Abstract: Nozzle apparatus for producing a liquid jet are disclosed. An example nozzle apparatus includes: (a) an outer nozzle housing defining a cavity and having an outlet defined at an apex of the cavity, (b) a cylindrical sidewall coupled to a base of the nozzle housing, where the cylindrical sidewall defines a plurality of arch-shaped voids and (c) an inner housing coupled to the outer nozzle housing, where the inner housing has a first end and a second end, where at least the first end of the inner housing is arranged within the cavity of the outer nozzle housing, where the inner housing defines a through-hole that is arranged concentric with the outlet of the outer nozzle housing.

Abstract: Nozzle apparatus for producing a liquid jet are disclosed. An example nozzle apparatus includes: (a) an outer nozzle housing defining a cavity and having an outlet defined at an apex of the cavity, (b) a cylindrical sidewall coupled to a base of the nozzle housing, where the cylindrical sidewall defines a plurality of arch-shaped voids and (c) an inner housing coupled to the outer nozzle housing, where the inner housing has a first end and a second end, where at least the first end of the inner housing is arranged within the cavity of the outer nozzle housing, where the inner housing defines a through-hole that is arranged concentric with the outlet of the outer nozzle housing.

Abstract: An injector apparatus and methods for use, where the injector apparatus comprises: (a) hydraulic stage having first and second ends and including a housing defining a cavity, a primary plunger disposed in the cavity and a secondary plunger, (b) a pressurization system coupled to the hydraulic stage's first end, where the primary plunger is in fluid communication with the pressurization system and is in mechanical communication with the secondary plunger, (c) a reservoir bore defined in the hydraulic stage housing and configured to receive the primary plunger's second end, where the secondary plunger is disposed within the reservoir bore and (d) a nozzle assembly including a housing, a gas tube and a nozzle capillary, where the nozzle capillary is partially disposed in and is substantially coaxial with the gas tube, where the nozzle capillary's first end is in fluid communication with the reservoir bore's second end.

Abstract: A nozzle for producing a liquid jet or a single-file stream of droplets of a fluid, methods using the nozzle, and an injector comprising the nozzle of the invention for providing the liquid jet or single-file stream of a fluid to a vacuum system are described.

Abstract: An injector apparatus and methods for use, where the injector apparatus comprises: (a) hydraulic stage having first and second ends and including a housing defining a cavity, a primary plunger disposed in the cavity and a secondary plunger, (b) a pressurization system coupled to the hydraulic stage's first end, where the primary plunger is in fluid communication with the pressurization system and is in mechanical communication with the secondary plunger, (c) a reservoir bore defined in the hydraulic stage housing and configured to receive the primary plunger's second end, where the secondary plunger is disposed within the reservoir bore and (d) a nozzle assembly including a housing, a gas tube and a nozzle capillary, where the nozzle capillary is partially disposed in and is substantially coaxial with the gas tube, where the nozzle capillary's first end is in fluid communication with the reservoir bore's second end.

Abstract: A nozzle for producing a liquid jet a fluid, methods using the nozzle, and an injector comprising the nozzle of the invention for providing the liquid jet of a fluid to a vacuum system are described.

Abstract: A non-direct contact ink-jet style printer is disclosed herein, which uses a superfluid cryogenic fluid such as superfluid helium as the ink medium. Superfluid helium is non-viscous thus enabling the print head of the present invention to print nanoscale characters onto a substrate. In one exemplary embodiment, dopants are injected into the ink droplets to load the droplets with dopants, which then deliver the dopants onto the substrate. Multiple nozzles and different dopants may be used with the embodiments disclosed herein to provide different outputs on the substrate. Spent or un-used droplets and dopants may be educted away and discarded or scrubbed for reuse. Methods for printing using superfluid helium are also discussed herein.

Abstract: Semiconductor nitride layers are produced using a corona discharge supersonic free-jet source producing an activated nitrogen molecule beam impacting a semiconductor substrate in the presence of a group III metal or impacting an oxide layer on a semiconductor substrate. The activated nitrogen molecules are of the form N2A3&Sgr;u+. Apparatus for producing the nitride layer on the substrate includes the corona discharge free-jet source, a skimmer to collimate the N2 beam and succeeding stages interconnected by collimators and evacuated to draw off background gases.

Abstract: Semiconductor nitride layers are produced using a corona discharge supersonic free-jet source producing an activated nitrogen molecule beam impacting a semiconductor substrate in the presence of a group III metal or impacting an oxide layer on a semiconductor substrate. The activated nitrogen molecules are of the form N2A3&Sgr;u+. Apparatus for producing the nitride layer on the substrate includes the corona discharge free-jet source, a skimmer to collimate the N2 beam and succeeding stages interconnected by collimators and evacuated to draw off background gases.

Abstract: In semiconductor devices such as laser diodes (LD) and light emitting diodes (LED) based on gallium nitride thin films, low defect density is desired in the gallium nitride film. In the fabrication of such devices on a silicon carbide substrate surface, the gallium nitride film is formed on the silicon carbide substrate after the substrate surface is etched using hydrogen at an elevated temperature. In another embodiment, an aluminum nitride film is formed as a buffer layer between the gallium nitride film and the silicon carbide substrate, and, prior to aluminum nitride formation, the substrate surface is etched using hydrogen at an elevated temperature.