2499 results about "Gallium nitride" patented technology

The present invention is an apparatus for deliverying high purity gallium trichloride in the vapor phase to a gallium nitride reactor, comprising; a source of carrier gas at an elevated pressure; a purifier to remove moisture from the carrier gas; a heater capable of heating the carrier gas to at least 80° C.; a container having a supply of gallium trichloride, a valve controlled inlet for the carrier gas having a dip tube with an outlet below the level of the gallium trichloride, a valve controlled outlet for removing the carrier gas and entrained gallium trichloride; a heater capable of heating sufficient to melt the gallium trichloride; a delivery line connected to the valve controlled outlet for carrying the entrained gallium trichloride to a reaction zone for gallium nitride. A process is also described for the apparatus.

Method and devices are disclosed for device manufacture of gallium nitride devices by growing a gallium nitride layer on a silicon substrate using Atomic Layer Deposition (ALD) followed by rapid thermal annealing. Gallium nitride is grown directly on silicon or on a barrier layer of aluminum nitride grown on the silicon substrate. One or both layers are thermally processed by rapid thermal annealing. Preferably the ALD process use a reaction temperature below 550° C. and preferable below 350° C. The rapid thermal annealing step raises the temperature of the coating surface to a temperature ranging from 550 to 1500° C. for less than 12 msec.

A method for large-scale manufacturing of gallium nitride boules. Large-area single crystal seed plates are suspended in a rack, placed in a large diameter autoclave or internally-heated high pressure apparatus along with ammonia and a mineralizer, and grown ammonothermally. The seed orientation and mounting geometry are chosen to provide efficient utilization of the seed plates and of the volume inside the autoclave or high pressure apparatus. The method is scalable up to very large volumes and is cost effective.

A III-nitride edge-emitting laser diode is formed on a surface of a III-nitride substrate having a semipolar orientation, wherein the III-nitride substrate is cleaved by creating a cleavage line along a direction substantially perpendicular to a nonpolar orientation of the III-nitride substrate, and then applying force along the cleavage line to create one or more cleaved facets of the III-nitride substrate, wherein the cleaved facets have an m-plane or a-plane orientation.

An optical device includes a gallium nitride substrate member having an m-plane nonpolar crystalline surface region characterized by an orientation of about −2 degrees to about 2 degrees towards (000-1) and less than about 0.5 degrees towards (11-20). The device also has a laser stripe region formed overlying a portion of the m-plane nonpolar crystalline orientation surface region. A first cleaved c-face facet is provided on one end of the laser stripe region, and a second cleaved c-face facet is provided on the other end of the laser stripe region.

An optical device, e.g., LED, laser. The device includes a non-polar gallium nitride substrate member having a slightly off-axis non-polar oriented crystalline surface plane. In a specific embodiment, the slightly off-axis non-polar oriented crystalline surface plane is up to about −0.6 degrees in a c-plane direction, but can be others. In a specific embodiment, the present invention provides a gallium nitride containing epitaxial layer formed overlying the slightly off-axis non-polar oriented crystalline surface plane. In a specific embodiment, the device includes a surface region overlying the gallium nitride epitaxial layer that is substantially free of hillocks.

A method for growing planar, semi-polar nitride film on a miscut spinel substrate, in which a large area of the planar, semi-polar nitride film is parallel to the substrate's surface. The planar films and substrates are: (1) {10{overscore (1)}1} gallium nitride (GaN) grown on a {100} spinel substrate miscut in specific directions, (2) {10{overscore (1)}3} gallium nitride (GaN) grown on a {110} spinel substrate, (3) {11{overscore (2)}2} gallium nitride (GaN) grown on a {1{overscore (1)}00} sapphire substrate, and (4) {11{overscore (1)}3} gallium nitride (GaN) grown on a {1{overscore (1)}00} sapphire substrate

Disclosed is a multi-quantum-well light emitting diode, which makes enormous adjustments and improvements over the conventional light emitting diode, and further utilizes a transparent contact layer of better transmittance efficiency, so as to significantly raise the illuminance of this light emitting diode and its light emission efficiency. The multi-quantum-well light emitting diode has a structure including: substrate, buffer layer, n-type gallium-nitride layer, active light-emitting-layer, p-type cladding layer, p-type contact layer, barrier buffer layer, transparent contact layer, and the n-type electrode layer.

