Patents by Inventor Amitava Bose

Amitava Bose has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20050242371
    Abstract: Particularly in high current applications, impact ionization induced electron-hole pairs are generated in the drain of an MOS transistor that can cause a parasitic bipolar transistor to become destructively conductive. The holes pass through the body region of the MOS transistor, which has intrinsic resistance, to the source, which is typically held at a relatively low voltage, such as ground. The hole current causes a voltage to develop in the body region, which acts as the base. This increased base voltage is what can cause the parasitic bipolar transistor to become conductive. The likelihood of this is greatly reduced by developing a voltage between the source, which acts as the emitter, and the body region by passing the channel current through an impedance between the source and the body region. This causes the emitter voltage to increase as the base voltage is increased and thereby prevent the parasitic bipolar transistor from becoming conductive.
    Type: Application
    Filed: April 30, 2004
    Publication date: November 3, 2005
    Inventors: Vishnu Khemka, Amitava Bose, Vijay Parthasarathy, Ronghua Zhu
  • Publication number: 20050245020
    Abstract: In one embodiment, semiconductor device 10 comprises a diode which uses isolation regions (34, 16, and 13) and a plurality of dopant concentrations (30, 20, 24, and 26) which may be used to limit the parasitic current that is injected into the semiconductor substrate (12). Various biases on the isolation regions (34, 16, and 13) may be used to affect the behavior of semiconductor device (10). In addition, a conductive layer (28) may be formed overlying the junction between anode (42) and cathode (40). This conductive layer (28) may decrease the electric field in selected regions in order to increase the maximum voltage that may be applied to cathode (40).
    Type: Application
    Filed: April 30, 2004
    Publication date: November 3, 2005
    Inventors: Ronghua Zhu, Amitava Bose, Vishnu Khemka, Vijay Parthasarathy
  • Patent number: 6933546
    Abstract: A semiconductor component comprises a first semiconductor region (110, 310), a second semiconductor region (120, 320) above the first semiconductor region, a third semiconductor region (130, 330) above the second semiconductor region, a fourth semiconductor region (140, 340) above the third semiconductor region, a fifth semiconductor region (150, 350) above the second semiconductor region and at least partially contiguous with the fourth semiconductor region, a sixth semiconductor region (160, 360) above and electrically shorted to the fifth semiconductor region, and an electrically insulating layer (180, 380) above the fourth semiconductor region and the fifth semiconductor region. A junction (145, 345) between the fourth semiconductor region and the fifth semiconductor region forms a zener diode junction, which is located only underneath the electrically insulating layer. In one embodiment, a seventh semiconductor region (170) circumscribes the third, fourth, fifth, and sixth semiconductor regions.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: August 23, 2005
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
  • Patent number: 6930027
    Abstract: A method of manufacturing a semiconductor component includes forming a first electrically insulating layer (120) and a second electrically insulating layer (130) over a semiconductor substrate (110). The method further includes etching a first trench (140) and a second trench (150) through the first and second electrically insulating layers and into the semiconductor substrate, and etching a third trench (610) through a bottom surface of the second trench and into the semiconductor substrate. The third trench has a first portion (920) and a second portion (930) interior to the first portion. The method still further includes forming a third electrically insulating layer (910) filling the first trench and the first portion of the third trench without filling the second portion of the third trench, and also includes forming a plug layer (1010) in the second portion of the third trench.
