Insulated Gate Field Effect Transistors Of Different Threshold Voltages In Same Integrated Circuit (e.g., Enhancement And Depletion Mode) Patents (Class 257/392)
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Patent number: 6703670Abstract: A semiconductor circuit with a depletion-mode transistor is formed with a method that eliminates the need for a separate mask and implant step to set the threshold voltage of the depletion-mode transistor. As a result, the method of the present invention reduces the cost and complexity associated with the fabrication of a semiconductor circuit that includes a depletion-mode transistor.Type: GrantFiled: April 3, 2001Date of Patent: March 9, 2004Assignee: National Semiconductor CorporationInventor: Terry Lines
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Patent number: 6700165Abstract: A semiconductor structure with common source line, the semiconductor structure has two word lines, some bit lines, a silicon-based layer and a suicide layer. The silicon-based layer is located between and electrically separated from these word lines, but is electrically coupled with these bit lines. The silicide layer is located over and electrically coupled with the silicon-based layer. Moreover, suicide layer and silicide layer could be replaced by a silicon-base conductor layer, and are directly electrically coupled with some separated doped regions that located inside a substrate.Type: GrantFiled: October 25, 2002Date of Patent: March 2, 2004Assignee: Winbond Electronics CorporationInventors: Po-An Chen, James Juen Hsu
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Patent number: 6696735Abstract: A semiconductor device according to one aspect of the present invention, is a semiconductor device comprising: a first MOS field effect transistor of an n-type including a first oxynitride film as a first gate insulator film; and a second MOS field effect transistor of a p-type including a second oxynitride film as a second gate insulator film, the second MOS field effect transistor being disposed adjacent to the first MOS field effect transistor; wherein a concentration of nitrogen in the first gate insulator film is different form that in the second gate insulator film.Type: GrantFiled: February 27, 2002Date of Patent: February 24, 2004Assignee: Kabushiki Kaisha ToshibaInventor: Hironobu Fukui
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Patent number: 6686633Abstract: A semiconductor device includes a memory array of static-random-access memory cells. The SRAM cells are formed using a process flow more closely associated with logic-type devices. The SRAM cells are formed using one semiconductor layer compared to at least three typically seen with SRAM cells. The SRAM cells include many features that allow its dimensions to be scaled to very small dimensions (less than 0.25 microns and possible down to 0.1 microns or even smaller). A unique process integration scheme allows formation of local interconnects (522 and 524), wherein each local interconnect (522, 524) cross couples the inverters of the SRAM and is formed within a single opening (70). Also, interconnect portions (104) of word lines are laterally offset from silicon portions (36) of the same word line, so that the interconnect portions do not interfere with bit line connections.Type: GrantFiled: August 31, 2000Date of Patent: February 3, 2004Assignee: Motorola, Inc.Inventors: Craig S. Lage, Mousumi Bhat, Yeong-Jyh Tom Lii, Andrew G. Nagy, Larry E. Frisa, Stanley M. Filipiak, David L. O'Meara, T. P. Ong, Michael P. Woo, Terry G. Sparks, Carol M. Gelatos
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Patent number: 6683353Abstract: In an integrated circuit device, there are various optimum gate lengths, thickness of gate oxide films, and threshold voltages according to the characteristics of circuits. In a semiconductor integrated circuit device in which the circuits are integrated on the same substrate, the manufacturing process is complicated in order to set the circuits to the optimum values. As a result, in association with deterioration in the yield and increase in the number of manufacturing days, the manufacturing cost increases. In order to solve the problems, according to the invention, transistors of high and low thresholds are used in a logic circuit, a memory cell uses a transistor of the same high threshold voltage and a low threshold voltage transistor, and an input/output circuit uses a transistor having the same high threshold voltage and the same concentration in a channel, and a thicker gate oxide film.Type: GrantFiled: November 21, 2002Date of Patent: January 27, 2004Assignee: Hitachi, Ltd.Inventors: Koichiro Ishibashi, Kenichi Osada
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Patent number: 6677780Abstract: In a level conversion circuit mounted in an integrated circuit device using a plurality of high- and low-voltage power supplies, the input to the differential inputs are provided. In a level-down circuit, MOS transistors that are not supplied with 3.3 V between the gate and drain and between the gate and source use a thin oxide layer. In a level-up circuit, a logic operation function is provided.Type: GrantFiled: November 26, 2002Date of Patent: January 13, 2004Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.Inventors: Kazuo Tanaka, Hiroyuki Mizuno, Rie Nishiyama, Manabu Miyamoto
