637 results about "Molecular beam epitaxy" patented technology

An electronic semiconductor device comprising a semiconductor base deposited on a semiconductor substrate by means of molecular beam epitaxy and source, drain and gate disposed on the base in a spaced relationghip to each other, the source and the drain comprising Pd/barrier/Au layers with the palladium layer being in contact with the device. The device is fabricated conventionally except the heat treating is at above about 170° C. for ¼-10 hours sufficient for the palladium layer to react with the base yielding reduced contact and access resistances and a narrower spacing between source and drain.

An article of manufacture comprises a substrate and a layer of N_(x)Y_(1−x)AlO₃ on the substrate where x is a molar fraction greater than zero and less than one, and N is an element selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. The article may be an electronic device further comprising an electrode electrically isolated from the substrate by the layer. In particular, the dielectric properties of the layer are such that the layer is especially although by no means exclusively useful for electrically isolating gate electrodes in field effect transistor devices. The layer may be formed on the substrate via molecular beam epitaxy.

A liquid metal evaporation source for use in Molecular Beam Epitaxy and related metal vacuum deposition techniques. An evaporator is maintained at a high temperature to evaporate a liquid metal, a reservoir for holding the liquid metal source is maintained at a temperature above the melting point of the metal but below the temperature in the evaporator, and a hollow transport tube connecting the evaporator and reservoir is maintained at a temperature between these temperatures. The reservoir is in the shape of a hollow cylinder with a close-fitting cylindrical piston which is used to force the liquid metal through the hollow transport tube into the evaporator. The liquid metal will not flow past the piston seal if a suitably small gap is formed between the piston and the reservoir walls wherein the surface tension of the liquid metal will exceed its hydrostatic pressure against the piston thus forming a leak-tight seal.

A semiconductor structure for providing an epitaxial zinc oxide layer having p-type conduction for semiconductor device manufacture and methods of depositing the p-type zinc oxide layer. A zinc oxide layer is deposited epitaxially by molecular beam epitaxy on a crystalline zinc oxide substrate. The zinc oxide layer incorporates a p-type dopant, such as nitrogen, in an atomic concentration adequate to provide p-type conduction. The p-type zinc oxide layer may further incorporate an atomic concentration of a compensating species, such as lithium, sufficient to electronically occupy excess donors therein so that the efficiency of the p-type dopant may be increased.

A hybrid beam deposition (HBD) system and methods according to the present invention utilizes a unique combination of pulsed laser deposition (PLD) technique and equipment with equipment and techniques that provide a radical oxygen rf-plasma stream to effectively increase the flux density of available reactive oxygen at a deposition substrate for the effective synthesis of metal oxide thin films. The HBD system and methods of the present invention further integrate molecular beam epitaxy (MBE) and/or chemical vapor deposition (CVD) techniques and equipment in combination with the PLD equipment and technique and the radical oxygen rf-plasma stream to provide elemental source materials for the synthesis of undoped and/or doped metal oxide thin films as well as synthesis of undoped and/or doped metal-based oxide alloy thin films.

The invention discloses a one-phase ferroelectric film capable of regulating effective resistance by ferroelectric polarization, a preparing method of the one-phase ferroelectric film and an effective resistance regulation mode. The one-phase ferroelectric film comprises B-bit-doped Bal-xSrxTil-yByO3, Pb(Fe1-yBy)O3, Pb(Co1-yBy)O3, (Pb1-xAx)(ZryTi1-y)O3, A-bit-doped Y1-xAxMnO3, Bil-xAxFeO3, and Bi4-xAxTi3O12. The one-phase ferroelectric film is prepared by using film preparing methods, such as pulsed laser deposition (PLD), laser molecular beam epitaxy (LMBE) and magnetron sputtering. The prepared ferroelectric film is 0.4-1000 nanometer in the thickness and has larger conductance and leakage current, as well as ferroelectricity and semiconductor performance. The invention provides a method for improving the antifatigue performance of the one-phase ferroelectric film. Turning frequency (x) of the ferroelectric polarization in the method can be increased to 102-1010; and the ferroelectric polarization is turned to regulate the effective resistance of the one-phase ferroelectric film.

A vector underwater sound transducer of resonant tunneling bionic type is prepared as applying semiconductor etching technique to each bottom-middle part of semiconductor substrate to be structure of cross cantilever beam, fixing micro cylindrical body at center of cross cantilever beam and setting resonant tunneling diode separately at end portions of four beams on cross cantilever beam.

A method to achieve high quality III-nitride epitaxial layers including AlN, AlGaN, GaN, InGaN, and AlInGaN, by supplying group III precursors constantly and group V precursors periodically with the epitaxial growth systems including metal organic chemical vapor deposition (MOCVD), hydride vapor phase epitaxy (HVPE), and molecular beam epitaxy (MBE).

The invention discloses a multi-junction solar cell based on a monocrystalline silicon substrate for the solar energy power generation, especially suitable for a high efficiency concentrated solar energy power generation system characterized by growing the multi-junction solar cell materials by using a silicon single-crystal wafer as a substrate through a Metal Organic Chemical Vapor Deposition (MOCVD) method or a Molecular Beam Epitaxy (MBE) method. Firstly a germanium-silicon alloy transition layer is grown on the silicon single-crystal wafer, then a germanium cell structure, an indium-gallium-arsenic cell structure and an indium-gallium-phosphorus cell structure are grown in turn. The invention employs the silicon single-crystal sheet instead of the germanium single-crystal wafer and the gallium arsenide single-crystal wafer, greatly reduces the multi-junction solar cell cost, improves the conversion efficiency of the silicon based solar cell and expedites the application and development of the solar energy power generation.

