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Showing papers on "Gallium nitride published in 1992"


Journal ArticleDOI
TL;DR: In this article, a high pressure structural phase transition was observed in gallium nitride at 47 GPa by means of Raman scattering and x-ray-absorption spectroscopy.
Abstract: Gallium nitride was studied by Raman scattering and x-ray-absorption spectroscopy up to 60 GPa. A high-pressure structural phase transition was observed in gallium nitride at 47 GPa by means of Raman scattering and x-ray-absorption spectroscopy. We also report the direct determination of the bulk modulus ${\mathit{B}}_{0}$ of this compound (245 GPa). Gr\"uneisen parameters of the four observed phonon modes were established. The transition pressure is compared with existing calculations.

501 citations


Journal ArticleDOI
TL;DR: In this article, GaN films have been epitaxially grown onto (001) Si by electron cyclotron resonance microwave-plasma assisted molecular beam epitaxy, using a two-step growth process, in which a GaN buffer is grown at relatively low temperatures and the rest of the film is growing at higher temperatures.
Abstract: GaN films have been epitaxially grown onto (001) Si by electron cyclotron resonance microwave‐plasma‐assisted molecular‐beam epitaxy, using a two‐step growth process, in which a GaN buffer is grown at relatively low temperatures and the rest of the film is grown at higher temperatures. This method of film growth was shown to lead to good single‐crystalline β‐GaN and to promote lateral growth resulting in smooth surface morphology. The full width at half‐maximum of the x‐ray rocking curve in the best case was found to be 60 min. Optical‐absorption measurements indicate that the band gap of β‐GaN is 3.2 eV and the index of the refraction below the absorption edge is 2.5. Conductivity measurements indicate that the films may have a carrier concentration below 1017 cm−3.

352 citations


Patent
30 Jan 1992
TL;DR: In this article, a gallium nitride-based compound semiconductor is grown on the surface of a buffer layer represented by formula Ga X Al 1-X N (0 <×≦1).
Abstract: Crystals of a gallium nitride-based compound semiconductor are grown on the surface of a buffer layer represented by formula Ga X Al 1-X N (0<×≦1). The crystallinity of the gallium nitride-based compound semiconductor grown on the surface of the buffer layer can be drastically improved.

270 citations


Journal ArticleDOI
TL;DR: In this paper, the current state of the art for producing semiconductor devices from these materials is evaluated, and recommendations for areas needing further research are outlined, as well as a review of current state-of-the-art techniques for these materials.
Abstract: Diamond, silicon carbide, gallium nitride, aluminum nitride, and boron nitride are currently under development for both electronic and optoelectronic semiconductor devices. Predictions based on their physical properties indicate that devices made from these materials should be far superior to currently available devices in high power, high frequency, and short wavelength applications. Yet actual device implementation requires that adequate materials processing technology exists. In this review, the current state of the art for producing semiconductor devices from these materials is evaluated, and recommendations for areas needing further research are outlined.

203 citations


Journal ArticleDOI
TL;DR: In this article, the authors used a GaN buffer layer on a sapphire substrate for gallium nitride (GaN) growth and obtained a maximum mobility of about 3000 cm2/V/s at around 70 K. This mobility value is the highest reported for GaN films.
Abstract: High‐quality gallium nitride (GaN) film was obtained using a GaN buffer layer on a sapphire substrate. Using low‐temperature Hall measurements, we obtained a maximum mobility about 3000 cm2/V s, at around 70 K. This mobility value is the highest reported, to our knowledge, for GaN films. The infrared radiation transmission intensity oscillations, which were caused by interference effects, were observed by means of an infrared radiation thermometer during GaN growth. The growth process of GaN film with GaN buffer layers was almost the same as that of GaN film with AlN buffer layers except when the thickness of GaN buffer layers was small. When the thickness of GaN buffer layers was small, an additional new growth process, in which the surface of GaN film became rough during the growth, was observed. The GaN growth with GaN buffer layers had a tendency to improve the surface morphology even if it became poor due to excess Si doping or low buffer layer thickness.