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Patent number: 6670683Abstract: A metal oxide semiconductor transistor having a slew-rate control is disclosed. The transistor having a slew-rate control includes an elongated diffusion area and an elongated gate overlying the diffusion area. The elongated diffusion area has at least two diffusion regions, each having a threshold voltage that is different from each other. The elongated gate has a gate contact at only one side of the elongated diffusion area.Type: GrantFiled: January 4, 2001Date of Patent: December 30, 2003Assignee: International Business Machines CorporationInventors: Kerry Bernstein, Anthony Correale, Jr., Terence Blackwell Hook, Douglas Willard Stout
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Patent number: 6667524Abstract: A first semiconductor element is a transistor for use in a memory cell region, and a second semiconductor element is a transistor for use in a peripheral circuit region. A first total impurity concentration of a first impurity diffusion region and a second impurity diffusion region of the first semiconductor element is higher than a second total impurity concentration of a fifth impurity diffusion region of the second semiconductor element. Thus, a semiconductor device with semiconductor elements having different threshold voltages is obtained.Type: GrantFiled: February 11, 2003Date of Patent: December 23, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Kiyohiko Sakakibara
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Patent number: 6661062Abstract: A capacitive element C1 having a small leakage current is formed by utilizing a gate oxide film 9B thicker than that of a MISFET of a logic section incorporated in a CMOS gate array, without increasing the number of steps of manufacturing the CMOS gate array. The capacitive element C1 has a gate electrode 10E. A part of the gate electrode 10E is made of a polycrystalline silicon film. The polycrystalline silicon film is doped with n-type impurities, so that the capacitive element may reliably operate even at a low power supply voltage.Type: GrantFiled: February 5, 2003Date of Patent: December 9, 2003Assignee: Hitachi, Ltd.Inventors: Kazuhisa Suzuki, Toshiro Takahashi, Yasunobu Yanagisawa, Yusuke Nonaka
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Patent number: 6653693Abstract: A semiconductor integrated circuit device of a low power consumption capable of performing under a low voltage has an array section 21 in which only low threshold voltage MOS FETs are formed, and areas other than the array section 21 in which high threshold voltage MOS FETs whose threshold voltage is higher than that of each low threshold voltage MOS FET formed in the array section are formed.Type: GrantFiled: March 4, 1998Date of Patent: November 25, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Hiroshi Makino
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Patent number: 6653694Abstract: A reference voltage circuit with a small change in output voltage with respect to temperature change has an enhancement mode MOS and a depletion mod MOS, a polarity of a gate of the enhancement mod MOS is opposite that of the transistor, and a polarity of a gate of the depletion mode MOS is the same as that of the transistor, and both the enhancement mode MOS and the depletion mode MOS are of the buried channel type. A dose amount of a counter channel doping impurity for setting a predetermined threshold is substantially the same for the enhancement mode MOS and the depletion mode MOS. Thus, threshold voltages and degrees of change of mutual conductance with temperature can be made the same for both MOS transistors and it is possible to provide the reference voltage circuit with a small change of the output voltage with respect to a temperature change.Type: GrantFiled: September 19, 2001Date of Patent: November 25, 2003Assignee: Seiko Instruments Inc.Inventor: Jun Osanai
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Publication number: 20030214001Abstract: A silicon oxide film with a film thickness of 5 to 7 nm is formed on a first region, a silicon oxynitride film with a film thickness of 2 to 3 nm, and a nitrogen concentration of 1 to 3 atom % is formed on a second region, and a silicon oxynitride film with a film thickness of 1 to 2 nm, and a nitrogen concentration of 3 to 5 atom % is formed on a third region on a silicon substrate. Then, radical nitriding is applied to the silicon oxide film, and the silicon oxynitride films.Type: ApplicationFiled: June 18, 2003Publication date: November 20, 2003Inventors: Yuri Yasuda, Naohiko Kimizuka
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Patent number: 6649984Abstract: In a memory circuit, a transistor formed in the same process as that of a logic transistor is used for peripheral circuitry except for a region to be supplied with high voltage. Thus, the manufacturing process can be simplified and a logic-merged memory operating at a high speed is provided.Type: GrantFiled: August 3, 2000Date of Patent: November 18, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hideyuki Noda, Kazutami Arimoto, Katsumi Dosaka, Takeshi Fujino
