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).

  • Patent number: 7476593
    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: Grant
    Filed: June 27, 2006
    Date of Patent: January 13, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Ronghua Zhu, Amitava Bose, Vishnu K. Khemka, Vijay Parthasarathy
  • Patent number: 7466006
    Abstract: Methods and apparatus are provided for reducing substrate leakage current of lateral RESURF diode devices. The diode device (60, 60?, 100) comprises first (39) and second (63) surface terminals overlying a semiconductor substrate (22) coupled to P (38, 32, 26) and N (24, 30, 46) type regions providing the diode action. An unavoidable parasitic vertical device (54, 92) permits leakage current to flow from the first terminal (39) to the substrate (22). This leakage current is reduced by having the diode device second terminal (63) comprise both N (46) and P (62) type regions coupled together by the second terminal (63). This forms a shorted base-collector lateral transistor (72) between the first (39) and second (63) terminals to provide the diode function. The gain of this lateral transistor (72) increases the proportion of first terminal (39) current that flows to the second terminal (63) rather than the substrate (22).
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: December 16, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu K. Khemka, Ronghua Zhu, Amitava Bose
  • Publication number: 20080293211
    Abstract: A semiconductor process and apparatus provide a high voltage deep trench capacitor structure (10) that is integrated in an integrated circuit, alone or in alignment with a fringe capacitor (5). The deep trench capacitor structure is constructed from a first capacitor plate (4) that is formed from a doped n-type SOI semiconductor layer (e.g., 4a-c). The second capacitor plate (3) is formed from a doped p-type polysilicon layer (3a) that is tied to the underlying substrate (1).
    Type: Application
    Filed: May 23, 2007
    Publication date: November 27, 2008
    Inventors: Ronghua Zhu, Vishnu Khemka, Amitava Bose, Todd C. Roggenbauer
  • Publication number: 20080265291
    Abstract: Apparatus and methods are provided for fabricating semiconductor devices with reduced bipolar effects. One apparatus includes a semiconductor body (120) including a surface and a transistor source (300) located in the semiconductor body proximate the surface, and the transistor source includes an area (310) of alternating conductivity regions (3110, 3120). Another apparatus includes a semiconductor body (120) including a first conductivity and a transistor source (500) located in the semiconductor body. The transistor source includes multiple regions (5120) including a second conductivity, wherein the regions and the semiconductor body form an area (510) of alternating regions of the first and second conductivities. One method includes implanting a semiconductor well (120) including a first conductivity in a substrate (110) and implanting a plurality of doped regions (5120) comprising a second conductivity in the semiconductor well.
    Type: Application
    Filed: April 30, 2007
    Publication date: October 30, 2008
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Ronghua Zhu, Amitava Bose, Vishnu K. Khemka, Todd C. Roggenbauer
  • Patent number: 7439584
    Abstract: Methods and apparatus are provided for reducing substrate leakage current of RESURF LDMOSFET devices.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: October 21, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu K. Khemka, Amitava Bose, Todd C. Roggenbauer, Ronghua Zhu
  • Patent number: 7436025
    Abstract: A semiconductor device 10 is provided. A first layer 12 has a first dopant type; a second layer 14 is provided over the first layer 12; and a third layer 16 is provided over the second layer and has the first dopant type. A plurality of first and second semiconductor regions 22, 24 are within the third layer. The first semiconductor region 22 has the first dopant type, and the second semiconductor region 24 has the second dopant type. The first and second semiconductor regions 22, 24 are disposed laterally to one another in an alternating pattern to form a super junction, and the super junction terminates with a final second semiconductor region 24, 24? of the second dopant type.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: October 14, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Ronghua Zhu, Amitava Bose, Vishnu K. Khemka, Todd C. Roggenbauer
  • Publication number: 20080191275
    Abstract: A improved MOSFET (50, 51, 75, 215) has a source (60) and drain (62) in a semiconductor body (56), surmounted by an insulated control gate (66) located over the body (56) between the source (60) and drain (62) and adapted to control a conductive channel (55) extending between the source (60) and drain (62). The insulated gate (66) is perforated by a series of openings (61) through which highly doped regions (69) in the form of a series of (e.g., square) dots (69) of the same conductivity type as the body (56) are provided, located in the channel (55), spaced apart from each other and from the source (60) and drain (62). These channel dots (69) are desirably electrically coupled to a highly doped contact (64) to the body (56). The resulting device (50, 51, 75, 215) has a greater SOA, higher breakdown voltage and higher HBM stress resistance than equivalent prior art devices (20) without the dotted channel. Threshold voltage is not affected.