The invention provides a method for growing GeSn alloy on a silicon (Si) substrate by molecular beam epitaxy. The method comprises the following steps of: 1, growing a first Ge material layer on the Si substrate; 2, growing a second Ge material layer on the first Ge material layer; 3, growing a first GeSn alloy layer on the second Ge material layer; and 4, growing a second GeSn alloy layer on the first GeSn alloy layer to finish the growth of the material.

The invention discloses an annular semiconductor laser of a vertical coupling structure and a preparing method thereof. An annular active resonator cavity is any one closed loop composed of ridge type waveguide and strip type waveguide, a P type electrode and an N type electrode are arranged on the annular active resonator cavity, laser light in the annular active resonator cavity is coupled to strip type straight waveguide through a vertical coupler, and the strip type straight waveguide outputs the laser light. An N type lower wrapping layer, a first gradual-change refractive index limiting layer, a first barrier layer, a multiple quantum well active layer, a second barrier layer, a second gradual-change refractive index limiting layer, a P type upper wrapping layer and a P type contacting layer which have preset thicknesses and concentration are successively formed by means of a metal organism chemical vapor deposition or molecular beam epitaxy method. A plurality of epitaxial layers are etched by using a SiO2 image as a mask, the etching depth is less than or equal to a first height and greater than or equal to a second height, and the annular active resonator cavity is transferred to a chip. The obtained annular semiconductor laser has the advantages of being simple in process, low in cost, stable in performance of parts, high in reliability and the like.

The invention discloses a platinum diselenide crystal material and a preparation method thereof. The preparation method comprises the following steps: 1) under a vacuum environment, evaporating and depositing a proper amount of high purity selenium on a metal platinum substrate; and 2) carrying out an annealing treatment, so that selenium atoms covering the surface of the substrate and platinum atoms on the substrate interact to form a two-dimensional ordered crystalline state membrane structure in a sandwich arrangement of selenium-platinum-selenium so as to obtain the platinum diselenide crystal material. The inorganic two-dimensional crystalline state material is a new member of a transitional metal disulfide compound family, expands the field of research on non-carbon based two-dimensional crystal materials, and has a wide application potential in future information electronics and apparatus development and research. According to the method disclosed by the invention, the platinum diselenide two-dimensional crystalline state material with a big area and a high quality is grown on a molecular beam epitaxial method, so that the electronic properties of the platinum diselenide crystalline state material and related applications and development are favorably researched.

A process for producing a free-standing III-N layer, where III denotes at least one element from group III of the periodic system, selected from Al, Ga and In, comprises depositing on a Li(Al,Ga)Ox substrate, where x is in a range between 1 and 3 inclusive, at least one first III-N layer by means of molecular beam epitaxy. A thick second III-N layer is deposited on the first III-N layer by means of a hydride vapor phase epitaxy. During cooling of the structure produced in this way, the Li(Al,Ga)Ox substrate completely or largely flakes off the III-N layers, or residues can be removed if necessary, by using etching liquid, such as aqua regia. A free-standing III-N substrate being substantially free of uncontrolled impurities and having advantageous properties is provided.

Gallium nitride is grown by plasma-assisted molecular-beam epitaxy on (111) and (001) silicon substrates using hafnium nitride buffer layers. Wurtzite GaN epitaxial layers are obtained on both the (111) and (001) HfN/Si surfaces, with crack-free thickness up to 1.2 m. However, growth on the (001) surface results in nearly stress-free films, suggesting that much thicker crack-free layers could be obtained.

MBE nitrogen sources of dimethylhydrazine, tertiarybutlyhydrazine, nitrogentrifloride, and NHx radicals. Those nitrogen sources are beneficial in forming nitrogen-containing materials on crystalline subtrates using MBE. Semiconductor lasers in general, and VCSEL in particular, that have nitrogen-containing layers can be formed using such nitrogen sources.

The invention relates to a macrolattice mismatch epitaxial material buffer layer structure containing a superlattice isolated layer and preparation thereof. N layers of strain-free superlattice isolated layer materials are inserted in a component gradual change buffer layer, wherein n is a natural number and is not smaller than 1 and not larger than 5. The preparation process comprises the following steps of: firstly, determining the parameters of growth temperature, beam source furnace temperature and other parameters; and then sequentially and alternately growing buffer layers with gradually increased strain capacities and strain-free superlattice isolated layer materials on a substrate by adopting a molecular beam epitaxy method until finishing the growth of a buffer layer reaching an expected strain capacity. The material contains the superlattice isolated layer and can ensure that relaxation can quickly and effectively occur to a macrolattice mismatch epitaxial material to release stress in the buffer layer so as to reduce the dislocation density of the epitaxial material on the buffer layer. Moreover, the uninterrupted growth of the material is carried out by adopting a conventional molecular beam epitaxy method, thus the invention has the advantages of easy control of operations, low cost, environmental protection, and the like.

The invention relates to an ultraviolet detector, in particular to an ultraviolet detector with high spectral selectivity and high sensitivity and a preparation method of the ultraviolet detector. A beta-Ga<2>O<3> film is deposited on an n-type 4H-SiC substrate through a laser molecular beam epitaxy technique; and a Ti/Au film is deposited on the n-type 4H-SiC substrate and the beta-Ga<2>O<3> film for use as an electrode by a mask through a radio-frequency magnetron sputtering technique. The ultraviolet detector has the advantages that the prepared ultraviolet detector has stable performance, has high selectivity and high sensitivity on an ultraviolet spectrum with a specific wavelength, is low in dark current, and can be applied to fire alarm, high-voltage line corona and detection of the spectrum with the specific wavelength; furthermore, the preparation method has the characteristics of being high in process controllability, simple in operation, good in universality and the like and has a great application prospect; and a repeated test has recoverability.