Using Channel Conductivity Dopant Of Opposite Type As That Of Source And Drain Patents (Class 438/291)
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Publication number: 20080283914Abstract: An impurity buried layer constructed by two buried regions formed by impurities of identical type exist, a buried region formed by an impurity having a slow diffusion speed is provided on the entire surface of a transistor formation region, and a buried region formed by an impurity having a fast diffusion speed is provided inwardly from beneath the inside end of an isolation insulating film serving as a region on which an electric field concentrates partially.Type: ApplicationFiled: May 15, 2008Publication date: November 20, 2008Applicant: NEC ELECTRONICS CORPORATIONInventor: Hiroki Fujii
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Publication number: 20080283937Abstract: Provided are a semiconductor device and a method for fabricating the same. The semiconductor device can include a transistor structure, including a gate dielectric on a substrate, a gate electrode on the gate dielectric, a spacer at sidewalls of the gate electrode, and source/drain regions in the substrate; and an interlayer dielectric on the transistor structure where an air gap is provided in a region between the spacer, the interlayer dielectric, and the source/drain region of the substrate.Type: ApplicationFiled: May 16, 2008Publication date: November 20, 2008Inventor: EUN JONG SHIN
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Publication number: 20080251841Abstract: The structure of the MOS transistor provided in this invention has LDD (lightly doped drain) and halo doped regions removed from the source, the drain or both regions in the substrate for improved linearity range when operated as a voltage-controlled resistor. The removal of the LDD and halo doped regions is performed by simply modifying the standard mask of the MOS process using a logic operation layer with no extra mask required.Type: ApplicationFiled: March 27, 2008Publication date: October 16, 2008Inventors: Kai-Yi Huang, Ta-Hsun Yeh, Yuh-Sheng Jean
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Patent number: 7427546Abstract: A transistor device includes a recess in a surface of semiconductor substrate, a gate insulation layer formed over an inner side of the recess, a gate conductor filling the recess in which the gate insulation layer is formed, and source and drain regions located over the substrate adjacent the recess. Among the advantages: the gate structure lowers overall gate resistance and reduces the short channel effect.Type: GrantFiled: December 22, 2006Date of Patent: September 23, 2008Assignee: Dongbu Hitek Co., Ltd.Inventor: Jeong-Ho Park
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Patent number: 7393767Abstract: A method for implanting a cell channel ion of semiconductor device is disclosed. In accordance with the method, the bit line contact region and the edge portion of the channel region adjacent to the bit line contact region in the cell region are subjected to a selective cell channel implant process two times using a ion implant mask and rest of the cell region is subjected to cell channel implant process only once so that a impurity concentration of the storage node contact region is maintained at a lower level for minimal leakage current in the storage node contact region.Type: GrantFiled: December 7, 2004Date of Patent: July 1, 2008Assignee: Hynix Semiconductor Inc.Inventors: Won Chang Lee, Woo Kyung Sun
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Patent number: 7381621Abstract: A MOSFET includes an insulated gate electrode on a surface of a semiconductor substrate having an impurity region of first conductivity type therein that extends to the surface. Source and drain regions of second conductivity type are provided in the impurity region. The source region includes a highly doped source contract region that extends to the surface and a lightly doped source extension. The lightly doped source extension extends laterally underneath a first end of the insulated gate electrode and defines a source-side P-N junction with the well region. The drain region includes a highly doped drain contact region that extends to the surface and a lightly doped drain extension. The lightly doped drain extension extends laterally underneath a second end of the insulated gate electrode and defines a drain-side P-N junction with the well region. This well region, which extends within the impurity region and defines a non-rectifying junction therewith, is more highly doped than the impurity region.Type: GrantFiled: January 5, 2007Date of Patent: June 3, 2008Assignee: Samsung Electronics Co., Ltd.Inventors: Sun-hak Lee, Kwang-dong Yoo
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Publication number: 20080121993Abstract: A semiconductor device includes a drift layer having a first conductivity type and a body region adjacent the drift layer. The body region has a second conductivity type opposite the first conductivity type and forms a p-n junction with the drift layer. The device further includes a contactor region in the body region and having the first conductivity type, and a shunt channel region extending through the body region from the contactor region to the drift layer. The shunt channel region has the first conductivity type. The device further includes a first terminal in electrical contact with the body region and the contactor region, and a second terminal in electrical contact with the drift layer.Type: ApplicationFiled: November 3, 2006Publication date: May 29, 2008Inventors: Allen Hefner, Sei-Hyung Ryu, Anant Agarwal
