Mosfet Substrate Bias Patents (Class 257/901)
  • Patent number: 5712509
    Abstract: A semiconductor integrated circuit structure includes a semiconductor substrate; an electronic element disposed in the substrate; a first electrically insulating layer disposed on the substrate and the electronic element; a first electrically conducting interconnection layer electrically connected to the electronic element and disposed at least partly on the first electrically insulating layer; a second electrically insulating layer disposed on the first electrically conducting interconnection layer; a second electrically conducting interconnection layer disposed on the second electrically insulating layer; and a through-hole penetrating the second electrically insulating layer to the first electrically conducting interconnection layer, part of the second interconnection layer being disposed within the through-hole and contacting the first electrically conducting interconnection layer wherein the first electrically conducting interconnection layer includes a current barrier including at least one opening in t
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: January 27, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeru Harada, Kenji Kishibe, Akira Ohisa, Hiroshi Mochizuki, Eisuke Tanaka
  • Patent number: 5612566
    Abstract: A bidirectional current blocking lateral power MOSFET including a source and a drain which are not shorted to a substrate, and voltages that are applied to the source and drain are both higher than the voltage at which the body is maintained (for an N-channel MOSFET) or lower than the voltage at which the body is maintained (for a P-channel MOSFET). The on-resistance of the MOSFET is improved by decreasing the conductance of the epi region and disposing a thin threshold adjust layer on the surface of the substrate between the source and drain regions. An optional second punchthrough preventing implant is disposed on the substrate surface.
    Type: Grant
    Filed: December 8, 1995
    Date of Patent: March 18, 1997
    Assignee: Siliconix incorporated
    Inventor: Richard K. Williams
  • Patent number: 5608253
    Abstract: A novel MOS transistor structure for improving device scaling by improving short channel control includes a buried back gate beneath a channel region of the MOS transistor. A separate contact to a well that is electrically communicated to the buried back gate improves short channel controls without performance degradations. In a preferred embodiment, the back gate is grounded when turning the n-channel MOS transistor off. In alternate embodiments, the buried layer produces retrograde p wells. In some applications, multiple buried layers may be used, with one or more being planar. CMOS devices may have independent, multiple buried back gates.
    Type: Grant
    Filed: March 22, 1995
    Date of Patent: March 4, 1997
    Assignee: Advanced Micro Devices Inc.
    Inventors: Yowjuang W. Liu, Kuang-Yeh Chang
  • Patent number: 5574298
    Abstract: A method for forming a gate array substrate contact and the contact resulting therefrom includes the steps of etching off polysilicon gate layers at the same time as cutting the polysilicon to form the gate array base cell (10). The method includes forming openings (40, 42, and 44) in the second insulating layer (34) and insulating layer (30) to connect a lead (46, 48, and 50) to the underlying substrate.
    Type: Grant
    Filed: August 29, 1995
    Date of Patent: November 12, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Masashi Hashimoto, Louis N. Hutter, S. Shivaling Mahant-Shetti
  • Patent number: 5554872
    Abstract: In a semiconductor device including a composite substrate formed by bonding first and second semiconductor substrates to each other through an oxide film and an insulator isolation trench formed from a major surface of the first semiconductor substrate to reach the oxide film and to surround an element forming region, when the potential of the second substrate is set at a potential higher than the minimum potential in the element forming region of the first substrate, an breakdown voltage can be increased. In a semiconductor integrated circuit having an element isolation region, a semiconductor device of a perfect dielectric isolation structure having an element forming region having a thickness smaller than that of the element forming region of a P-N junction isolation structure is used to reduce, e.g., a base curvature influence, thereby obtaining a further high breakdown voltage.
    Type: Grant
    Filed: March 27, 1995
    Date of Patent: September 10, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiro Baba, Shunichi Hiraki, Akihiko Osawa
  • Patent number: 5548150
    Abstract: A high-resistant p-silicon layer is formed on a silicon substrate through a silicon oxide film. N-source and n-drain layers are selectively formed in the surface of the high-resistant p-silicon layer. A gate electrode is formed through a gate insulating film on a channel region between the source and drain layers. To induce an n-inverted layer under the gate electrode, a p-base layer is formed in the high-resistant p-silicon layer. A depletion layer extending from a pn junction between the n-drain layer and the high-resistant p-silicon layer reaches the silicon oxide film in a thermal equilibrium state. Part of the high-resistant p-silicon layer extends into a channel region between the drain and base layers. The drain and base layers are connected to each other through part of the depletion layer in the thermal equilibrium state. A field effect transistor having a high-speed operation is provided.