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Patent number: 6646313Abstract: A method for manufacturing a semiconductor integrated circuit device including a first field effect transistor having a gate insulating film formed over a first element forming region of a main surface of a semiconductor substrate; and a second field effect transistor having a gate insulating film formed over a second element forming region of the main surface of the semiconductor substrate and made thinner than the gate insulating film of the first field effect transistor.Type: GrantFiled: September 25, 2001Date of Patent: November 11, 2003Assignee: Hitachi, LtdInventors: Shoji Shukuri, Norio Suzuki, Yasuhiro Taniguchi
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Patent number: 6642557Abstract: A MOSFET structure in which the channel region is contiguous with the semiconductor substrate while the source and drain junctions are substantially isolated from the substrate, includes a dielectric volume formed adjacent and subjacent to portions of the source and drain regions. In a further aspect of the invention, a process for forming an isolated junction in a bulk semiconductor includes forming a dielectric volume adjacent and subjacent to portions of the source and drain regions.Type: GrantFiled: April 9, 1999Date of Patent: November 4, 2003Assignee: Intel CorporationInventor: Chunlin Liang
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Patent number: 6642588Abstract: An SRAM memory cell is provided having a pair of cross-coupled CMOS inverters. The sources of the pull-up transistors forming each of the CMOS inverters are coupled to VCC through parasitic resistance of the substrate in which each is formed. The source of the p-type pull-up transistor is therefore always at a potential less than or equal to the potential of the N-well such that the emitter-base junction of the parasitic PNP transistor cannot become forward biased and latch-up cannot occur.Type: GrantFiled: July 20, 2000Date of Patent: November 4, 2003Assignee: Micron Technology, Inc.Inventors: John D. Porter, William N. Thompson
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Patent number: 6627962Abstract: A semiconductor memory and its manufacturing method enable high-integrated memory cell to be realized easily. The semiconductor memory according to the present invention has an impurity diffusion region with a second conductive type that is opposite to a first conductive type on a surface of a semiconductor substrate with the first conductive type. Further, the semiconductor memory has structure in which there are provided a floating gate electrode formed on the semiconductor substrate via a gate insulator, and a control gate electrode formed on the floating gate electrode via an interelectrode insulating film. Furthermore, there are provided the gate insulator on the surface of the semiconductor substrate with the exception of an impurity diffusion region, and a third insulating film with film thickness thicker than that of the gate insulator on the surface of the impurity diffusion region.Type: GrantFiled: May 2, 2001Date of Patent: September 30, 2003Assignee: NEC Electronics CorporationInventor: Kazuhiro Tasaka
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Patent number: 6627963Abstract: The present invention provides a process for fabricating merged integrated circuits on a semiconductor wafer substrate. The process comprises forming a gate oxide on the semiconductor wafer substrate, forming a first transistor having a first gate on the gate oxide, and forming a second transistor having a second gate on the same gate oxide. The first transistor is optimized to a first operating voltage by varying a physical property of the first gate, varying a first tub doping profile, or varying a first source/drain doping profile. The second transistor is optimized to a second operating voltage by varying a physical property of the second gate, varying a second tub doping profile, or varying a second source/drain doping profile of the second transistor. These physical characteristics may be changed in any combination or singly to achieve the determined optimization of the operating voltage of any given transistor.Type: GrantFiled: February 20, 2001Date of Patent: September 30, 2003Assignee: Agere Systems Inc.Inventors: William T. Cochran, Isik C. Kizilyalli, Morgan J. Thoma
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Patent number: 6624468Abstract: In a semiconductor device in which a non-volatile memory element and a p-channel IGFET are mounted on a single substrate, a nitride atom density of a tunnel insulating film of the non-volatile memory element is set to be higher than a nitride atom density of a gate insulating film of the p-channel IGFET. With respect to a manufacturing method, a region where the gate insulating film of the p-channel IGFET is covered by a thick buffer silicon oxide film when nitrifying the tunnel insulating film of the non-volatile memory element. The buffer silicon oxide film can be reliably removed when the gate insulating film is formed, because no nitride film is made between the substrate and the buffer silicon oxide film.Type: GrantFiled: May 24, 2002Date of Patent: September 23, 2003Assignee: Kabushiki Kaisha ToshibaInventor: Masataka Takebuchi
