With Non-planar Semiconductor Surface (e.g., Groove, Mesa, Bevel, Etc.) Patents (Class 257/586)
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Patent number: 5289024Abstract: A bipolar transistor having a base intrinsic region, collector region, and emitter region. The emitter region, collector region, and base intrinsic region each having at least a portion thereof adjacent to an oxide isolation region. The base intrinsic region having a diffusion compensation region therein abutting the oxide isolation region. The diffusion compensation region compensates for the intrinsic concentrations segregating during oxidation, and also compensates for oxide charge contribution to the base region. The additional dopant in the compensation region results in only a small increase in the desired BJT performance and adds minimal complexity in manufacturing. The invention results in the controlled placement of dopants near the "birds's beak" between the emitter and base providing I.sub.CEO leakage current reduction at the emitter edge without affecting the bulk of the active intrinsic base.Type: GrantFiled: April 7, 1993Date of Patent: February 22, 1994Assignee: National Semiconductor CorporationInventor: George E. Ganschow
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Patent number: 5286996Abstract: A self-aligned process for fabricating high performance bipolar transistors for integrated circuits includes the formation of a collector contact and intrinsic collector region within an opening at the face of a semiconductor substrate. In particular, layers of oxide and polysilicon are formed on the surface of a substrate. An opening is then formed in both layers followed by the implantation of a buried collector region into the substrate at the exposed substrate face through the opening. Polysilicon contacts to the buried layer are then formed on the sidewalls of the opening. These contacts join with the polysilicon layer to form a collector contact. An oxide is then grown on the collector contact. A monocrystalline intrinsic collector is then formed from the exposed substrate face adjacent said collector contact. In this manner, the buried collector, collector contact and intrinsic collector are all formed in a self-aligned manner.Type: GrantFiled: December 31, 1991Date of Patent: February 15, 1994Assignee: Purdue Research FoundationInventors: Gerold W. Neudeck, Rashid Bashir
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Patent number: 5286997Abstract: Generally, and in one form of the invention a method is disclosed for forming a subcollector for bipolar transistors comprising the steps of epitaxially depositing a subcollector layer 22 on a substrate 20, the subcollector containing a co-deposited dopant; etching the subcollector layer to define an active device region; depositing a collector layer 24 above the subcollector layer; depositing a base layer 25 above the collector layer 24; and depositing an emitter layer 27 above the base layer 25, whereby the subcollector layer does not extend beyond the active device region and is of low resistance.Type: GrantFiled: March 31, 1992Date of Patent: February 15, 1994Assignee: Texas Instruments IncorporatedInventor: Darrell Hill
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Patent number: 5278083Abstract: Generally, and in one form of the invention, a method is disclosed for contacting a feature on an integrated circuit comprising: depositing a removable planarizing material 14 around the feature 10 so that a portion of the feature 10 extends above the removable planarizing material 14; depositing a masking layer 18 above the removable planarizing material 14, the masking layer 18 covering all but an exposed region above the feature 10 and an area around the feature; depositing an interconnect contact material 20 on the exposed region; and removing the masking layer 18 and the removable planarizing material 14, leaving the interconnect contact material 20 deposited on the exposed region, whereby a reliable, low capacitance, electrical contact is made to a very small feature 10.Type: GrantFiled: October 16, 1992Date of Patent: January 11, 1994Assignee: Texas Instruments IncorporatedInventors: Darrell G. Hill, William U. Liu
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Patent number: 5274265Abstract: A semiconductor device and a method of manufacture thereof by which the device is formed without an epitaxial growth process are provided. The semiconductor device has low circuit resistance and is highly reliable due to a sufficient device strength. Although a base layer or other devices are formed in an N.sup.- type silicon layer, the process of epitaxial growth is eliminated, because the semiconductor substrate (2) consists entirely of the N.sup.- type silicon. Further, the substrate has a bottom recessed part (4) which extends near a base layer (21). A collector electrode (8) is attached to the bottom recessed part (4), allowing collector resistance to be reduced. Moreover, the substrate (2) is not formed thin throughout, partly provided with the bottom recessed part (4). As a result, the resulting semiconductor device holds a sufficient strength.Type: GrantFiled: April 3, 1992Date of Patent: December 28, 1993Assignee: Rohm Co., Ltd.Inventor: Masataka Tsuruta
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Patent number: 5272095Abstract: A method of manufacturing heterojunction transistors having self-aligned contacts. In manufacturing a heterojunction bipolar transistor, a collector and a base layer are deposited on a substrate. A masking layer is deposited on the base layer and selectively etched to form an aperture therein, exposing the base layer. An emitter having a mesa structure is grown epitaxially on the exposed base layer to produce lateral overhang portions. The overhang portions may be formed by continuing the epitaxial growth to form lateral overgrowth portions overlapping the masking material. The masking layer is removed and self-aligned contacts are formed to the base and emitter regions using the lateral overhang portions which provide separation between the emitter structure and the contacts to the base layer.Type: GrantFiled: March 18, 1992Date of Patent: December 21, 1993Assignee: Research Triangle InstituteInventors: Paul M. Enquist, David B. Slater, Jr.
