Abstract: High frequency performance of (e.g., silicon) bipolar devices (40, 100, 100?) is improved by reducing the capacitive coupling (Cbc) between the extrinsic base contact (46) and the collector (44, 44?, 44?). A dielectric ledge (453, 453?) is created during fabrication to separate the extrinsic base contract (46) from the collector (44, 44?, 44?) periphery (441). The dielectric ledge (453, 453?) underlies the transition region (461) where the extrinsic base contact (46) is coupled to the intrinsic base. (472) During device fabrication, a multi layer dielectric stack (45) is formed adjacent the intrinsic base (472) that allows the simultaneous creation of an undercut region (457, 457?) in which the intrinsic base (472) to extrinsic base contact (46) transition region (461) can be formed.
Abstract: A semiconductor device includes a drift layer having a first conductivity type and a body region adjacent the drift layer. The body region has a second conductivity type opposite the first conductivity type and forms a p-n junction with the drift layer. The device further includes a contactor region in the body region and having the first conductivity type, and a shunt channel region extending through the body region from the contactor region to the drift layer. The shunt channel region has the first conductivity type. The device further includes a first terminal in electrical contact with the body region and the contactor region, and a second terminal in electrical contact with the drift layer.
Type:
Grant
Filed:
November 3, 2006
Date of Patent:
October 6, 2009
Assignee:
Cree, Inc.
Inventors:
Allen Hefner, Sei-Hyung Ryu, Anant Agarwal
Abstract: A vertical field effect transistor includes: an active region with a bundle of linear structures functioning as a channel region; a lower electrode, functioning as one of source and drain regions; an upper electrode, functioning as the other of the source and drain regions; a gate electrode for controlling the electric conductivity of at least a portion of the bundle of linear structures included in the active region; and a gate insulating film arranged between the active region and the gate electrode to electrically isolate the gate electrode from the bundle of linear structures. The transistor further includes a dielectric portion between the upper and lower electrodes. The upper electrode is located over the lower electrode with the dielectric portion interposed and includes an overhanging portion sticking out laterally from over the dielectric portion. The active region is located right under the overhanging portion of the upper electrode.
Abstract: Disclosed are embodiments of a hetero-junction bipolar transistor (HBT) structure and method of forming the structure that provides substantially lower collector-to-base parasitic capacitance and collector resistance, while also lowering or maintaining base-to-emitter capacitance, emitter resistance and base resistance in order to achieve frequency capabilities in the THz range. The HBT is a collector-up HBT in which a dielectric layer and optional sidewall spacers separate the raised extrinsic base and the collector so as to reduce collector-to-base capacitance. A lower portion of the collector is single crystalline semiconductor so as to reduce collector resistance. The raised extrinsic base and the intrinsic base are stacked single crystalline epitaxial layers, where link-up is automatic and self-aligned, so as to reduce base resistance. The emitter is a heavily doped region below the top surface of a single crystalline semiconductor substrate so as to reduce emitter resistance.
Abstract: A method of fabricating a hetero-junction bipolar transistor (HBT) is disclosed, where the HBT has a structure incorporating a hetero-junction bipolar structure disposed on a substrate including of silicon crystalline orientation <110>. The hetero-junction bipolar structure may include an emitter, a base and a collector. The substrate may include a shallow-trench-isolation (STI) region and a deep trench region on which the collector is disposed. The substrate may include of a region of silicon crystalline orientation <100> in addition to silicon crystalline orientation <110> to form a composite substrate by using hybrid orientation technology (HOT). The region of crystalline orientation <100> may be disposed on crystalline orientation <110>. Alternatively, the region of silicon crystalline orientation <110> may be disposed on crystalline orientation <100>.
Type:
Application
Filed:
January 4, 2008
Publication date:
July 9, 2009
Applicant:
INTERNATIONAL BUSINESS MACHINES CORPORATION
Abstract: Semiconductor devices and fabrication methods are provided, in which metal transistor gates are provided for MOS transistors. A rare earth-rare earth alloy incorporated metal nitride layer is formed above a gate dielectric. This process provides adjustment of the gate electrode work function, thereby tuning the threshold voltage of the resulting NMOS transistors.