192 citations


Patent
Makoto Tamaki1, Takahiro Kozawa1
30 Oct 1992
TL;DR: A light-emitting device comprises an n-type layer made of an ntype gallium nitride-based compound of the formula Alx Ga1-x N, wherein 0≦X < 1, and an i-type surface made of a semi-insulating I-type compound semiconductor and doped with a p-type impurity for junction with the ntype layer as mentioned in this paper.
Abstract: A light-emitting device comprises an n-type layer made of an n-type gallium nitride-based compound of the formula Alx Ga1-x N, wherein 0≦X<1, and an i-type layer formed on the n-type layer and made of a semi-insulating i-type gallium nitride-based compound semiconductor and doped with a p-type impurity for junction with the n-type layer. A first electrode is formed on the surface of the i-type layer and made of a transparent conductive film and a second electrode is formed to connect to the n-type layer through the i-type layer. The device is so arranged that light is emitted from the side of the i-type layer to the outside. When an electric current is supplied to the first electrode from a wire contacted thereto, the first electrode is held entirely at a uniform potential. Light is emitted from the entire interface beneath the first electrode and can thus be picked up from the first electrode which is optically transparent.

141 citations


Journal ArticleDOI
TL;DR: In this paper, cubic GaN epitaxial films were successfully grown on (100) GaAs sunstrates by metalorganic vapor phase epitaxy (MOVPE) using 1,1-dimethylhydrazine (DMHy) as the nitrogen source material.

129 citations


Patent
08 Jun 1992
TL;DR: In this article, the authors presented an Al x Ga 1-x N ultraviolet detector with extremely high responsivity at over 200 to 365 nanometers and a very sharp long wavelength cutoff.
Abstract: The invention is an Al x Ga 1-x N ultraviolet detector with extremely high responsivity at over 200 to 365 nanometers and a very sharp long wavelength cutoff. The active layer for the sensors is a single crystal Al x Ga 1-x N preferably deposited over a basal plane sapphire substrate using a switched atomic layer epitaxy process.

95 citations


Journal ArticleDOI
TL;DR: In this paper, the total energy of both structures as well as of the zincblende structure was calculated, for different unit cell volumes, using first-principles non-local pseudopotentials.

76 citations


Journal ArticleDOI
TL;DR: In this first-principles total-energy calculation on gallium nitride, the ground state of GaN is a zinc-blende structure, and the difference between these two phases is around 1.4 mRy.
Abstract: A first-principles total-energy calculation is performed on gallium nitride (GaN). The equilibrium lattice parameters, the bulk modulus, and the cohesive energy of GaN in the wurtzite structure is calculated and compared with experimental values. In our calculation, the ground state of GaN is a zinc-blende structure, and the difference between these two phases is around 1.4 mRy.

71 citations


Patent
18 Mar 1992
TL;DR: In this paper, a method of preparing highly insulating GaN single crystal films in a molecular beam epitaxial growth chamber is described, where a single crystal substrate is provided with the appropriate lattice match for the desired crystal structure of GaN. The desired film is deposited by exposing the substrate to Ga and nitrogen sources in a two step growth process using a low temperature nucleation step and a high temperature growth step.
Abstract: This invention relates to a method of preparing highly insulating GaN single crystal films in a molecular beam epitaxial growth chamber. A single crystal substrate is provided with the appropriate lattice match for the desired crystal structure of GaN. A molecular beam source of Ga and source of activated atomic and ionic nitrogen are provided within the growth chamber. The desired film is deposited by exposing the substrate to Ga and nitrogen sources in a two step growth process using a low temperature nucleation step and a high temperature growth step. The low temperature process is carried out at 100°-400° C. and the high temperature process is carried out at 600°-900° C. The preferred source of activated nitrogen is an electron cyclotron resonance microwave plasma.

Journal ArticleDOI
TL;DR: In this paper, the growth of quaternary InGaAlN has been studied and its potential as a light-emitting diode has been shown. But the growth conditions for single-crystal GaAlN were not discussed.