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Patent number: 5266830Abstract: According to the present invention, the hetero junction bipolar transistor (HBT) is provided which includes an emitter layer consisting of a first semiconductor of a first conductive type and being in mesa form; a base layer being in contact with the emitter layer and consisting of a second semiconductor of a second conductive type having a narrower band gap than the first semiconductor; and a collector layer being in contact with the base layer and consisting of a third semiconductor of a first conductive type having a broader band gap than the second semiconductor. In this HBT, a monolayer sulfur film is formed so as to cover the exposed periphery of the heterointerface between the emitter layer and the base layer.Type: GrantFiled: August 2, 1991Date of Patent: November 30, 1993Assignee: Sharp Kabushiki KaishaInventor: Hiroya Sato
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Patent number: 5266819Abstract: A C-up HBT is made to operate in the microwave/millimeter frequency range by self-aligning the collector uprisers on the base relative to proton damaged emitter regions and the base contacts which minimizes carrier injection into the extrinsic base. The use of about 7-10% indium in the indium gallium arsenide base is sufficient to stop the FREON-12 etch at the base after totally etching through the collector and single self-aligning mask.Type: GrantFiled: May 13, 1991Date of Patent: November 30, 1993Assignee: Rockwell International CorporationInventors: Mau Chung F. Chang, Peter M. Asbeck
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Patent number: 5258644Abstract: An improved bipolar transistor is provided which can be formed using a number of process steps which are similar to those used for forming MOSFETs. As such, the bipolar transistor is particularly useful in BiCMOS device arrangements. In accordance with one embodiment, a bipolar transistor is formed so that at least one of the emitter and collector regions has a high impurity region and a low impurity region. The collector and emitter regions of the device are formed in the base region to be spaced apart from one another, and the base electrode is arranged to cover the area of the base region between them. In an alternative embodiment, two collector regions can be provided in a base region on opposite sides of an emitter which is also formed in the base region. Two base electrodes can then be respectively provided in the areas between the two collectors and the emitter region. The bipolar transistors are particularly useful for forming a horizontal bipolar transistor structure.Type: GrantFiled: July 23, 1992Date of Patent: November 2, 1993Assignee: Hitachi, Ltd.Inventors: Akihiro Tamba, Yutaka Kobayashi, Tetsurou Matsumoto
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Patent number: 5258642Abstract: Semiconductor devices having a reduced parasitic capacitance while having a maximum acceptable current similar to those of prior devices, and a method of manufacturing thereof are disclosed. The inventive device has a hole at the bottom of which an insulating film separated from the hole walls is located, a semiconductor film being present in the hole, which is connected to the semiconductor substrate adjacent to the insulating film and a conductor film constituting a portion of the hole wall, and extends onto the insulating film so as to cover at least part of the film.Type: GrantFiled: July 10, 1992Date of Patent: November 2, 1993Assignee: Fujitsu LimitedInventor: Shunji Nakamura
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Patent number: 5252841Abstract: The base-collector capacitance in a heterojunction bipolar transistor (HBT) (50) is reduced, thereby providing increased cutoff frequency and power gain, by eliminating a portion of a collector contact layer (54) which normally underlies a base electrode (66). A similar effect may be produced by forming the collector contact layer (54) such that it initially extends into the area (54c) under the base electrode (66), and subsequently rendering the collector contact layer (54) in this area (54c) semiinsulative by proton bombardment. A ballast resistor layer (70) is formed between an emitter layer (62) and an overlying emitter electrode (68) to prevent thermal runaway and hot spot formation. A plurality of the HBTs (50) may be arranged in a distributed amplifier configuration (80) including contact electrode bus lines (84,88) having a geometry designed to provide high thermal efficiency, and input and output circuit matching characteristics.Type: GrantFiled: January 19, 1993Date of Patent: October 12, 1993Assignee: Hughes Aircraft CompanyInventors: Cheng P. Wen, Chan S. Wu, Peter Chu