    Type: Grant
    Filed: February 18, 2003
    Date of Patent: August 16, 2005
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vijay Parthasarathy, Vishnu Khemka, Ronghua Zhu, Amitava Bose, Todd Roggenbauer, Paul Hui, Michael C. Butner
  • Patent number: 6882023
    Abstract: A semiconductor component includes a RESURF transistor (100, 200, 300, 400, 500) that includes a first semiconductor region (110, 210, 310, 410, 510) having a first conductivity type and an electrically-floating semiconductor region (115, 215, 315, 415, 515, 545) having a second conductivity type located above the first semiconductor region. The RESURF transistor further includes a second semiconductor region (120, 220, 320, 420, 520) having the first conductivity type located above the electrically-floating semiconductor region, a third semiconductor region (130, 230) having the first conductivity type located above the second semiconductor region, and a fourth semiconductor region (140, 240, 340, 440, 540) having the second conductivity type located above the second semiconductor region.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: April 19, 2005
    Assignee: Motorola, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
  • Patent number: 6815780
    Abstract: A semiconductor component includes a semiconductor substrate (210) having a first conductivity type, a semiconductor epitaxial layer (220) having the first conductivity type located over the semiconductor substrate, a first semiconductor device (110) and a second semiconductor device (130) located in the semiconductor epitaxial layer and including, respectively, a first semiconductor region (120) and a second semiconductor region (140), both having the second conductivity type, an ohmic contact region (150) in the semiconductor epitaxial layer having the first conductivity type and located between the first and second semiconductor devices, and at least one electrically insulating trench (160, 360) located in the semiconductor epitaxial layer and circumscribing at least the first semiconductor device. The semiconductor epitaxial layer has a doping concentration lower than a doping concentration of the semiconductor substrate.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: November 9, 2004
    Assignee: Motorola, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
  • Publication number: 20040207047
    Abstract: A semiconductor component includes a semiconductor substrate (210) having a first conductivity type, a semiconductor epitaxial layer (220) having the first conductivity type located over the semiconductor substrate, a first semiconductor device (110) and a second semiconductor device (130) located in the semiconductor epitaxial layer and including, respectively, a first semiconductor region (120) and a second semiconductor region (140), both having the second conductivity type, an ohmic contact region (150) in the semiconductor epitaxial layer having the first conductivity type and located between the first and second semiconductor devices, and at least one electrically insulating trench (160, 360) located in the semiconductor epitaxial layer and circumscribing at least the first semiconductor device. The semiconductor epitaxial layer has a doping concentration lower than a doping concentration of the semiconductor substrate.
    Type: Application
    Filed: April 15, 2003
    Publication date: October 21, 2004
    Applicant: Motorola, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
  • Publication number: 20040183098
    Abstract: A semiconductor component comprises a first semiconductor region (110, 310), a second semiconductor region (120, 320) above the first semiconductor region, a third semiconductor region (130, 330) above the second semiconductor region, a fourth semiconductor region (140, 340) above the third semiconductor region, a fifth semiconductor region (150, 350) above the second semiconductor region and at least partially contiguous with the fourth semiconductor region, a sixth semiconductor region (160, 360) above and electrically shorted to the fifth semiconductor region, and an electrically insulating layer (180, 380) above the fourth semiconductor region and the fifth semiconductor region. A junction (145, 345) between the fourth semiconductor region and the fifth semiconductor region forms a zener diode junction, which is located only underneath the electrically insulating layer. In one embodiment, a seventh semiconductor region (170) circumscribes the third, fourth, fifth, and sixth semiconductor regions.
    Type: Application
    Filed: March 17, 2003
    Publication date: September 23, 2004
    Applicant: Motorola, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
  • Publication number: 20040161931
    Abstract: A method of manufacturing a semiconductor component includes forming a first electrically insulating layer (120) and a second electrically insulating layer (130) over a semiconductor substrate (110). The method further includes etching a first trench (140) and a second trench (150) through the first and second electrically insulating layers and into the semiconductor substrate, and etching a third trench (610) through a bottom surface of the second trench and into the semiconductor substrate. The third trench has a first portion (920) and a second portion (930) interior to the first portion. The method still further includes forming a third electrically insulating layer (910) filling the first trench and the first portion of the third trench without filling the second portion of the third trench, and also includes forming a plug layer (1010) in the second portion of the third trench.
    Type: Application
    Filed: February 18, 2003
    Publication date: August 19, 2004
    Applicant: Motorola, Inc.