Patent
Takahiro Kozawa1
26 Feb 1992
TL;DR: A gallium nitride semiconductor light-emitting device (LEMS) as mentioned in this paper was constructed by forming, on a substrate of semiconductor or insulator, at least an N layer of n-type gallium oxide semiconductor and an I layer of semi-insulating gallium dioxide semiconductor one after another, forming a first electrode on the I layer; forming directly under the first electrode a low-resistance region, which leads to at least the N layer, by heating.
Abstract: A gallium nitride semiconductor light-emitting device comprising: a substrate of semiconductor or insulator; an N layer of n-type gallium nitride semiconductor (Al×Ga 1-x N:0≦×≦1); an I layer of semiinsulating gallium nitride semiconductor (Al x Ga 1-x N:0≦×≦1); a first electrode formed on the I layer; a low-resistance region extending from the first electrode through the I layer at least to the N layer and formed by diffusion of the material of the first electrode; and a second electrode formed on the I layer isolatedly from the first electrode. This device is manufactured by: forming, on a substrate of semiconductor or insulator, at least an N layer of n-type gallium nitride semiconductor and an I layer of semiinsulating gallium nitride semiconductor one after another; forming a first electrode on the I layer; forming directly under the first electrode a low-resistance region, which leads to at least the N layer through the I layer, by heating; and forming, on the I layer, a second electrode isolatedly from the first electrode.

Patent
07 Aug 1992
TL;DR: In this paper, a light-emitting semiconductor device that uses a gallium nitride compound semiconductor (Al x Ga 1-x N) is presented, in which the n-layer is of double-layer structure including an n − layer of low carrier concentration and an n + layer of high carrier concentration.
Abstract: Disclosed herein are (1) a light-emitting semiconductor device that uses a gallium nitride compound semiconductor (Al x Ga 1-x N) in which the n-layer of n-type gallium nitride compound semiconductor (Al x Ga 1-x N) is of double-layer structure including an n-layer of low carrier concentration and an n + -layer of high carrier concentration, the former being adjacent to the i-layer of insulating gallium nitride compound semiconductor (Al x Ga 1-x N); (2) a light-emitting semiconductor device of similar structure as above in which the i-layer is of double-layer structure including an i L -layer of low impurity concentration containing p-type impurities in comparatively low concentration and an i H -layer of high impurity concentration containing p-type impurities in comparatively high concentration, the former being adjacent to the n-layer; (3) a light-emitting semiconductor device having both of the above-mentioned features and (4) a method of producing a layer of an n-type gallium nitride compound semiconductor (Al x Ga 1-x N) having a controlled conductivity from an organometallic compound by vapor phase epitaxy, by feeding a silicon-containing gas and other raw material gases together at a controlled mixing ratio.


Patent
04 Nov 1992
TL;DR: In this paper, a gallium nitride type semiconductor device with a single crystal of (Ga l-x Al x ) l-y In y N, which suppresses the occurrence of crystal defects and thus has very high crystallization and considerably excellent flatness, and a method of fabricating the same.
Abstract: Disclosed are a gallium nitride type semiconductor device that has a single crystal of (Ga l-x Al x ) l-y In y N, which suppresses the occurrence of crystal defects and thus has very high crystallization and considerably excellent flatness, and a method of fabricating the same. The gallium nitride type semiconductor device comprises a silicon substrate, an intermediate layer consisting of a compound containing at least aluminum and nitrogen and formed on the silicon substrate, and a crystal layer of (Ga l-x Al x ) l-y In y N (0≦x≦1, 0≦y≦1, excluding the case of x=1 and y=0). According to the method of fabricating a gallium nitride base semiconductor device, a silicon single crystal substrate is kept at a temperature of 400 to 1300° C. and is held in the atmosphere where a metaloganic compound containing at least aluminum and a nitrogen-containing compound are present to form a thin intermediate layer containing at least aluminum and nitrogen on a part or the entirety of the surface of the single crystal substrate, and then at least one layer or multiple layers of a single crystal of (Ga l- x Al x ) l-y In y N are formed on the intermediate layer.