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: August 20, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ichiro Omura, Akio Nakagawa, Tadashi Sakai, Masayuki Sekimura, Hideyuki Funaki
  • Patent number: 5497023
    Abstract: Disclosed is a semiconductor device, such as a semiconductor memory device, having structure wherein invasion of minority carriers from the semiconductor substrate into components of the device, formed on the substrate, can be avoided. The semiconductor memory device can be an SRAM or DRAM, for example, and includes a memory array and peripheral circuit on a substrate. In one aspect of the present invention, a buried layer of the same conductivity type as that of the substrate, but with a higher impurity concentration than that of the substrate, is provided beneath at least one of the peripheral circuit and memory array. A further region can extend from the buried layer, for example, to the surface of the semiconductor substrate, the buried layer and further region in combination acting as a shield to prevent minority carriers from penetrating to the device elements.
    Type: Grant
    Filed: December 8, 1994
    Date of Patent: March 5, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Shinji Nakazato, Hideaki Uchida, Yoshikasu Saito, Masahiro Yamamura, Yutaka Kobayashi, Takahide Ikeda, Ryoichi Hori, Goro Kitsukawa, Kiyoo Itoh, Nobuo Tanba, Takao Watanabe, Katsuhiro Shimohigashi, Noriyuki Homma
  • Patent number: 5485029
    Abstract: A semiconductor chip having an on-chip ground plane comprising a low resistivity semiconductor region in a plurality of non-device regions of the chip and reach-through regions electrically connected to the low resistivity semiconductor region. One or more front-side contacts are used to electrically connect the reach-through regions and the low resistivity semiconductor region to a ground potential to electrically ground the on-chip ground plane.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: January 16, 1996
    Assignee: International Business Machines Corporation
    Inventors: Emmanuel F. Crabbe, Keith A. Jenkins, Jeffrey L. Snare
  • Patent number: 5475255
    Abstract: A circuit die 100 with improved substrate noise isolation may be achieved by providing a first circuit element 102 and a second circuit element 103 on a substrate 101. The first circuit element 102 generally injects noise into the substrate 101 while the second circuit element 103 is adversely affected by noise being carried in the substrate 101. To reduce the noise interference, a noise isolation ring 104-017 may be placed around the first circuit element 102 and/or the second circuit element 103 wherein the noise isolation ring is of a conducted material. A first lead 202 is electrically connected to a first circuit element 102, a second lead 205 is electrically connected to the second circuit element 103, and a third lead 201 is electrically connected to the noise isolation ring 105, wherein the third lead 201 is electrically isolated from both the first and second leads 202 and 205.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: December 12, 1995
    Assignee: Motorola Inc.
    Inventors: Kuntal Joardar, Jeffrey D. Ganger, Sangil Park
  • Patent number: 5473183
    Abstract: The present invention is directed to a CMOS inverter in which an N-FET (Qn) formed of an N-type source region (2S), a drain region (2D) and a gate electrode (2G) and a P-FET (Qp) formed of a P-type source region (3S), a drain region (3D) and a gate electrode (3G) are formed on an N-type silicon substrate (1n). A first well region (4p) is formed under the N-FET (Qn) and P-FET (Qp). Further, an N-type well region (5n) is formed on the P-FET (Qp) within the first well region (4p). Thus, an influence exerted by a back-gate effect from the substrate can be prevented completely, whereby a phase displacement relative to a pulse response to a CMOS peripheral logic circuit and a malfunction can be avoided.
    Type: Grant
    Filed: September 7, 1994
    Date of Patent: December 5, 1995
    Assignee: Sony Corporation
    Inventor: Kazuya Yonemoto
  • Patent number: 5428237
    Abstract: An insulated gate type transistor includes a plurality of major electrode regions, a channel region provided between the plurality of major electrode regions, a gate electrode provided on the channel region with a gate insulating film therebetween, and a semiconductor region provided in contact with the channel region, the semiconductor region having the same conductivity type as that of the channel region and a higher impurity concentration than the channel region. The gate electrode has at least two opposing portions. The plurality of major electrode regions are provided on an substrate insulating film. The transistor is activated in a state where the semiconductor region is maintained at a predetermined voltage. A semiconductor device includes a plurality of memory cells, each of which includes the aforementioned insulated gate type transistor and an electrically breakable memory element provided on one of the major electrode regions.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: June 27, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Yuzurihara, Mamoru Miyawaki, Akira Ishizaki, Genzo Momma, Tetsunobu Kochi
  • Patent number: 5416339
    Abstract: A semiconductor device for switching comprises a semiconductor substrate (10), three conductive regions (14, 16, 20) for providing a path for electrons to or from desired locations of the semiconductor substrate (10) formed at locations spaced apart on the surface of the semiconductor substrate (10, 28), a device (22, 24) for causing a current between the first and second conductive regions (14, 16), and a device (18) for forming electric field for diverting the caused current to the third conductive region (20). Since the current flowing to the first and second conductive regions (14, 16) is diverted to the third conductive region (20), switching operation between the first and second conductive regions (14, 16) is implemented.