Type:
Application
Filed:
September 8, 2008
Publication date:
July 2, 2009
Applicant:
Texas Instruments Incorporated
Inventors:
Hiroaki Niimi, Manuel Angel Quevedo-Lopez
Abstract: A device comprises a first sub-collector formed in an upper portion of a substrate and a lower portion of a first epitaxial layer and a second sub-collector formed in an upper portion of the first epitaxial layer and a lower portion of a second epitaxial layer. The device further comprises a reach-through structure connecting the first and second sub-collectors and an N-well formed in a portion of the second epitaxial layer and in contact with the second sub-collector and the reach-through structure. The device further comprises N+ diffusion regions in contact with the N-well, a P+ diffusion region in contact with the N-well, and shallow trench isolation structures between the N+ and P+ diffusion regions.
Type:
Application
Filed:
September 24, 2008
Publication date:
February 12, 2009
Applicant:
INTERNATIONAL BUSINESS MACHINES CORPORATION
Inventors:
Xuefeng LIU, Robert M. Rassel, Steven H. Voldman
Abstract: A semiconductor device is provided. In one example, a semiconductor device has a D-HBT structure which include a base layer formed from InGaAs and an emitter layer and a collector layer both formed from InGaP in such a way as to hold said base layer between them, wherein said InGaAs has a composition such that the content of In is smaller than 53% and said InGaP has a composition such that the content of In is just enough to make the lattice constant of said emitter layer and collector layer equal to the lattice constant of said base layer. This semiconductor device realizes a large current gain while keeping the high-speed operation owing to the base layer of InGaAs having good carrier mobility. In addition, it can be formed on a large wafer as the substrate.
Abstract: A semiconductor device includes an emitter layer: a base layer; and a collector layer, wherein the collector layer and the emitter layer each include a heavily doped thin sublayer having a high impurity concentration, and each of the heavily doped thin sublayers has an impurity concentration higher than those of semiconductor layers adjacent to each heavily doped thin sublayer.
Abstract: A hetero-junction bipolar transistor includes a sub-collector layer formed on a substrate and having conductivity, a first collector layer formed on the sub-collector layer and a second collector layer formed on the first collector layer and having the same conductive type as a conductive type of the sub-collector layer. In the first collector layer, a delta-doped layer is provided.
Type:
Application
Filed:
June 25, 2008
Publication date:
October 30, 2008
Applicant:
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Abstract: A heterojunction bipolar transistor comprising a substrate; a collector on the substrate; a base layer on the collector; an emitter layer on the base layer; the emitter layer comprising an upper emitter layer and a lower emitter layer between the upper emitter layer and base; the collector, base and emitter layers being npn or pnp doped respectively; characterised in that the lower emitter layer has a larger bandgap than the base layer and is AlxIn1-xP or GaxAl1-xP, x being in the range 0+ to 1.
Abstract: Semiconductor device structures for use with bipolar junction transistors and methods of fabricating such semiconductor device structures. The semiconductor device structure includes a semiconductor body having a top surface and sidewalls extending from the top surface to an insulating layer, a first region including a first semiconductor material with a first conductivity type, and a second region including a second semiconductor material with a second conductivity type. The first and second regions each extend across the top surface and the sidewalls of the semiconductor body. The device structure further includes a junction defined between the first and second regions and extending across the top surface and the sidewalls of the semiconductor body.
Type:
Application
Filed:
May 30, 2008
Publication date:
September 18, 2008
Applicant:
INTERNATIONAL BUSINESS MACHINES CORPORATION
Inventors:
Kangguo Cheng, Louis Lu-Chen Hsu, Jack Allan Mandelman
Abstract: Bipolar transistors and methods of forming the bipolar transistors. The method including forming a P-type collector in a silicon substrate; forming an intrinsic base on the collector, the intrinsic base including a first N-type dopant species, germanium and carbon; forming an N-type extrinsic base over a first region and a second region of the intrinsic base, the first region over the collector and the second region over a dielectric adjacent to the collector, the N-type extrinsic base containing or not containing carbon; and forming a P-type emitter on the first region of the intrinsic base.