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Patent number: 5252849Abstract: A transistor is formed as either a bipolar transistor (10) or an MOS transistor (11). Each transistor (10 or 11) has a substrate (12). Bipolar transistor (10) has a first current electrode (26) underlying a control electrode (28), and a second current electrode (32) overlying the control electrode (28). MOS transistor (11) has a first current electrode (54) underlying a channel region (56), and a source lightly doped region (58) and a source heavily doped region (60) overlying the channel region (56). A control electrode conductive layer (40) is laterally adjacent a sidewall dielectric layer (48), and sidewall dielectric layer (48) is laterally adjacent channel region (56). Conductive layer (40) functions as a gate electrode for transistor (11). Each of the transistors (10 and 11) is vertically integrated such as in a vertically integrated BiMOS circuit. Transistors (10 and 11) can be electrically isolated by isolation ( 64 and 66).Type: GrantFiled: March 2, 1992Date of Patent: October 12, 1993Assignee: Motorola, Inc.Inventors: Jon T. Fitch, Carlos A. Mazure, Keith E. Witek, James D. Hayden
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Patent number: 5250826Abstract: A III-V compound planar HBT-FET device integrates field effect transistors (FETs) with heterojunction bipolar transistors (HBTs) formed on the same semiconductor substrate. An HBT fabricated on the substrate includes a collector, a base, and an emitter. The HBT emitter comprises a lightly doped layer of a first conductivity type deposited atop a heavily doped base layer of a second conductivity type, a lightly doped emitter cap layer of the first conductivity type deposited atop the emitter layer, and a heavily doped emitter contact layer of the first conductivity type deposited atop the emitter cap layer. A FET, isolated from the HBT by areas of ion implantation, is formed in the layers of material deposited during fabrication of the HBT. The FET has a source and a drain formed in the heavily doped emitter contact layer, a gate recess etched in the emitter contact layer between the source and drain, and a Schottky gate metal contact deposited on the lightly doped emitter cap layer exposed in the gate recess.Type: GrantFiled: September 23, 1992Date of Patent: October 5, 1993Assignee: Rockwell International CorporationInventors: Mau-Chung F. Chang, Peter M. Asbeck, Richard L. Pierson, Jr.
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Patent number: 5235206Abstract: A method of manufacturing a vertical bipolar transistor including the steps of: providing a semiconductor substrate including a first region of a first conductivity type; forming an extrinsic base region of a second conductivity type in the surface of the first region, the extrinsic base region generally bounding a portion of the first region; forming by ion implantation a linking region of the second conductivity type in the surface of the bounded portion of the first region so as to electrically link generally opposing edges of the extrinsic base region through the linking region; forming an insulating spacer over the junction between the extrinsic base region and the linking region so as to generally bound a portion of the linking region within the portion of the first region; etching the surface of the bounded portion of the linking region a short distance into the linking region; forming by epitaxial growth a first layer of semiconductor material of the second conductivity type on the etched surface of tType: GrantFiled: April 7, 1992Date of Patent: August 10, 1993Assignee: International Business Machines CorporationInventors: Brian H. Desilets, Chang-Ming Hsieh, Louis L. Hsu
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Patent number: 5214302Abstract: A semiconductor integrated circuit device having a structure in which each of the following regions, that is, a first region for forming the base and emitter regions of each of the bipolar transistors, a second region for forming the collector lead-out region of the bipolar transistor, and a third region for forming each of the MISFETs, is projected from the main surface of a semiconductor substrate, whereby it is possible to effect isolation between the MISFETs and between these MISFETs and the bipolar transistors with the same isolation structure and in the same manufacturing step as those for the isolation between the bipolar transistors. In this device, furthermore, the base region of the bipolar transistor is electrically and self-alignedly connected to a base electrode which is formed over the main surface so as to surround the emitter region.Type: GrantFiled: December 13, 1991Date of Patent: May 25, 1993Assignee: Hitachi, Ltd.Inventors: Akihisa Uchida, Keiichi Higeta, Nobuo Tamba, Masanori Odaka, Katsumi Ogiue
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Patent number: 5177584Abstract: A bipolar SRAM which includes a forward bipolar transistor and a reverse bipolar transistor on an identical semiconductor substrate, is disclosed. Concretely, the base region of the reverse bipolar transistor is formed at a deeper position of the substrate than the base region of the forward bipolar transistor, thereby to heighten the cutoff frequency f.sub.T of the reverse bipolar transistor.Type: GrantFiled: January 28, 1991Date of Patent: January 5, 1993Assignee: Hitachi, Ltd.Inventors: Akihisa Uchida, Yuji Yatsuda, Katsumi Ogiue, Kazuo Nakazato, Takahiro Onai