In Compound Semiconductor Material (e.g., Gaas) Patents (Class 257/631)
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Patent number: 6504185Abstract: A compound semiconductor device is formed having a plurality of FETs exhibiting the same electrode ratio of a difference between a surface area of the active region and the combined overlapping surface area of the source and drain ohmic electrodes to the combined overlapping surface area of the source and drain ohmic electrodes. As such, precise control of a threshold voltage of the FETs is achieved. The compound semiconductor device is also formed so as to include a plurality of resistors having the same ratio of a difference between a surface area of the resistivity region and the combined overlapping surface area of the pair electrodes to the combined overlapping surface area of the pair electrodes. In this manner, a resistivity of the resistor is precisely controlled.Type: GrantFiled: June 5, 2001Date of Patent: January 7, 2003Assignee: Oki Electric Industry Co., Ltd.Inventor: Nobusuke Yamamoto
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Patent number: 6469389Abstract: Within an integrated circuit, a contact plug with a height not extending above the level of the gate/wordline nitride is nonetheless provided with a relatively large contact area or landing pad, significantly larger than the source/drain region to which the contact plug is electrically connected. Methods for producing the inventive contact plug include (1) use of a nitride facet etch, either (a) during a nitride spacer formation etch or (b) during a BPSG etch; (2) using at least one of (a) an isotropic photoresist etch or partial descum to narrow BPSG spacers above the gate/wordline nitride, and (b) a nitride step etch to etch the shoulder area of the gate/wordline nitride exposed by a BPSG etch; and (3) polishing a BPSG layer down to the top of a gate/wordline nitride before any doped polysilicon plug fill, masking for BPSG etch and performing a BPSG etch, etching the photoresist layer through a partial descum, and etching the shoulder area of the gate/wordline nitride exposed thereby.Type: GrantFiled: May 9, 2000Date of Patent: October 22, 2002Assignee: Micron Technolgy, Inc.Inventors: Werner Juengling, Kirk Prall, Gordon Haller, David Keller, Tyler Lowrey
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Patent number: 6429471Abstract: Disclosed is a compound semiconductor field effect transistor. The compound semiconductor field effect transistor has a charge absorption layer and a semiconductor laminated structure. The charge absorption layer includes a compound semiconductor layer of a first conductive type formed in a part of a compound semiconductor substrate having a semi-insulating layer. The semiconductor laminated structure includes at least an active layer including a compound semiconductor layer of a second conductive type epitaxially grown so as to cover the charge absorption layer and a region of the semi-insulating surface where the charge absorption layer is not formed. A source electrode is formed on the semiconductor laminated structure, being electrically connected to the charge absorption layer.Type: GrantFiled: May 26, 2000Date of Patent: August 6, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Takahiro Yokoyama, Hidetoshi Ishida, Yorito Ota, Daisuke Ueda
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Publication number: 20020096683Abstract: High quality epitaxial layers of GaN can be grown overlying large silicon wafers (200) by forming an amorphous layer (210) on the substrate. The amorphous layer dissipates strain and permits the growth of a high quality GaN layer (208). Any lattice mismatch between the GaN layer and the underlying substrate is taken care of by the amorphous layer.Type: ApplicationFiled: January 19, 2001Publication date: July 25, 2002Applicant: Motorola, Inc.Inventors: Jamal Ramdani, Lyndee L. Hilt
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Publication number: 20020047123Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.Type: ApplicationFiled: November 7, 2001Publication date: April 25, 2002Applicant: MOTOROLA, INC.Inventors: Jamal Ramdani, Ravindranath Droopad, Lyndee L. Hilt
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Publication number: 20020047143Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.Type: ApplicationFiled: November 7, 2001Publication date: April 25, 2002Applicant: MOTOROLA, INC.Inventors: Jamal Ramdani, Ravindranath Droopad, Lyndee L. Hilt
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Patent number: 6335562Abstract: Single event upset failure are suppressed in GaAs-based electronics by implanting the GaAs substrate with an appropriate dose of O and at least one of either Al, Cr, or In.Type: GrantFiled: December 9, 1999Date of Patent: January 1, 2002Assignee: The United States of America as represented by the Secretary of the NavyInventors: Harry B. Dietrich, Jin U. Kang, Bela Molnar, Michael Y. Frankel
