640 results about "Molecular beam epitaxy" patented technology

Methods of semiconductor device fabrication are disclosed. An exemplary method includes processes of depositing a first pattern on a semiconductor substrate, wherein the first pattern defines wide and narrow spaces; depositing spacer material over the first pattern on the substrate; etching the spacer material such that the spacer material is removed from horizontal surfaces of the substrate and the first pattern but remains adjacent to vertical surfaces of a wide space defined by the first pattern and remains within narrow a space defined by the first pattern; and removing the first pattern from the substrate. In one embodiment, the first pattern can comprise sacrificial material, which can include, for example, polysilicon material. The deposition can comprise physical vapor deposition, chemical vapor deposition, electrochemical deposition, molecular beam epitaxy, atomic layer deposition or other deposition techniques. According to another embodiment, features for lines and logic device components having a width greater than that of the lines are formed in the spacer material in the same mask layer.

Tantalum and titanium source reagents are described, including tantalum amide and tantalum silicon nitride precursors for the deposition of tantalum nitride material on a substrate by processes such as chemical vapor deposition, assisted chemical vapor deposition, ion implantation, molecular beam epitaxy and rapid thermal processing. The precursors may be employed to form diffusion barrier layers on microlectronic device structures enabling the use of copper metallization and ferroelectric thin films in device construction.

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 AlGaN composition is provided comprising a group III-Nitride active region layer, for use in an active region of a UV light emitting device, wherein light-generation occurs through radiative recombination of carriers in nanometer scale size, compositionally inhomogeneous regions having band-gap energy less than the surrounding material. Further, a semiconductor UV light emitting device having an active region layer comprised of the AlGaN composition above is provided, as well as a method of producing the AlGaN composition and semiconductor UV light emitting device, involving molecular beam epitaxy.

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.

The present invention provides a method for growing a lateral epitaxy of the gallium nitride and its compound semiconductors, comprising the following steps: growing an intrinsic gallium nitride on the ( 0001 ) crystal face of sapphire or the ( 111 ) of silicon or the ( 0001 ) of silicon carbide using the metal organic chemical vapor deposition or the molecule beam epitaxy or the hydride vapor epitaxy; then depositing on it a layer of silicon nitride or silicon dioxide or silicon nitride-oxide as the mask area; patterning the mask area using the photolithography and wet or dry etch techniques, the pattern of the mask area being designed into the pattern structure of the triangle or parallelogram or rhombus or hexagon with the included angles of 60 or 120 degrees or the combination of above shapes which are constituted of the [ 10 - 10 ] crystal direction of gallium nitride on the edge of the adjacent windows; and finally growing the secondary epitaxy, that is, lateral epitaxy of gallium nitride and its compound using the metal organic vapor deposition or the molecule beam epitaxy or the hydride vapor epitaxy.

4H-InGaAlN alloy based optoelectronic and electronic devices on non-polar face are formed on 4H-AlN or 4H-AlGaN on (11-20) a-face 4H-SiC substrates. Typically, non polar 4H-AlN is grown on 4H-SiC (11-20) by molecular beam epitaxy (MBE). Subsequently, III-V nitride device layers are grown by metal organic chemical vapor deposition (MOCVD) with 4H-polytype for all of the layers. The non-polar device does not contain any built-in electric field due to the spontaneous and piezoelectric polarization. The optoelectonic devices on the non-polar face exhibits higher emission efficiency with shorter emission wavelength because the electrons and holes are not spatially separated in the quantum well. Vertical device configuration for lasers and light emitting diodes(LEDs) using conductive 4H-AlGaN interlayer on conductive 4H-SiC substrates makes the chip size and series resistance smaller. The elimination of such electric field also improves the performance of high speed and high power transistors. The details of the epitaxial growth s and the processing procedures for the non-polar III-V nitride devices on the non-polar SiC substrates are also disclosed.

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.

Multi-quantum well (MQW) spatial light modulator devices are disclosed that are capable of achieving reasonable quantum efficiencies and high contrast ratios in order to close an optical communication link by resolving the logical on or off state. The device both modulates and detects light through the use of the quantum well design and resonant cavity enhancement. Based on the materials (e.g., InGaAs / InAlAs) and their band structures, this device can be configured to communicate in the eye-safe wavelength range (e.g., 1550±20 nm). The device can be fabricated using standard photolithographic processes such as molecular beam epitaxy (MBE) and inductively coupled plasma (ICP) reactive ion etching (RIE).