    Type: Application
    Filed: February 14, 2007
    Publication date: August 14, 2008
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Vishnu K. Khemka, Amitava Bose, Todd C. Roggenbauer, Ronghua Zhu
  • Publication number: 20080191305
    Abstract: A low leakage bipolar Schottky diode (20, 40, 87) is formed by parallel lightly doped N (32, 52, 103) and P (22, 42, 100) regions adapted to form superjunction regions. First ends of the P regions (22, 42, 100) are terminated by P+ layers (21, 41, 121) and second, opposed ends of the N regions (32, 52, 103) are terminated by N+ layers (31, 51, 131). Silicide layers (24, 34, 44, 54, 134, 124) are provided in contact with both ends of the parallel N and P regions (22, 32, 42, 52, 100, 103), thereby forming at the first end ohmic contacts (28, 48) with the P+ regions (21, 41, 121) and Schottky contacts (37, 57) with the N regions 32, 52, 103) and at the second, opposite end, ohmic contacts (38, 58) with the N+ regions (31, 51, 131) and Schottky contacts (27, 47) with the P regions (22, 42, 100). When forward biased current flows in both N (32, 52) and P (22, 42) regions thereby reducing the forward drop.
    Type: Application
    Filed: February 14, 2007
    Publication date: August 14, 2008
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Vishnu K. Khemka, Amitava Bose, Todd C. Roggenbauer, Ronghua Zhu
  • Patent number: 7405128
    Abstract: A improved MOSFET (50, 51, 75, 215) has a source (60) and drain (62) in a semiconductor body (56), surmounted by an insulated control gate (66) located over the body (56) between the source (60) and drain (62) and adapted to control a conductive channel (55) extending between the source (60) and drain (62). The insulated gate (66) is perforated by a series of openings (61) through which highly doped regions (69) in the form of a series of (e.g., square) dots (69) of the same conductivity type as the body (56) are provided, located in the channel (55), spaced apart from each other and from the source (60) and drain (62). These channel dots (69) are desirably electrically coupled to a highly doped contact (64) to the body (56). The resulting device (50, 51, 75, 215) has a greater SOA, higher breakdown voltage and higher HBM stress resistance than equivalent prior art devices (20) without the dotted channel. Threshold voltage is not affected.
    Type: Grant
    Filed: February 14, 2007
    Date of Patent: July 29, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu K. Khemka, Amitava Bose, Todd C. Roggenbauer, Ronghua Zhu
  • Publication number: 20080124889
    Abstract: A process of forming an electronic device can include providing a semiconductor-on-insulator substrate including a substrate, a first semiconductor layer, and a buried insulating layer lying between the first semiconductor layer and the substrate. The process can also include forming a field isolation region within the semiconductor layer, and forming an opening extending through the semiconductor layer and the buried insulating layer to expose the substrate. The process can further include forming a conductive structure within the opening, wherein the conductive structure abuts the substrate.
    Type: Application
    Filed: November 3, 2006
    Publication date: May 29, 2008
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Todd C. ROGGENBAUER, Vishnu K. KHEMKA, Ronghua ZHU, Amitava BOSE, Paul HUI, Xiaoqiu HUANG, Van WONG
  • Publication number: 20080122025
    Abstract: An electronic device can include a substrate, a buried insulating layer overlying the substrate, and a semiconductor layer overlying the buried insulating layer, wherein the semiconductor layer is substantially monocrystalline. The electronic device can also include a conductive structure extending through the semiconductor layer and buried insulating layer and abutting the substrate, and an insulating spacer lying between the conductive structure and each of the semiconductor layer and the buried insulating layer.
    Type: Application
    Filed: November 3, 2006
    Publication date: May 29, 2008
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Todd C. Roggenbauer, Vishnu K. Khemka, Ronghua Zhu, Amitava Bose, Paul Hui, Xiaoqiu Huang
  • Publication number: 20080113498
    Abstract: Methods and apparatus are provided for semiconductor device (60, 95, 100, 106). The semiconductor device (60, 95, 100, 106), comprises a first region (64, 70) of a first conductivity type extending to a first surface (80), a second region (66) of a second, opposite, conductivity type forming with the first region (70) a first PN junction (65) extending to the first surface (80), a contact region (68) of the second conductivity type in the second region (66) at the first surface (80) and spaced apart from the first PN junction (65) by a first distance (LDS), and a third region (82, 96-98, 108) of the first conductivity type and of a second length (LBR), underlying the second region (66) and forming a second PN junction (63) therewith spaced apart from the first surface (80) and located closer to the first PN junction (65) than to the contact region (68). The breakdown voltage is enhanced without degrading other useful properties of the device (60, 95, 100, 106).