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Patent number: 7348243Abstract: A transistor and a method for fabricating the same is disclosed, to uniformly provide impurity ions in impurity areas, and to prevent a short channel effect, in which the method for fabricating the transistor includes steps of forming a plurality of channel ion implantation areas having different depths in a first conductive type semiconductor substrate; forming a pillar by selectively etching the first conductive type semiconductor substrate; sequentially depositing a gate insulating layer and a conductive layer for a gate electrode on the first conductive type semiconductor substrate including the pillar; forming the gate electrode by selectively patterning the conductive layer; and forming second conductive type source/drain impurity ion areas in the first conductive type semiconductor substrate corresponding to the top of the pillar and both sidewalls of the pillar.Type: GrantFiled: December 24, 2004Date of Patent: March 25, 2008Assignee: Dongbu Electronics Co., Ltd.Inventor: Hag Dong Kim
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Patent number: 7344947Abstract: Methods fabricate DEMOS devices having varied channel lengths and substantially similar threshold voltages. A threshold voltage is selected for first and second devices. First and second well regions are formed. First and second drain extension regions are formed within the well regions. First and second back gate regions are formed within the well regions according to the selected threshold voltage. First and second gate structures are formed over the first and second well regions having varied channel lengths. A first source region is formed in the first back gate region and a first drain region is formed in the first drain extension region. A second source region is formed in the second back gate region and a second drain region is formed in the drain extension region.Type: GrantFiled: April 27, 2006Date of Patent: March 18, 2008Assignee: Texas Instruments IncorporatedInventors: Victor Ivanov, Jozef Czeslaw Mitros
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Publication number: 20080029813Abstract: In a high voltage MOS transistor, in a portion immediately below the gate electrode, peaks of concentration distribution in depth direction of a first conductivity type impurity and a second conductivity type impurity in the drain offset region are in the same depth, the second conductivity type impurity being higher concentrated than the first conductivity type impurity.Type: ApplicationFiled: August 6, 2007Publication date: February 7, 2008Applicant: NEC Electronics CorporationInventor: Hiroshi YANAGIGAWA
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Publication number: 20080023761Abstract: Semiconductor devices and methods of fabricating the same are provided. According to an example embodiment, a semiconductor device may include an active region disposed in a substrate and having first conductivity type impurity ions, a gate electrode crossing on the active region, a source region disposed within the active region at one a first side of the gate electrode, a drain region disposed within the active region at the a second side of the gate electrode, a source lightly doped drain (LDD) region disposed within the active region, extending toward the gate electrode from the source region, and having second conductivity type impurity ions, a drain LDD region disposed within the active region, extending toward the gate electrode from the drain region, and having the second conductivity type impurity ions in a concentration higher than the source LDD region, and a first halo region disposed within the active region, surrounding the source LDD region, and having the first conductivity type impurity ions.Type: ApplicationFiled: June 28, 2007Publication date: January 31, 2008Inventors: Mu-Kyeng Jung, Xiao Quan Wang, Bai-Sun Kong
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Patent number: 7288445Abstract: Accordingly, the present invention provides a double gated transistor and a method for forming the same that results in improved device performance and density. The preferred embodiment of the present invention uses provides a double gated transistor with asymmetric gate doping, where one of the double gates is doped degenerately n-type and the other degenerately p-type. By doping on of the gates n-type, and the other p-type, the threshold voltage of the resulting device is improved. In particular, by asymmetrically doping the two gates, the resulting transistor can, with adequate doping of the body, have a threshold voltage in a range that enables low-voltage CMOS operation. For example, a transistor can be created that has a threshold voltage between 0V and 0.5V for nFETs and between 0 and ?0.5V for pFETs.Type: GrantFiled: May 9, 2005Date of Patent: October 30, 2007Assignee: International Business Machines CorporationInventors: Andres Bryant, Meikei Ieong, K. Paul Muller, Edward J. Nowak, David M. Fried, Jed Rankin
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Patent number: 7279388Abstract: Disclosed is a method for manufacturing a transistor in a semiconductor device, which can improve a device's refresh characteristics. The method includes: providing a silicon substrate having active and field regions; performing a channel ion implantation into the substrate; sequentially forming a hard mask film and a photoresist pattern exposing a gate formation region where the channel ion implantation occurred; performing a second, higher concentration channel ion implantation using the photoresist pattern as a mask, forming doped regions in the substrate at the gate formation region and sides; etching a hard mask using the photoresist pattern as a barrier; removing the photoresist pattern; etching the substrate using a portion of the remaining hard mask as a barrier forming a groove; removing the remaining hard mask; forming a gate in the groove where the hard mask was removed; and forming source and drain regions at both sides of the gate.Type: GrantFiled: June 16, 2005Date of Patent: October 9, 2007Assignee: Hynix Semiconductor Inc.Inventors: Yong Soo Kim, Se Aug Jang, Jae Geun Oh