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.

Solar cell structures formed using molecular beam epitaxy (MBE) that can achieve improved power efficiencies in relation to prior art thin film solar cell structures are provided. A reverse p-n junction solar cell device and methods for forming the reverse p-n junction solar cell device using MBE are described. A variety of n-p junction and reverse p-n junction solar cell devices and related methods of manufacturing are provided. N-intrinsic-p junction and reverse p-intrinsic-n junction solar cell devices are also described.

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.

Field effect transistors, methods of fabricating a carbon insulating layer using molecular beam epitaxy and methods of fabricating a field effect transistor using the same are provided, the methods of fabricating the carbon insulating layer include maintaining a substrate disposed in a molecular beam epitaxy chamber at a temperature in a range of about 300° C. to about 500° C. and maintaining the chamber in vacuum of 10−11 Torr or less prior to performing an epitaxy process, and supplying a carbon source to the chamber to form a carbon insulating layer on the substrate. The carbon insulating layer is formed of diamond-like carbon and tetrahedral amorphous carbon.

Expungement ions, preferably including hydrogen ions, are implanted into a face of a first, preferably silicon, substrate such that there will be a maximum concentration of the expungement ions at a predetermined depth from the face. Subsequently a monocrystalline Group II-VI semiconductor layer, or two or more such layers, is / are grown on the face, as by means of molecular beam epitaxy. After this a second, preselected substrate is attached to an upper face of the Group II-VI layer(s). Next, the implanted expungement ions are used to expunge most of the first substrate from a remnant thereof, from the grown II-VI layer, and from the second substrate. In another embodiment, a group II-VI layer is grown on a first substrate silicon and an ionic implantation is conducted such that a maximum concentration of expungement ions occurs either in the silicon substrate at a predetermined depth from its interface with the II-VI layer or in the first Group II-VI semiconductor layer at a predetermined depth from the top face of the Group II-VI semiconductor layer. Thereafter all of the first substrate is expunged from the rest of the workpiece. Thin monocrystalline Group II-VI semiconductor structures may thus be mounted to substrates of the fabricator's choice; these substrates may be semiconductors, integrated circuits, MEMS structures, polymeric, metal or glass, may be flexible and may be curved.

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.

The invention relates to the technical field of detectors, in particular to a three-mesa p-Pi-n structured III-nitride semiconductor avalanche photodetector and a preparation method of the three-mesa p-Pi-n structured III-nitride semiconductor avalanche photodetector. The three-mesa p-Pi-n structured III-nitride semiconductor avalanche photodetector comprises a substrate, a buffer layer, an n-type doping nitride ohmic electrode contact layer, a Pi-type nitride active layer, a p-type doping nitride layer, a p-type heavy-doping nitride ohmic contact layer, n-type ohmic contact electrodes and a p-type ohmic contact electrode, wherein the buffer layer, the n-type doping nitride ohmic electrode contact layer, the Pi-type nitride active layer, the p-type doping nitride layer and the p-type heavy-doping nitride ohmic contact layer are sequentially grown on the substrate through epitaxial growth methods such as a molecular beam epitaxial method or an organometallic chemical vapor deposition epitaxial method; the n-type ohmic contact electrodes are manufactured on the n-type layer, and the p-type ohmic contact electrode is manufactured on the p-type layer. The three-mesa p-Pi-n structured III-nitride semiconductor avalanche photodetector can solve the problems that a traditional p-i-n structured device leaks a large number of currents and the edge of the traditional p-i-n structured device can be broken through easily in advance; moreover, a three-mesa structure conducts double-suppression protection on edge electric fields of a strong electric field region and a weak electric field region of a p-Pi-n structured device, so that the edge electric field is effectively prevented from being broken through in advance.

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.

Hydrogen gas sensors employ an epitaxial layer of the thermodynamically stable form of aluminum nitride (AlN) as the “insulator” in an MIS structure having a thin metal gate electrode suitable for catalytic dissociate of hydrogen, such as palladium, on a semiconductor substrate. The AlN is deposited by a low temperature technique known as Plasma Source Molecular Beam Epitaxy (PSMBE). When silicon (Si) is used the semiconducting substrate, the electrical behavior of the device is that of a normal nonlinear MIS capacitor. When a silicon carbide (SiC) is used, the electrical behavior of the device is that of a rectifying diode. Preferred structures are Pd / AlN / Si and Pd / AlN / SiC wherein the SiC is preferably 6H—SiC.