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.degree. C. and the high temperature process is carried out at 600-900.degree. C. The preferred source of activated nitrogen is an electron cyclotron resonance microwave plasma.

Abstract: A method for growing a single crystal III-V compound semiconductor layer, in which grown by vapor deposition on a first single crystal III-V compound semiconductor layer including at least Ga and N is a second single crystal III-V compound semiconductor layer different from the first layer and including at least Ga and N, comprises the steps of: growing a buffer layer other than single crystal and having substantially the same composition as that of the second layer by vapor deposition on the first layer; and growing the second layer on the buffer layer. A method for growing a single crystal AlGaN layer on a single crystal GaN layer by vapor deposition, comprises the steps of: growing a buffer layer of a III-V compound semiconductor including at least Ga and N on the single crystal GaN layer by vapor deposition; and growing the single crystal AlGaN layer on the buffer layer by vapor deposition.

Abstract: A nitrogen-group III compound semiconductor satisfying the formula Al.sub.x Ga.sub.y In.sub.1-x-y N, inclusive of x=0, y=0 and x=y=0, and a method for producing the same comprising the steps of forming a zinc oxide (ZnO) intermediate layer on a sapphire substrate, forming a nitrogen-group III semiconductor layer satisfying the formula Al.sub.x Ga.sub.y In.sub.1-x-y N, inclusive of x=0, y=0 and x=y=0 on the intermediate ZnO layer, and separating the intermediate ZnO layer by wet etching with an etching liquid only for the ZnO layer.

Abstract: A light emitting device having higher blue luminance is obtained. A gallium nitride compound layer is formed on a GaAs substrate, and thereafter the GaAs substrate is at least partially removed for forming the light emitting device. Due to the removal of the GaAs substrate, the quantity of light absorption is reduced as compared with the case of leaving the overall GaAs substrate. Thus, a light emitting device having high blue luminance is obtained.

Abstract: A process for producing a semiconductor emitting device of group III nitride semiconductor having a crystal layer (Al.sub.x Ga.sub.1-x).sub.1-y In.sub.y N (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) includes; a step of forming at least one pn-junction or pin-junction and a crystal layer (Al.sub.x Ga.sub.1-x).sub.1-y In.sub.y N (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) to which a group II element is added; and a step of forming electrodes on the crystal layer. The process further includes an electric-field-assisted annealing treatment in which the pn-junction or pin-junction is heated to the predetermined temperature range while forming and maintaining an electric field across the pn-junction or pin-junction for at least partial time period of the predetermined temperature range via the electrodes.

Abstract: Thin films of aluminum nitride are deposited at 350 K on silicon, GaAs, fused quartz, and KBr substrates using gas-phase 193 nm excimer laser photolysis of trimethylamine alane and ammonia precursors without a thermally induced or a spontaneous reaction between them, resulting in AlN thin films that are amorphous, smooth and featureless having a band gap of 5.8 eV, a refractive index of 2.0, a breakdown electric field breakdown of 10.sup.8 V/m, a low-frequency dielectric constant of 6.0-6.9, high-frequency dielectric constant of 3.9-4.0, well suited for many thin film applications.

Abstract: A method for heat-treating a semiconductor body comprising steps of: (a) disposing a susceptor on one surface of the semiconductor body, and disposing a protection plate in such a manner that the other surface of the semiconductor faces to a surface the protection plate, (b) heat-treating the semiconductor body, wherein the susceptor and the protection plate comprises at least one member selected from the group consisting of gallium nitride, aluminum nitride and boron nitride, and at least one of the susceptor and the protection plate has an absorber of infrared ray.

Abstract: The subject invention provides a method of enhancing the etch rate of boron nitride which comprises doping a layer of boron nitride with an element from Group IVA of the Periodic Table of the Elements, such as silicon, carbon, or germanium. The doped boron nitride layer can be wet etched at a faster rate with hot phosphoric acid than was possible prior to doping the boron nitride.

Abstract: N-type c-BN is a heat-resistant material with a wide band gap. Ohmic electrodes are indispensable for making semiconductor devices utilizing n-type c-BN. The electrodes proposed so far are likely to deteriorate in an atmosphere of high temperature. The degradation of electrodes hinders the production of semiconductor devices utilizing c-BN. A heat-resistant ohmic electrode is produced by forming a low contact resistance layer of a boride or a nitride of Ti, Zr or Hf on a heated c-BN and by covering the low resistance layer by an Au layer. Otherwise an ohmic electrode is produced by forming a low contact resistance layer of one of Ti, Zr, Hf, etc. on c-BN, making a diffusion barrier layer of W, Mo, Ta or Pt and depositing an Au layer on the diffusion barrier layer.