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Publication number: 20010045621Abstract: By exploiting an intense correlation exhibited between the distribution of lattice distortions in a wafer and the distribution of the threshold voltages of field effect transistors, the distribution of the lattice distortions in the wafer si reduced, thereby to mitigate the distribution of the characteristics of the semiconductor elements in the wafer. The difference between the maximum value and minimum value of the lattice distortions of a GaAs single crystal at a normal temperature is set to at most 4×10−5, and the density of Si atoms contained in the GaAs single crystal is set to at most 1×1016 cm−3, whereby the characteristics of semiconductor elements whose parent material is the GaAs single crystal can be made uniform.Type: ApplicationFiled: July 25, 2001Publication date: November 29, 2001Inventors: Yoshihisa Fujisaki, Yukio Takano, Tsutomu Ishiba
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Patent number: 6252262Abstract: A passivating layer is provided for a III-V semiconductor. The passivating layer is preferably made of Fe and is used with III-V (especially GaAs) devices. At least one full monolayer of the passivating layer is formed, so that one full monolayer of the passivating layer bonds with one full monolayer of the atomic species of the semiconductor.Type: GrantFiled: December 15, 1998Date of Patent: June 26, 2001Assignee: The United States of America as represented by the Secretary of the NavyInventors: B. T. Jonker, O. J. Glembocki, R. T. Holm
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Patent number: 6232623Abstract: To improve crystallographic property of a nitride III-V compound semiconductor layer grown on a sapphire substrate, a plurality of recesses are made on a major surface of the sapphire substrate, and the nitride III-V compound semiconductor layer is grown thereon. At least a part of the inner surface of each recess makes an angle not less than 10 degrees with respect to the major surface of the sapphire substrate. The recesses are buried with nitride III-V compound semiconductor crystal having a higher Al composition ratio than the nitride III-V compound semiconductor layer, such as AlxGa1−xN crystal whose Al composition ratio x is 0.2 or more, for example. Each recess has a depth not less than 25 nm and a width not less than 30 nm. The recesses may be made either upon thermal cleaning of the sapphire substrate or by using lithography and etching, thermal etching, or the like.Type: GrantFiled: June 17, 1999Date of Patent: May 15, 2001Assignee: Sony CorporationInventor: Etsuo Morita
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Patent number: 6144050Abstract: A semiconductor device having a barrier film comprising an extremely thin film formed of one or more monolayers each comprised of a two-dimensional array of metal atoms. In one exemplary aspect, the barrier film is used for preventing the diffusion of atoms of another material, such as a copper conductor, into a substrate, such as a semiconducting material or an insulating material. In one mode of making the semiconductor device, the barrier film is formed by depositing a precursor, such as a metal halide (e.g., BaF.sub.2), onto the substrate material, and then annealing the resulting film on the substrate material to remove all of the constituents of the temporary heteroepitaxial film except for a monolayer of metal atoms left behind as attached to the surface of the substrate. A conductor, such as copper, deposited onto the barrier film is effectively prevented from diffusing into the substrate material even when the barrier film is only one or several monolayers in thickness.Type: GrantFiled: August 20, 1998Date of Patent: November 7, 2000Assignee: The United States of America as represented by the Secretary of the NavyInventors: Michael F. Stumborg, Francisco Santiago, Tak Kin Chu, Kevin A. Boulais
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Patent number: 6015979Abstract: Nitride-based semiconductor element comprises a first layer, a mask formed on the first layer and has a plurality of opening portions, a nitride-based compound semiconductor layer formed on the mask, the nitride-based compound semiconductor layer including a first region having threading dislocations produced in such a manner that, in approximately a middle portion between two adjacent ones of the plurality of opening portions in the mask, a plurality of dislocations extend in a vertical direction to a surface of the mask, and a second region which comprises portions other than the middle portions and free from the dislocations, and a desired element structure formed on the semiconductor layer.Type: GrantFiled: August 28, 1998Date of Patent: January 18, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Lisa Sugiura, Masayuki Ishikawa, Shinya Nunoue, Masaaki Onomura, Masahiro Yamamoto