Journal ArticleDOI
TL;DR: In this paper, the growth was carried out by the vapor phase reaction of the Ga-Br2-PH3-NH3-N2 system at a substrate temperature of 980°C.
Abstract: Gallium nitride phosphide single crystals having the maximum composition of x~0.09 were epitaxially deposited on (0001) sapphire substrates. The growth was carried out by the vapor phase reaction of the Ga-Br2-PH3-NH3-N2 system. The above maximum composition was attained at a substrate temperature of 980°C.

Patent
12 Nov 1992
TL;DR: In this article, a gallium nitride type semiconductor device comprises a silicon substrate, an intermediate layer consisting of a compound containing at least aluminum and nitrogen and formed on the silicon substrate and a crystal layer of (Ga1-xAlx)1-yInyN (0≦x≦1, 0≦y≦ 1, excluding the case of x = 1 and y = 0).
Abstract: A gallium nitride type semiconductor device comprises a silicon substrate, an intermediate layer consisting of a compound containing at least aluminum and nitrogen and formed on the silicon substrate, and a crystal layer of (Ga1-xAlx)1-yInyN (0≦x≦1, 0≦y≦1, excluding the case of x = 1 and y = 0). The aluminum/nitrogen intermediate layer suppresses the occurrence of crystal defects and thus the (Ga1-xAlx)1-yInyN layer has very high crystallization and flatness. In a method of fabrication a silicon single crystal substrate is kept at a temperature of 400 to 1300°C and is held in an atmosphere of a metaloganic compound containing at least aluminum and a nitrogen containing compound to form a thin intermediate layer containing at least aluminum and nitrogen on a part or on the entirety of the surface of the single crystal substrate. At least one layer or multiple layers of a single crystal of (Ga1-xAlx)1-yInyN are then formed on the intermediate layer.

Journal ArticleDOI
TL;DR: In the field of wide bandgap semiconductors, recent developments in the mainstream world of silicon may have gone unremarked as discussed by the authors, however, the large number of defects and difficulties in preparing n-and p-type material have hampered their broader application.

Patent
28 Apr 1992
TL;DR: In this article, a light emission pattern at the blue luminous region of a GaN compound semiconductor light-emitting diode close to a surface light emission from a point light emission and to improve the luminous intensity of the diode was changed.
Abstract: PURPOSE: To change a light emission pattern at the blue luminous region of a GaN compound semiconductor light-emitting diode close to a surface light emission from a point light emission and to improve the luminous intensity of the diode CONSTITUTION: An electrode 80 to a high-carrier concentration n + layer 3 and an electrode 70 to a high-impurity concentration iH layer 52 are provided The electrodes 70 and 80 are respectively constituted of first Ni layers 71 and 81 of a thickness of 100Å, second Ni layers 72 and 82 of a thickness of 1000Å, Al layers 73 and 83 of a thickness of 1500Å, Ti layers 74 and 84 of a thickness of 1000Å and third Ni layers 75 and 85 of a thickness of 2500Å As the Ni layers are formed into a double structure, relaxation layers can be respectively formed between the Ni layers and the Ni layers can be prevented from being peeled As a result of joining GaN with the Ni layers, the threshold voltage at the time of light emission of a GaN compound semiconductor light-emitting diode is reduced and at the same time, the luminous luminance of the diode is improved Moreover, a light emission pattern at the blue luminous region of the diode can be brought close to a surface light emission from a point light emission and the luminous intensity of the whole diode is improved COPYRIGHT: (C)1993,JPO&Japio

Patent
09 May 1992
TL;DR: In this paper, the authors proposed a method of cutting a wafer in desired shape and size without marring the crystal property of a gallium nitride compound semiconductor and besides favorably in yield rate by preventing the occurrence of the cracking and chipping of a cut face when cutting the gallium n-ride compound wafer wherein the substrate is sapphire.
Abstract: PURPOSE: To provide a method of cutting a wafer in desired shape and size without marring the crystal property of a gallium nitride compound semiconductor and besides favorably in yield rate by preventing the occurrence of the cracking and chipping of a cut face when cutting the gallium nitride compound semiconductor wafer wherein the substrate is sapphire. CONSTITUTION: This method comprises a dicing process of cutting a groove 3 deeper than the thickness of a gallium nitride compound semiconductor layer 2 by a dicer from above a gallium nitride compound semiconductor layer 2, a polishing process of thinning the thickness of a sapphire substrate 1 by polishing, a scribe process of cutting a scribe line 4 by a scriber from above the groove 3 made in the dicing process, and a separation process of separating a wafer into chip shape after the scribe process. COPYRIGHT: (C)1993,JPO&Japio