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Patent number: 7259054Abstract: With the objective of suppressing or preventing a kink effect in the operation of a semiconductor device having a high breakdown voltage field effect transistor, n+ type semiconductor regions, each having a conduction type opposite to p+ type semiconductor regions for a source and drain of a high breakdown voltage pMIS, are disposed in a boundary region between each of trench type isolation portions at both ends, in a gate width direction, of a channel region of the high breakdown voltage pMIS and a semiconductor substrate at positions spaced away from p? type semiconductor regions, each having a field relaxing function, of the high breakdown voltage pMIS, so as not to contact the p? type semiconductor regions (on the drain side, in particular). The n+ type semiconductor regions extend to positions deeper than the trench type isolation portions.Type: GrantFiled: November 15, 2004Date of Patent: August 21, 2007Assignee: Renesas Technology Corp.Inventors: Hideki Yasuoka, Keiichi Yoshizumi, Masami Koketsu
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Patent number: 7247541Abstract: A semiconductor device comprises a plurality of gate structures formed on a substrate, a gate spacer formed on a sidewall of the gate structures, a semiconductor pattern formed on the substrate between the gate structures, a first impurity region and a second impurity region formed in the semiconductor pattern and at surface portions of the substrate, respectively, wherein the first and second impurity regions include a first conductive type impurity, and a channel doping region surrounding the first impurity region, wherein the channel doping region includes a second conductive type impurity.Type: GrantFiled: June 30, 2005Date of Patent: July 24, 2007Assignee: Samsung Electronics Co., Ltd.Inventors: Jin-Woo Lee, Cheol-Ju Yun, Hyeoung-Won Seo
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Publication number: 20070155078Abstract: A semiconductor device including at least one of: lightly doped drain regions over a semiconductor substrate; a gate insulating layer over a semiconductor substrate between lightly doped drain regions; and/or a gate formed at an upper side of a gate insulating layer. A lower width of a gate may be less than an interval between lightly doped drain regions. An upper width of a gate may be greater than an interval between lightly doped drain regions.Type: ApplicationFiled: December 21, 2006Publication date: July 5, 2007Inventors: Sung Ho Kwak, Sung Moo Kim
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Patent number: 7217624Abstract: The present invention relates to a non-volatile memory device having conductive sidewall spacers and a method for fabricating the same. The non-volatile memory device includes: a substrate; a gate insulation layer formed on the substrate; a gate structure formed on the gate insulation layer; a pair of sidewall spacers formed on sidewalls of the gate structure; a pair of conductive sidewall spacers for trapping/detrapping charges formed on the pair of sidewall spacers; a pair of lightly doped drain regions formed in the substrate disposed beneath the sidewalls of the gate structure; and a pair of source/drain regions formed in the substrate disposed beneath edge portions of the pair of conductive sidewall spacers.Type: GrantFiled: December 30, 2004Date of Patent: May 15, 2007Assignee: Hynix Semiconductor Inc.Inventors: Kwan-Yong Lim, Heung-Jae Cho, Yong-Soo Kim, Se-Aug Jang, Hyun-Chul Sohn
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Patent number: 7208385Abstract: A structure for making a LDMOS transistor (100) includes an interdigitated source finger (26) and a drain finger (21) on a substrate (15). Termination regions (35, 37) are formed at the tips of the source finger and drain finger. A drain (45) of a second conductivity type is formed in the substrate of a first conductivity type. A field reduction region (7) of a second conductivity type is formed in the drain and is wrapped around the termination regions for controlling the depletion at the tip and providing higher voltage breakdown of the transistor.Type: GrantFiled: April 11, 2005Date of Patent: April 24, 2007Assignee: Semiconductor Components Industries, L.L.C.Inventors: Zia Hossain, Mohamed Imam, Joe Fulton
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Patent number: 7195967Abstract: In a channel region between the source/drain diffusion layers, impurities of the same conductivity type as the well are doped in an area apart from the diffusion regions. By using as a mask the gate formed in advance, tilted ion implantation in opposite directions is performed to form the diffusion layers and heavily impurity doped region of the same conductivity type as the well in a self-alignment manner relative to the gate.Type: GrantFiled: November 6, 2003Date of Patent: March 27, 2007Assignee: Renesas Technology Corp.Inventors: Yoshitaka Sasago, Takashi Kobayashi