The invention concerns a method for producing a gallium nitride (GaN) epitaxial layer characterised in that it consists in depositing on a substrate a dielectric layer acting as a mask and depositing on the masked gallium nitride, by epitaxial deposit, so as to induce the deposit of gallium nitride patterns and the anisotropic lateral growth of said patterns, the lateral growth being pursued until the different patterns coalesce. The deposit of the gallium nitride patterns can be carried out ex-situ by dielectric etching or in-situ by treating the substrate for coating it with a dielectric film whereof the thickness is of the order of one angstrom. The invention also concerns the gallium nitride layers obtained by said method.

In a method for producing a resonant cavity light emitting device, a seed gallium nitride crystal (14) and a source material (30) are arranged in a nitrogen-containing superheated fluid (44) disposed in a sealed container (10) disposed in a multiple-zone furnace (50). Gallium nitride material is grown on the seed gallium nitride crystal (14) to produce a single-crystal gallium nitride substrate (106, 106′). Said growing includes applying a temporally varying thermal gradient (100, 100′, 102, 102′) between the seed gallium nitride crystal (14) and the source material (30) to produce an increasing growth rate during at least a portion of the growing. A stack of group III-nitride layers (112) is deposited on the single-crystal gallium nitride substrate (106, 106′), including a first mirror sub-stack (116) and an active region (120) adapted for fabrication into one or more resonant cavity light emitting devices (108, 150, 160, 170, 180).

A light emitting diode comprising a light emitting diode element 20 mounted on a glass epoxy substrate 12, this light emitting diode element 20 being protected at its surface side by a resin seal member 33, in which: a light emitting diode element for blue luminescence, formed of gallium nitride type compound semiconductor is used as the above-mentioned light emitting diode element 20; and a fluorescent material containing layer 21 composed of a fluorescent material containing layer 21 composed of a fluorescent material dispersed into an adhesive is arranged on the back side of this light emitting diode element. On the back side of the light emitting diode element 20, blue luminescence is converted in wavelength to produce white luminescence of high intensity.

A new transparent conducting oxide (TCO), which can be expressed as Al_xGa_3−x−yIn_5+ySn_2−zO_16−2z; 0≦x<1, 0<y<3, 0≦z<2, has been used to improve the brightness and current spreading in GaN base LED process. The optical properties of this system are superior to regular Ni/Au transparent conducting layer in blue-green region, and the new Al₂O₃—Ga₂O₃—In₂O₃—SnO₂ system is able to increase the brightness at 1.5˜2.5 time to compare to regular process. Furthermore, the new transparent conducting oxide thin film has the highest conductivity, which is better than the Ni/Au transparent conducting thin film.

An optical device capable of emitting light having a wavelength ranging from about 490 to about 580 nanometers has a gallium nitride substrate with a semipolar crystalline surface region characterized by an orientation of greater than 3 degrees from (11-22) towards (0001) but less than about 50 degrees. A laser stripe formed on the substrate has a cavity orientation substantially parallel to the m-direction.

A method of forming a device structure including a selectively-deposited gallium nitride layer is disclosed.

A method of fabricating a gallium nitride-based semiconductor structure on a substrate includes the steps of forming a mask having at least one opening therein directly on the substrate, growing a buffer layer through the opening, and growing a layer of gallium nitride upwardly from the buffer layer and laterally across the mask. During growth of the gallium nitride from the mask, the vertical and horizontal growth rates of the gallium nitride layer are maintained at rates sufficient to prevent polycrystalline material nucleating on said mask from interrupting the lateral growth of the gallium nitride layer. In an alternative embodiment, the method includes forming at least one raised portion defining adjacent trenches in the substrate and forming a mask on the substrate, the mask having at least one opening over the upper surface of the raised portion. A buffer layer may be grown from the upper surface of the raised portion. The gallium nitride layer is then grown laterally by pendeoepitaxy over the trenches.

A method of growing highly planar, fully transparent and specular m-plane gallium nitride (GaN) films. The method provides for a significant reduction in structural defect densities via a lateral overgrowth technique. High quality, uniform, thick m-plane GaN films are produced for use as substrates for polarization-free device growth.

A method for forming optical devices includes providing a gallium nitride substrate having a crystalline surface region and a backside region. The backside is subjected to a laser scribing process to form scribe regions. Metal contacts overly the scribe regions.

A method of growing highly planar, fully transparent and specular m-plane gallium nitride (GaN) films. The method provides for a significant reduction in structural defect densities via a lateral overgrowth technique. High quality, uniform, thick m-plane GaN films are produced for use as substrates for polarization-free device growth.

A normally-off cascode power switch circuit is disclosed fabricated in wide bandgap semiconductor material such as silicon carbide or gallium nitride and which is capable of conducting current in the forward and reverse direction under the influence of a positive gate bias. The switch includes cascoded junction field effect transistors (JFETs) that enable increased gain, and hence blocking voltage, while minimizing specific on-resistance.

The invention relates to a substrate for epitaxy, especially for preparation of nitride semiconductor layers. Invention covers a bulk nitride mono-crystal characterized in that it is a mono-crystal of gallium nitride and its cross-section in a plane perpendicular to c-axis of hexagonal lattice of gallium nitride has a surface area greater than 100 mm², it is more than 1.0 μm thick and its C-plane surface dislocation density is less than 10⁶/cm², while its volume is sufficient to produce at least one further-processable non-polar A-plane or M-plane plate having a surface area at least 100 mm². More generally, the present invention covers a bulk nitride mono-crystal which is characterized in that it is a mono-crystal of gallium-containing nitride and its cross-section in a plane perpendicular to c-axis of hexagonal lattice of gallium-containing nitride has a surface area greater than 100 mm², it is more 1.0 μm thick and its surface dislocation density is less than 10⁶/cm². Mono-crystals according to the present invention are suitable for epitaxial growth of nitride semiconductor layers. Due to their good crystalline quality they are suitable for use in opto-electronics for manufacturing opto-electronic semiconductor devices based on nitrides, in particular for manufacturing semiconductor laser diodes and laser devices. The a.m bulk mono-crystals of gallium-containing nitride are crystallized on seed crystals. Various seed crystals may be used. The bulk mono-crystals of gallium-containing nitride are crystallized by a method involving dissolution of a gallium-containing feedstock in a supercritical solvent and crystallization of a gallium nitride on a surface of seed crystal, at temperature higher and/or pressure lower than in the dissolution process.

A method of manufacturing a vertical GaN-based LED comprises forming a light emission structure in which an n-type GaN-based semiconductor layer, an active layer, and a p-type GaN-based semiconductor layer are sequentially laminated on a substrate; etching the light emission structure such that the light emission structure is divided into units of LED; forming a p-electrode on each of the divided light emission structures; filling a non-conductive material between the divided light emission structures; forming a metal seed layer on the resulting structure; forming a first plated layer on the metal seed layer excluding a region between the light emission structures; forming a second plated layer on the metal seed layer between the first plated layers; separating the substrate from the light emission structures; removing the non-conductive material between the light emission structures exposed by separating the substrate; forming an n-electrode on the n-type GaN-based semiconductor layer; and removing portions of the metal seed layer and the second plated layer between the light emission structures.

Large area, uniformly low dislocation density single crystal III-V nitride material, e.g., gallium nitride having a large area of greater than 15 cm², a thickness of at least 1 mm, an average dislocation density not exceeding 5E5 cm⁻², and a dislocation density standard deviation ratio of less than 25%. Such material can be formed on a substrate by a process including (i) a first phase of growing the III-V nitride material on the substrate under pitted growth conditions, e.g., forming pits over at least 50% of the growth surface of the III-V nitride material, wherein the pit density on the growth surface is at least 10² pits/cm² of the growth surface, and (ii) a second phase of growing the III-V nitride material under pit-filling conditions.

Optical devices such as LEDs and lasers are discloses. The devices include a non-polar gallium nitride substrate member having an off-axis non-polar oriented crystalline surface plane. The off-axis non-polar oriented crystalline surface plane can be up to about −0.6 degrees in a c-plane direction and up to about −20 degrees in a c-plane direction in certain embodiments. In certain embodiments, a gallium nitride containing epitaxial layer is formed overlying the off-axis non-polar oriented crystalline surface plane. In certain embodiments, devices include a surface region overlying the gallium nitride epitaxial layer that is substantially free of hillocks.

A dispersion-free high electron mobility transistor (HEMT), comprised of a substrate; a semi-insulating buffer layer, comprised of gallium nitride (GaN) or aluminum gallium nitride (AlGaN), deposited on the substrate, an AlGaN barrier layer, with an aluminum (Al) mole fraction larger than that of the semi-insulating buffer layer, deposited on the semi-insulating buffer layer, an n-type doped graded AlGaN layer deposited on the AlGaN barrier layer, wherein an Al mole fraction is decreased from a bottom of the n-type doped graded AlGaN layer to a top of the n-type doped graded AlGaN layer, and a cap layer, comprised of GaN or AlGaN with an Al mole fraction smaller than that of the AlGaN barrier layer, deposited on the n-type doped graded AlGaN layer.

The invention includes providing gallium nitride materials including thermally conductive regions and methods to form such materials. The gallium nitride materials may be used to form semiconductor devices. The thermally conductive regions may include heat spreading layers and heat sinks. Heat spreading layers distribute heat generated during device operation over relatively large areas to prevent excessive localized heating. Heat sinks typically are formed at either the backside or topside of the device and facilitate heat dissipation to the environment. It may be preferable for devices to include a heat spreading layer which is connected to a heat sink at the backside of the device. A variety of semiconductor devices may utilize features of the invention including devices on silicon substrates and devices which generate large amounts of heat such as power transistors.

Highly planar non-polar a-plane GaN films are grown by hydride vapor phase epitaxy (HVPE). The resulting films are suitable for subsequent device regrowth by a variety of growth techniques

The present invention relates to an epitaxial structure having one or more structural epitaxial layers, including a gallium nitride (GaN) layer, which is deposited on a substrate, and a method of growing the epitaxial structure, wherein the structural epitaxial layers can be separated from the substrate. In general, a sacrificial epitaxial layer is deposited on the substrate between the substrate and the structural epitaxial layers, and the structural epitaxial layers are deposited on the sacrificial layer. After growth, the structural epitaxial layers are separated from the substrate by oxidizing the sacrificial layer. The structural epitaxial layers include a nucleation layer deposited on the sacrificial layer and a gallium nitride layer deposited on the nucleation layer. Optionally, the oxidation of the sacrificial layer may also oxidize the nucleation layer.

A method of growing single-crystals of a cubic (zinc blende) form of gallium nitride, the method comprising the steps of: placing into a reaction tube or acid resistant vessel a gallium source, anhydrous ammonia, an acid mineralizer and a metal halide salt selected from the group consisting of alkali metal halides, copper halides, tin halides, lanthanide halides and combinations thereof; closing said reaction tube or vessel; heating said reaction tube; cooling said reaction tube or vessel; and collecting single-crystals of cubic (zinc blende) form of GaN; wherein said reaction tube or vessel has a temperature gradient with a hot zone of at least 250° C., wherein said reaction tube or vessel has a temperature gradient with a cool zone of at least 150° C., and wherein said acid mineralizer has a sufficient concentration to permit chemical transport of GaN in said reaction tube or vessel from said hot zone to said cool zone due to said temperature gradient within said reaction tube or vessel.

A gallium and nitrogen containing substrate structure includes a handle substrate member having a first surface and a second surface and a transferred thickness of gallium and nitrogen material. The structure has a gallium and nitrogen containing active region grown overlying the transferred thickness and a recessed region formed within a portion of the handle substrate member. The substrate structure has a conductive material formed within the recessed region configured to transfer thermal energy from at least the transferred thickness of gallium and nitrogen material.

In one embodiment a method for fabricating a compound nitride semiconductor device comprising positioning one or more substrates on a susceptor in a processing region of a metal organic chemical vapor deposition (MOCVD) chamber comprising a showerhead, depositing a gallium nitride layer over the substrate with a thermal chemical-vapor-deposition process within the MOCVD chamber by flowing a first gallium containing precursor and a first nitrogen containing precursor through the showerhead into the MOCVD chamber, removing the one or more substrates from the MOCVD chamber without exposing the one or more substrates to atmosphere, flowing a chlorine gas into the processing chamber to remove contaminants from the showerhead, transferring the one or more substrates into the MOCVD chamber after removing contaminants from the showerhead, and depositing an InGaN layer over the GaN layer with a thermal chemical-vapor-deposition process within the MOCVD chamber is provided.