Journal ArticleDOI
TL;DR: In this article, gallium nitride and aluminium nitride films have been grown on various substrates at temperatures between 600 and 700 °C by photochemical vapor deposition where the optical source is an excimer laser or a xenon lamp.

Patent
06 Feb 1992
TL;DR: In this article, a thin gallium nitride semiconductor laminate was constructed on a sapphire substrate with an off-angle of 0.8 degree by means of CBE method.
Abstract: PURPOSE:To obtain a thin gallium nitride semiconductor laminate film preferable as an electronic element. CONSTITUTION:Thin gallium nitride semiconductor films are laminated on a sapphire substrate with an off-angle of 0.8 degree or less by means of CBE method. A thin semiconductor laminate film with a structure wherein the thin gallium nitride semiconductor films having a flat surface and good crystallization can be obtained on the sapphire substrate with an off-angle of 0.8 degree or less. This is preferable as a light emitting element, a light receiving element or a thin semiconductor film laminate body for a transistor operating at a high temperature.

Journal ArticleDOI
TL;DR: In this article, the reaction of hydrazoic acid, HN3, with trimethylgallium to produce thin-film gallium nitride under very low-pressure chemical vapour deposition (VLPCVD) conditions is described.
Abstract: The reaction of hydrazoic acid, HN3, with trimethylgallium to produce thin-film gallium nitride under very-low-pressure chemical vapour deposition (VLPCVD) conditions is described. Data are presented which show that at 10–6 mbar the product GaN is crystalline and strongly oriented on the substrate sapphire (0001) crystal face. Some potential advantages of using HN3 rather than the conventional precursor NH3, for nitride film production, are mentioned.

Patent
08 Dec 1992
TL;DR: In this paper, an insulating protective film is formed on n-type and p-type gallium nitride compound semiconductor layers except on the parts of a pair of electrode layers.
Abstract: PURPOSE:To realize a blue color light emitting device which facilitates the elimination of a short-circuit by a method wherein an insulating protective film is formed on n-type and p-type gallium nitride compound semiconductor layers except on the parts of a pair of electrode layers. CONSTITUTION:An LED chip 2 has a sapphire substrate 4 and a compound semiconductor layer. The compound semiconductor layer is composed of an n-type GaN layer 6, an n-type InGaN layer 8 and a p-type GaN layer 10 which are built up on the sapphire substrate 4 successively. An electrode layer 12 and an electrode layer 14 are provided on the p-type GaN layer 10 and the n-type GaN layer 6 respectively. The parts of the n-type InGaN layer 8 and the p-type GaN layer 10 are removed by etching. An insulating protective film 16 is formed over the exposed n-type GaN layer 6 and the remaining p-type GaN layer 10. A pair of lead frames 22 and 24 are bonded to the nickel and aluminum electrode layers 12 and 14 with conductive adhesive layers 18 and 20 therebetween respectively. With this constitution, the short-circuit between the electrodes can be eliminated by the insulating protective film 16 and a blue color light-emitting device having an improved reliability can be realized.