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Patent number: 6621116Abstract: An EPROM structure includes a NMOS transistor integrated with a capacitor. The terminal names of the NMOS transistor follow the conventional nomenclature: drain, source, body and gate. The gate of the NMOS transistor is connected directly and exclusively to one of the capacitor plates. In this configuration, the gate is now referred to as the “floating gate”. The remaining side of the capacitor is referred to as the “control gate”.Type: GrantFiled: December 20, 2001Date of Patent: September 16, 2003Inventor: Michael David Church
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Patent number: 6621129Abstract: A MROM memory cell structure for storing multi level bit information is disclosed. First of all, a substrate is provided. The substrate has first and second trenches therein, wherein the first trench is deeper than second trench. A conformnal dielectric layer formed on sidewall and bottom of the first and second trenches. A conductive layer filled in the first and second trenches and on the substrate. A first doped region is formed under the first trench. A second doped region is formed under the second trench. A third doped region is formed in surface of the substrate and between the first and second trenches.Type: GrantFiled: May 24, 2002Date of Patent: September 16, 2003Assignee: Macronix International Co., Ltd.Inventors: Chun-Jung Lin, Ful-Long Ni, Chang-Ju Chen
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Patent number: 6621117Abstract: A semiconductor device includes: a semiconductor substrate having a memory cell section and a peripheral circuit section defined in a plane; a floating gate electrode formed on semiconductor substrate in the memory cell section; a control gate electrode laminated thereabove; a gate electrode as a peripheral circuit electrode formed in one-layer-structure on semiconductor substrate in the peripheral circuit section; a first dummy electrode formed in the peripheral circuit section so as to have approximately same thickness as floating gate electrode; and a second dummy electrode laminated thereabove so as to have approximately same thickness as control gate electrode.Type: GrantFiled: July 10, 2002Date of Patent: September 16, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuhiro Araki, Satoshi Shimizu
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Patent number: 6617633Abstract: A vertical read-only memory (ROM) is provided, which includes a gate on a substrate, a source/drain at the bottom of a trench in the substrate, a polysilicon bit-line in the trench, and a dielectric layer separating the polysilicon bit-line and the side-walls of the trench. The polysilicon bit-line electrically connects with the source/drain. The substrate of the side-wall of the trench adjacent to the gate serves as a coding region.Type: GrantFiled: January 15, 2002Date of Patent: September 9, 2003Assignee: Macronix International Co., Ltd.Inventor: Shui-Chin Huang
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Patent number: 6608355Abstract: A semiconductor integrated contains a first MOS transistor of a first conductivity type formed on a surface of a semiconductor substrate, and a second MOS transistor of the first conductivity type having a drain-source breakdown voltage lower than that of the first MOS transistor. The second MOS transistor is used as an anti-fuse, which can be changed to a conductive state with a low writing voltage that does not damage the first MOS transistor. The second MOS transistor is fabricated such that a concentration of a second conductivity type impurity in at least a portion of the channel region adjacent to the drain region is higher than that in a corresponding portion of the first MOS transistor.Type: GrantFiled: February 19, 2002Date of Patent: August 19, 2003Assignee: Kawasaki Microelectronics, Ltd.Inventors: Ryuji Ariyoshi, Isamu Kuno, Takahito Fukushima, Junji Aoike
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Publication number: 20030151099Abstract: A semiconductor device and a manufacturing method thereof permitting the quality of gate insulating films to be prevented from deteriorating and thereby permitting electrical characteristics of the device to be prevented from deteriorating are provided. In a semiconductor device including a plurality of field effect transistors, an oxidation protection film 21 is formed on a side of one gate electrode 19.Type: ApplicationFiled: February 24, 2003Publication date: August 14, 2003Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Kenji Yoshiyama, Motoshige Igarashi, Keiichi Yamada, Katsuya Okada, Keiichi Higashitani
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Patent number: 6600212Abstract: A semiconductor device has a semiconductor substrate, a first transistor having a first gate electrode formed of a polycrystalline silicon germanium film as formed above said semiconductor substrate, and a second transistor having a second gate electrode which is formed of a polycrystalline silicon germanium film as formed above the semiconductor substrate and which is different in concentration of germanium from the first gate electrode.Type: GrantFiled: February 26, 2002Date of Patent: July 29, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Mariko Takayanagi, Hironobu Fukui