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Patent number: 7192836Abstract: A method and system for providing a halo implant to a semiconductor device is disclosed. The method and system includes providing a thin photoresist layer that covers a substantial amount of an active area including a source region and a drain region of the semiconductor device. The method and system further includes providing the halo implant to the semiconductor device, using the thin photoresist layer as a mask. Utilizing this thin photoresist layer, taking into account other height variables, the source and drain regions can be opened only as needed. At a 45° angle, the implant can be delivered to all transistors in the circuit in the targeted area as well as getting only a large amount of the dose (up to ¾ of the dose) to the transistor edge which sits on the trench edge.Type: GrantFiled: February 3, 2000Date of Patent: March 20, 2007Assignee: Advanced Micro Devices, Inc.Inventors: Ahmad Ghaemmaghami, Zoran Krivokapic, Brian Swanson
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Patent number: 7179714Abstract: There is provided a method of fabricating a MOS transistor having a fully silicided gate, including forming a gate pattern and gate spacers on a semiconductor substrate, the gate pattern including a lower gate pattern, an insulating layer pattern, and an upper gate pattern, which are sequentially stacked. Source/drain regions are formed by implanting impurity ions into an active region using the gate pattern and the gate spacers as ion implantation masks. Then, a protecting layer is formed on the semiconductor substrate having the gate pattern, and the protecting layer is planarized until the upper gate pattern is exposed. Then, by removing the exposed upper gate pattern and the insulating layer pattern, the lower gate pattern is exposed. Then, the protecting layer is selectively removed, thereby exposing the source/drain regions. The exposed lower gate pattern is fully converted to a gate silicide layer, and a silicide layer is concurrently formed on the surfaces of the source/drain regions.Type: GrantFiled: February 24, 2005Date of Patent: February 20, 2007Assignee: Samsung Electronics Co., Ltd.Inventors: You-Jean Chang, Myoung-Hwan Oh, Hee-Sung Kang, Choong-Ryul Ryou
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Patent number: 7176538Abstract: A MOSFET includes an insulated gate electrode on a surface of a semiconductor substrate having an impurity region of first conductivity type therein that extends to the surface. Source and drain regions of second conductivity type are provided in the impurity region. The source region includes a highly doped source contract region that extends to the surface and a lightly doped source extension. The lightly doped source extension extends laterally underneath a first end of the insulated gate electrode and defines a source-side P-N junction with the well region. The drain region includes a highly doped drain contact region that extends to the surface and a lightly doped drain extension. The lightly doped drain extension extends laterally underneath a second end of the insulated gate electrode and defines a drain-side P-N junction with the well region. This well region, which extends within the impurity region and defines a non-rectifying junction therewith, is more highly doped than the impurity region.Type: GrantFiled: June 3, 2004Date of Patent: February 13, 2007Assignee: Samsung Electronics Co., Ltd.Inventors: Sun-hak Lee, Kwang-dong Yoo
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Patent number: 7141477Abstract: Into a channel formation region of a semiconductor substrate of p-type silicon, indium ions are implanted at an implantation energy of about 70 keV and a dose of about 5×1013/cm2, thereby forming a p-doped channel layer. Next, germanium ions are implanted into the upper portion of the semiconductor substrate at an implantation energy of about 250 keV and a dose of about 1×1016/cm2, thereby forming an amorphous layer in a region of the semiconductor substrate deeper than the p-doped channel layer.Type: GrantFiled: October 2, 2003Date of Patent: November 28, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventor: Taiji Noda
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Patent number: 7091093Abstract: A gate electrode is formed over a semiconductor region with a gate insulating film interposed therebetween. An extended high-concentration dopant diffused layer of a first conductivity type is formed in part of the semiconductor region beside the gate electrode through diffusion of a first dopant. A pocket dopant diffused layer of a second conductivity type is formed under the extended high-concentration dopant diffused layer through diffusion of heavy ions. The pocket dopant diffused layer includes a segregated part that has been formed through segregation of the heavy ions.Type: GrantFiled: September 15, 2000Date of Patent: August 15, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Taiji Noda, Hiroyuki Umimoto, Shinji Odanaka
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Patent number: 7081416Abstract: The invention includes methods of forming field effect transistor gates. In one implementation, a series of layers is formed proximate a semiconductive material channel region. The layers comprise a gate dielectric layer and a conductive metal-comprising layer having an ion implanted polysilicon layer received therebetween. Patterned masking material is formed over the series of layers. Using the patterned masking material as a mask, etching is conducted through the conductive metal-comprising layer and only partially into the ion implanted polysilicon layer. After such etching, the ion implanted polysilicon is annealed effective to electrically activate implanted impurity atoms received therein. Other aspects and implementations are contemplated.Type: GrantFiled: April 4, 2003Date of Patent: July 25, 2006Assignee: Micron Technology, Inc.Inventors: John K. Zahurak, David K. Hwang