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Patent number: 6008525Abstract: A minority carrier device includes at least one junction of at least two dissimilar materials, at least one of which is a semiconductor, and a passivating layer on at least one surface of the device. The passivating layer includes a Group 13 element and a chalcogenide component. Embodiments of the minority carrier device include, for example, laser diodes, light emitting diodes, heterojunction bipolar transistors, and solar cells.Type: GrantFiled: December 18, 1997Date of Patent: December 28, 1999Assignees: President and Fellows of Harvard College, TriQuint Semiconductor, Inc., The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Andrew R. Barron, Aloysius F. Hepp, Phillip P. Jenkins, Andrew N. MacInnes
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Patent number: 5965935Abstract: A microstrip line device is disclosed of the type which typically includes a strip conductor disposed on the top of a substrate. The device further includes a layer of dielectric material disposed between the strip conductor and the substrate for reducing the dissipation loss in these devices. In order to accomplish this, the dielectric layer has a dielectric constant which is less than the dielectric constant of the substrate.Type: GrantFiled: November 5, 1997Date of Patent: October 12, 1999Assignee: ITT Industries, Inc.Inventors: Inder J. Bahl, Edward L. Griffin
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Patent number: 5949095Abstract: A carrier transfer layer of compound semiconductor material is disposed on or over a support substrate, and a gate electrode of conductive material is disposed on or over the carrier transfer layer at a partial region thereof. A cap layer of non-doped compound semiconductor material is disposed on or over the carrier transfer layer at both sides of the gate electrode. The thickness of the cap layer is 100 nm or thicker. two current electrodes are formed in ohmic contact with the carrier transfer layer. An enhancement mode MESFET is provided whose gain and output power are suppressed from being lowered.Type: GrantFiled: August 13, 1996Date of Patent: September 7, 1999Assignee: Fujitsu LimitedInventors: Masaki Nagahara, Yasunori Tateno, Masahiko Takikawa
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Patent number: 5945718Abstract: A self-aligned enhancement mode metal-oxide-compound semiconductor FET (10) includes a stoichiometric Ga.sub.2 O.sub.3 gate oxide layer (14) positioned on upper surface (16) of a compound semiconductor wafer structure (13). The stoichiometric Ga.sub.2 O.sub.3 layer forms an atomically abrupt interface with the compound semiconductor wafer structure. A refractory metal gate electrode (17) is positioned on upper surface (18) of the stoichiometric Ga.sub.2 O.sub.3 gate oxide layer (14). The refractory metal is stable on the stoichiometric Ga.sub.2 O.sub.3 gate oxide layer at elevated temperature. Self-aligned source and drain areas, and source and drain contacts (19, 20) are positioned on the source and drain areas (21, 22).Type: GrantFiled: February 12, 1998Date of Patent: August 31, 1999Assignee: Motorola Inc.Inventors: Matthias Passlack, Jonathan Kwadwo Abrokwah, Zhiyi Yu
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Patent number: 5942792Abstract: A multi-layer structure inserted onto an interface between a compound semiconductor region and a highly resistive material region includes an epitaxial silicon layer up to 1.5 nm thick in contact with the compound semiconductor region and an amorphous silicon layer from 1 to 10 nm thick in contact with the highly resistive material region and laminated on the epitaxial silicon layer.Type: GrantFiled: May 4, 1998Date of Patent: August 24, 1999Assignee: NEC CorporationInventor: Yosuke Miyoshi
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Patent number: 5930611Abstract: A semiconductor device is fabricated by the step of forming a gate insulation film of a GaS film on a compound semiconductor layer; the step of forming an inter-layer insulation film on the gate insulation film; the step of etching the inter-layer insulation film selectively with respect to the gate insulation film by the use of an etchant containing hydrogen fluoride and ammonium fluoride, the step of exposing a prescribed region of the gate insulation film; and the step of forming a gate electrode on the exposed gate insulation film.Type: GrantFiled: September 4, 1997Date of Patent: July 27, 1999Assignee: Fujitsu LimitedInventor: Naoya Okamoto
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Patent number: 5903037Abstract: It has been found that a Ga-oxide-containing layer is substantially not etched in HF solution if the layer is a Ga-Gd-oxide with Gd:Ga atomic ratio of more than about 1:7.5, preferably more than 1:4 or even 1:2. This facilitates removal of a protective dielectric (typically SiO.sub.2) layer after an ohmic contact anneal, with the Ga-Gd-oxide gate oxide layer serving as etch stop and not being adversely affected by contact with the HF etchant. Gd-Ge-oxide also exhibits a composition-dependent etch rate in HCl:H.sub.2 O.Type: GrantFiled: February 24, 1997Date of Patent: May 11, 1999Assignee: Lucent Technologies Inc.Inventors: Alfred Yi Cho, Minghwei Hong, James Robert Lothian, Joseph Petrus Mannaerts, Fan Ren