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Publication number: 20030137014Abstract: A capacitive element C1 having a small leakage current is formed by utilizing a gate oxide film 9B thicker than that of a MISFET of a logic section incorporated in a CMOS gate array, without increasing the number of steps of manufacturing the CMOS gate array. The capacitive element C1 has a gate electrode 10E. A part of the gate electrode 10E is made of a polycrystalline silicon film. The polycrystalline silicon film is doped with n-type impurities, so that the capacitive element may reliably operate even at a low power supply voltage.Type: ApplicationFiled: February 5, 2003Publication date: July 24, 2003Inventors: Kazuhisa Suzuki, Toshiro Takahashi, Yasunobu Yanagisawa, Yusuke Nonaka
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Publication number: 20030132500Abstract: Both a non-volatile memory (NVM) and a dynamic nanocrystal memory (DNM) are integrated on a semiconductor substrate. Control gates and control dielectrics with embedded nanocrystals or discrete storage elements are formed over differing thicknesses of tunnel dielectrics to form the two memories. Source and drain regions are formed within the semiconductor substrate adjacent to the tunnel dielectrics. Various methods can be used to form a thin tunnel oxide and a thick tunnel oxide by adding minimum processing steps.Type: ApplicationFiled: January 21, 2003Publication date: July 17, 2003Inventors: Robert E. Jones, Bruce E. White
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Patent number: 6593191Abstract: A method of fabricating a buried channel FET including providing a relaxed SiGe layer on a substrate, providing a channel layer on the relaxed SiGe layer, providing a SiGe cap layer on the channel layer, and ion implanting a dopant supply. The dopant supply can be ion implanted in either the SiGe cap layer or the relaxed SiGe layer. In another embodiment, there is provided a method of fabricating a circuit including providing at least one strained channel, enhancement mode FET, and at least one strained channel, depletion mode FET on a substrate, and ion implanting a dopant supply in the depletion mode FET.Type: GrantFiled: May 16, 2001Date of Patent: July 15, 2003Assignee: Amberwave Systems CorporationInventor: Eugene A. Fitzgerald
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Comparator, display apparatus using comparator for driving system, and driving method for comparator
Patent number: 6590570Abstract: A comparator which can operate stably against an absolute value distribution of a threshold voltage among MOS transistors and has a wide allowable range against the threshold voltage dispersion and besides allows reduction in power consumption. The comparator employs a single MOS transistor, and a resistance element is connected between the drain electrode of the MOS transistor and a power supply. A capacitor is connected between the gate electrode of the MOS transistor and a dc potential point, and a switch is connected between the gate electrode and the drain electrode. A comparison reference level and comparison input data are inputted in a time series to the source electrode of the MOS transistor, and the MOS transistor performs a comparation operation.Type: GrantFiled: May 9, 2000Date of Patent: July 8, 2003Assignee: Sony CorporationInventor: Yasuhito Maki -
Publication number: 20030122198Abstract: A method for processing dual threshold nMOSFETs and pMOSFETs requiring only one additional masking and implantation operation over single threshold MOSFETs is disclosed. The additional mask and implant operation both enhances the threshold voltage doping of one type of FET and compensates the threshold voltage doping of another type of FET. Where a first threshold voltage implant sets the threshold voltage for an NMOS device to a low threshold voltage, and a second threshold voltage implant sets the threshold voltage for a PMOS device to a high threshold voltage, a third implant may both enhance a NMOS device threshold implant to set the threshold voltage high while compensating a PMOS device threshold implant to set the threshold voltage low.Type: ApplicationFiled: January 2, 2002Publication date: July 3, 2003Inventors: Ian R. Post, Kaizad Mistry
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Patent number: 6586805Abstract: In a non-volatile semiconductor memory device and a method for manufacturing the device, each memory cell and its select Tr have the same gate insulating film as a Vcc Tr. Further, the gate electrodes of a Vpp Tr and Vcc Tr are realized by the use of a first polysilicon layer. A material such as salicide or a metal, which differs from second polysilicon (which forms a control gate layer), may be provided on the first polysilicon layer. With the above features, a non-volatile semiconductor memory device can be manufactured by reduced steps and be operated at high speed in a reliable manner.Type: GrantFiled: May 3, 2002Date of Patent: July 1, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Toshitake Yaegashi, Kazuhiro Shimizu, Seiichi Aritome