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Patent number: 7060572Abstract: A MOSFET with a short channel structure and manufacturing processes for the same are described. The MOSFET has a substrate, a channel region, a source/drain region, a gate dielectric layer and a conductive layer. The channel region in the substrate includes a first region and a second region, in which the first region has a first threshold voltage and the second region has a second threshold voltage, respectively. The first threshold voltage is smaller than the second threshold voltage. The first threshold voltage of the first region can also be adjusted to reduce or increase effectively the resistance of the MOSFET when the MOSFET is turned on or off. Additionally, the first region has a shallower junction depth than that of the normal source/drain extension.Type: GrantFiled: August 11, 2004Date of Patent: June 13, 2006Assignee: Winbond Electronics CorporationInventor: Wen-Yueh Jang
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Patent number: 7053450Abstract: A MISFET in a semiconductor device has a gate insulating film provided on a substrate, a gate electrode provided on the gate insulating film, sidewalls provided on the side surfaces of the gate electrode, lightly doped diffusion layers provided in the respective regions of the substrate located below the edge portions of the gate electrodes, heavily doped diffusion layers provided in the respective regions of the substrate located laterally below the gate electrode and the sidewalls, and pocket diffusion layers covering the lower portions of the lightly doped diffusion layers and parts of the side surfaces thereof in overlapping relation with each other below the gate electrode. Impurity concentrations in the pocket diffusion layers are set such that the threshold of the MISFET has a desired value.Type: GrantFiled: April 29, 2004Date of Patent: May 30, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventor: Naoki Kotani
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Patent number: 7033894Abstract: A method for modulating the flatband voltage of semiconductor devices includes post-deposition annealing of a high-k dielectric film deposited by chemical vapor deposition, for example. The modulation of the flatband voltage, and thus, the threshold voltage of MOSFET devices, is achieved by post-deposition annealing of the high-k dielectric film and control of the annealing parameters. These include annealing gases, annealing temperatures and annealing times.Type: GrantFiled: August 5, 2003Date of Patent: April 25, 2006Assignee: Advanced Micro Devices, Inc.Inventors: Huicai Zhong, Joong Jeon
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Patent number: 7012006Abstract: A ROM embedded DRAM provides ROM cells that can be programmed to a single state. The ROM cells include capacitors having a storage node. The storage node is processed to have a substantially high substrate leakage. The ROM cells, therefore, are hard programmed to a logic zero state. Bias techniques can be used to read un-programmed ROM cells accurately. As described, sense amplifier circuitry can be offset in one embodiment to default to the un-programmed state. In another embodiment, bias circuitry is coupled to bit lines to favor the un-programmed state. A differential pre-charge operation can also be used in another embodiment.Type: GrantFiled: August 23, 2004Date of Patent: March 14, 2006Assignee: Micron Technology, Inc.Inventors: Casey Kurth, Scott Derner, Phillip G. Wald
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Patent number: 7001816Abstract: A ROM embedded DRAM provides ROM cells that can be programmed to a single state. The ROM cells include capacitors having a storage node. The storage node is processed to have a substantially high substrate leakage. The ROM cells, therefore, are hard programmed to a logic zero state. Bias techniques can be used to read un-programmed ROM cells accurately. As described, sense amplifier circuitry can be offset in one embodiment to default to the un-programmed state. In another embodiment, bias circuitry is coupled to bit lines to favor the un-programmed state. A differential pre-charge operation can also be used in another embodiment.Type: GrantFiled: August 24, 2004Date of Patent: February 21, 2006Assignee: Micron Technology, Inc.Inventors: Casey Kurth, Scott Derner, Phillip G. Wald
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Patent number: 6987049Abstract: In an example method for fabricating a transistor in a semiconductor device, a buffer insulation layer and a first insulation layer are deposited and etched, and poly electrodes for an LDD are formed on sidewalls of thereof. After a local channel region is formed into a semiconductor substrate by an impurity ion implantation process, a trench-shaped gate insulation layer is deposited on the gate region. A gate electrode material is deposited into the trench-shaped region and planarized by a blanket etchback or a CMP process. After a silicide is formed by a salicidation process, a second insulation layer and a third insulation layer are formed thereon, sequentially. Contact holes for a gate electrode, a source electrode and a drain electrode may etched and a conductive material may be filled therein, thereby forming a gate plug, a source contact plug and a drain plug.Type: GrantFiled: December 30, 2003Date of Patent: January 17, 2006Assignee: DongbuAnam Semiconductor, Inc.Inventor: Cheolsoo Park
