V-gate Patents (Class 438/271)
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Patent number: 7259069Abstract: A semiconductor device and a method of manufacturing the same is disclosed. A trench is formed in an active region of a semiconductor substrate. A doped layer is formed on the inner walls of the trench. The trench is filled up with a first semiconductor layer. A gate insulating layer is formed on the first semiconductor layer and the substrate. Two gate electrodes are formed on the gate insulating layer such that the trench is located in between two gate electrodes. First and second impurity regions are formed in the substrate on both sides of each of the gate electrodes. Since the doped layer is locally formed in the trench area, the source and drain regions are completely separated from the heavily doped layer to weaken the electric field of PN junction, thereby improving refresh and preventing punchthrough between the source and drain.Type: GrantFiled: September 15, 2005Date of Patent: August 21, 2007Assignee: Samsung Electronics Co., Ltd.Inventors: Nak-Jin Son, Ji-Young Kim
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Patent number: 7232727Abstract: Disclosed is a method for fabricating a semiconductor device with a plurality of recessed channel regions. This method includes the steps of: forming a plurality of device isolation layers in a substrate; forming a hard mask nitride layer, a hard mask oxide layer and a hard mask polysilicon layer on the device isolation and the substrate, thereby obtaining a hard mask pattern; forming a plurality of trenches in the predetermined regions of the substrate with use of the hard mask pattern to expose a plurality of recessed channel regions; selectively removing the hard mask pattern; and forming a plurality of gate structures in the plurality of trenches.Type: GrantFiled: December 22, 2004Date of Patent: June 19, 2007Assignee: Hynix Semiconductor, Inc.Inventor: Soo-Young Park
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Patent number: 7221020Abstract: Self-aligned recessed gate structures and method of formation are disclosed. Field oxide area for isolation are first formed in a semiconductor substrate. A plurality of columns are defined in an insulating layer formed over the semiconductor substrate subsequent to which a thin sacrificial oxide layer is formed over exposed regions of the semiconductor substrate but not over the field oxide areas. A dielectric material is then provided on sidewalls of each column and over portions of the sacrificial oxide layer and of the field oxide areas. A first etch is conducted to form a first set of trenches within the semiconductor substrate and a plurality of recesses within the field oxide areas. A second etch is conducted to remove dielectric residue remaining on the sidewalls of the columns and to form a second set of trenches. Polysilicon is then deposited within the second set of trenches and within the recesses to form recessed conductive gates.Type: GrantFiled: December 1, 2004Date of Patent: May 22, 2007Assignee: Micron Technology, Inc.Inventor: Luan C. Tran
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Patent number: 7208375Abstract: A technique for improving a ruggedness of a transistor against breakdown is provided. In a transistor of the present invention, a height of filling regions is higher than that of buried regions, so that a withstanding voltage of the filling regions is higher than that of the buried regions. Therefore, since avalanche breakdown occurs in an active region, causing an avalanche breakdown current to flow through the active region having a large area, current concentration does not occur. As a result, a ruggedness of an element against breakdown is increased.Type: GrantFiled: October 19, 2004Date of Patent: April 24, 2007Assignee: Shindengen Electric Manufacturing Co., Ltd.Inventors: Toru Kurosaki, Hiroaki Shishido, Mizue Kitada, Shinji Kunori, Kosuke Ohshima
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Patent number: 7205199Abstract: A method of forming a recess channel trench pattern for forming a recess channel transistor is provided. A mask layer is formed on a semiconductor substrate, which is then patterned to expose an active region and a portion of an adjacent device isolating layer with an isolated hole type pattern. Using this mask layer the semiconductor substrate and the device isolating layer portion are selectively and anisotropically etched, thereby forming a recess channel trench with an isolated hole type pattern. The mask layer may be patterned to be a curved line type. In this case, the once linear portion is curved to allow the device isolating layer portion exposed by the patterned mask layer to be spaced apart from an adjacent active region. The semiconductor substrate and the device isolating layer portion are then etched, thereby forming a recess channel trench with a curved line type pattern.Type: GrantFiled: August 13, 2004Date of Patent: April 17, 2007Assignee: Samsung Electronics Co., Ltd.Inventors: Jong-Chul Park, Yong-Sun Ko, Tae-Hyuk Ahn
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Patent number: 7189621Abstract: Described is a method for fabricating a semiconductor device having an FET of a trench-gate structure obtained by disposing a conductive layer, which will be a gate, in a trench extended in the main surface of a semiconductor substrate, wherein the upper surface of the trench-gate conductive layer is formed higher than the main surface of the semiconductor substrate and the trench gate conductive layer and gate insulating film are formed in the trench and over the main surface of the semiconductor substrate at the periphery of the trench.Type: GrantFiled: November 12, 2004Date of Patent: March 13, 2007Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.Inventors: Hiroshi Inagawa, Nobuo Machida, Kentaro Ooishi