    Inventors: Vijay Parthasarathy, Vishnu Khemka, Ronghua Zhu, Amitava Bose, Todd Roggenbauer, Paul Hui, Michael C. Butner
  • Patent number: 6750524
    Abstract: A RESURF super-junction device (51) is provided which comprises a plurality of electrodes (53) disposed in a layer of a first material (61) having a first conductivity type. Each of the plurality of electrodes contains a second material (57) of a second conductivity type which is encased in a dielectric material (55).
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: June 15, 2004
    Assignee: Motorola Freescale Semiconductor
    Inventors: Vijay Parthasarthy, Vishnu Khemka, Ronghua Zhu, Amitava Bose
  • Patent number: 6734524
    Abstract: An electronic component includes a semiconductor substrate (110), an epitaxial semiconductor layer (120, 221, 222) over the semiconductor substrate, and a semiconductor region (130, 230) in the epitaxial semiconductor layer. The epitaxial semiconductor layer has an upper surface (123). A first portion (121) of the epitaxial semiconductor layer is located below the semiconductor region, and a second portion (122) of the epitaxial semiconductor layer is located above the semiconductor region. The semiconductor substrate and the first portion of the epitaxial semiconductor layer have a first conductivity type, and the semiconductor region has a second conductivity type. At least one electrically insulating trench (140, 240) extends from the upper surface of the epitaxial semiconductor layer into at least a portion of the semiconductor region. The semiconductor substrate has a doping concentration higher than a doping concentration of the first portion of the epitaxial semiconductor layer.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: May 11, 2004
    Assignee: Motorola, Inc.
    Inventors: Vijay Parthasarathy, Vishnu Khemka, Ronghua Zhu, Amitava Bose, Todd Roggenbauer, Paul Hui
  • Publication number: 20040084744
    Abstract: A semiconductor component includes a RESURF transistor (100, 200, 300, 400, 500) that includes a first semiconductor region (110, 210, 310, 410, 510) having a first conductivity type and an electrically-floating semiconductor region (115, 215, 315, 415, 515, 545) having a second conductivity type located above the first semiconductor region. The RESURF transistor further includes a second semiconductor region (120, 220, 320, 420, 520) having the first conductivity type located above the electrically-floating semiconductor region, a third semiconductor region (130, 230) having the first conductivity type located above the second semiconductor region, and a fourth semiconductor region (140, 240, 340, 440, 540) having the second conductivity type located above the second semiconductor region.
    Type: Application
    Filed: October 31, 2002
    Publication date: May 6, 2004
    Applicant: Motorola, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
  • Patent number: 6703895
    Abstract: An embodiment of a method of redistributing power in a semiconductor component includes varying a saturation current between a drain terminal (330) and a source terminal (320) of a field effect transistor (FET) (200, 500). The FET is at least a portion of the semiconductor component. The threshold voltage of the FET is maintained substantially constant across the FET while the drain-to-source saturation current per unit area is varied across the FET. In one embodiment, the drain-to-source saturation current per unit area is varied such that it is lower at a center of the FET than at a periphery of the FET. In particular embodiments, the drain-to-source saturation current per unit area may be varied across the FET by changing one or more of the gate-to-source voltage, the channel length, the channel width, the gate oxide thickness, and the channel mobility across the FET.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: March 9, 2004
    Assignee: Motorola, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
  • Patent number: 6693339
    Abstract: A semiconductor component includes a first semiconductor region (110, 210) having a first conductivity type and a second semiconductor region (120, 220) above the first semiconductor region and having a second conductivity type. The semiconductor component further comprises a third semiconductor region (130, 230) above the second semiconductor region and having the first conductivity type, a fourth semiconductor region (140, 240) above the third semiconductor region and having the second conductivity type, a fifth semiconductor region (150, 250) above the third semiconductor region and having the first conductivity type, a sixth semiconductor region (160, 260) substantially enclosed within the fifth semiconductor region and having the second conductivity type, and a seventh semiconductor region (170, 270) above the first semiconductor region and having the second conductivity type.