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Patent number: 6579736Abstract: By appropriately selecting the structure of top gate type or staggered type TFTs disposed in the respective circuits of a semiconductor device depending on the function of the circuits, the operating characteristics and the reliability of the semiconductor device is improved. An LDD region (107) the whole of which overlaps a gate electrode is provided in a first n-channel type TFT of a controlling circuit. LDD regions (111) and (112) at least part of which overlaps a gate electrode are provided in a second n-channel type TFT of the control circuit. LDD regions (117) to (120) which do not overlap a gate electrode through offset regions are provided in an n-channel type TFT of a pixel matrix circuit. By making different the concentration of LDD regions of the control circuit and the concentration of the pixel matrix circuit, optimized circuit operation is obtained.Type: GrantFiled: April 17, 2002Date of Patent: June 17, 2003Assignee: Semiconductor Energy Laboratory Co. Ltd.Inventor: Shunpei Yamazaki
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Patent number: 6576959Abstract: A semiconductor circuit for multi-voltage operation having built-in electrostatic discharge (ESD) protection is described, comprising a drain extended nMOS transistor and a pnpn silicon controlled rectifier (SCR) merged with the transistor so that a dual npn structure is created and both the source of the transistor and the cathode of the SCR are connected to electrical ground potential, forming a dual cathode, whereby the ESD protection is enhanced. The rectifier has a diffusion region, forming an abrupt junction, resistively coupled to the drain, whereby the electrical breakdown-to-substrate of the SCR can be triggered prior to the breakdown of the nMOS transistor drain. The SCR has anode and cathode regions spaced apart by semiconductor surface regions and insulating layers positioned over the surface regions with a thickness suitable for high voltage operation and ESD protection.Type: GrantFiled: September 5, 2001Date of Patent: June 10, 2003Assignee: Texas Instruments IncorporatedInventors: Keith E. Kunz, Charvaka Duvvury, Hisashi Shichijo
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Patent number: 6573575Abstract: In a semiconductor device including a plurality of n-channel transistors having different threshold voltages and each having a gate electrode including an n-type polysilicon film, the impurity concentration of the n-type polysilicon film included in the gate electrode of an n-channel transistor having a relatively high threshold, is lower than the impurity concentration of the n-type polysilicon film included in the gate electrode of an n-channel transistor having a relatively low threshold. Thus, the n-channel transistor having a relatively high threshold can be realized in the semiconductor device, without various problems such as an increased leak current caused by increasing the impurity concentration of the channel region, the lowered subthreshold factor caused by using the p+ polysilicon film in the gate electrode, the deteriorated insulating performance of the gate oxide film, the increased number of fabricating steps, or the dropped reliability of the transistor.Type: GrantFiled: October 6, 2000Date of Patent: June 3, 2003Assignee: NEC Electronics CorporationInventor: Yasushi Yamazaki
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Publication number: 20030094659Abstract: A method of forming an MOS integrated circuit having at least two types of NFET, each type having a different threshold voltage, and at least two types of PFET, each type having a different threshold voltage, includes forming at least four active regions in a substrate, each region having a different doping profile. A conventional two threshold voltage CMOS process is modified to produce four transistor threshold voltages with only one additional masked implant operation. This additional implant raises the threshold voltage of one type of MOSFET while lowering that of the other MOSFET type.Type: ApplicationFiled: November 18, 1999Publication date: May 22, 2003Inventors: KAIZAD R. MISTRY, IAN R. POST
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Patent number: 6563180Abstract: In an integrated circuit device, there are various optimum gate lengths, thickness of gate oxide films, and threshold voltages according to the characteristics of circuits. In a semiconductor integrated circuit device in which the circuits are integrated on the same substrate, the manufacturing process is complicated in order to set the circuits to the optimum values. As a result, in association with deterioration in the yield and increase in the number of manufacturing days, the manufacturing cost increases. In order to solve the problems, according to the invention, transistors of high and low thresholds are used in a logic circuit, a memory cell uses a transistor of the same high threshold voltage and a low threshold voltage transistor, and an input/output circuit uses a transistor having the same high threshold voltage and the same concentration in a channel, and a thicker gate oxide film.Type: GrantFiled: April 1, 2002Date of Patent: May 13, 2003Assignee: Hitachi, Ltd.Inventors: Koichiro Ishibashi, Kenichi Osada
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Patent number: 6563159Abstract: Provided is a substrate of a semiconductor integrated circuit which can easily manufacture an integrated circuit having a soft error resistance, a latch up resistance and an ESD resistance increased. A thickness of a semiconductor surface layer having a lower impurity concentration than that of each of substrate single crystals 51 and 55 is varied according to a resistance which should be possessed by each section such as a memory cell section 5, a logic section 6, an input-output section 8 or the like for a region where each section is to be formed.Type: GrantFiled: May 27, 1998Date of Patent: May 13, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tatsuya Kunikiyo, Ken-ichiro Sonoda