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Patent number: 7160793Abstract: A RESURF trench gate MOSFET has a sufficiently small pitch (close spacing of neighbouring trenches) that intermediate areas of the drain drift region are depleted in the blocking condition of the MOSFET. However, premature breakdown can still occur in this known device structure at the perimeter/edge of the active device area and/or adjacent the gate bondpad. To counter premature breakdown, the invention adopts two principles: the gate bondpad is either connected to an underlying stripe trench network surrounded by active cells, or is directly on top of the active cells, and a compatible 2D edge termination scheme is provided around the RESURF active device area. These principles can be implemented in various cellular layouts e.g.Type: GrantFiled: February 25, 2005Date of Patent: January 9, 2007Assignee: NXP B.V.Inventors: Raymond J. E. Hueting, Erwin A. Hijzen, Michael A. A. In't Zandt
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Patent number: 7157755Abstract: Method and structure for optimizing dual damascene patterning with polymeric dielectric materials are disclosed. Certain embodiments of the invention comprise polymeric sacrificial light absorbing materials (“polymer SLAM”) functionalized to have a controllable solubility switch wherein such polymeric materials have substantially the same etch rate as conventionally utilized polymeric dielectric materials, and subsequent to chemical modification of solubility-modifying protecting groups comprising the SLAM materials by thermal treatment or in-situ generation of an acid, such SLAM materials become soluble in weak bases, such as those conventionally utilized to remove materials in lithography treatments.Type: GrantFiled: February 11, 2005Date of Patent: January 2, 2007Assignee: Intel CorporationInventor: Michael D. Goodner
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Patent number: 7153745Abstract: Recessed gate transistor structures and methods for making the same prevent a short between a gate conductive layer formed on a non-active region and an active region by forming an insulation layer therebetween, even though a misalignment is generated in forming a gate. The method and structure reduce the capacitance between gates. The method includes forming a device isolation film for defining an active region and a non-active region, on a predetermined region of a semiconductor substrate. First and second insulation layers are formed on an entire face of the substrate. A recess is formed in a portion of the active region. A gate insulation layer is formed within the recess, and then a first gate conductive layer is formed within the recess. A second gate conductive layer is formed on the second insulation layer and the first gate conductive layer. Subsequently, source/drain regions are formed.Type: GrantFiled: October 12, 2004Date of Patent: December 26, 2006Assignee: Samsung Electronics Co., Ltd.Inventors: Min-Hee Cho, Ji-Young Kim
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Patent number: 7122431Abstract: Methods of forming a unit cell of a metal oxide semiconductor (MOS) transistor are provided. An integrated circuit substrate is formed. A MOS transistor is formed on the integrated circuit substrate. The MOS transistor has a source region, a drain region and a gate. The gate is between the source region and the drain region. The first and second spaced apart buffer regions are formed beneath the source region and the drain region and between respective ones of the source region and integrated circuit substrate and the drain region and the integrated circuit substrate.Type: GrantFiled: January 9, 2004Date of Patent: October 17, 2006Assignee: Samsung Electronics Co., Ltd.Inventors: Sung-Min Kim, Dong-Gun Park, Sung-Young Lee, Hye-Jin Cho, Eun-Jung Yun, Shin-Ae Lee, Chang-Woo Oh, Jeong-Dong Choe
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Patent number: 7094640Abstract: A method of forming a trench MOSFET device includes depositing an epitaxial layer over a substrate, both having the first conductivity type, the epitaxial layer having a lower majority carrier concentration than the substrate, forming a body region of a second conductivity type within an upper portion of the epitaxial layer, etching a trench extending into the epitaxial layer from an upper surface of the epitaxial layer, the trench extending to a greater depth from the upper surface of the epitaxial layer than the body region, forming a doped region of the first conductivity type between a bottom portion of the trench and substrate, the doped region having a majority carrier concentration that is lower than that of the substrate and higher than that of the epitaxial layer, wherein the doped region is diffused and spans 100% of the distance from the trench bottom portion to the substrate, forming an insulating layer lining at least a portion of the trench, forming a conductive region within the trench adjacentType: GrantFiled: December 1, 2003Date of Patent: August 22, 2006Assignee: General Semiconductor, Inc.Inventors: Fwu-Iuan Hshieh, Koon Chong So, John E. Amato, Yan Man Tsui
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Patent number: 7091080Abstract: A vertical MOSFET has a substrate of a first conductivity type. A channel region of a second conductivity type is diffused into the substrate. A gate is disposed at least partially over the channel region. A source region of a second conductivity type is disposed proximate to the gate and adjacent to the channel region. The channel region includes a depletion implant area proximate to the gate. The depletion implant species is of the second conductivity type to reduce the concentration of the first conductivity type in the channel region without increasing the conductivity in the drain/drift region.Type: GrantFiled: February 26, 2002Date of Patent: August 15, 2006Assignee: International Rectifier CorporationInventors: Kyle Spring, Jianjun Cao, Thomas Herman
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Patent number: 7053006Abstract: Oxide layers, including gate oxide layers having different thicknesses, are formed, plasma nitridized, and oxidized in an oxygen atmosphere containing hydrogen at a high temperature. Electron trap sites and stress occurring during plasma nitridation may be removed during oxidation.Type: GrantFiled: April 7, 2003Date of Patent: May 30, 2006Assignee: Samsung Electronics Co., Ltd.Inventors: Sang-jin Hyun, Sug-hun Hong, Yu-gyun Shin
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Patent number: 7049194Abstract: A trench DMOS transistor device that comprises: (a) a substrate of a first conductivity type; (b) an epitaxial layer of first conductivity type over the substrate, wherein the epitaxial layer has a lower majority carrier concentration than the substrate; (c) a trench extending into the epitaxial layer from an upper surface of the epitaxial layer; (d) an insulating layer lining at least a portion of the trench; (e) a conductive region within the trench adjacent the insulating layer; (f) a body region of a second conductivity type provided within an upper portion of the epitaxial layer and adjacent the trench; (g) a source region of first conductivity type within an upper portion of the body region and adjacent the trench; and (h) one or more low resistivity deep regions extending into the device from an upper surface of the epitaxial layer. The low resistivity deep region acts to provide electrical contact with the substrate, which is a common drain region for the device.Type: GrantFiled: December 1, 2003Date of Patent: May 23, 2006Assignee: General Semiconductor, Inc.Inventors: Fwu-Iuan Hshieh, Koon Chong So, William John Nelson, John E. Amato
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Patent number: 7041572Abstract: A fabrication method for a semiconductor device. On a semiconductor silicon substrate with a first type conductivity, an epitaxial layer with a second type conductivity and an oxide layer on the epitaxial layer are formed with at least a deep trench. Ion implantation is used to form an ion diffusion region with the first type conductivity which is formed in the epitaxial layer and surrounds the sidewall and bottom of the deep trench. An oxide liner is formed on the sidewall and bottom of the deep trench, and then an undoped polysilicon layer is formed to fill the deep trench. The combination of the ion diffusion region and the undoped polysilicon layer serves as a deep trench isolation structure.Type: GrantFiled: March 8, 2004Date of Patent: May 9, 2006Assignee: Vanguard International Semiconductor CorporationInventors: Jia-Wei Yang, Chih-Cherng Liao
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Patent number: 7018899Abstract: Methods for fabricating LDMOS transistors are disclosed. A disclosed method includes: forming a device isolation structure in a semiconductor substrate through an STI process; forming a photoresist pattern exposing the device isolation structure; forming double diffused wells by implanting ions into the substrate; removing the exposed device isolation structure; and removing the photoresist pattern.Type: GrantFiled: December 30, 2004Date of Patent: March 28, 2006Assignee: DongbuAnam Semiconductor, Inc.Inventor: Woong Je Sung
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Patent number: 6998676Abstract: A semiconductor device has a fin-type transistor formed in a projecting semiconductor region. The projecting semiconductor region is formed on a major surface of a semiconductor substrate of a first conductivity type. A gate electrode of the fin-type transistor is formed on at least opposed side surfaces of the projecting semiconductor region, with a gate insulating film interposed. Source and drain regions are formed in the projecting semiconductor region such that the source and drain regions sandwich the gate electrode. A channel region of the first conductivity type is formed in the projecting semiconductor region between the source and drain regions. The following relationship is established: TFIN?(?/4qNCH)1/2 where TFIN is a width of the projecting semiconductor region, NCH is an impurity concentration in the channel region, ? is a dielectric constant of a semiconductor material of the projecting semiconductor region, and q is an elementary charge.Type: GrantFiled: December 23, 2003Date of Patent: February 14, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Masaki Kondo, Ryota Katsumata
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Patent number: 6987040Abstract: A MOSFET device (50) has a trench (60) extending from a major surface (56) of the device (50). Within the trench (60), a gate structure (62) is formed where the top surface (64) is below the major surface (56). Source regions (66, 68) are formed along a vertical wall (84) inside of the trench (60). The source regions (66, 68) have a horizontal component along the major surface (56) and a vertical component extending the vertical wall (84). The majority of the source regions (66, 68) are formed along the vertical wall (84) within the trench (60). A typical aspect ratio of the vertical length of the source regions (66, 68) to the horizontal width is greater than 3:1. An Inter-layer dielectric (ILD) layer (74) is formed on the gate structure (62) within the trench (60) below the major surface (56).Type: GrantFiled: September 27, 2004Date of Patent: January 17, 2006Assignee: Semiconductor Components Industries, L.L.C.Inventor: Prasad Venkatraman
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Patent number: 6977203Abstract: A method of forming a trench within a semiconductor substrate. The method comprises, for example, the following: (a) providing a semiconductor substrate; (b) providing a patterned first CVD-deposited masking material layer having a first aperture over the semiconductor substrate; (c) depositing a second CVD-deposited masking material layer over the first masking material layer; (d) etching the second masking material layer until a second aperture that is narrower than the first aperture is created in the second masking material within the first aperture; and (e) etching the semiconductor substrate through the second aperture such that a trench is formed in the semiconductor substrate. In preferred embodiments, the method of the present invention is used in the formation of trench MOSFET devices.Type: GrantFiled: November 20, 2001Date of Patent: December 20, 2005Assignee: General Semiconductor, Inc.Inventors: Fwu-Iuan Hshieh, Koon Chong So, John E. Amato, Brian D. Pratt
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Patent number: 6956264Abstract: In semiconductor devices which include an insulated trench electrode (11) in a trench (20), for example, trench-gate field effect power transistors and trenched Schottky diodes, a cavity (23) is provided between the bottom (25) of the trench electrode (11) and the bottom (27) of the trench (20) to reduce the dielectric coupling between the trench electrode (11) and the body portion at the bottom (27) of the trench in a compact manner. In power transistors, the reduction in dielectric coupling reduces switching power losses, and in Schottky diodes, it enables the trench width to be reduced.Type: GrantFiled: December 3, 2002Date of Patent: October 18, 2005Assignee: Koninklijke Philips Electronics N.V.Inventors: Erwin A. Hijzen, Michael A. A. In't Zandt, Raymond J. E. Hueting
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Patent number: 6921698Abstract: A method for fabricating a thin film transistor (TFT) is described. A MoNb gate is formed on a substrate, and an insulating layer is formed on the substrate covering the gate. A channel layer is formed on the insulating layer above the gate, and a source/drain is formed on the channel layer to constitute a TFT. Since the gate is constituted of a MoNb layer, the contact resistance thereof can be reduced.Type: GrantFiled: September 29, 2003Date of Patent: July 26, 2005Assignee: Chunghwa Picture Tubes, Ltd.Inventors: Yu-Chou Lee, Wen-Kuang Tsao
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Patent number: 6916712Abstract: An improved trench MOS-gated device comprises a monocrystalline semiconductor substrate on which is disposed a doped upper layer. The upper layer includes at an upper surface a plurality of heavily doped body regions having a first polarity and overlying a drain region. The upper layer further includes at its upper surface a plurality of heavily doped source regions having a second polarity opposite that of the body regions A gate trench extends from the upper surface of the upper layer to the drain region and separates one source region from another. The trench has a floor and sidewalls comprising a layer of dielectric material and contains a conductive gate material filled to a selected level and an isolation layer of dielectric material that overlies the gate material and substantially fills the trench. The upper surface of the overlying layer of dielectric material in the trench is thus substantially coplanar with the upper surface of the upper layer.Type: GrantFiled: November 9, 2001Date of Patent: July 12, 2005Assignee: Fairchild Semiconductor CorporationInventors: Christopher B. Kocon, Jun Zeng
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Patent number: 6888196Abstract: In a vertical MOSFET comprises: a semiconductor layer (1, 2, 9, 10) having first and second surfaces opposite to each other and trenches (6) formed on the first surface; trench gates (8) formed in the trenches; a unit cell formed in a region of the semiconductor layer surrounded by the trench gates, the unit cell comprising a base layer (9) and a source layer (10) formed on the base layer and having the first surface as a principal semiconductor surface, the unit cell having a contact hole (12) formed on a center of the principal semiconductor surface and extending from the principal semiconductor surface through the source layer to an inside of the base layer; a contact (17) formed in the contact hole; a source electrode (18) formed on the contact; and a drain electrode (19) formed on the second surface, the contact is formed to a depth different to a peak depth which is a position having a maximum impurity-concentration in a depth direction of the base layer.Type: GrantFiled: April 24, 2003Date of Patent: May 3, 2005Assignee: NEC Electronics CorporationInventor: Kenya Kobayashi
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Patent number: 6875657Abstract: A process for manufacturing a trench MIS device includes depositing a conformal nitride layer in the trench; etching the nitride layer to create an exposed area at the bottom of the trench; and heating the substrate and thereby growing an oxide layer in the exposed area. This process causes the mask layer to “lift off”, creating a “bird's beak” structure. This becomes a “transition region”, where the thickness of the oxide layer decreases gradually in a direction away from the exposed area. The method further includes diffusing a dopant into the substrate, the dopant forming a PN junction with a remaining portion of said substrate, and controlling the diffusion such that the PN junction intersects the trench in the transition region. Because the thickness of the oxide layer decreases gradually, the PN junction does not need to be located at a particular point, i.e., there is a margin of error. This improves the manufacturability of the device and enhances its breakdown characteristics.Type: GrantFiled: March 26, 2002Date of Patent: April 5, 2005Assignee: Siliconix incorporatedInventors: Christiana Yue, Mohamed N. Darwish, Frederick P. Giles, Kam Hong Lui, Kuo-In Chen, Kyle Terrill, Deva N. Pattanayak
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Patent number: 6867083Abstract: A transistor (10, 30, 60) is formed to have a body contact (16, 36, 69) that has a minimal contact to the sides of the source region (14, 34, 63). This increases the density and reduces on-resistance of the transistor (10, 30, 60).Type: GrantFiled: May 1, 2003Date of Patent: March 15, 2005Assignee: Semiconductor Components Industries, LLCInventors: Mohamed Imam, Jefferson W. Hall
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Patent number: 6861701Abstract: Power MOSFETs and fabrication processes for power MOSFETs use a continuous conductive gate structure within trenches to avoid problems arising from device topology caused when a gate bus extends above a substrate surface. The conductive gate structure forms gates in device trenches in an active device region and forms a gate bus in a gate bus trench. The gate bus trench that connects to the device trenches can be wide to facilitate forming a gate contact to the gate bus, while the device trenches can be narrow to maximize device density. CMP process can be used to planarize the conductive gate structure and/or overlying insulating layers. The processes are compatible with processes forming self-aligned or conventional contacts in the active device region.Type: GrantFiled: March 5, 2003Date of Patent: March 1, 2005Assignees: Advanced Analogic Technologies, Inc., Advanced Analogic Technologies (Hong Kong) LimitedInventors: Richard K. Williams, Michael E. Cornell, Wai Tien Chan
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Patent number: 6855982Abstract: A method of manufacturing an integrated circuit with a strained semiconductor channel region. The method can provide a double gate structure. The gate structure can be provided in and above a trench. The trench can be formed in a compound semiconductor material such as a silicon-germanium material. The strained semiconductor can increase the charge mobility associated with the transistor. A silicon-on-insulator substrate can be used.Type: GrantFiled: February 2, 2004Date of Patent: February 15, 2005Assignee: Advanced Micro Devices, Inc.Inventors: Qi Xiang, James N. Pan, Ming Ren Lin
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Patent number: 6855601Abstract: The trench-gate (11) of, for example, a cellular power MOSFET comprises doped poly-Si or other semiconductor material (11a) adjacent to the gate dielectric layer (17) adjacent to the channel-accommodating region (15) of the device. The gate (11) also comprises a sizeable silicide part (11b) that reduces gate resistance. This silicide part (11b) protrudes upwardly from the trench (20) over a distance (z) typically larger than the width (w) of the trench (20), so forming an upstanding part (11b) of a metal silicide material between its top and sidewalls above the level of the body surface (10a). The gate dielectric layer (17) at least adjacent to the channel-accommodating region (15) is protected from the metal silicide by at least the semiconductor part (11a) of the gate and by the protrusion (z) of the silicide part (11b) upwardly above the level of the body surface (10a).Type: GrantFiled: December 11, 2003Date of Patent: February 15, 2005Assignee: Koninklijke Philips Electronics N.V.Inventor: Mark A. Gajda
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Patent number: 6841825Abstract: A technique for improving a ruggedness of a transistor against breakdown is provided. In a transistor of the present invention, a height of filling regions is higher than that of buried regions, so that a withstanding voltage of the filling regions is higher than that of the buried regions. Therefore, since avalanche breakdown occurs in an active region, causing an avalanche breakdown current to flow through the active region having a large area, current concentration does not occur. As a result, a ruggedness of an element against breakdown is increased.Type: GrantFiled: June 2, 2003Date of Patent: January 11, 2005Assignee: Shindengen Electric Manufacturing Co., Ltd.Inventors: Toru Kurosaki, Hiroaki Shishido, Mizue Kitada, Shinji Kunori, Kosuke Ohshima
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Patent number: 6821851Abstract: A method of fabricating a VRG MOSFET includes the steps of: (a) forming a VRG multilayer stack; (b) forming a trench in the stack; (c) depositing an ultra thin, amorphous semiconductor (&agr;-semic) layer on the sidewalls of the trench (portions of the ultra thin layer on the sidewalls of the trench will ultimately form the channel or ultra thin body (UTB) of the MOSFET); (d) forming a thicker, &agr;-semic sacrificial layer on the ultra thin layer; (e) annealing the &agr;-semic layers to recrystallize them into single crystal layers; (f) selectively removing the recrystallized sacrificial layer; and (g) performing additional steps to complete the VRG MOSFET. In general, the sacrificial layer should facilitate the recrystallization of the ultra thin layer into single crystal material.Type: GrantFiled: August 27, 2003Date of Patent: November 23, 2004Assignee: Agere Systems Inc.Inventors: John Michael Hergenrother, Pranav Kalavade
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Patent number: 6821834Abstract: Fin-type field effect transistors are fabricated on a semiconductor substrate. Rectangular fins are formed on the substrate in a rectangular pattern of rows and columns and gate electrodes are deposited on at least two sides of the fins. The gate electrodes are implanted with ions at an angle &thgr; to a line perpendicular to the substrate, such that D≈H tan &thgr;, where D is the distance between fins in adjacent rows or columns and H is the height of the fins.Type: GrantFiled: December 4, 2002Date of Patent: November 23, 2004Inventor: Yoshiyuki Ando
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Patent number: 6818948Abstract: A split gate flash memory device and method of fabricating the same. A cell of the split gate flash memory device in accordance with the invention is disposed in a cell trench within a substrate to achieve higher integration of memory cells.Type: GrantFiled: July 16, 2003Date of Patent: November 16, 2004Assignee: Nanya Technology CorporationInventor: Chi-Hui Lin
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Patent number: 6818939Abstract: In one embodiment, a compound semiconductor vertical FET device (11) includes a first trench (29) formed in a body of semiconductor material (13), and a second trench (34) formed within the first trench (29) to define a channel region (61). A doped gate region (59) is then formed on the sidewalls and the bottom surface of the second trench (34). Source regions (26) are formed on opposite sides of the double trench structure (28). Localized gate contact regions (79) couple individual doped gate regions (59) together. Contacts (84, 85, 87) are then formed to the localized gate contact regions (79), the source regions (26), and an opposing surface (21) of the body of semiconductor material (13). The structure provides a compound semiconductor vertical FET device (11, 41, 711, 712, 811, 812) having enhanced blocking capability and improved switching performance.Type: GrantFiled: July 18, 2003Date of Patent: November 16, 2004Assignee: Semiconductor Components Industries, L.L.C.Inventor: Peyman Hadizad
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Patent number: 6818947Abstract: In a power semiconductor device 10, a continuous trench has an outer circumferential portion 58 that includes a field plate and inner portions 28 that carry include one or more gate runners 34 to that the gate runners and the field plate are integral with each other. The trench structure 58, 28 is simpler to form and takes up less surface space that the separate structures of the prior art. The trench is lined with an insulator and further filled with conductive polysilicon and a top insulator.Type: GrantFiled: September 19, 2002Date of Patent: November 16, 2004Assignee: Fairchild Semiconductor CorporationInventors: Thomas E. Grebs, Christopher B. Kocon, Rodney S. Ridley, Sr., Gary M. Dolny, Nathan Lawrence Kraft, Louise E. Skurkey
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Patent number: 6818946Abstract: A MOSFET device (50) has a trench (60) extending from a major surface (56) of the device (50). Within the trench (60), a gate structure (62) is formed where the top surface (64) is below the major surface (56). Source regions (66,68) are formed along a vertical wall (84) inside of the trench (60). The source regions (66,68) have a horizontal component along the major surface (56) and a vertical component extending the vertical wall (84). The majority of the source regions (66,68) are formed along the vertical wall (84) within the trench (60). A typical aspect ratio of the vertical length of the source regions (66,68) to the horizontal width is greater than 3:1. An Inter-layer dielectric (ILD) layer (74) is formed on the gate structure (62) within the trench (60) below the major surface (56).Type: GrantFiled: August 28, 2000Date of Patent: November 16, 2004Assignee: Semiconductor Components Industries, L.L.C.Inventor: Prasad Venkatraman
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Patent number: 6806174Abstract: Semiconductor devices and methods for fabrication the same are disclosed. An illustrated method of fabricating a semiconductor device comprises: forming a trench on a substrate; forming a gate electrode by depositing and planarizing an oxide layer and polysilicon on the substrate including the trench; forming a gate oxide layer and a polysilicon layer on the substrate; forming source/drain regions by a photo process; and forming a contact plug on at least one of the source/drain regions. By controlling the overlap between the gate and the source/drain regions using a source/drain mask, current control becomes easy and a device sensitive to current control is easily fabricated. Sufficient spaces between the gate and the contact(s) due to the buried type gate make the fabrication processes easy.Type: GrantFiled: January 15, 2004Date of Patent: October 19, 2004Assignee: ANAM Semiconductor, Inc.Inventor: Ik Soo Do
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Patent number: 6798013Abstract: A unique cell structure for use in flash memory cell and a method of fabricating the memory cell. More particularly, a vertically integrated transistor having a pair of floating gates is fabricated within a trench in a substrate. The floating gates are fabricated using sidewall spacers within the trench. A doped region is buried at the bottom of the trench. The structure can be fabricated such that the buried doped region provides a connecting layer in a multi-bit flash memory cell. Alternatively, the buried doped region may be used as a buried bitline in a single bit flash memory cell.Type: GrantFiled: August 28, 2002Date of Patent: September 28, 2004Inventor: Fernando Gonzalez
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Patent number: 6777293Abstract: A double diffused MOS (DMOS) transistor structure is provided that uses a trench trough suitable for high-density integration with mixed signal analog and digital circuit applications. The DMOS device can be added to any advanced CMOS process-using shallow trench isolation by adding additional process steps for trench trough formation, a trench implant and a P-body implant. The trench trough and trench implant provide a novel method of forming a drain extension for a high-voltage DMOS device.Type: GrantFiled: December 1, 2003Date of Patent: August 17, 2004Assignee: National Semiconductor CorporationInventor: Waclaw C. Koscielniak
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Patent number: 6777743Abstract: An insulating gate type semiconductor device has a plurality of trench gate electrodes provided substantially in parallel. In this semiconductor device, among the trench gate electrodes, a thinning-out trench gate electrode excluding a channel-forming trench gate electrode is insulated from a gate wire and is connected to an emitter electrode or to a predetermined electric potential generating device for generating a negative electric potential with respect to an emitter potential. With this construction, a gate capacitance is decreased without drawbacks such as a decline of manufacturing yield and an increase in gate wire resistance, there are decreased oscillations of waveforms of voltage and current when in switching in the case of an element having a large area and operating the elements in parallel.Type: GrantFiled: February 4, 2002Date of Patent: August 17, 2004Assignee: Kabushiki Kaisha ToshibaInventor: Shigeru Hasegawa
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Patent number: 6764906Abstract: A trench MOSFET is formed in a structure which includes a P-type epitaxial layer overlying an N+ substrate. A trench is formed in the epitaxial layer. A deep implanted N layer is formed below the trench at the interface between the substrate and the epitaxial layer, and N-type dopant is implant through the bottom of the trench to form an N region in the epitaxial layer below the trench but above and separated from the deep N layer. The structure is heated to cause the N layer to diffuse upward and the N region to diffuse downward. The diffusions merge to form a continuous N-type drain-drift region extending from the bottom of the trench to the substrate. Alternatively, the drain-drift region may be formed by implanting N-type dopant through the bottom of the trench at different energies, creating a stack of N-type regions that extend from the bottom of the trench to the substrate.Type: GrantFiled: December 12, 2002Date of Patent: July 20, 2004Assignee: Siliconix incorporatedInventor: Mohamed N. Darwish
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Patent number: 6713814Abstract: A double diffused MOS (DMOS) transistor structure is provided that uses a trench trough suitable for high-density integration with mixed signal analog and digital circuit applications. The DMOS device can be added to any advanced CMOS process using shallow trench isolation by adding additional process steps for trench trough formation, a trench implant and a P-body implant. The trench trough and trench implant provide a novel method of forming a drain extension for a high-voltage DMOS device.Type: GrantFiled: August 5, 2002Date of Patent: March 30, 2004Assignee: National Semiconductor CorporationInventor: Waclaw C. Koscielniak
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Patent number: 6710402Abstract: Disclosed are a vertical MOS transistor which lowers the gate resistance, improves the high frequency characteristics, and improves the yield compared with a conventional one and a method of manufacturing the same. When gate voltage is applied to a gate electrode, a channel is formed in a body region along a trench, and electrons or current flow(s) from a drain layer to a source layer. Here, a gate in the trench has a laminated structure of a polycrystalline silicon film and a metal silicide. Therefore, a gate resistance is lowered and the high frequency characteristics are improved. Further, according to the structure and the method of manufacturing, a concave portion generated at an upper portion of the gate in the trench when etching for forming the gate is less liable to be generated, and thus, malfunction and insufficient reliability due to the concave portion can be avoided.Type: GrantFiled: June 1, 2001Date of Patent: March 23, 2004Assignee: Seiko Instruments Inc.Inventor: Hirofumi Harada
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Patent number: 6693011Abstract: A power MOS element includes a drift region with a doping of a first doping type, a channel region with a doping of a second doping type which is complementary to said first doping type and which borders on said channel region and said drift region, and a source region with a doping of said first doping type, said source region bordering on said channel region. Furthermore, said power MOS element includes a plurality of basically parallel gate trenches which extend to said drift region and which comprise an electrically conductive material which is insulated from the transistor region by an insulator. The individual gate trenches are connected by a connecting gate trench, a gate contact only being connected in an electrically conductive way to the active gate trenches via contact holes in said connecting gate trench.Type: GrantFiled: August 21, 2002Date of Patent: February 17, 2004Assignee: Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung e.V.Inventors: Uwe Wahl, Holger Vogt
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Patent number: 6686625Abstract: The semiconductor component can be controlled by the field effect and it blocks in both directions. The component has a semiconductor body with a first connecting zone, a second connecting zone and a channel zone formed between the first and the second connecting zone. A control electrode is formed adjacent to the channel zone such that it is isolated from the semiconductor body. In order to avoid a reduction in the withstand voltage due to a parasitic bipolar transistor, a recombination zone, which is formed from a material that assists the recombination of charge carriers of the first and second conductivity types, is formed in the channel zone and the second connecting zone.Type: GrantFiled: December 5, 2001Date of Patent: February 3, 2004Assignee: Infineon Technologies AGInventor: Jenoe Tihanyi