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Patent number: 6972236Abstract: A device structure and method for forming graded junction using a implant process. Embodiments of the invention comprise implanting ions into said silicon substrate to form doped regions adjacent to said gate. The orientation of the channel region in the Si crystal structure (channel direction <100>) in combination with the large angle tilt and twist implant process produce doped regions that have a more graded junction. The orientation and implant process creates more channeling of ions. The channeling of ions creates a more graded junction. When implemented on a HV MOS TX, the graded junction of the LDD increases the breakdown voltage. Another embodiment is a FET with an annular shaped channel region.Type: GrantFiled: January 30, 2004Date of Patent: December 6, 2005Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Yisuo Li, Xiaohong Jiang, Francis Benistant
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Patent number: 6972234Abstract: A method of fabricating CMOS devices suitable for high voltage and low voltage applications, while maintaining minimum channel lengths for the devices. In one embodiment, pocket implants (310) are formed in a minimum channel device causing a reverse channel effect. The reverse channel effect is optimized for the minimum channel length of the device. Field implants (120), enhancement implants (130), and wells (140) are all formed using a single mask.Type: GrantFiled: June 28, 2000Date of Patent: December 6, 2005Assignee: Altera CorporationInventors: Raminda U. Madurawe, David K. Y. Liu
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Patent number: 6951793Abstract: A low-temperature polysilicon thin film transistor having a buried LDD structure is provided. Two heavily doped regions are formed in a semiconductor layer and distributed just below a surface of the semiconductor layer. Two LDD regions are both sandwiched between the two heavily doped regions in a direction substantially parallel to the surface of semiconductor layer, and separated from the surface of the semiconductor layer by a portion of the semiconductor layer. The process for producing such a thin film transistor is also provided. A first, a second and a third doping materials are injected into a semiconductor layer in different directions to form heavily doped regions and LDD regions.Type: GrantFiled: May 27, 2004Date of Patent: October 4, 2005Assignee: Toppoly Optoelectronics Corp.Inventor: An Shih
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Patent number: 6936517Abstract: A method of fabricating a transistor of a semiconductor device is disclosed. The method of fabricating a transistor comprises forming a sacrificial layer on a substrate; forming a source/drain region in the substrate by performing a first ion implantation using the sacrificial layer as a mask; forming a barrier layer over the substrate with the sacrificial layer; removing a portion of the sacrificial layer to form an opening through which a portion of the substrate is exposed; performing a second ion implantation using the opening as a mask to implant ions for adjustment of a threshold voltage of the substrate; forming a gate electrode on the substrate exposed through the opening; and performing a third ion implantation to adjust doping concentration in the gate electrode. Accordingly, the present invention can reduce the occurrences of a short channel effect and a reverse short channel effect in a transistor.Type: GrantFiled: December 30, 2003Date of Patent: August 30, 2005Assignee: DongbuAnam Semiconductor, Inc.Inventors: Chee Hong Choi, Tae Woo Kim
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Patent number: 6930004Abstract: A method of formation of a deep trench vertical transistor is provided. A deep trench with a sidewall in a doped semiconductor substrate is formed. The semiconductor substrate includes a counterdoped drain region in the surface thereof and a channel alongside the sidewall. The drain region has a top level and a bottom level. A counterdoped source region is formed in the substrate juxtaposed with the sidewall below the channel. A gate oxide layer is formed on the sidewalls of the trench juxtaposed with a gate conductor. Perform the step of recessing the gate conductor below the bottom level of the drain region followed by performing angled ion implantation at an angle ?+? with respect to vertical of a counterdopant into the channel below the source region and performing angled ion implantation at an angle ? with respect to vertical of a dopant into the channel below the source.Type: GrantFiled: August 13, 2003Date of Patent: August 16, 2005Assignee: International Business Machines CorporationInventors: Geng Wang, Kevin Mcstay, Mary Elizabeth Weybright, Yujun Li, Dureseti Chidambarrao
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Patent number: 6927137Abstract: A method of forming a retrograde well in a transistor is provided. A transistor structure having a substrate, a gate, and a gate oxide layer between the substrate and the gate is formed. The substrate includes a channel region located generally below the gate. A first dopant is implanted into the channel region. A second dopant is implanted into the substrate to form a doped source region and a doped drain region. A third dopant is implanted into the gate oxide layer. A source/drain anneal is performed to form a source and a drain in the doped source region and the doped drain region, respectively. The source/drain anneal causes a portion of the first dopant in the channel region to be attracted by the third dopant into the gate oxide layer.Type: GrantFiled: December 1, 2003Date of Patent: August 9, 2005Assignee: Texas Instruments IncorporatedInventors: Srinivasan Chakravarthi, Pr Chidambaram, Robert C. Bowen, Haowen Bu