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Patent number: 5825055Abstract: This is a method for fabricating a structure useful in semiconductor circuitry. The method comprises: growing a germanium layer 28 directly or indirectly on a semiconductor substrate 20; and depositing a high-dielectric constant oxide 32 (e.g. a ferroelectric oxide) on the germanium layer. Preferably, the germanium layer is epitaxially grown on the semiconductor substrate. This is also a semiconductor structure, comprising: a semiconductor substrate; a germanium layer on the semiconductor substrate; and a high-dielectric constant oxide on the germanium layer. Preferably the germanium layer is single-crystal. Preferably the substrate is silicon and the germanium layer is less than about 1 nm thick or the substrate is gallium arsenide (in which case the thickness of the germanium layer is not as important). A second germanium layer 40 may be grown on top of the high-dielectric constant oxide and a conducting layer 42 (possibly epitaxial) grown on the second germanium layer.Type: GrantFiled: January 3, 1997Date of Patent: October 20, 1998Assignee: Texas Instruments IncorporatedInventor: Scott R. Summerfelt
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Patent number: 5811843Abstract: A field effect transistor includes a semi-insulating III-V compound semiconductor substrate; a channel layer disposed on the substrate; an n type electron supply layer disposed on the channel layer and comprising a mixed crystalline compound semiconductor layer including AlAs; an n type ohmic contact layer disposed on the electron supply layer; source and drain electrodes disposed on the ohmic contact layer; an opening in a region between the source and drain electrodes penetrating the ohmic contact layer; a gate electrode disposed in the opening and making a Schotty contact; and a surface protection film of a semiconductor material free of Al, In, and As, covering the opening except where the gate electrode is present. Fluorine is prevented from getting into the electron supply layer with no increase in transconductance or source resistance by providing a layer between the source and a channel, and between the gate and the channel.Type: GrantFiled: February 24, 1997Date of Patent: September 22, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshitsugu Yamamoto, Norio Hayafuji
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Patent number: 5796127Abstract: A method of fabricating a semiconductor device includes forming a first mixed crystal semiconductor layer of AlAs and InAs; applying a solution containing a material easily combining with fluorine to the surface of the first mixed crystal semiconductor layer exposed to the atmosphere so that the material combines with fluorine that sticks to the surface of the first mixed crystal semiconductor layer; and annealing the first mixed crystal semiconductor layer in a vacuum. In this method, since the fluorine on the surface of the first mixed crystal semiconductor layer exposed to the atmosphere combines with the material included in the solution and is removed together with the material, a first mixed crystal semiconductor layer having no fluorine is produced. Therefore, unwanted infiltration of fluorine into the first mixed crystal semiconductor layer is avoided, resulting in a highly reliable semiconductor device with desired characteristics.Type: GrantFiled: August 21, 1997Date of Patent: August 18, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Norio Hayafuji, Yoshitsugu Yamamoto, Hirotaka Kizuki
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Patent number: 5760462Abstract: A majority carrier device includes a bulk active region and a thin-film passivating layer on the bulk active region. The thin-film passivating layer includes a Group 13 element and a chalcogenide component. In one embodiment, the majority carrier device is a metal, passivating layer, semiconductor, field-effect transistor. The transistor includes an active layer and thin-film passivating layer on the active layer. The thin-film passivating layer includes a Group 13 element and a chalcogenide component. Source and drain contacts are disposed on the active layer or the passivating layer. A gate contact is disposed on the passivating layer between the source contact and the drain contact.Type: GrantFiled: March 19, 1997Date of Patent: June 2, 1998Assignees: President and Fellows of Harvard College, TriQuint Semiconductor, Inc.Inventors: Andrew R. Barron, Phillip P. Jenkins, Andrew N. MacInnes, Aloysius F. Hepp
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Patent number: 5753968Abstract: A microstrip line device is disclosed of the type which typically includes a strip conductor disposed on the top of a substrate. The device further includes a layer of dielectric material disposed between the strip conductor and the substrate for reducing the dissipation loss in these devices. In order to accomplish this, the dielectric layer has a dielectric constant which is less than the dielectric constant of the substrate.Type: GrantFiled: August 5, 1996Date of Patent: May 19, 1998Assignee: ITT Industries, Inc.Inventors: Inder J. Bahl, Edward L. Griffin