    Type: Application
    Filed: November 15, 2006
    Publication date: May 15, 2008
    Inventors: Vishnu K. Khemka, Amitava Bose, Todd C. Roggenbauer, Ronghua Zhu
  • Patent number: 7355260
    Abstract: A conductive layer includes a first portion that forms a Schottky region with an underlying first region having a first conductivity type. A second region of a second conductivity type underlies the first region, where the second conductivity type is opposite the first conductivity type. A third region of the first conductivity type immediately underlies the second region and is electrically coupled to a cathode of the device.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: April 8, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu K. Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
  • Publication number: 20080079122
    Abstract: A semiconductor device 10 is provided. A first layer 12 has a first dopant type; a second layer 14 is provided over the first layer 12; and a third layer 16 is provided over the second layer and has the first dopant type. A plurality of first and second semiconductor regions 22, 24 are within the third layer. The first semiconductor region 22 has the first dopant type, and the second semiconductor region 24 has the second dopant type. The first and second semiconductor regions 22, 24 are disposed laterally to one another in an alternating pattern to form a super junction, and the super junction terminates with a final second semiconductor region 24, 24? of the second dopant type.
    Type: Application
    Filed: September 29, 2006
    Publication date: April 3, 2008
    Inventors: Ronghua Zhu, Amitava Bose, Vishnu K. Khemka, Todd C. Roggenbauer
  • Patent number: 7329566
    Abstract: A semiconductor component and method of manufacture, including an insulated gate bipolar transistor (IGBT) (100, 200) that includes a semiconductor substrate (110) having a first conductivity type and buried semiconductor region (115) having a second conductivity type located above the semiconductor substrate. The IGBT further includes a first semiconductor region (120) having the first conductivity type located above the buried semiconductor region, a second semiconductor region (130) having the second conductivity type located above at least a portion of the first semiconductor region, an emitter (150) having the second conductivity type disposed in the second semiconductor region, and a collector (170) having the second conductivity type disposed in the first semiconductor region. A sinker region (140) is provided to electrically tie the buried semiconductor region (115) to the second semiconductor region (130).
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: February 12, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu K. Khemka, Amitava Bose, Ronghua Zhu
  • Patent number: 7309638
    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: July 14, 2005
    Date of Patent: December 18, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
  • Patent number: 7282386
    Abstract: A Schottky device having a plurality of unit cells, each having a Schottky contact portion, surrounded by a termination structure that causes depletion regions to form in a vertical and horizontal direction, relative to a surface of the device, during a reverse bias voltage condition.
    Type: Grant
    Filed: April 29, 2005
    Date of Patent: October 16, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu K. Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
  • Patent number: 7276419
    Abstract: A semiconductor device may include first, second, and third semiconductor layers. The first and third layers may have a first dopant type, and the second layer may have a second dopant type. A first region within the third semiconductor layer may have the second dopant type. A second region between the first region and the second semiconductor layer may have the first dopant type. A third region above the second region may have the first dopant type. A fourth semiconductor region adjacent to the third region may have a first concentration of the second dopant type. A source contact region may have a second concentration of the second dopant type adjacent to the third semiconductor region and adjacent to the fourth semiconductor region. The second concentration may be higher than the first concentration.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: October 2, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Vishnu Khemka, John M. Pigott, Ronghua Zhu, Amitava Bose, Randall C. Gray, Jeffrey J. Braun
  • Publication number: 20070221967
    Abstract: A semiconductor device may include a semiconductor substrate having a first dopant type. A first semiconductor region within the semiconductor substrate may have a plurality of first and second portions (44, 54). The first portions (44) may have a first thickness, and the second portions (54) may have a second thickness. The first semiconductor region may have a second dopant type. A plurality of second semiconductor regions (42) within the semiconductor substrate may each be positioned at least one of directly below and directly above a respective one of the first portions (44) of the first semiconductor region and laterally between a respective pair of the second portions (54) of the first semiconductor region. A third semiconductor region (56) within the semiconductor substrate may have the first dopant type. A gate electrode (64) may be over at least a portion of the first semiconductor region and at least a portion of the third semiconductor region (56).
    Type: Application
    Filed: March 27, 2006
    Publication date: September 27, 2007
    Inventors: Vishnu Khemka, Amitava Bose, Todd Roggenbauer, Ronghua Zhu
  • Publication number: 20070224738
    Abstract: A microelectronic assembly and a method for constructing a microelectronic assembly are provided. The microelectronic assembly may include a semiconductor substrate with an isolation trench (62) formed therein. The isolation trench (62) may have first and second opposing inner walls (74, 76) and a floor (78). First and second conductive plates (106) may be formed over the first and second opposing inner walls (74, 76) of the isolation trench (62) respectively such that there is a gap (90) between the first and second conductive plates (106). First and second semiconductor devices (114) may be formed in the semiconductor substrate on opposing sides of the isolation trench (62). The method may include forming a trench (62) in a semiconductor substrate, forming first and second conductive plates (106) within the trench, and forming first and second semiconductor devices (114) in the semiconductor substrate on opposing sides of the trench (62).
    Type: Application
    Filed: March 27, 2006
    Publication date: September 27, 2007
    Inventors: Vishnu Khemka, Amitava Bose, Todd Roggenbauer, Ronghua Zhu