Impurity Concentration Variation Patents (Class 257/219)
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Patent number: 6146953Abstract: A fabrication method for a MOSFET device including the steps of forming a first insulating film on a semiconductor substrate wherein an active region and an isolated region are defined, forming a channel ion region by implanting impurity ions into the active region of the semiconductor substrate, forming a first conductive film pattern on a portion of the semiconductor substrate which corresponds to the channel ion region, forming a channel region having lower concentration than the channel ion region by implanting impurity ions in a different type from the ions in the channel ion region into a center portion of the channel ion region through the first conductive film pattern, forming a second conductive film pattern on the first conductive film pattern, forming an impurity region of low concentration in the semiconductor substrate with the first and second conductive film patterns as a mask, forming a sidewall spacer at both sides of the first and second conductive film patterns, and forming an impurity regiType: GrantFiled: September 4, 1998Date of Patent: November 14, 2000Assignee: Hyundai Electronics Industries Co., Ltd.Inventors: Kye-Nam Lee, Jeong-Hwan Son
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Patent number: 6081007Abstract: A gate insulating film and gate electrodes are formed on a substrate containing N-type impurities such as P or As. Under the gate insulating film is a gate region on both sides of which are a first and a second source drain region. The gate region is furnished in its central part with a high-concentration channel injection region containing N-type impurities at a concentration higher than that of the substrate. Between the high-concentration channel injection region on the one hand and the first and the second source drain region and on the other hand, there are formed a first and a second low-concentration channel injection region and having substantially the same impurity concentration as that of the substrate.Type: GrantFiled: January 7, 1999Date of Patent: June 27, 2000Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Takeru Matsuoka
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Patent number: 6081662Abstract: In a trench isolation structure having active regions at a main surface of a silicon substrate isolated by providing a gate electrode on an insulation film formed in a trench with a gate oxide film thereunder, the insulation film has a vertical cross section configuration wherein the carrier concentration of the active region at the proximity of the upper edge corner of the trench becomes lower than the carrier concentration at the center of the active region in a state where a predetermined bias voltage is applied to the gate electrode. According to this structure, electric field concentration at the edge of the trench isolation can be relaxed and generation of an inverse narrow channel effect suppressed. Therefore, the subthreshold characteristics can be improved.Type: GrantFiled: September 29, 1997Date of Patent: June 27, 2000Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takaaki Murakami, Kenji Yasumura, Toshiyuki Oishi, Katsuomi Shiozawa
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Patent number: 6043536Abstract: In a semiconductor device including a full depletion MISFET transistor made by using a SOI layer and intended to stabilize a predetermined threshold value while holding the threshold value sensitivity to fluctuation in thickness of the SOI layer even upon changes in impurity concentration of a channel region of the MISFET transistor by changing a back gate voltage in accordance with the impurity concentration of the channel region, thickness of the SOI layer is determined to reduce changes in threshold value, and impurity concentration of the channel region is measured by using a detector element to adjust the back gate voltage in response to the measured value. Thus, the desired threshold voltage can be maintained.Type: GrantFiled: May 18, 1999Date of Patent: March 28, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Toshinori Numata, Mitsuhiro Noguchi
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Patent number: 5910672Abstract: This invention provides a semiconductor device with a SOI structure and a method of manufacturing the same, preventing deterioration in and making improvement in device characteristics. Nitrogen ion implantation into NMOS and PMOS regions (NR, PR) with resists (22b) and (22c) as masks, respectively, introduces nitrogen ions into channel doped layers (31). The subsequent thermal treatment provides a structure with the channel doped layers (31) containing nitrogen having a prescribed concentration distribution in the depth direction.Type: GrantFiled: July 7, 1997Date of Patent: June 8, 1999Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Toshiaki Iwamatsu, Takashi Ipposhi
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Patent number: 5861642Abstract: The semiconductor device of the present invention is equipped with a plurality of photodiodes, a horizontal transfer part and a vertical transfer part, and in particular, the horizontal transfer part or the vertical transfer part has a configuration described as in the following. Namely, the device has a semiconductor region which is formed by regularly and consecutively arranging a plurality of blocks of the same conductivity type, where each of the plurality of the blocks is equipped with three regions of mutually different impurity concentrations, clock pulses are applied to two regions out of the three regions and the voltage of the high level or low level of the clock pulse is applied to the remaining region out of the three regions as a constant potential.Type: GrantFiled: August 2, 1996Date of Patent: January 19, 1999Assignee: NEC CorporationInventor: Yasutaka Nakashiba
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Patent number: 5793070Abstract: A charge transfer device including a semiconductor substrate, a gate electrode provided in association with the substrate, the gate electrode having a corresponding channel region through which charge is propagated, the channel region having a predetermined potential; and means associated with the channel region for reducing charge trapping and recombination effects. In one aspect of the present invention, the reducing means includes a potential pocket defined within the channel region having a greater potential than the predetermined potential of said channel region. The potential pocket has a width dimension which is less than the corresponding width dimension of the channel region. The potential pocket is positioned in the center of the gate electrode, and is positioned so as to be aligned with a front edge of the gate electrode.Type: GrantFiled: April 24, 1996Date of Patent: August 11, 1998Assignee: Massachusetts Institute of TechnologyInventor: Barry E. Burke