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Patent number: 5686756Abstract: A compound semiconductor field effect transistor has a semiconductive layer made of a compound which consists of a single III group element and a single V group element or a compound which consists of two III group elements and a single V group element in the periodic table and a passivation film for protecting the surface of the semiconductive layer. This passivation film is formed of a chalcopyrite made of a compound which consists of a single I group element, a single III group element and two VI group elements or chalcopyrite made of a compound which consists of a single II group element, a single IV group element and two V group elements in the periodic table. Those chalcopyrites have lattice constants close to or equal to a lattice constant of the semiconductive layer. Those chalcopyrites have band gaps wider than that of the semiconductive layer. The semiconductive layer may be GaAs and InP. The chalcopyrite may be (Cu.sub.0.12 Ag.sub.0.88)AlS.sub.2 and (Zn.sub.0.04 Cd.sub.0.96)SiP.sub.2.Type: GrantFiled: January 17, 1996Date of Patent: November 11, 1997Assignee: NEC CorporationInventor: Yasuko Hori
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Patent number: 5682046Abstract: A heterojunction bipolar transistor has a support substrate, a collector layer formed on the support substrate, a base layer formed on the collector layer containing arsenic as group V element, a first emitter layer formed on the base layer, containing phosphorus as group V element, and having a band gap wider than the base layer, an emitter passivation layer formed on the first emitter layer made of semiconductor having a function of passivating the surface of the first emitter layer, and a base electrode forming an ohmic contact with the base layer. The whole upper surface of the base layer is covered with the first emitter layer and base electrode, the whole upper surface of the first emitter layer is covered with the emitter passivation layer, and the region of the first emitter layer adjacent to the edge of the base electrode is depleted throughout the full depth thereof.Type: GrantFiled: November 3, 1995Date of Patent: October 28, 1997Assignee: Fujitsu LimitedInventors: Tsuyoshi Takahashi, Hiroshi Yamada, Kazukiyo Joshin, Shigehiko Sasa
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Patent number: 5677565Abstract: A method of fabricating a semiconductor wafer includes preparing a semiconductor wafer of a monocrystalline compound semiconductor having a side surface and upper and lower surfaces, and upper and lower corners at the intersections of the side surface and the upper and lower surfaces, respectively; and producing a non-monocrystalline region at the side surface of the semiconductor wafer including the corners. Since the semiconductor wafer includes a non-monocrystalline part at the side surface including the corners, even when a crack is produced in the non-monocrystalline part, unwanted cleaving of the wafer from the crack does not occur.Type: GrantFiled: November 15, 1995Date of Patent: October 14, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Shinji Funaba
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Patent number: 5650638Abstract: A semiconductor device comprises at least one semiconductor layer (1-3) of SiC and a layer (6) applied on at least a portion of an edge surface (19) of said SiC-layer so as to passivate this edge surface portion. At least the portion of said passivation layer closest to said edge surface portion of the SiC-layer is made of a first crystalline material, and the passivation layer comprises a portion made of a second material having AIN as only component or as a major component of a crystalline alloy constituting said second material.Type: GrantFiled: May 8, 1995Date of Patent: July 22, 1997Assignee: ABB Research Ltd.Inventors: Christopher Harris, Andrei Konstantinov, Erik Janzen
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Patent number: 5646437Abstract: The light receiving or back-side surface (22) of an indium antimonide (InSb) photodetector device (10) substrate (12) is cleaned to remove all native oxides of indium and antimony therefrom. A passivation layer (26) is then formed on the surface (22) of a material such as silicon dioxide, silicon suboxide and/or silicon nitride which does not react with InSb to form a structure which would have carrier traps therein and cause flashing. The device (10) is capable of detecting radiation over a continuous spectral range including the infrared, visible and ultraviolet regions.Type: GrantFiled: June 2, 1994Date of Patent: July 8, 1997Assignee: Santa Barbara Research CenterInventors: Ichiro Kasai, John R. Toman
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Patent number: 5616947Abstract: A semiconductor device including a GaAs semiconductor substrate, an insulating layer which is made of material selected from the group MgS, MgSSe and CaZnS and is formed on the GaAs substrate, and a conductive electrode formed on the insulating layer.Type: GrantFiled: May 31, 1996Date of Patent: April 1, 1997Assignee: Matsushita Electric Industrial Co., Ltd.Inventor: Akiyoshi Tamura