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Patent number: 6905932Abstract: A semiconductor device (100) and a method for constructing a semiconductor device (100) are disclosed. A trench isolation structure (112) and an active region (110) are formed proximate an outer surface of a semiconductor layer (108). An epitaxial layer (111) is deposited outwardly from the trench isolation structure (112). A first insulator layer (116) and a second insulator layer (118) are grown proximate to the epitaxial layer (111). A gate stack (123) that includes portions of the first insulator layer (116 and the second insulator layer (118) is formed outwardly from the epitaxial layer (111). The gate stack (123) also includes a gate (122) with a narrow region (130) and a wide region (132) formed proximate the second insulator layer (118. The epitaxial layer (111) is heated to a temperature sufficient to allow for the epitaxial layer (111) to form a source/drain implant region (126) in the active region (110).Type: GrantFiled: November 21, 2003Date of Patent: June 14, 2005Assignee: Texas Instruments IncorporatedInventors: Gregory E. Howard, Jeffrey Babcock, Angelo Pinto
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Patent number: 6893928Abstract: To provide a cavity in the portion of the silicon substrate which lies beneath the channel region of the MOS transistor.Type: GrantFiled: March 18, 2003Date of Patent: May 17, 2005Assignee: Kabushiki Kaisha ToshibaInventors: Tsutomu Sato, Ichiro Mizushima, Yoshitaka Tsunashima, Toshihiko Iinuma, Kiyotaka Miyano
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Patent number: 6893921Abstract: In a nonvolatile memory cell, the floating gate (160) has an upward protruding portion. This portion can be formed as a spacer over a sidewall of the select gate (140). The spacer can be formed from a layer (160.2) deposited after the layer (160.1) which provides a lower portion of the floating gate. Alternatively, the upward protruding portion and the lower portion can be formed from the same layers or sub-layers all of which are present in both portions. The control gate (170) can be defined without photolithography. Other embodiments are also provided.Type: GrantFiled: April 10, 2003Date of Patent: May 17, 2005Assignee: Mosel Vitelic, Inc.Inventor: Yi Ding
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Patent number: 6884686Abstract: A high voltage semiconductor device includes a drain region disposed within a semiconductor substrate. The semiconductor device further includes a field oxide layer disposed outwardly from the drain region of the semiconductor substrate. The semiconductor device also includes a floating ring structure disposed inwardly from at least a portion of the field oxide layer. In one particular embodiment, a device parameter degradation associated with the semiconductor device comprises one (1) percent or less after approximately five hundred (500) seconds of accelerated lifetime operation.Type: GrantFiled: October 22, 2003Date of Patent: April 26, 2005Assignee: Texas Instruments IncorporatedInventor: Sameer P. Pendharkar
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Patent number: 6881634Abstract: In one embodiment, a buried-channel transistor is fabricated by masking a portion of an active region adjacent to a trench and implanting a dopant in an exposed portion of the active region to adjust a threshold voltage of the transistor. By masking a portion of the active region, the dopant is substantially prevented from getting in a region near an edge of the trench. Among other advantages, this results in reduced leakage current.Type: GrantFiled: August 30, 2002Date of Patent: April 19, 2005Assignee: Cypress Semiconductor CorporationInventor: Jeffrey T. Watt
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Patent number: 6879007Abstract: A semiconductor device has at least one high-voltage and low-voltage transistor on a single substrate. The reliability of the high-voltage transistor is enhanced by performing a LDD implantation in only the high-voltage transistor prior to conducting an oxidation process to protect the substrate and gate electrode. After the oxidation process is performed, the low-voltage transistor is subjected to an LDD implantation process. The resultant semiconductor device provides a high-voltage transistor having a deeper LDD region junction depth than the low-voltage transistor, ensuring reliability and performance.Type: GrantFiled: August 8, 2002Date of Patent: April 12, 2005Assignee: Sharp Kabushiki KaishaInventor: Yoshiji Takamura
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Patent number: 6873008Abstract: An asymmetrical channel implant from source to drain improves short channel characteristics. The implant provides a relatively high VT net dopant adjacent to the source region and a relatively low VT net dopant in the remainder of the channel region. One way to achieve this arrangement with disposable gate processing is to add disposable sidewalls inside the gate opening (after removing the disposable gate), patterning to selectively remove the source or gate side sidewalls, implant the source and drain regions and remove the remaining sidewall and the proceed. According to a second embodiment, wherein the channel implant can be symmetrical, a relatively low net VT implant is provided in the central region of the channel and a relatively high net VT implant is provided in the channel regions adjacent to the source and drain regions.Type: GrantFiled: October 10, 2003Date of Patent: March 29, 2005Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Amitava Chatterjee