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Patent number: 6563182Abstract: Second insulating films of gate insulating films each are composed of a high-permittivity dielectric film having a relative dielectric constant of 8 or more and at least one of the high-permittivity dielectric films constituting the second insulating films is doped with at least one kind of impurity metal ions. The valence number of the impurity metal ions differs by 1 from that of metal ions constituting the high-permittivity dielectric films. Due to this doping, at least one of the density and polarity of charged defects in the high-permittivity dielectric films differs between the second insulating films. The threshold voltage of each MISFET is controlled independently.Type: GrantFiled: September 18, 2001Date of Patent: May 13, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Tsuyoshi Horikawa
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Patent number: 6559489Abstract: A semiconductor device capable of a high-speed operation is provided. The semiconductor device is provided with low concentration impurity regions, a gate electrode formed with gate oxide film interposed between the gate electrode and a silicon substrate, an etching stopper, an interlayer insulating film having a contact hole and having an etching rate greater than that of the etching stopper, a high concentration impurity region formed by implanting an impurity into the silicon substrate through the contact hole, a plug layer filling the contact hole, and an interconnection layer.Type: GrantFiled: April 7, 2000Date of Patent: May 6, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Ryuichi Kosugi, Shigeki Ohbayashi
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Patent number: 6555968Abstract: To provide a light emitting device having a highly definite pixel portion. An anode (102) and a bank (104) orthogonal to the anode (102) are formed on an insulator (101). A portion of the bank (104) (controlling bank 104b) is made of a metal film. By applying a voltage thereto, an electric field is formed, and a track of an EL material that is charged with an electric charge can be controlled. Thus, it becomes possible to control a film deposition position of an EL layer with precision by utilizing the above method.Type: GrantFiled: June 21, 2002Date of Patent: April 29, 2003Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Masaaki Hiroki, Takeshi Fukunaga
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Patent number: 6552397Abstract: A charge pump formed in a silicon-on-insulator (SOI) substrate is disclosed. The charge pump comprises a SOI layer formed on a substrate. Formed in the silicon of the SOI is a first p-body and a second p-body. Also formed in the silicon is a n+ region that extends down to the insulator so that the n+ region separates the first p-body and second p-body. Finally, a gate structure is formed atop of a portion of the first p-body and a portion of the n+ region. The gate structure is separated from the 1st p-body and n+ region by gate oxide, and it serves as charge pump capacitor. Both the diode turn-on (when gate is pulsing high and forward biasing the p-body to n+ junction), and GIDL current (when the gate is pulsing low, and generates GIDL hole currents from n+ surface to p-body) will result in a “short” of the p-body and n+ region; this ensures the proper operation of charge pump.Type: GrantFiled: June 23, 2000Date of Patent: April 22, 2003Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.Inventor: Min-hwa Chi
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Patent number: 6551882Abstract: In a MOS transistor of an LDD structure, a cobalt silicide film is formed in a region where adjacent gates are formed widely apart from each other, but is not formed in a region where adjacent gates are formed close to each other. The particular construction permits suppressing the leak current through the PN junction that is generated under the influence of the metal silicide compound in the region where adjacent gates are formed close to each other, and also permits ensuring the signal processing at a high speed in the region where adjacent gates are formed widely apart from each other.Type: GrantFiled: March 27, 2001Date of Patent: April 22, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Akiko Nomachi, Hiroshi Takato, Tadaomi Sakurai, Hiroshi Naruse, Koichi Kokubun, Hideaki Harakawa
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Patent number: 6552377Abstract: A method for making a ULSI MOSFET includes depositing a high-k gate insulator on a silicon substrate and then depositing a field oxide layer over the gate insulator. The field oxide layer is masked with photoresist and the photoresist patterned to establish first gate windows, and the oxide below the windows is then etched away to establish first gate voids in the oxide. The first gate voids are filled with a first metallic gate electrode material that is suitable for establishing a gate electrode of, e.g., an N-channel MOSFET. Second gate voids are similarly made in the oxide and filled with a second gate electrode material that is suitable for establishing a gate electrode of, e.g., an P-channel MOSFET or another N-channel MOSFET having a different threshold voltage than the first MOSFET. With this structure, plural threshold design voltages are supported in a single ULSI chip that uses high-k gate insulator technology.Type: GrantFiled: March 22, 2000Date of Patent: April 22, 2003Assignee: Advanced Micro Devices, Inc.Inventor: Bin Yu