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: February 17, 2004
    Assignee: Motorola, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
  • Publication number: 20030214009
    Abstract: A RESURF super-junction device (51) is provided which comprises a plurality of electrodes (53) disposed in a layer of a first material (61) having a first conductivity type. Each of the plurality of electrodes contains a second material (57) of a second conductivity type which is encased in a dielectric material (55).
    Type: Application
    Filed: May 14, 2002
    Publication date: November 20, 2003
    Applicant: Motorola Inc.
    Inventors: Vijay Parthasarathy, Vishnu Khemka, Ronghua Zhu, Amitava Bose
  • Patent number: 6573562
    Abstract: A semiconductor component includes a semiconductor substrate (110) having first and second portions (111, 112) with a first conductivity type, a transistor (120) at least partially located in the semiconductor substrate, and a switching circuit (150, 350, 650, 850). The transistor includes (i) a first doped region in the first portion of the semiconductor substrate and having the first conductivity type (ii) a terminal, which includes a second doped region having a second conductivity type and located in the first portion of the semiconductor substrate and over the first doped region, and (iii) a third doped region having the second conductivity type and located in the semiconductor substrate below the first portion of the semiconductor substrate and above the second portion of the semiconductor substrate. The switching circuit is electrically coupled to the third doped region to adjust the bias of the third doped region.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: June 3, 2003
    Assignee: Motorola, Inc.
    Inventors: Vijay Parthasarathy, Ronghua Zhu, Vishnu K. Khemka, Amitava Bose
  • Publication number: 20030080381
    Abstract: A semiconductor component includes a semiconductor substrate (110) having first and second portions (111, 112) with a first conductivity type, a transistor (120) at least partially located in the semiconductor substrate, and a switching circuit (150, 350, 650, 850). The transistor includes (i) a first doped region in the first portion of the semiconductor substrate and having the first conductivity type (ii) a terminal, which includes a second doped region having a second conductivity type and located in the first portion of the semiconductor substrate and over the first doped region, and (iii) a third doped region having the second conductivity type and located in the semiconductor substrate below the first portion of the semiconductor substrate and above the second portion of the semiconductor substrate. The switching circuit is electrically coupled to the third doped region to adjust the bias of the third doped region.
    Type: Application
    Filed: October 31, 2001
    Publication date: May 1, 2003
    Inventors: Vijay Parthasarathy, Ronghua Zhu, Vishnu K. Khemka, Amitava Bose
  • Patent number: 6528849
    Abstract: A MOSFET includes a source region, a first channel region proximate to the source region, a first gate region adjacent to the first base region, a drain region, a second channel region proximate to the drain region, and a second gate region adjacent to the second channel region. A first channel is formed within the first channel region in dependence upon a first voltage applied to the first gate region with respect to at least a first portion of the source region, and a second channel is formed within the second channel region in dependence upon a second voltage applied to the second gate region with respect to at least a second portion of the drain region. The MOSFET further includes a drift region coupled between the first channel region and the second channel region, where the drift region includes a set of alternating columns, each of which is also coupled between the first base region and the second base region.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: March 4, 2003
    Assignee: Motorola, Inc.
    Inventors: Vishnu K. Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
  • Patent number: 5492858
    Abstract: Disclosed is a method of planarizing the surface of a silicon wafer in integrated circuit manufacture where shallow trench isolation techniques are employed. The etched trenches are first coated with a silicon nitride protective liner before the trenches and active area mesas are conformally coated with a layer of silicon oxide. The conformal oxide then is steam annealed to densify the conformal oxide, and then the surface of the silicon wafer is etched and polished back down to the tops of the active area mesas, to form a substantially planar surface.
    Type: Grant
    Filed: April 20, 1994
    Date of Patent: February 20, 1996
    Assignee: Digital Equipment Corporation
    Inventors: Amitava Bose, Marion M. Garver, Andre I. Nasr, Steven S. Cooperman