Patents by Inventor William D. French

William D. French 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: 20120184077
    Abstract: An insulated-gate field-effect transistor (100) provided along an upper surface of a semiconductor body contains a pair of source/drain zones (240 and 242) laterally separated by a channel zone (244). A gate electrode (262) overlies a gate dielectric layer (260) above the channel zone. Each source/drain zone includes a main portion (240M or 242M) and a more lightly doped lateral extension (240E or 242E) laterally continuous with the main portion and extending laterally under the gate electrode. The lateral extensions, which terminate the channel zone along the upper semiconductor surface, are respectively largely defined by a pair of semiconductor dopants of different atomic weights. With the transistor being an asymmetric device, the source/drain zones constitute a source and a drain. The lateral extension of the source is then more lightly doped than, and defined with dopant of higher atomic weight, than the lateral extension of the drain.
    Type: Application
    Filed: May 3, 2011
    Publication date: July 19, 2012
    Inventors: Sandeep R. Bahl, William D. French, Constantin Bulucea
  • Patent number: 8101479
    Abstract: A gate electrode (302) of a field-effect transistor (102) is defined above, and vertically separated by a gate dielectric layer (300) from, a channel-zone portion (284) of body material of a semiconductor body. Semiconductor dopant is introduced into the body material to define a more heavily doped pocket portion (290) using the gate electrode as a dopant-blocking shield. A spacer (304T) having a dielectric portion situated along the gate electrode, a dielectric portion situated along the body, and a filler portion (SC) largely occupying the space between the other two spacer portions is provided. Semiconductor dopant is introduced into the body to define a pair of source/drain portions (280M and 282M) using the gate electrode and spacer as a dopant-blocking shield. The filler spacer portion is removed to convert the spacer to an L shape (304). Electrical contacts (310 and 312) are formed respectively to the source/drain portions.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: January 24, 2012
    Assignee: National Semiconductor Corporation
    Inventors: D. Courtney Parker, Donald M. Archer, Sandeep R. Bahl, Constantin Bulucea, William D. French, Peter B. Johnson, Jeng-Jiun Yang
  • Patent number: 8084827
    Abstract: A group of high-performance like-polarity insulated-gate field-effect transistors (100, 108, 112, 116, 120, and 124 or 102, 110, 114, 118, 122, and 126) have selectably different configurations of lateral source/drain extensions, halo pockets, and gate dielectric thicknesses suitable for a semiconductor fabrication platform that provides a wide variety of transistors for analog and/or digital applications. Each transistor has a pair of source/drain zones, a gate dielectric layer, and a gate electrode. Each source/drain zone includes a main portion and a more lightly doped lateral extension. The lateral extension of one of the source/drain zones of one of the transistors is more heavily doped or/and extends less deeply below the upper semiconductor surface than the lateral extension of one of the source/drain zones of another of the transistors.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: December 27, 2011
    Assignee: National Semiconductor Corporation
    Inventors: Constantin Bulucea, William D. French, Donald M. Archer, Jeng-Jiun Yang, Sandeep R. Bahl, D. Courtney Parker
  • Patent number: 7973372
    Abstract: An insulated-gate field-effect transistor (100) provided along an upper surface of a semiconductor body contains a pair of source/drain zones (240 and 242) laterally separated by a channel zone (244). A gate electrode (262) overlies a gate dielectric layer (260) above the channel zone. Each source/drain zone includes a main portion (240M or 242M) and a more lightly doped lateral extension (240E or 242E) laterally continuous with the main portion and extending laterally under the gate electrode. The lateral extensions, which terminate the channel zone along the upper semiconductor surface, are respectively largely defined by a pair of semiconductor dopants of different atomic weights. With the transistor being an asymmetric device, the source/drain zones constitute a source and a drain. The lateral extension of the source is defined with dopant of higher atomic weight than the lateral extension of the drain.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: July 5, 2011
    Assignee: National Semiconductor Corporation
    Inventors: Sandeep R. Bahl, William D. French, Constantin Bulucea
  • Patent number: 7968921
    Abstract: An asymmetric insulated-gate field-effect transistor (100) has a source (240) and a drain (242) laterally separated by a channel zone (244) of body material (180) of a semiconductor body. A gate electrode (262) overlies a gate dielectric layer (260) above the channel zone. A more heavily doped pocket portion (250) of the body material extends largely along only the source. Each of the source and drain has a main portion (240M or 242M) and a more lightly doped lateral extension (240E or 242E). The drain extension is more lightly doped than the source extension. The maximum concentration of the semiconductor dopant defining the two extensions occurs deeper in the drain extension than in the source extension. Additionally or alternatively, the drain extension extends further laterally below the gate electrode than the source extension. These features enable the threshold voltage to be highly stable with operational time.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: June 28, 2011