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Patent number: 6852599Abstract: A method for fabricating a metal oxide semiconductor (MOS) transistor, which can reduce the junction capacitance without degradation of transistor characteristics including forming a buffer oxide layer on a semiconductor substrate; successively conducting ion implantations for well formation and field stop formation in the substrate through the buffer oxide layer; removing the buffer oxide layer; forming and patterning a sacrificial layer to form a trench successively conducting ion implantations for threshold voltage adjustment and punch stop formation on the semiconductor substrate area exposed by the trench; forming a gate oxide layer on the exposed surface of the substrate; forming a polysilicon layer so as to completely fill the trench; polishing the polysilicon layer to form a gate electrode; removing the sacrificial layer; forming an LDD region in the substrate; forming spacers on side walls of the gate electrode; and forming source/drain regions.Type: GrantFiled: July 25, 2003Date of Patent: February 8, 2005Assignee: Dongbu Electronics Co., Ltd.Inventor: Tae W Kim
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Patent number: 6838347Abstract: A method for reducing line edge roughness (LER) of a semiconductor gate structure includes patterning a photoresist layer formed over an oxide hardmask layer. The photoresist layer is etched so as to transfer a photoresist pattern to the oxide hardmask layer, the photoresist pattern having an initial LER. The exposed surfaces of the oxide hardmask are etched with a chemical oxide removal (COR) so as to form a reaction product on the exposed surfaces, wherein concave portions of the exposed surfaces are etched at a reduced rate with respect to convex portions of the exposed surfaces.Type: GrantFiled: September 23, 2003Date of Patent: January 4, 2005Assignee: International Business Machines CorporationInventors: Joyce C. Liu, Wesley C. Natzle, Richard S. Wise, Hongwen Yan, Bidan Zhang
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Publication number: 20040198004Abstract: A method for adjusting Vt while minimizing parasitic capacitance for low voltage high speed semiconductor devices. The method uses shadow effects and an angled punch through prevention implant between vertical structures to provide a graded implant. The implant angle is greater than or equal to arc tangent of S/H where S is the horizontal distance between, and H is the height of, such vertical structures.Type: ApplicationFiled: April 26, 2004Publication date: October 7, 2004Inventor: Luan C. Tran
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Patent number: 6800511Abstract: The present invention relates to a method for fabricating semiconductor device with negative differential conductance or transconductance. According to the present invention, a fabrication process thereof can be simplified by using an SOI (Silicon-On-Insulator) substrate, and a tunneling device exhibiting the negative differential conductance or transconductance at room temperature can be implemented by using P+-N+ junction barriers as tunneling barriers and implanting impurity ions into a channel region so that their density is higher than the effective density of states where electrons or holes can exist thereon. Since the semiconductor device with the negative differential conductance or transconductance can be also be implemented even at room temperature, there is an advantage in that the present invention can be applied to an SRAM or a logic device using a device which can be turned on/off in response to a specific voltage. Further, according to the fabrication method of the present invention.Type: GrantFiled: July 7, 2003Date of Patent: October 5, 2004Assignee: Seoul National University Industry FoundationInventors: Byung Gook Park, Jong Duk Lee, Kyung Rok Kim
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Patent number: 6790754Abstract: Method for forming contact electrodes in a semiconductor device are disclosed. An example method comprises sequentially forming a pad oxide layer, a pad nitrate layer, a dummy oxide layer, and a capping nitride layer on a substrate. These layers and the substrate are then patterned to form a trench. The trench us filled with an insulating material to form a device isolation stripe. The resulting structure is then patterned to form a trench. Spacers are formed on the sidewalls of the trench and ions are implanted into the substrate beneath the trench to form local channel portions. A gate insulating layer and a gate electrode are then formed by deposition. Thereafter, the dummy oxide layer and the capping nitride layer are removed and source/drain portions are defined. Contact electrodes are then formed by deposition of a metal layer.Type: GrantFiled: December 29, 2003Date of Patent: September 14, 2004Assignee: Dongbu ElectronicsInventor: Cheolsoo Park
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Patent number: 6790756Abstract: A method for creating a self-aligned channel implant with elevated source/drain areas. Forming a thin dielectric layer on top of a silicon substrate, a thick layer of oxide is deposited over this dielectric. An opening is exposed and etched through the layer of oxide, through the dielectric and into the underlying silicon substrate creating a shallow trench in the substrate. By performing the channel implant LDD implant, pocket implant, forming the gate spacers and electrode, removing the thick layer of oxide and forming the S/D regions a gate electrode has been created with elevated S/D regions. By forming the gate spacers, performing channel implant, forming the gate electrode, removing the thick layer of oxide and performing S/D implant a gate electrode has been created with elevated S/D regions and disposable spacers.Type: GrantFiled: March 11, 2003Date of Patent: September 14, 2004Assignee: Taiwan Semiconductor Manufacturing CompanyInventors: Chu-Wei Hu, Jiue-Wen Weng, Chung-Te Lin, So Wein Kuo