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Patent number: 6687114Abstract: A memory cell having a transistor and a capacitor formed in a silicon substrate. The capacitor is formed with a lower electrically conductive plate etched in a projected surface area of the silicon substrate. The lower electrically conductive plate has at least one cross section in the shape of a vee, where the sides of the vee are disposed at an angle of about fifty-five degrees from a top surface of the silicon substrate. The surface area of the lower electrically conductive plate is about seventy-three percent larger than the projected surface area of the silicon substrate in which the lower electrically conductive plate is etched. A capacitor dielectric layer is formed of a first deposited dielectric layer, which is disposed adjacent the lower electrically conductive plate. A top electrically conductive plate is disposed adjacent the capacitor dielectric layer and opposite the lower electrically conductive plate.Type: GrantFiled: March 31, 2003Date of Patent: February 3, 2004Assignee: LSI Logic CorporationInventors: Arvind Kamath, Ruggero Castagnetti
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Patent number: 6680511Abstract: The present invention provide integrated circuit devices and methods of fabricating the same that include a microelectronic substrate and a conductive layer disposed on the microelectronic substrate. An insulating layer is disposed on the conductive layer and the insulating layer includes an overhanging portion that extends beyond the conductive layer. A sidewall insulating region is disposed laterally adjacent to a sidewall of the conductive layer and extends between the overhanging portion of the insulating layer and the microelectronic substrate.Type: GrantFiled: January 18, 2002Date of Patent: January 20, 2004Assignee: Samsung Electronics Co., Ltd.Inventors: Hyoung-Joon Kim, Young-Wook Park, Byeong-Yun Nam
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Patent number: 6664592Abstract: A semiconductor device includes a semiconductor substrate, a gate insulator film formed on a bottom surface and a side surface of a groove formed in the semiconductor substrate, a gate electrode having a lower portion buried in the groove on whose bottom and side surface the gate insulator film is formed, and an upper portion protruding a surface of said semiconductor substrate, and source region and a drain region formed on a surface of the semiconductor substrate in such a way as to sandwich the gate electrode. A thickness of the upper portion of the gate electrode protruding the surface of the semiconductor substrate is equal to or greater than twice a thickness of the lower portion of the gate electrode buried in the groove.Type: GrantFiled: December 30, 2002Date of Patent: December 16, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Seiji Inumiya, Tomohiro Saito, Atsushi Yagishita, Katsuhiko Hieda, Toshihiko Iinuma
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Patent number: 6653691Abstract: Integrated power devices include a plurality of field effect transistor unit cells and a Faraday shield layer that reduces parasitic gate-to-drain capacitance (Cgd) and concomitantly improves high frequency switching performance. These power devices may include a field effect transistor in an active portion of a semiconductor substrate and a gate electrode that is electrically connected to a gate of the field effect transistor. A Faraday shield layer is provided between at least a first portion of the gate electrode and a drain of the field effect transistor in order to capacitively decouple the first portion of the gate electrode from the drain. The gate electrode and drain typically extend adjacent opposing faces of the semiconductor substrate. The Faraday shield layer is preferably electrically connected to a source of the field effect transistor and provides edge termination.Type: GrantFiled: November 5, 2001Date of Patent: November 25, 2003Assignee: Silicon Semiconductor CorporationInventor: Bantval Jayant Baliga
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Patent number: 6635535Abstract: A power MOSFET 100 has a source metal 112 that contacts silicided source regions 114 through vias 160 etched in an insulating layer 200. The silicide layer 225 provides for a relatively small but highly conductive contact and thus reduces RDSON. The insulating material may be any suitable material including and not limited to one or a combination of materials such as BPSG, PSG, silicon dioxide and silicon nitride. The insulating layer is relatively thin and does not extend deeply into the gate trench, thereby reducing capacitance.Type: GrantFiled: November 20, 2001Date of Patent: October 21, 2003Assignee: Fairchild Semiconductor CorporationInventors: Jifa Hao, Rodney S. Ridley, Gary M. Dolny
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Patent number: 6586800Abstract: A trench-gate MOSFET or ACCUFET has its gate (21) in a first trench (20) that extends through a channel-accommodating body region (15) to a drain region (14). Within the transistor cells, a second trench (40) comprising deposited highly-doped semiconductor material (41) extends to the drain region (14). This highly-doped material (41) is of opposite conductivity type to the drain region (14) and, together with a possible out-diffusion profile (42), forms a localized region (41, 42) that is separated from the first trench (20) by the body region 15. A source electrode (23) contacts the source region (13) and the whole top area of the localized region (41, 42). In a MOSFET, the localized region (41, 42) provides protection against turning on of the cell's parasitic bipolar transistor. In an ACCUFET (FIG. 9), the localized region (41, 42) depletes the channel-accommodating body region (15A).Type: GrantFiled: May 11, 2001Date of Patent: July 1, 2003Assignee: Koninklijke Philips Electronics N.V.Inventor: Adam R. Brown