Patent
22 Jan 1992
TL;DR: In this article, a method for forming p-type of gallium nitride compound semiconductor in which gallium n-drone compound is formed in a stable low resistance p type and a light emitting unit is formed either in a double heterostructure or single heterostructures is provided.
Abstract: PURPOSE: To provide a method for forming p-type of gallium nitride compound semiconductor in which gallium nitride compound semiconductor doped with p-type impurity such as Mg, Zn, etc., is formed in a stable low resistance p-type and a light emitting unit is formed in a double heterostructure or single heterostructure. CONSTITUTION: After gallium nitride compound semiconductor represented by a general formula GaXAl 1- XN (0≤X≤1) doped with p-type impurity is grown by a vapor growth method, a surface temperature of a gallium nitride compound semiconductor layer is enhanced to 600° or higher, and irradiated with an electron beam. COPYRIGHT: (C)1993,JPO&Japio

Patent
18 Jun 1992
TL;DR: In this paper, the authors proposed to improve quality by intermittently supplying a Ga-contg raw material, using light including the wavelength shorter than the wavelength corresponding to the forbidden band width of the GaN and using a raw material contg specific molecules as an N-ContG raw material.
Abstract: PURPOSE:To improve quality by intermittently supplying a Ga-contg raw material, using light including the wavelength shorter than the wavelength corresponding to the forbidden band width of GaN and using a raw material contg specific molecules as an N-contg raw material CONSTITUTION:The inside of a vacuum vessel 1 is evacuated to a high vacuum and after a substrate 3 is heated to 500 to 750 degC, an Xe lamp 9 is lighted up The Xe lamp light 10a contg the wavelength shorter than the wavelength corresponding to the forbidden band width of the GaN is collimated by a collimator 11 The substrate 3 is irradiated with the collimated beam 10b spectrally split by a half mirror 12 The beam 10b is adjusted to the intensity suitable for the formation of the thin film and the cracking of the raw material contg N, such as alkylamine, with which the oxidation energy level in an adsorption state exists between the transmission band energy level and valency band energy level on the surface of the GaN The gaseous Ga-contg raw material and gaseous NH3 are then supplied at prescribed equiv ratios from cylinders 6a and 6b and gaseous H2 and the N-contg gaseous raw material from cylinders 6c and 6d to form the GaN thin film The supply of the Ga-contg raw material is then stopped temporarily and only the N-contg raw material is supplied and simultaneously, the substrate is irradiated with the light The GaN thin film is thus obtd by alternately repeating the formation of the GaN thin film and the packing of the N to the holes of the N in the thin film

Patent
09 Jun 1992
TL;DR: In this article, a light emitting diode 10 has a sapphire board 1, and a buffer layer 2, a high carrier concentration n type layer 3, a low-carrier concentration n-type layer 4 and an i type layer 50 are sequentially formed thereon.
Abstract: PURPOSE:To lower an operating voltage and to improve emitted blue light intensity by realizing a light emitting element having novel p-n junction of gallium nitride compound semiconductor and an electrode leading structure. CONSTITUTION:A light emitting diode 10 has a sapphire board 1, and a buffer layer 2, a high carrier concentration n type layer 3, a low carrier concentration n-type layer 4 and an i-type layer 50 are sequentially formed thereon. A p-type layer 5 is formed on a predetermined region of the layer 50. A hole 15 is formed from the upper surface of the layer 5 to the layer 3 through the layers 50, 4, and an electrode 52 connected to the layer 3 through the hole 15 is formed on the layer 50. An electrode 51 to the layer 5 is formed on the layer 5. The electrode 52 to the layer 3 is subjected to dielectric isolation by means of the layer 50. Accordingly, the layer 5 is formed with a p-n junction longitudinally, and is subjected to dielectric insulator-isolated laterally by the layer 50. With the configuration, a driving voltage can be lowered, and emitted blue light intensity can be improved.


Journal ArticleDOI
TL;DR: In this paper, a gallium nitride film was grown on (111) gallium arsenide substrates using reactive rf magnetron sputtering and X-ray diffraction patterns revealed (0002) GaN peak with a fullwidth-half-maximum (FWHM) as narrow as 0.17{degree.
Abstract: Gallium Nitride films were grown on (111) gallium arsenide substrates using reactive rf magnetron sputtering. Despite a 20% lattice mismatch and different crystal structure, wurtzite. Heteroepitaxy was observed for growth temperatures between 550-600{degrees}C. X-ray diffraction patterns revealed (0002) GaN peak with a full-width-half-maximum (FWHM) as narrow as 0.17{degree}. Possible surface reconstructions to explain the epitaxial growth are presented.