    Type: Grant
    Filed: October 1, 1990
    Date of Patent: May 16, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masato Fujinaga, Norihiko Kotani, Tsuyoshi Yamano
  • Patent number: 5309008
    Abstract: A p-type silicon substrate is arranged on an n-type silicon substrate and a trench is formed in the p-type silicon substrate. An insulating film for separating elements from the other is formed along the upper side wall of the trench. A diffusion layer which serves as a capacitor electrode, and a capacitor insulating film are formed in the substrate along the lower side wall of the trench. A storage electrode is formed in the trench. This storage electrode is connected to a diffusion layer of MOSFET via the electrode and the diffusion layer. Even when the diameter of the trench is made small, the surface area of the storage electrode can be kept large enough because the diffusion layer which serves as the capacitor electrode is formed in the substrate along the side wall of the trench.
    Type: Grant
    Filed: February 25, 1993
    Date of Patent: May 3, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshiharu Watanabe
  • Patent number: 5286992
    Abstract: A semiconductor or substrate of a first conductivity type includes a well structure of a second conductivity type formed therein. A first low voltage MOS transistor includes spaced apart source and drain regions of the first conductivity type in the well. A first transistor gate lies above a channel region which is disposed between the source and drain regions of the first low voltage MOS transistor and is separated therefrom by a gate dielectric having a first thickness. A second high voltage transistor includes spaced apart source and drain regions of the first conductivity type in the well. A second transistor gate lies above a channel region which is disposed between the source and drain regions of the second high voltage transistor and is separated therefrom by a gate dielectric having a second thickness which is greater than the thickness of the gate dielectric of the first low voltage MOS transistor.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: February 15, 1994
    Assignee: Actel Corporation
    Inventors: Michael G. Ahrens, Douglas C. Galbraith, Abdelshafy Eltoukhy
  • Patent number: 5241575
    Abstract: An image sensing device that outputs a signal logarithmically proportional to the intensity of the incident light. The image sensing device makes use of a sub-threshold current flowing between the drain and source of a MOS transistor when the gate voltage is below the threshold voltage (above which the MOS transistor is nominally conductive and below which nominally non-conductive). Since the logarithmic conversion is done in the photosensing section of a solid-state image sensing device, the output from the device is already compressed and is easily handled by a small capacity CCD. Some output systems for the image sensing device of the present invention are also described.
    Type: Grant
    Filed: September 9, 1992
    Date of Patent: August 31, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Shigehiro Miyatake, Kenji Takada, Jun Hasegawa, Yasuhiro Nanba
  • Patent number: 5185275
    Abstract: A process for improving the high voltage performances of a MOSFET transistor, and suppressing parasitic current induced snap-back behavior by placing a heavily doped P+ region around the grounded source. A first P+ region is placed adjacently to and in contact with the source and its metal lead, and a second P+ region may be placed under and in contact with the source and first P+ region, or form a layer under the entire transistor connected to the source by a P+ plug. Additional grounding of the source may be accomplished by a succession of alternating P+ region and N+ regions along the source edge.
    Type: Grant
    Filed: March 30, 1992
    Date of Patent: February 9, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Kirk Prall
  • Patent number: 5185535
    Abstract: Complimentary metal oxide silicon transistors fabricated on silicon-on-insulator substrates are configured to allow separately controllable and independent backgate bias for adjacent complimentary devices on the same substrate. By means of deep implantation of boron, a backgate bias P- well (26,126) is positioned on the N-substrate (17,117) at a front surface of the N- substrate behind the N channel transistor of a complimentary pair. The backgate bias P- well (26,126) is provided with an electrical contact (48,148) at the front of the device, as is the N- silicon substrate to enable independent application of separate bias voltage of different polarities and appropriate magnitude.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: February 9, 1993
    Assignee: Hughes Aircraft Company
    Inventors: Joseph E. Farb, Mei Li, Chen-Chi P. Chang, Maw-Rong Chin
  • Patent number: 5160989
    Abstract: A semiconductor over insulator transistor is provided preferably of a lightly doped drain ("LDD") profile. LDD transistor (74) includes a semiconductor mesa (76) formed over an insulating layer (94) which overlies a semiconductor substrate (96). Semiconductor mesa (76) includes a source region (78) and a drain region (80) at opposite ends thereof. A body node (82) is disposed between source and drain regions (78,80). A low resistance contact region (98) lies along substantially the entire width of body region (82) and contacts a vertical contact which permits electrical contact from the top surface of semiconductor mesa (76) to low resistance contact region (98). Low resistance contact region (98) may be extended to fully underlie source region (78) such that the vertical contact may be moved away from body node (82).
    Type: Grant
    Filed: June 13, 1989
    Date of Patent: November 3, 1992
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston