Source Region And Drain Region Having Nonsymmetrical Structure About Gate Electrode (epo) Patents (Class 257/E29.268)
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Patent number: 7576388Abstract: MOSFET devices for RF applications that use a trench-gate in place of the lateral gate conventionally used in lateral MOSFET devices. A trench-gate provides devices with a single, short channel for high frequency gain. Embodiments of the present invention provide devices with an asymmetric oxide in the trench gate, as well as LDD regions that lower the gate-drain capacitance for improved RF performance. Refinements to these TG-LDMOS devices include placing a source-shield conductor below the gate and placing two gates in a trench-gate region. These improve device high-frequency performance by decreasing gate-to-drain capacitance. Further refinements include adding a charge balance region to the LDD region and adding source-to-substrate or drain-to-substrate vias.Type: GrantFiled: September 26, 2004Date of Patent: August 18, 2009Assignee: Fairchild Semiconductor CorporationInventors: Peter H. Wilson, Steven Sapp
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Patent number: 7566934Abstract: A semiconductor device is formed on an SOI substrate having a silicon layer formed on an insulating layer. A transistor element is formed in the silicon layer of the SOI substrate. An isolation film for electrically isolating the transistor element is formed in the silicon layer of the SOI substrate by LOCOS so that a parasitic transistor is formed. Impurity diffusion regions are disposed at an end of the isolation film and at a boundary of a source region of the transistor element with a channel forming region. The impurity diffusion regions have a polarity opposite to that of the source region. A current path due to a parasitic channel in the parasitic transistor is suppressed.Type: GrantFiled: February 16, 2007Date of Patent: July 28, 2009Assignee: Seiko Instruments Inc.Inventor: Hisashi Hasegawa
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Patent number: 7560348Abstract: A PMOS device can be designed and manufactured in accordance with the invention to locate its drain junction breakdown point and maximum impact ionization point to reduce or eliminate drain breakdown voltage walk-in. In some embodiments, the drain junction breakdown point and maximum impact ionization point are located sufficiently far from the gate that the device exhibits no significant drain breakdown voltage walk-in. The device can be a high voltage power transistor having an extended drain region including a P-type lightly doped drain (P-LDD) implant, with drain junction breakdown and maximum impact ionization points appropriately located by controlling the implant dose employed to produce the P-LDD implant.Type: GrantFiled: February 14, 2007Date of Patent: July 14, 2009Assignee: National Semiconductor CorporationInventors: Douglas Brisbin, Andrew Strachan
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Publication number: 20090167662Abstract: A cellular transistor includes an N-type heavily doped (N+) buried layer (NBL), an N-well connected to the NBL, an N+ layer connected to the N-well and multiple drains. The N-well is formed after formation of the NBL. The N+ layer is formed after formation of the N-well. The multiple drains are connected to the NBL via the N-well and the N+ layer.Type: ApplicationFiled: March 6, 2009Publication date: July 2, 2009Inventors: Jungcheng KAO, Yanjun Li
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Patent number: 7527994Abstract: The present invention provides amorphous silicon thin-film transistors and methods of making such transistors for use with active matrix displays. In particular, one aspect of the present invention provides transistors having a structure based on a channel passivated structure wherein the amorphous silicon layer thickness and the channel length can be optimized. In another aspect of the present invention thin-film transistor structures that include a contact enhancement layer that can provide a low threshold voltage are provided.Type: GrantFiled: September 1, 2004Date of Patent: May 5, 2009Assignee: Honeywell International Inc.Inventors: Kalluri R. Sarma, Charles S. Chanley
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Patent number: 7525150Abstract: A method of fabricating a high voltage MOS transistor with a medium operation voltage on a semiconductor wafer. The transistor has a double diffused drain (DDD) and a medium operation voltage such as 6 to 10 volts, which is advantageous for applications having both low and higher operation transistor devices. The second diffusion region of the DDD is self-aligned to the spacer on the sidewalls of the gate and gate dielectric, so that the transistor size may be decreased.Type: GrantFiled: April 7, 2004Date of Patent: April 28, 2009Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Fu-Hsin Chen, Yi-Chun Lin, Ruey-Hsin Liu
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Publication number: 20090090980Abstract: The present invention proposes a new asymmetric-lightly-doped drain (LDD) metal oxide semiconductor (MOS) transistor that is fully embedded in a CMOS logic. The radio frequency (RF) power performance of both conventional and asymmetric MOS transistor is measured and compared. The output power can be improved by 38% at peak power-added efficiency (PAE). The PAE is also improved by 16% at 10-dBm output power and 2.4 GHz. These significant improvements of RF power performance by this new MOS transistor make the RF-CMOS system-on-chip design a step further. Index Terms—Lightly-doped-drain (LDD), metal oxide semiconductor field effect transistor (MOSFET), metal oxide semiconductor (MOS) transistor, radio frequency (RF) power transistor.Type: ApplicationFiled: October 8, 2007Publication date: April 9, 2009Inventors: Mingchu King, Albert Chin
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Patent number: 7514747Abstract: A semiconductor device formed in a silicon-on-insulator substrate includes a silicon channel region located between silicon source and drain regions, and a low-carrier-concentration layer that underlies the channel region. The low-carrier-concentration layer makes contact with both the channel region and the source region. The channel region and the low-carrier-concentration layer are of the same conductive type, but the low-carrier-concentration layer is doped to have a lower carrier concentration than the channel region. The low-carrier-concentration layer eliminates the floating substrate effect, because carriers that would otherwise accumulate in the channel region can escape through the low-carrier-concentration layer into the source region.Type: GrantFiled: May 18, 2007Date of Patent: April 7, 2009Assignee: Oki Semiconductor Co., Ltd.Inventor: Koichi Fukuda
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Publication number: 20080296677Abstract: A semiconductor device is provided with a silicon pillar formed substantially perpendicularly to a main surface of a substrate, a gate electrode covering side surface of the silicon pillar via a gate insulation film, a conductive layer provided on an upper part of the silicon pillar, a cylindrical sidewall insulation film intervening between the conductive layer and the gate electrode so as to insulate therebetween. An inner wall of the side wall insulation film is in contact with the conductive layer, and an outer wall of the side wall insulation film is in contact with the gate electrode.Type: ApplicationFiled: May 30, 2008Publication date: December 4, 2008Applicant: ELPIDA MEMORY, INCInventor: Yoshihiro TAKAISHI
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Publication number: 20080290422Abstract: A semiconductor structure. The structure includes (a) a semiconductor channel region, (b) a semiconductor source block in direct physical contact with the semiconductor channel region; (c) a source contact region in direct physical contact with the semiconductor source block, wherein the source contact region comprises a first electrically conducting material, and wherein the semiconductor source block physically isolates the source contact region from the semiconductor channel region, and (d) a drain contact region in direct physical contact with the semiconductor channel region, wherein the semiconductor channel region is disposed between the semiconductor source block and the drain contact region, and wherein the drain contact region comprises a second electrically conducting material; and (e) a gate stack in direct physical contact with the semiconductor channel region.Type: ApplicationFiled: July 8, 2008Publication date: November 27, 2008Inventor: Edward J. Nowak
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Publication number: 20080237707Abstract: A semiconductor device includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of the first conductivity type provided on the first semiconductor layer, having a lower impurity concentration than the first semiconductor layer, a third semiconductor layer of a second conductivity type provided on the second semiconductor layer, a base region of the second conductivity type provided in the third semiconductor layer, a source region of the first conductivity type provided in the base region, a first drain region of the first conductivity type provided in the third semiconductor layer, the first drain region being apart from the base region, a lightly doped drain region of the first conductivity type provided between the first drain region and the source region, the lightly doped drain region being in contact with the first drain region, the lightly doped drain having lower impurity concentration than the first drain region, a second drain region of the first conductivity tType: ApplicationFiled: November 30, 2007Publication date: October 2, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Fumito SUZUKI, Koichi Endo
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Patent number: 7420241Abstract: A semiconductor memory device includes a memory cell which includes a first gate insulation film provided on the semiconductor substrate; a floating gate electrode provided on the first gate insulation film; a second gate insulation film provided on the floating gate electrode; a control gate electrode provided on the second gate insulation film; a source layer and a drain layer that are provided in the semiconductor substrate, the source layer and the drain layer respectively being provided either side of a channel region which is below the floating gate electrode; a source electrode that is electrically connected to the source layer; a buffer film provided on the drain layer; and a memory cell including a drain electrode electrically connected to the drain layer through the buffer film, wherein when viewing the surface of the semiconductor substrate from above, an overlapped area between the floating gate electrode and the drain layer is smaller than an overlapped area between the floating gate electrode anType: GrantFiled: November 21, 2005Date of Patent: September 2, 2008Assignee: Kabushiki Kaisha ToshibaInventor: Takamitsu Ishihara
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Patent number: 7408234Abstract: An object of the present invention is to provide a semiconductor device that is able to realize a low on-resistance maintaining a high drain-to-source breakdown voltage, and a method for manufacturing thereof, the present invention including: a supporting substrate; a semiconductor layer having a P? type active region that is formed on the supporting substrate, interposing a buried oxide film between the semiconductor layer and the supporting substrate; and a gate electrode that is formed on the semiconductor layer, interposing a gate oxide film and a part of a LOCOS film between the gate electrode and the semiconductor layer, wherein the P? type active region has: an N+ type source region; a P type body region; a P+ type back gate contact region; an N type drain offset region; an N+ type drain contact region; and an N type drain buffer region that is formed in a limited region between the N type drain offset region and the P type body region, and the N type drain buffer region is in contact with a source sidType: GrantFiled: June 23, 2005Date of Patent: August 5, 2008Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hisao Ichijo, Hiroyoshi Ogura, Yoshinobu Sato, Teruhisa Ikuta
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Patent number: 7388256Abstract: In a technique to improve the high-frequency power gain of an LDMOS, the distance from the surface of a passivation film covering electrode pads to the rear surface of a silicon substrate is set into 200 ?m or less, or a trench of 2 ?m or more in thickness, in which an insulating film or a conductor is embedded, is formed between a region where a p type impurity is diffused, when a p+ type source penetrating layer is formed, and the channel region of a third LDMOS, so as to extend from the front surface of a semiconductor layer toward a silicon substrate. This trench restrains the p+ type source penetrating layer from spreading to the channel region, thereby lowering the inductance or the resistance of the source and improving the high-frequency power gain.Type: GrantFiled: June 28, 2006Date of Patent: June 17, 2008Assignee: Renesas Technology Corp.Inventors: Kingo Kurotani, Takeshi Sakamoto, Michio Yano, Kenichi Nagura
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Patent number: 7372095Abstract: An integrated semiconductor circuit includes a transistor and a strip conductor (11). The transistor includes a first (1) and a second source/drain region (2) and a gate electrode. The strip conductor (11) is electrically insulated from a semiconductor body at least by a gate dielectric and forms the gate electrode in the area of the transistor. The strip conductor (11) extends along a first direction (x) in the area of the transistor. The second source/drain region (2) is arranged offset with respect to the first source/drain region (1) in the first direction (x). The transistor thus formed has an inversion channel (K1) that only extends between two corner areas (1a, 2a) facing one another of the first and of the second source/drain region, i.e. is much narrower than in the case of a conventional transistor.Type: GrantFiled: August 26, 2005Date of Patent: May 13, 2008Assignee: Infineon Technologies AGInventor: Joerg Vollrath
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Patent number: 7355245Abstract: A field effect transistor (FET) device includes a gate conductor formed over a semiconductor substrate, a source region having a source extension that overlaps and extends under the gate conductor, and a drain region having a drain extension that overlaps and extends under the gate conductor only at selected locations along the width of the gate conductor.Type: GrantFiled: March 28, 2007Date of Patent: April 8, 2008Assignee: International Business Machines CorporationInventors: Huilong Zhu, Oleg Gluschenkov
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Publication number: 20080054356Abstract: Under a sidewall formed over a side wall of a gate electrode, a low-concentration LDD region and a high-concentration LDD region which is extremely shallow and apart from a region under the gate electrode are formed. Further, a source/drain region is formed outside these LDD regions. Since the extremely shallow high-concentration LDD region is formed under the sidewall, even if hot carriers are accumulated in the sidewall, depletion due to the hot carriers can be suppressed. Further, since the high-concentration LDD region is formed apart from a region under the gate electrode, a transverse electric field in the channel is sufficiently relaxed, so that characteristic deterioration due to a threshold shift can be suppressed.Type: ApplicationFiled: September 5, 2007Publication date: March 6, 2008Applicant: FUJITSU LIMITEDInventor: Eiji Yoshida
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Publication number: 20080042198Abstract: Embodiments relate to a Drain Extended Metal-Oxide-Semiconductor (DEMOS) structure in which a drain region may be longer than a source region. In embodiments, the DEMOS may include a gate insulating film and a gate electrode sequentially layered over a semiconductor substrate, a spacer formed at a sidewall of a gate electrode toward the source region, an insulating film pattern formed at a sidewall of the gate electrode toward the drain region to provide a great spacing between the gate electrode and the drain region, the source region formed in the substrate to be in alignment with an edge of the spacer, and the drain region formed in the substrate to be in alignment with an edge of the insulating film pattern. The spacer and the insulating film pattern may be silicon oxide films.Type: ApplicationFiled: August 16, 2007Publication date: February 21, 2008Inventor: Chul-Jin Yoon
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Patent number: 7332772Abstract: A semiconductor device, having a recessed gate and asymmetric dopant regions, comprises a semiconductor substrate having a trench with a first sidewall and a second sidewall, the heights of which are different from each other, a gate insulating layer pattern disposed on the semiconductor substrate, a gate stack disposed on the semiconductor such that the gate stack protrudes from the surface of the semiconductor substrate while the gate stack fills the trench, and first and second dopant regions disposed at the upper part of the semiconductor substrate adjacent to the first and second sidewalls of the trench, respectively, such that the first and second dopant regions have different steps.Type: GrantFiled: November 29, 2005Date of Patent: February 19, 2008Assignee: Hynix Semiconductor Inc.Inventors: Kyoung Bong Rouh, Seung Woo Seung, Min Yong Lee
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Patent number: 7307314Abstract: A LDMOS transistor having a gate shield provides reduced drain coupling to the gate shield and source by restricting the thickness of the gate shield and by confining a source contact to the source region without overlap of the gate.Type: GrantFiled: June 16, 2004Date of Patent: December 11, 2007Assignee: Cree Microwave LLCInventors: Jeff Babcock, Johan Agus Darmawan, John Mason, Ly Diep
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Patent number: 7253482Abstract: A field effect transistor (FET) device includes a gate conductor formed over a semiconductor substrate, a source region having a source extension that overlaps and extends under the gate conductor, and a drain region having a drain extension that overlaps and extends under the gate conductor only at selected locations along the width of the gate conductor.Type: GrantFiled: August 3, 2005Date of Patent: August 7, 2007Assignee: International Business Machines CorporationInventors: Huilong Zhu, Oleg Gluschenkov
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Patent number: 7161210Abstract: A semiconductor device is provided with a gate electrode formed over a substrate that has gate oxide films disposed thereon. Source-drain regions of low and high concentration are formed next to the gate electrode. A diffusion region width of the source side of the source-drain regions is smaller than at least a diffusion region width of the drain side.Type: GrantFiled: December 17, 2003Date of Patent: January 9, 2007Assignee: Sanyo Electric Co., Ltd.Inventors: Eiji Nishibe, Shuichi Kikuchi, Takuya Suzuki
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Patent number: 7112844Abstract: The objectives of the present invention are achieving TFTs having a small off current and TFT structures optimal for the driving conditions of a pixel portion and driver circuits, and providing a technique of making the differently structured TFTs without increasing the number of manufacturing steps and the production costs. A semiconductor device has a semiconductor layer, a gate insulating film on the semiconductor layer, and a gate electrode on the gate insulating film. The semiconductor layer contains a channel forming region, a region containing a first concentration impurity element, a region containing a second concentration impurity element, and a region containing a third concentration impurity element. The gate electrode is formed by laminating an electrode (A) and an electrode (B).Type: GrantFiled: April 17, 2002Date of Patent: September 26, 2006Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Ritsuko Nagao, Masahiko Hayakawa