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Patent number: 5567980Abstract: A method of forming a native oxide from an aluminum-bearing Group III-V semiconductor material is provided. The method entails exposing the aluminum-bearing Group III-V semiconductor material to a water-containing environment and a temperature of at least about 375.degree. C. to convert at least a portion of said aluminum-bearing material to a native oxide characterized in that the thickness of said native oxide is substantially the same as or less than the thickness of that portion of said aluminum-bearing Group III-V semiconductor material thus converted. The native oxide thus formed has particular utility in electrical and optoelectrical devices, such as lasers.Type: GrantFiled: January 26, 1995Date of Patent: October 22, 1996Assignee: The Board Of Trustees Of The University Of IllinoisInventors: Nick Holonyak, Jr., John M. Dallesasse
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Patent number: 5557141Abstract: A group III-V compound semiconductor doped with an impurity, having an undoped film of SiOx and a film for preventing the diffusion of Group V atoms (e.g., an SiN film) are formed on a crystal of Group III-V compound semiconductor in which the silicon in the SiOx film is diffused into the Group III-V compound semiconductor, thereby forming a doped layer.Type: GrantFiled: March 30, 1994Date of Patent: September 17, 1996Assignee: Sanyo Electric Co., Ltd.Inventors: Yasoo Harada, Shigeharu Matsushita, Satoshi Terada, Emi Fujii, Takashi Kurose, Takayoshi Higashino, Takashi Yamada, Akihito Nagamatsu, Daijirou Inoue, Kouji Matsumura
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Patent number: 5541118Abstract: A process for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness.Type: GrantFiled: May 22, 1995Date of Patent: July 30, 1996Assignee: Midwest Research InstituteInventors: Dean H. Levi, Art J. Nelson, Richard K. Ahrenkiel
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Patent number: 5541426Abstract: A semiconductor device is provided with a surface-inactivated semiconductor layer provided on the surface of a compound semiconductor on which surface a semiconductor layer forming the depletion layer is provided, the semiconductor layer forming the depletion layer being of a conduction type opposite that of the compound semiconductor, and having a carrier density and thickness being capable of forming a depletion layer on the compound semiconductor. When a depletion layer is formed on the surface of the compound semiconductor by the semiconductor layer forming the depletion layer, the depletion layer has no charge so that the concentration of electrical fields is relaxed, the surface of the semiconductor is stabilized, and excellent dielectric breakdown performance is obtained.Type: GrantFiled: March 2, 1995Date of Patent: July 30, 1996Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Masaaki Abe, Ken-ichi Nonaka
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Patent number: 5539248Abstract: A semiconductor device with an improved insulating and passivating layer including the steps of providing a gallium arsenide substrate with a surface, and crystallographically lattice matching an insulating and passivating layer of indium gallium fluoride on the surface of the gallium arsenide substrate. In one embodiment the semiconductor device is a FET and the layer of indium gallium fluoride covers at least an inter-channel area surrounding the gate.Type: GrantFiled: November 13, 1995Date of Patent: July 23, 1996Assignee: MotorolaInventors: Jonathan K. Abrokwah, Danny L. Thompson, Zhiguo Wang
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Patent number: 5517039Abstract: LEDs and other semiconductor devices fabricated with III-V materials and having exposed Al-bearing surfaces passivated with native oxides are disclosed. A known high temperature water vapor oxidation process is used to passivate the exposed layers of Al-bearing III-V semiconductor materials in confined-emission spot LEDs and other light emitting devices. These devices exhibit greatly improved wet, high temperature operating life, with little to no degradation in light output when exposed to such conditions.Type: GrantFiled: November 14, 1994Date of Patent: May 14, 1996Assignee: Hewlett-Packard CompanyInventors: Nick Holonyak, Jr., Tim A. Richard, Mark R. Keever, Fred A. Kish, Chun Lei, Serge Rudaz
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Patent number: 5497024Abstract: A combination of a semiconductor region essentially consisting of Al.sub.x Ga.sub.1-x As (0.ltoreq.x.ltoreq.1), an insulating film formed on the surface of the semiconductor region and essentially consisting of GaAs.sub.x P.sub.y O.sub.z (w, y, z>0), and a passivation film formed on the insulating film and made of an insulating material different from the insulating film. The laminated insulating film has an extremely low leakage current. An excellent MISFET can be realized by forming a gate electrode on the surface of the laminated insulating film.Type: GrantFiled: April 5, 1994Date of Patent: March 5, 1996Assignees: Asahi Kogyosha Co., Ltd., Kazuo Hattori, Fujitsu LimitedInventors: Akira Shibuya, Kazuo Hattori, Masashi Ozeki