Abstract: A heterojunction bipolar transistor includes a first conductivity type subcollector layer, a first collector layer containing a first conductivity type impurity, a third collector layer containing a higher concentration of the first conductivity type impurity than the first collector layer, a second collector layer containing a lower concentration of the first conductivity type impurity than the first collector layer, a second conductivity type base layer, a first conductivity type emitter layer containing a semiconductor with a wider bandgap than the base layer, and a first conductivity type emitter cap layer.
Abstract: A semiconductor material which has a high carbon dopant concentration includes gallium, indium, arsenic and nitrogen. The disclosed semiconductor materials have a low sheet resistivity because of the high carbon dopant concentrations obtained. The material can be the base layer of gallium arsenide-based heterojunction bipolar transistors and can be lattice-matched to gallium arsenide emitter and/or collector layers by controlling concentrations of indium and nitrogen in the base layer. The base layer can have a graded band gap that is formed by changing the flow rates during deposition of III and V additive elements employed to reduce band gap relative to different III-V elements that represent the bulk of the layer. The flow rates of the III and V additive elements maintain an essentially constant doping-mobility product value during deposition and can be regulated to obtain pre-selected base-emitter voltages at junctions within a resulting transistor.
Type:
Grant
Filed:
October 20, 2004
Date of Patent:
March 18, 2008
Assignee:
Kopin Corporation
Inventors:
Roger E. Welser, Paul M. DeLuca, Charles R. Lutz, Kevin S. Stevens, Noren Pan
Abstract: A bipolar transistor having a base electrode of an air bridge structure is simplified in structure and enhanced in the degree of freedom of a contact position of a base wiring line with the base electrode. The bipolar transistor has a semiconductor mesa portion having a base layer formed on an upper face thereof, and a base electrode contacts with the base layer and has a floating extension which extends from the semiconductor mesa portion to a space on the outer side with respect to the semiconductor mesa portion. The floating extension is used as a contact portion for a base wiring line to the base electrode.
Abstract: The Invention Is A Method For Making Power Device On A Semiconductor Wafer, Where The Backside Of The Wafer Has Been Thinned In Selected Regions To A Thickness Of About 25 Um By Reactive Ion Etching.
Type:
Grant
Filed:
September 22, 2006
Date of Patent:
October 16, 2007
Assignee:
The United States of America as represented by the Secretary of the Navy
Abstract: A memory structure having a vertically oriented access transistor with an annular gate region and a method for fabricating the structure. More specifically, a transistor is fabricated such that the channel of the transistor extends outward with respect to the surface of the substrate. An annular gate is fabricated around the vertical channel such that it partially or completely surrounds the channel. A buried annular bitline may also be implemented. After the vertically oriented transistor is fabricated with the annular gate, a storage device may be fabricated over the transistor to provide a memory cell.
Abstract: A process and intermediate DRAM structure formed by providing a substrate having an array of trenches containing trench capacitors underlying vertical transistors in an array area separated by isolation trenches residing in both array and support areas. A top oxide nitride (TON) liner is deposited over array and support areas so as to directly contact the fill in the isolation trenches. An array top oxide (ATO) is then deposited directly over the TON liner such that during subsequent processing, the TON protects the isolation trench oxide from any divot opening etches while maintaining the isolation trench oxide height fixed during the ATO process. In further processing the intermediate structure, ATO and TON are removed from the support area only, leaving remaining portions of both ATO and TON only in the array area, such that the TON liner separates the ATO from the isolation trench fill.
Type:
Grant
Filed:
April 19, 2005
Date of Patent:
August 15, 2006
Assignees:
International Business Machines Corporation, Infineon Technologies North America Corp.