nanometric delta doped layers in epitaxial diamond includes providing a dummy gas load with gas impedance equivalent to the reactor, and switching gas supplied between the reactor and the gas dummy load without stopping either flow, thereby enabling rapid flow and rapid gas switching without turbulence. An atomically smooth, undamaged substrate can be prepared, preferably in the (100) plane, by etching the surface after polishing to remove subsurface damage. A gas phase chemical getter reactant such as hydrogen disulfide can be used to suppress incorporation of residual boron into the intrinsic layers. Embodiments can produce interfaces between doped and mobile layers that provide at least 100 cm/Vsec carrier mobility and 10cmsheet carrier concentration.

CVD reactor and method for nanometric delta doping of diamond

A heterojunction between thin films of NCD and 4H&#x2014;SiC was developed. Undoped and B-doped NCDs were deposited on both n&#x2212; and p&#x2212; SiC epilayers. I-V measurements on p+ NCD/n&#x2212; SiC indicated Schottky rectifying behavior with a turn-on voltage of around 0.2 V. The current increased over eight orders of magnitude with an ideality factor of 1.17 at 30&#xb0; C. Ideal energy-band diagrams suggested a possible conduction mechanism for electron transport from the SiC conduction band to either the valence band or acceptor level of the NCD film.

Transparent nanocrystalline diamond contacts to wide bandgap semiconductor devices

A method of making a Schottky diode comprising the steps of: providing a single crystal diamond comprising a surface; placing the single crystal diamond in a CVD system; heating the diamond to a temperature of at least about 950&deg; C.; providing a gas mixture capable of growing diamond film and comprising a sulfur compound through the CVD system; growing an epitaxial diamond film on the surface of the single crystal diamond; baking the diamond at a temperature of at least about 650&deg; C. in air for a period of time that minimizes oxidation of the diamond; and fabricating a Schottky diode comprising the diamond film. A Schottky diode comprising an epitaxial diamond film and capable of blocking at least about 6 kV in a distance of no more than about 300 &mgr;m.

Method of manufacturing high voltage schottky diamond diodes with low boron doping

An apparatus for emitting electrons is provided. The apparatus includes a subsurface emitter having a sharp tip, a substrate including a base, and electrical continuity between the tip, the base, and an external circuit. This emitter structure may be used to form individual emitters or arrays of emitters. Also provided is a method of making electron emitters which is comprised of implanting energetic ions into a diamond lattice to form cones or other continuous regions of damaged diamond. These regions are more electrically conducting than the surrounding diamond lattice, and have locally sharp tips at or near the point of entry of the ion into the diamond. The tips may then also be additionally coated with a layer of a wide band-gap semiconductor. An electrically conducting material may also be placed in proximity to the tips to generate an electric field sufficient to extract electrons from the conducting tips into either the region above the surface, or into the wide band-gap semiconductor layer in contact with the tips. Electrical contact is made to the electrically conducting damage tracks and the electrical circuit may be completed with an electrically conducting material on the surface of the wide band-gap semiconductor or diamond, or in the ambient above the surface of the emitter. The surface of the wideband gap semiconductor or diamond may be chemically modified to enhance the emission of electrons from the surface.

Apparatus for emitting electrons comprising a subsurface emitter structure

A method for fabricating an electron emitter. This emitter structure may be used to form individual emitters or arrays of emitters. The method is comprised of implanting energetic ions into a diamond lattice to form cones or other continuous regions of damaged diamond. These regions are more electrically conducting than the surrounding diamond lattice, and have locally sharp tips at or near the point of entry of the ion into the diamond. The tips may then also be additionally coated with a layer of a wide band-gap semiconductor. An electrically conducting material may also be placed in proximity to the tips to generate an electric field sufficient to extract electrons from the conducting tips into either the region above the surface, or into the wide band-gap semiconductor layer in contact with the tips. Electrical contact is made to the electrically conducting damage tracks and the electrical circuit may be completed with an electrically conducting material on the surface of the wide band-gap semiconductor or diamond, or in the ambient above the surface of the emitter. The surface of the wideband gap semiconductor or diamond may be chemically modified to enhance the emission of electrons from the surface.

Method of making electron emitters

A sealed, metal oxide, electrodeless discharge lamp having a high emission ntensity in the visible 400-700 nm range. Within the sealed container assembly of the lamp there is a source of metal atoms capable of forming a volatile oxide and a source of an oxygen containing gas. The lamp produces a plasma and volatilizes the metal into the plasma. Preferably the lamp is at a low pressure of about 20-40 torr and the metals are molybdenum or tungsten. Power is applied by inductively coupled electromagnetic radiation. A regenerative agent such as a halogen is added for recycling any deposited metal into the gas phase and to form a volatile compound with the source of metal atoms. The agent lowers the temperatures needed to volatilize the metal into the plasma. The lamp is operated by first providing energy at a low level to initiate the plasma and then supplying the metal atoms into the plasma.

Metal oxide discharge lamp

A method for the chemical vapor deposition of diamond includes the steps of:

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Huntingtown, MD, United States of America

James E Butler