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Patent number: 5473171Abstract: This is a method for fabricating a structure useful in semiconductor circuitry. The method comprises: growing a germanium layer 28 directly or indirectly on a semiconductor substrate 20; and depositing a high-dielectric constant oxide 32 (e.g. a ferroelectric oxide) on the germanium layer. Preferably, the germanium layer is epitaxially grown on the semiconductor substrate. This is also a semiconductor structure, comprising: a semiconductor substrate; a germanium layer on the semiconductor substrate; and a high-dielectric constant oxide on the germanium layer. Preferably the germanium layer is single-crystal. Preferably the substrate is silicon and the germanium layer is less than about 1 nm thick or the substrate is gallium arsenide (in which case the thickness of the germanium layer is not as important). A second germanium layer 40 may be grown on top of the high-dielectric constant oxide and a conducting layer 42 (possibly epitaxial) grown on the second germanium layer.Type: GrantFiled: April 4, 1994Date of Patent: December 5, 1995Assignee: Texas Instruments IncorporatedInventor: Scott R. Summerfelt
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Patent number: 5449943Abstract: The light receiving or back-side surface (22) of an indium antimonide (InSb) photodetector device (10) substrate (12) is cleaned to remove all oxides of indium and antimony therefrom. Passivation and/or partially visible light blocking layers (26, 28) are then formed thereon of a material which does not react with InSb to form a structure which would have carrier traps therein and cause flashing. The optical cutoff wavelength and thickness of the partially visible light blocking layer (28) are selected to suppress the avalanche effect in the device (10) at visible wavelengths. This enables the device (10) to operate effectively over a wide wavelength range including the visible and infrared bands. The passivation and/or partially visible light blocking layers (26, 28) may be a thin layer of a semiconductor such as germanium, or silicon dioxide and/or silicon nitride followed by a partially visible light blocking silicon layer.Type: GrantFiled: June 2, 1994Date of Patent: September 12, 1995Assignee: Santa Barbara Research CenterInventors: Ichiro Kasai, Herbert L. Hettich, Stephen L. Lawrence
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Patent number: 5410167Abstract: A silicon nitride film 2 is formed on a GaAs substrate 1 and patterned to selectively expose the GaAS substrate surface in uniformly distributed areas having a width of not greater than 1 .mu.m. A non-doped GaAs buffer layer is grown on the GaAs substrate to completely cover the silicon nitride film. Then, a semiconductor multilayer structure including a non-doped GaAs layer is formed on the non-doped GaAs buffer layer. When a semiconductor integrated circuit device is manufactured using this semiconductor substrate, side gate effect can be effectively reduced due to the existence of the silicon nitride pattern and the buffer layer.Type: GrantFiled: July 9, 1993Date of Patent: April 25, 1995Assignee: Fujitsu LimitedInventor: Junji Saito
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Patent number: 5396089Abstract: A unipolar electronic component is proposed with a quasi one dimensional carrier channel which has all the characteristics of an FET. This component can be very simply produced, has "self-alignment" and linear gates with a low capacity in place of planar gates. In this way a very high operating frequency of the component is possible. The structure comprises an initially homogenous 2D-layer with a high carrier mobility which is formed by epitaxy of for example GaAs. The implantation of focussed ions (for example Ga.sup.+ with 100 keV) locally destroys the conductivity of the electron layer. The irradiated regions remain insulating at low temperature or room temperature even after illuminating the cristal with bandgap radiation. The writing in of the insulating layer is carried out along two paths on the chip so that the 2D-carrier layer is subdivided into three regions insulated from one another.Type: GrantFiled: March 22, 1993Date of Patent: March 7, 1995Assignee: Max-Planck-Gesellschaft zur Forderung der WissenschaftenInventors: Andreas D. Wieck, Klaus Ploog
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Patent number: 5378905Abstract: There is interposed a buffer film composed of IIa group fluoride and having characteristics of orientation to a surface direction (111), in which mismatching in lattice constant with a crystal element of a semiconductor substrate is large and mismatching in lattice constant with IV-VI group compound ferroelectric substance is small, between the semiconductor substrate having a surface direction (100) and a ferroelectric gate film comprising the IV-VI group compound ferroelectric substance and having characteristics of polarization to the surface direction (111). Since the buffer film is an orientation film in the direction of (111) without influenced by a crystal element of the semiconductor substrate serving as a base material, the ferroelectric gate film can be oriented in the direction of (111) which is the same as the direction of polarization of the ferroelectric substance.Type: GrantFiled: February 18, 1993Date of Patent: January 3, 1995Assignee: Rohm Co., Ltd.Inventor: Takashi Nakamura