Abstract: An anti-reflective coating (ARC) (20) is formed over a reflective, conductive layer (18), such as polysilicon or aluminum, in a semiconductor device (10). The ARC is an aluminum nitride layer. During photolithography, the ARC absorbs radiation waves (30), particularly absorbing wavelengths under 300 nanometers, such as deep ultraviolet (DUV) radiation at 248 nanometers. Being absorbed by the ARC, the radiation waves are prevented from reflecting off the underlying conductive layer. Thus, resist mask (34) is patterned and developed true to the pattern on lithography mask (24), resulting in accurate replication into appropriate layers of the device.

Abstract: A method for heat-treating a compound semiconductor comprising a step of heat-treating a susceptor in a manner as to be disposed on a surface of the compound semiconductor with oposing each other, the susceptor comprising a compound of nitrogen and a group III element such as aluminum nitride.

Abstract: A manufacturable III-V semiconductor gate structure having small geometries is fabricated. A silicon nitride layer is formed on a III-V semiconductor material and a dielectric layer comprised of aluminum is formed on the silicon nitride layer. Another dielectric layer comprised of silicon and oxygen is formed over the dielectric layer comprised of aluminum. The dielectric layer comprised of aluminum acts as an etch stop for the etching of the dielectric layer comprised of silicon and oxygen with a high power reactive ion etch. The dielectric layer comprised of aluminum may then be etched with a wet etchant which does not substantially etch the silicon nitride layer. Damage to the surface of the semiconductor material by exposure to the high power reactive ion etch is prevented by forming the dielectric layer comprised of aluminum between the silicon nitride layer and the dielectric layer comprised of silicon and oxygen.

Abstract: An ohmic electrode is formed on a cBN crystal to form a cBN semiconductor device which is used as a solid electronic element. The cBN semiconductor device may be of an n-type, a p-type or a pn junction type wherein molybdenum is deposited onto an n-type doped region of the cBN crystal or platinum is deposited onto a p-type doped region to thereby form an electrode with ohmic characteristic. The deposition of the molybdenum or the platinum is conducted by using a vapor deposition method followed by heating the attached substance at a temperature of 300.degree. C.-1100.degree. C. in an inactive gas atmosphere. The cBN semiconductor device can be used as a solid electronic element or an optoelectronic element for rectifiers, transistors, light emitting diodes and so on and integrated elements thereof.

Abstract: Disclosed are a gallium nitride type semiconductor device that has a single crystal of (Ga.sub.1-x Al.sub.x).sub.1-y In.sub.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.sub.1-x Al.sub.x).sub.1-y In.sub.y N (0.ltoreq.x.gtoreq.1, 0.ltoreq.y.ltoreq.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.degree. to 1300.degree. C.

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.degree.-400.degree. C. and the high temperature process is carried out at 600.degree.-900.degree. C. The preferred source of activated nitrogen is an electron cyclotron resonance microwave plasma.

Abstract: A transition-metal silicide process includes the formation of a boron nitride capping layer overlying a transition-metal layer. In one embodiment, a transition-metal layer (30) is deposited onto a silicon surface (22), and onto a polysilicon gate electrode (12). A capping layer (32), which can be either boron nitride or boron oxynitride is deposited onto the transition-metal layer (30), and an annealing process is carried out to form a transition-metal/silicon alloy layer (34, 36, 38) at the silicon surface (22), and on the gate electrode (12). The capping layer (32) overlies the transition-metal layer (30) during the annealing process and prevents the formation of an oxide layer at the silicon surfaces (22, 12). After the annealing process is complete, the capping layer (13) is removed by a selective wet etch process, and a second annealing step is carried out to form a transition-metal silicide layer (40, 42, 44).

Abstract: A non-silyated, ternary boron nitride film (18, 38) is provided for semiconductor device applications. The non-silyated, ternary boron nitride film is preferably formed by plasma-enhanced chemical vapor deposition using non-silyated compounds of boron, nitrogen, and either oxygen, germanium, germanium oxide, fluorine, or carbon. In one embodiment, boron oxynitride (BNO) is deposited in a plasma-enhanced chemical vapor deposition reactor using ammonia (NH.sub.3), diborane (B.sub.2 H.sub.6), and nitrous oxide (N.sub.2 O). The BNO film has a dielectric constant of about 3.3 and exhibits a negligible removal rate in a commercial polishing apparatus. Because of its low dielectric constant and high hardness, the ternary boron nitride film formed in accordance with the invention can be advantageously used as a polish-stop layer and as a interlevel dielectric layer in a semiconductor device.

Abstract: A high electron mobility transistor is disclosed, which takes advantage of the increased mobility due to a two dimensional electron gas occurring in GaN/Al.sub.x Ga.sub.1-x N heterojunctions. These structures are deposited on basal plane sapphire using low pressure metalorganic chemical vapor deposition. The electron mobility of the heterojunction is approximately 620 cm.sup.2 per volt second at room temperature as compared to 56 cm.sup.2 per volt second for bulk GaN of the same thickness deposited under identical conditions. The mobility of the bulk sample peaked at 62 cm.sup.2 per volt second at 180.degree. K. and decreased to 19 cm.sup.2 per volt second at 77.degree. K. The mobility for the heterostructure, however, increased to a value of 1,600 cm.sup.2 per volt second at 77.degree. K. and saturated at 4.degree. K.

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.times.Ga.sub.1-x N:0.ltoreq..times..ltoreq.1); an I layer of semiinsulating gallium nitride semiconductor (Al.sub.x Ga.sub.1-x N:0.ltoreq..times..ltoreq.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.

Abstract: A deep submicron transistor fabrication method that employs only optical lithography involves the formation of a relatively wide aperture using optical techniques; the formation of composite sidewalls having differential etch resistance in the aperture to define a final aperture width less than that available with conventional optical techniques; the etching of the final aperture to expose a controlled channel length; the implantation of the channel through the aperture; and the implantation of source and drain with the sidewalls protecting previously doped LDD regions in the active area.

Abstract: A bipolar transistor is formed from epitaxial cubic boron nitride grown on a silicon substrate which is a three to two commensurate layer deposited by pulsed laser evaporation techniques. The thin film, cubic boron nitride bipolar transistor is in epitaxial registry with an underlying single crystal silicon substrate. The bipolar transistor is particularly suitable for high temperature applications.

Abstract: The invention is a method of growing intrinsic, substantially undoped single crystal gallium nitride with a donor concentration of 7.times.10.sup.17 cm.sup.-3 or less. The method comprises introducing a source of nitrogen into a reaction chamber containing a growth surface while introducing a source of gallium into the same reaction chamber and while directing nitrogen atoms and gallium atoms to a growth surface upon which gallium nitride will grow.

Abstract: A material for high-vacuum vessels characterized by depositing a mixture film of stainless steel and boron nitride on the surface of a metal or an alloy through the sputtering process, and heating and precipitating hexagonal boron nitride onto the surface thereof.

Abstract: A method for forming a transistor which may be suitable for high temperature application is provided. A single crystal silicon substrate has an overlaying layer of epitaxially grown cubic boron nitride in crystallographic registry with the silicon substrate. The cubic boron nitride is epitaxially grown using laser ablation techniques and provides an electrically resistive and thermally conductive barrier. An active layer of epitaxial silicon is then grown from the layer of cubic boron nitride, such that the overlaying layer of epitaxial silicon is in crystallographic registry with the layer of boron nitride which is in crystallographic registry with the underlying silicon substrate. Appropriately doped source and drain regions and a gate electrode are provided to form the transistor.

Abstract: A compound semiconductor material includes Ga.sub.x Al.sub.1-x N (wherein 0.ltoreq.x.ltoreq.1) containing B and P and having a zinc blend type crystal structure. A compound semiconductor element includes Ga.sub.x Al.sub.1-x N (wherein 0.ltoreq.x.ltoreq.1) layer having a zinc blend type crystal structure. A method of manufacturing a compound semiconductor element includes the step of sequentially forming a BP layer and a Ga.sub.x Al.sub.1-x N (wherein 0.ltoreq.x.ltoreq.1) layer on a substrate so as to form a heterojunction by using a metal organic chemical vapor deposition apparatus having a plurality of reaction regions, and moving the substrate between the plurality of reaction regions.

Abstract: A process for producing an ohmic electrode for p-type cBN is disclosed, which process comprises the steps of: providing a thin alloy film composed of Au and Be, the weight ratio of Be being from 0.1 to 15% by weight, on p-type cBN; providing a thin film of a metal selected from Ni, Cr, Mo, and Pt on the thin alloy film; and subjecting the p-type cBN having the films thus provided to a heat-treatment in an inert gas or in vacuo at a temperature of from 350.degree. C. to 600.degree. C.

Abstract: A composite material useful as a diode capable of operating at a high temperature, i.e., 500.degree. to 600.degree. C. or a semiconductor optical device capable of emitting ultraviolet rays is provided which comprises an electrically insulating single crystal diamond substrate and single crystal cubic boron nitride directly formed on one surface of the single crystal diamond in such a manner that the single crystal cubic boron nitride has the same plane index as the substrate.

Abstract: Disclosed is an integrated circuit process which includes forming two types of active devices: a first set of IGFETs has silicide gates, and the second set has TiN gates. The same TiN thin film layer also provides local interconnect. Optionally the TiN-gate devices may be used for high-voltage devices and the silicide-gate devices used for logic devices. The TiN gates in the second set of transistors and the TiN interconnect are formed by providing a thin film insulator pattern, depositing a titanium layer overall, heating the titanium in a nitrogen bearing atmosphere, and subsequently etching the titanium nitride obtained.

Abstract: The present invention provides a method for inhibiting the oxidation of a titanium layer during the direct reaction of the titanium with exposed silicon areas of an integrated circuit. In one embodiment of the present invention, a titanium nitride layer is formed on the surface of the titanium layer in the reactor where the titanium layer is deposited. The titanium nitride layer provides an effective barrier against oxidation. Thus, the formation of titanium dioxide is inhibited. In addition, in those areas where titanium nitride local interconnect is to be formed between diffused areas, the extra thickness provided by the top titanium nitride layer adds in the integrity of the conductive layers. By conducting the silicidation in a nitride atmosphere, diffusion of the nitride from the titanium nitride layer into the titanium layer and substitution of those lost nitrogen atoms by the atmosphere occurs thus providing a blocking layer for the formation of titanium silicide shorts.

Abstract: The specification discloses a polycrystalline boron nitride of high purity and high density consisting essentially of rhombohedral crystals in which the three-fold rotation axes, parallel to the c-axis in the notation of hexagonal crystal system, of the crystals have a preferred orientation. The polycrystalline rhombohedral boron nitride can be obtained as bulk or thin film articles with desired shapes by chemical vapor deposition including the steps of introducing a source gas of boron and a source gas into a reactor containing a heated substrate and depositing boron nitride onto the heated substrate, wherein a diffusion layer of the source gas of nitrogen and/or the carrier gas is formed around the substrate. The polycrystalline rhombohedral boron nitride such obtained is very useful in applications such as crucibles for melting semiconductors, various jigs for high temperature services, high-frequency insulator, microwave transmission window and source material of boron for semiconductor.

Abstract: A method for growing a single crystal of cubic boron nitride semiconductor in a growing container sealed under high pressure and high temperature conditions, which comprises dissolving in a dopant-containing boron nitride solvent a boron nitride starting material placed at a high temperature zone in the growing container, and providing a temperature gradient to the solvent so that the temperature dependence of the solubility is utilized to let the single crystal form and grow at a low temperature zone in the growing container.

Abstract: In organometallic vapor phase hetero-epitaxial processes for growing Al.sub.x Ga.sub.1-x N films on a sapphire substrate, the substrate is subjected to a preheat treatment of brief duration, such as less than 2 minutes, at relatively low temperatures in an atmosphere comprising Al-containing organometallic compound, NH.sub.3 and H.sub.2 gases, prior to the hetero epitaxial growth of Al.sub.x Ga.sub.1-x N films. Thus, single crystalline Al.sub.x Ga.sub.1-x N layers of high uniformity and high quality having smooth, flat surfaces are provided. Multi-layers grown according to the process of the invention are free from cracks and have preferable UV or blue light emission properties.

Abstract: There is disclosed an aluminum nitride substrate which comprises a substrate composed of an aluminum nitride sintered product; an electroconductive metallized layer composed of titanium nitride and at least one selected from the group consisting of molybdenum, tungsten, tantalum, an element in group III of the periodic table, an element in group IVa of the same, a rare earth element, an actinide element and a compound containing these elements; and an electroconductive protective layer laminated in this order on the aluminum nitride sintered product.

Abstract: An MOS device having a gate electrode and interconnect of titanium nitride and especially titanium nitride which is formed by low pressure chemical vapor deposition. In a more specific embodiment the titanium nitride gate electrode and interconnect have a silicon layer thereover to improve oxidation protection.