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Publication number: 20030067044Abstract: A semiconductor device may be formed with a floating body positioned over an insulator in a semiconductor structure. A gate may be formed over the floating body but spaced therefrom. The semiconductor structure may include doped regions surrounding the floating body The floating body provides a distributed capacitance and resistance along its length to form an integrated RC circuit. The extent of the resistance is a function of the cross-sectional area of the floating body along the source and drain regions and its capacitance is a function of the spacing between the doped regions and the body and between the gate and the body. In some embodiments of the present invention, compensation for input voltage variations may be achieved.Type: ApplicationFiled: November 18, 2002Publication date: April 10, 2003Inventors: Harry Muljono, Stefan Rusu
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Patent number: 6545327Abstract: A manufacturing method produces a semiconductor IC device which can maintain a low power consumption for electronic circuits and form gate-isolation layers of different thicknesses without increasing the manufacturing cost. The semiconductor IC device has gate-isolation layers of different thicknesses on the same semiconductor substrate surface. To form such gate-isolation layers, a silicon dioxide layer is formed in first and second regions. The dopant-concentration is adjusted in silicon dioxide layer that is to have a thickness different from the above silicon dioxide layer thickness in the second region B. A carbon-containing semiconductor layer is selectively formed in either the first region or the second region. Therefore, there is no need for additional steps for forming silicon dioxide layers of different thicknesses in the first region and in the second region.Type: GrantFiled: April 30, 2001Date of Patent: April 8, 2003Assignee: Toshiba CorporationInventor: Masakatsu Tsuchiaki
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Patent number: 6541823Abstract: A semiconductor device and a manufacturing method thereof permitting the quality of gate insulating films to be prevented from deteriorating and thereby permitting electrical characteristics of the device to be prevented from deteriorating are provided. In a semiconductor device including a plurality of field effect transistors, an oxidation protection film 21 is formed on a side of one gate electrode 19.Type: GrantFiled: March 11, 1998Date of Patent: April 1, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kenji Yoshiyama, Motoshige Igarashi, Keiichi Yamada, Katsuya Okada, Keiichi Higashitani
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Publication number: 20030057502Abstract: The depletion N-channel transistor has a drain region formed in a circular shape and a gate region having a circular-shaped contour, disposed therein surrounding the drain region. A source region is disposed outside the gate region, surrounding the drain region and spaced a predetermined distance away from an element-isolating oxide film. For instance, a P+ diffused layer is formed outside the source region, and the P+ diffused layer spaces the source region a predetermined distance away from the element-isolating oxide film. In the P+ diffused layer is formed a contact hole 10 that is common to the P+ diffused layer and the source region, and the gate region and the drain region are disposed concentrically with each other.Type: ApplicationFiled: August 9, 2002Publication date: March 27, 2003Inventor: Fumitoshi Yamamoto
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Patent number: 6538293Abstract: A capacitive element C1 having a small leakage current is formed by utilizing a gate oxide film 9B thicker than that of a MISFET of a logic section incorporated in a CMOS gate array, without increasing the number of steps of manufacturing the CMOS gate array. The capacitive element C1 has a gate electrode 10E. A part of the gate electrode 10E is made of a polycrystalline silicon film. The polycrystalline silicon film is doped with n-type impurities, so that the capacitive element may reliably operate even at a low power-supply voltage.Type: GrantFiled: May 10, 2002Date of Patent: March 25, 2003Assignee: Hitachi, Ltd.Inventors: Kazuhisa Suzuki, Toshiro Takahashi, Yasunobu Yanagisawa, Yusuke Nonaka
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Patent number: 6534819Abstract: A two transistor programmable logic cell 100 is used in programmable logic devices. The cell 100 has a backgate 3 that holds charge to program one of the two transistors into a logic 1 or a logic 0 state. Programmable logic devices are scalable to fine geometries and high densities and may be programmed to perform multiple logic functions on the same substrate.Type: GrantFiled: August 30, 2001Date of Patent: March 18, 2003Assignee: Cornell Research Foundation, Inc.Inventors: Sandip Tiwari, Arvind Kumar