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Patent number: 5322573Abstract: The invention features a thin light transmissive layer of the ternary semiconductor indium aluminum arsenide (InAlAs) as a front surface passivation or "window" layer for p-on-n InP solar cells. The window layers of the invention effectively reduce front surface recombination of the object semiconductors thereby increasing the efficiency of the cells.Type: GrantFiled: October 2, 1992Date of Patent: June 21, 1994Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Raj K. Jain, Geoffrey A. Landis
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Patent number: 5302840Abstract: A HEMT type semiconductor device includes a semiconductor substrate, a buffer semiconductor layer formed on the substrate, a first semiconductor well layer formed on the buffer layer and serving as a first conductivity type channel layer, a second semiconductor well layer formed on the first well layer and serving as a second conductivity type opposite the first conductivity, a channel layer and a potential barrier layer formed on the second well layer and forming a potential barrier for carriers. The substrate is made of GaAs or InP, and the layers are successively and epitaxially grown on the substrate. A two dimensional hole gas and a two dimensional electron gas are confined in the first well layer and in the second well layer, respectively.Type: GrantFiled: June 17, 1992Date of Patent: April 12, 1994Assignee: Fujitsu LimitedInventor: Masahiko Takikawa
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Patent number: 5264714Abstract: A thin-film electroluminescence device has transparent electrodes formed on a transparent substrate, a lower dielectric layer formed on the substrate having the transparent electrodes, a luminescent layer formed on the lower dielectric layer, an upper dielectric layer formed on the luminescent layer, and back electrodes formed on the upper dielectric layer. At least one of the upper and lower dielectric layers includes a SiN:H film formed in contact with the luminescent layer by a plasma chemical vapor deposition method. The SiN:H film contains N--H bonds of 1.2.times.10.sup.22 /cm.sup.3 or less to control an amount of change in emission-start voltage to 30 V or less.Type: GrantFiled: October 3, 1991Date of Patent: November 23, 1993Assignee: Sharp Kabushiki KaishaInventors: Hiroaki Nakaya, Takuo Yamashita, Takashi Ogura, Masaru Yoshida
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Patent number: 5248635Abstract: In a method of forming and passivating device regions in III-V semiconductor substrates, a substrate surface is pretreated in a halogen-carbon plasma prior to depositing of insulating or passivating layers. Devices produced by pretreating the substrate surface have considerably better electrical values than devices fabricated without this pretreatment. In particular, devices fabricated with this pretreatment have a low reverse current (dark current).Type: GrantFiled: May 29, 1991Date of Patent: September 28, 1993Assignee: Alcatel N.V.Inventors: Jamal Bouayad-Amine, Wolfgang Kuebart, Joachim Scherb
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Patent number: 5247349Abstract: Pnictide thin films, particularly phosphorus, grown on III-V semiconductors, particularly InP, GaP, and GaAs, are amorphous and have a novel layer-like, puckered sheet-like local order. The thin films are typically 400 Angstroms thick and grown preferably by molecular beam deposition, although other processes such as vacuum evaporation, sputtering, chemical vapor deposition, and deposition from a liquid melt may be used. The layers are grown on the <100> <110>, and surfaces of the III-V crystals. The pnictide layer reduces the density of surface states, and allows the depletion layer to be modulated, the surface barrier reduced, the electron concentration at the surface increased, and there is a decrease in the surface recombination velocity and an increase in the photoluminescence intensity.Type: GrantFiled: August 22, 1990Date of Patent: September 21, 1993Assignee: Stauffer Chemical CompanyInventors: Diego J. Olego, John A. Baumann, Rozalie Schachter, Harvey B. Serreze, William E. Spicer, Paul M. Raccah
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Patent number: 5206534Abstract: In the case of a photocell based on gallium arsenide or indium phosphide, a layer of amorphous, hydrogenous carbon (a-C:H) having a thickness of .ltoreq.0.1 .mu.m and a specific electrical resistance of .gtoreq.10.sup.6 .OMEGA..cm is placed on a layer of p-doped gallium arsenide (GaAs) or indium phosphide (InP).Type: GrantFiled: August 20, 1991Date of Patent: April 27, 1993Assignee: Siemens AktiengesellschaftInventors: Siegfried Birkle, Johann Kammermaier, Gerhard Rittmayer