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Patent number: 5705836Abstract: In a charge coupled device having a plurality of output structures, the plurality of output structures including first and second output structures, a channel structure is defined in a channel region beneath a gate electrode and coupled to each of the plurality of output structures. The channel structure includes a plurality of area structures, each area structure being characterized by a uniform potential which is different from the potential characterizing each of the other area structures. The plurality of area structures are arranged within the channel region to define a first increasing stepped potential gradient from any point within the channel region to the first output structure and define a second increasing stepped potential gradient from any point within the channel region to the second output structure.Type: GrantFiled: May 22, 1995Date of Patent: January 6, 1998Assignee: Dalsa, Inc.Inventors: Suhail Agwani, Stacy Royce Kamasz, Michael George Farrier
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Patent number: 5635738Abstract: An infrared solid-state image sensing apparatus is provided with a plurality of photoelectric converting sections arranged vertically and horizontally in a matrix pattern on a semiconductor substrate of a first conducting type; a plurality of vertical CCDs which have first buried channels of a second conducting type and electrodes disposed thereon with an insulating film between and which are disposed adjacently to the photoelectric converting sections; and a horizontal CCD having a second buried channel of the second conducting type and electrodes disposed thereon with an insulating film between and which is disposed adjacently to one side of the vertical CCDs. The first and second buried channels are provided with a low-concentration region having a uniform diffusion depth. Further, the surface of each first buried channel is provided with a high-concentration region of the second conducting type having a higher concentration than that of the surface of the second buried channel.Type: GrantFiled: December 20, 1994Date of Patent: June 3, 1997Assignee: Nikon CorporationInventors: Masahiro Shoda, Keiichi Akagawa, Tetsuya Tomofuji
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Patent number: 5612554Abstract: In a charge detection device of a charge coupled device, an unnecessary overlap between a floating gate and other gates are reduced. A gate of a source follower amplifier is also formed in an active region. Further, the floating gate is connected to a gate of the source follower amplifier, and a bias gate and the floating gate overlap above a field oxide film. A bias gate voltage is controlled according to fluctuations of floating gate voltage. Thus, floating gate potential is kept constant.Type: GrantFiled: June 22, 1994Date of Patent: March 18, 1997Assignee: Matsushita Electric Industrial Co., Ltd.Inventor: Hiromasa Funakoshi
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Patent number: 5608242Abstract: A CCD shift register includes a first gate electrode, a second gate electrode disposed adjacent to and longitudinally spaced from the first gate electrode, and a buried layer having a first dopant impurity concentration. The first gate electrode is disposed over the buried layer so as to define a first buried layer area. The second gate electrode is disposed over the buried layer so as to define a second buried layer area greater than the first buried layer area. In the buried layer, a trench region is formed so as to have a second dopant impurity concentration greater than the first dopant impurity concentration. The first gate electrode is disposed over the trench region so as to define a first trench area. The second gate electrode being disposed over the trench region so as to define a second trench area less than the first trench area.Type: GrantFiled: October 11, 1994Date of Patent: March 4, 1997Assignee: Dalsa, Inc.Inventors: Stacy R. Kamasz, Michael G. Farrier
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Patent number: 5574307Abstract: A semiconductor apparatus has a silicon substrate sliced off from a silicon ingot produced by the pulling method or floating zone method, wherein the concentration of interstitial oxygen in a region with a depth of approximately 10 .mu.m or less from a device forming surface is minimum except for the device forming surface. According to the present invention, in the semiconductor apparatus production process, in the inner region with a depth of approximately 10 .mu.m from the device forming surface of the silicon substrate, the inner region affecting the device operation, oxygen does not precipitate. Moreover, in a more inner region, oxygen precipitates, thereby providing a gettering effect with respect to metal impurities.Type: GrantFiled: December 16, 1994Date of Patent: November 12, 1996Assignee: Kabushiki Kaisha ToshibaInventors: Mokuji Kageyama, Yoshiaki Matsushita
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Patent number: 5548142Abstract: A solid-state imaging device capable of removing undesired influences, includes a semiconductor substrate having one of conductive types, a well layer arranged on the substrate and having the other conductive type opposite to the substrate, photo-sensitive pixels recessed in a matrix having a predetermined number and having the conductive type opposite to the well layer to generate signal charges corresponding to an incident light amount, a transfer channel formed along one direction of the photosensitive pixels arranged by the conductive type as the same as that of the substrate to transfer the signal charges generated by the photosensitive pixels, an electrode provided to the transfer channel on a side opposite to the substrate to supply an electric field to the transfer channel, and a barrier well formed of the impurity semiconductor material of the conductive type opposite to the conductive type of the semiconductor substrate in the manner that an impurity density of the well layer becomes longer along thType: GrantFiled: May 17, 1995Date of Patent: August 20, 1996Assignee: Kabushiki Kaisha ToshibaInventor: Kenichi Arakawa
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Patent number: 5448089Abstract: A charge-coupled device having an improved charge-transfer efficiency over a broad temperature range.Type: GrantFiled: March 29, 1994Date of Patent: September 5, 1995Assignee: Eastman Kodak CompanyInventors: Edmund K. Banghart, Edward T. Nelson, William F. DesJardin, James P. Lavine, Bruce C. Burkey
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Patent number: 5198881Abstract: A surface electron barrier region is formed on a semiconductor membrane device by a single step laser process which produces a sharp doping profile in a surface region above the light penetration depth. Enhanced quantum efficiency is observed, and by selectively forming barrier layers of differing depth, a CCD device architecture for two-color sensitivity is achieved. The barrier layer results in enhanced membrane-type and radiation hardened bipolar and CMOS devices.Type: GrantFiled: August 7, 1991Date of Patent: March 30, 1993Assignee: Massachusetts Institute of TechnologyInventors: Jammy C. Huang, Mordechai Rothschild, Barry E. Burke, Daniel J. Ehrlich, Bernard B. Kosicki