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Showing papers on "Gallium nitride published in 1989"


Journal ArticleDOI
TL;DR: In this paper, the growth of cubic phase single-crystal thin-film GaN using a modified molecular-beam epitaxy technique was reported, but to activate nitrogen gas prior to deposition, a microwave glow discharge was used.
Abstract: Gallium nitride is a compound semiconductor with a wide direct band gap (3.45 eV) and a large saturated electron drift velocity. Nearly all single‐crystal thin films grown to date have been wurtzite (hexagonal) structure. Cubic GaN has the potential for higher saturated electron drift velocity and somewhat lower band gap. These properties could increase its applicability for high‐frequency devices (such as impact ionization avalanche transit time diodes) as well as short‐wavelength light emitting diodes and semiconductor lasers. This paper reports the growth of cubic phase single‐crystal thin‐film GaN using a modified molecular‐beam epitaxy technique. A standard effusion cell was used for gallium, but to activate nitrogen gas prior to deposition, a microwave glow discharge was used. Auger electron spectroscopy showed a nominally stoichiometric GaN film. Transmission electron microscopy with selected area diffraction indicated the crystal structure to be zinc blende.

315 citations



Patent
07 Jul 1989
TL;DR: In this paper, the gallium nitride layer is connected as an emitter to cause electron injection into the silicon carbide or gallium arsenide layer, and small electrodes are connected to the small electrodes to minimize blockage of radiation.
Abstract: A device having high temperature operating characteristics is provided by depositing n-type cubic gallium nitride on n-type cubic silicon carbide to provide an ohmic contact or electrode. High temperature operating characteristics are also provided in a device having a pn heterojunction between a layer of cubic p-type silicon carbide or gallium arsenide and a first layer of cubic n-type gallium nitride. In a power transistor, a second layer of n-type gallium nitride is deposited on the other surface of the silicon carbide or gallium arsenide to form a pn heterojunction. The gallium nitride layer that is connected as an emitter is forward biased to cause electron injection into the silicon carbide or gallium arsenide layer. In a phototransistor device having high temperature operating characteristics, a transparent layer of cubic n-type gallium nitride is deposited on each side of either cubic p-type silicon carbide or gallium arsenide. Small electrodes are connected to the gallium nitride to minimize blockage of radiation. The radiation passes through either or both gallium nitride layers and across the pn junction to generate a potential between the electrodes. Direction-sensing and position-sensing devices having high temperature and high photon energy operating characteristics are also provided using layers of silicon carbide or gallium arsenide, and gallium nitride.

41 citations


Patent
29 Aug 1989
TL;DR: In this article, a semiconductor, injection mode light emitting device includes a body of semiconductor material having a quantum mode region formed of alternating layers of gallium nitride and either indium or aluminum nitride.
Abstract: A semiconductor, injection mode light emitting device includes a body of a semiconductor material having a quantum mode region formed of alternating layers of gallium nitride and either indium nitride or aluminum nitride. A region of N-type gallium nitride is on one side of the quantum well region and is adapted to inject electrons into the quantum mode region. A region of P-type gallium phosphide is on the other side of the quantum well region and is adapted to inject holes into the quantum mode region. A barrier region of insulating gallium nitride is between the P-type region and the quantum well region and serves to block the flow of electrons from the quantum well region into the P-type region. Conductive contacts are provided on the N-type region and the P-type region.

29 citations


Patent
30 Mar 1989
TL;DR: In this article, a pure blue light-emitting diode was obtained by forming an N-type gallium nitride compound semiconductor layer composed of a Ga 1-x Al x N single crystal onto a substrate for crystal growth.
Abstract: PURPOSE: To obtain a pure blue light-emitting diode by forming an N-type gallium nitride compound semiconductor layer composed of a Ga 1-x Al x N single crystal onto a substrate for crystal growth and then an I-type Ga 1-x Al x N layer doped with magnesium as an insulating layer and a light-emitting layer. CONSTITUTION: A reaction tube 1 is evacuated previously, the insulator substrate 3 of sapphire, etc., is installed into the tube 1 as the hydrogen atmosphere of atmospheric pressure, an organic gallium compound, an organic group III element compound and ammonia are introduced under a gaseous state from one end of the reaction tube 1, and an N-type gallium nitride compound semiconductor layer consisting of the single crystal layer of Ga 1-x Al x N (1>x≥0) is formed onto the substrate 3. An organic magnesium compound is introduced into the reaction tube 1 under the gaseous state as a raw material gas, and an I-type gallium nitride compound semiconductor layer to which magnesium is added is shaped as an insulating layer and a light-emitting layer. Accordingly, a pure blue light-emitting diode is obtained. COPYRIGHT: (C)1990,JPO&Japio

19 citations


Patent
01 Mar 1989
TL;DR: In this article, the gallium nitride compound semiconductor was grown on a sapphire substrate to a thickness of 100 to 500Å at a growing temperature of 400 to 900°C.
Abstract: PURPOSE: To improve crystallinity of a gallium nitride compound semiconductor grown on a sapphire substrate and to provide a blue-light-emitting element having high light-emitting efficiency by providing a buffer layer of aluminum nitride on the sapphire substrate and then growing the gallium nitride compound semicon. ductor on the buffer layer. CONSTITUTION: When a gallium nitride compound semiconductor film (containing Al x Ga 2-x N; X=0) is vapor grown on a sapphire substrate 60 by using an organic metal compound gas, it is grown on the substrate 60 to a thickness of 100 to 500Å at a growing temperature of 400 to 900°C. Prior to growth of the gallium nitride compound semiconductor, a buffer layer of aluminum nitride (AlN) 61 having wurtzite structure in which microcrystals or polycrystals are mixed in irregular crystals is provided on the substrate 60. Then, the gallium nitride compound semiconductor (containing AI x Ga 1-x N; X=0) is grown on the buffer layer. According to this method, the gallium nitride compound semiconductor grown on the buffer layer is allowed to have improved crystallinity and hence the light-emitting has desirable blue light emitting properties. COPYRIGHT: (C)1990,JPO&Japio

19 citations


Patent
22 Sep 1989
TL;DR: In this article, a gallium nitride compound semiconductor (GaN) is formed on a sapphire substrate with an AlN buffer layer between, a mask is mounted, dry-etch is carried out by plasma gas of CCl 2 F 2 2 gas and plate of Ar gas, and aluminum is deposited using a stainless plate as a mask.
Abstract: PURPOSE: To form an electrode of good ohmic properties in a gallium nitride compound semiconductor by dry-etching an electrode formation part of a compound semiconductor by plasma gas of compound gas containing carbon and chroline and/or fluorine, by further carrying out dry-etch by plasma gas of inert gas and by depositing aluminum. CONSTITUTION: When an aluminum electrode 6 is formed on a compound semiconductor 3 which contains at least gallium and nitride, an electrode formation part 5 of the compound semiconductor 3 is dry-etched by plasma gas of compound gas containing chroline and/of fluorine. After the etched electrode formation part 5 is further dry-etched by plasma gas of inert gas, aluminum is deposited on the electrode formation part 5. For example, an n-type GaN layer 3 is formed on a sapphire substrate 1 with an AlN buffer layer 2 between, a mask 4 composed of sapphire is mounted, dry-etch is carried out by plasma gas of CCl 2 F 2 gas and plasma gas of Ar gas, and aluminum is deposited using a stainless plate as a mask. An electrode 6 is formed in this way. COPYRIGHT: (C)1991,JPO&Japio

8 citations


Patent
01 Dec 1989
TL;DR: In this article, a textured substrate is disclosed which is amenable to deposition thereon of epitaxial single crystal films of materials such as diamond, cubic boron nitride, bboron phosphide, beta-silicon carbide and gallium nitride.
Abstract: A textured substrate is disclosed which is amenable to deposition thereon of epitaxial single crystal films of materials such as diamond, cubic boron nitride, boron phosphide, beta-silicon carbide, and gallium nitride. The textured substrate comprises a base (10) having a generally planar main top surface (20) from which upwardly extends a regular array of posts (18), the base (10) being formed of single crystal material which is crystallographically compatible with epitaxial single crystal materials (34, 36) to be deposited thereon. The single crystal epitaxial layers (34, 36) are formed on top surfaces (24) of the posts (18) which preferably have a quadrilateral cross-section, e.g., a square cross-section whose sides are from about 0.5 to about 20 micrometers in length, to accommodate the formation of substantially defect-free, single crystal epitaxial layers (34, 36) thereon. The single crystal epitaxial layer may be selectively doped to provide for p-type (34) and p+ doped (36) regions thereof, to accommodate fabrication of semiconductor devices such as field effect transistors.

8 citations


Journal ArticleDOI
TL;DR: In this paper, a system for the generation of atomic nitrogen at low gas flow and high efficiency, needed for reactive deposition of gallium nitride by the ICB technique, has been built.
Abstract: The atomic form of nitrogen may be very effective in the formation of nitrides in reactive thin film deposition. One of the compounds of great interest to the optoelectronic industry is gallium nitride, a potential material for manufacturing blue light emitting diodes and color displays. A system for the generation of atomic nitrogen at low gas flow and high efficiency, needed for reactive deposition of gallium nitride by the ICB technique, has been built. Its operation is based on the dissociation of molecular nitrogen in a microwave cavity at the frequency of 2.45 GHz. To prevent the high purity gas from becoming contaminated no electrodes come into contact with the plasma discharge. A method of measuring the effective yield of atomic nitrogen is also described. A high atomic nitrogen concentration of 1.2% at low gas flow has been achieved. The relationship between gas flow rate, dissociation efficiency, and the vacuum requirements of the deposition process is discussed.

3 citations