    Assignee: National Semiconductor Corporation
    Inventors: Constantin Bulucea, William D. French, Sandeep R. Bahl, Jeng-Jiun Yang, D. Courtney Parker, Peter B. Johnson, Donald M. Archer
  • Publication number: 20100244150
    Abstract: An insulated-gate field-effect transistor (100) provided along an upper surface of a semiconductor body contains a pair of source/drain zones (240 and 242) laterally separated by a channel zone (244). A gate electrode (262) overlies a gate dielectric layer (260) above the channel zone. Each source/drain zone includes a main portion (240M or 242M) and a more lightly doped lateral extension (240E or 242E) laterally continuous with the main portion and extending laterally under the gate electrode. The lateral extensions, which terminate the channel zone along the upper semiconductor surface, are respectively largely defined by a pair of semiconductor dopants of different atomic weights. With the transistor being an asymmetric device, the source/drain zones constitute a source and a drain. The lateral extension of the source is then more lightly doped than, and defined with dopant of higher atomic weight, than the lateral extension of the drain.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventors: Sandeep R. Bahl, William D. French, Constantin Bulucea
  • Publication number: 20100244131
    Abstract: An asymmetric insulated-gate field-effect transistor (100 or 102) has a source (240 or 280) and a drain (242 or 282) laterally separated by a channel zone (244 or 284) of body material (180 or 182) of a semiconductor body. A gate electrode (262 or 302) overlies a gate dielectric layer (260 or 300) above the channel zone. A more heavily doped pocket portion (250 or 290) of the body material extends largely along only the source. The source has a main source portion (240M or 280M) and a more lightly doped lateral source extension (240E or 280E). The drain has a main portion (242M or 282M) and a more lightly doped lateral drain extension (242E or 282E). The drain extension is more lightly doped than the source extension. The maximum concentration of the semiconductor dopant defining the two extensions occurs deeper in the drain extension than in the source extension. Additionally or alternatively, the drain extension extends further laterally below the gate electrode than the source extension.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventors: Constantin Bulucea, William D. French, Sandeep R. Bahl, Jeng-Jiun Yang, D. Courtney Parker, Peter B. Johnson, Donald M. Archer
  • Publication number: 20100244128
    Abstract: A semiconductor structure, which serves as the core of a semiconductor fabrication platform, has a combination of empty-well regions and filled-well regions variously used by electronic elements, particularly insulated-gate field-effect transistors (“IGFETs”), to achieve desired electronic characteristics. A relatively small amount of semiconductor well dopant is near the top of an empty well. A considerable amount of semiconductor well dopant is near the top of a filled well. Some IGFETs (100, 102, 112, 114, 124, and 126) utilize empty wells (180, 182, 192, 194, 204, and 206) in achieving desired transistor characteristics. Other IGFETs (108, 110, 116, 118, 120, and 122) utilize filled wells (188, 190, 196, 198, 200, and 202) in achieving desired transistor characteristics.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventors: Constantin Bulucea, Sandeep R. Bahl, William D. French, Jeng-Jiun Yang, Donald M. Archer, D. Courtney Parker, Prasad Chaparala
  • Publication number: 20100244130
    Abstract: Insulated-gate field-effect transistors (“IGFETs”), both symmetric and asymmetric, suitable for a semiconductor fabrication platform that provides IGFETs for analog and digital applications, including mixed-signal applications, utilize empty-well regions in achieving high performance. A relatively small amount of semiconductor well dopant is near the top of each empty well. Each IGFET (100, 102, 112, 114, 124, or 126) has a pair of source/drain zones laterally separated by a channel zone of body material of the empty well (180, 182, 192, 194, 204, or 206). A gate electrode overlies a gate dielectric layer above the channel zone. Each source/drain zone (240, 242, 280, 282, 520, 522, 550, 552, 720, 722, 752, or 752) has a main portion (240M, 242M, 280M, 282M, 520M, 522M, 550M, 552M, 720M, 722M, 752M, or 752M) and a more lightly doped lateral extension (240E, 242E, 280E, 282E, 520E, 522E, 550E, 552E, 720E, 722E, 752E, or 752E).
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventors: Constantin Bulucea, Jeng-Jiun Yang, William D. French, Sandeep R. Bahl, D. Courtney Parker
  • Publication number: 20100244106
    Abstract: Fabrication of an asymmetric field-effect transistor (100) entails defining a gate electrode (262) above, and vertically separated by a gate dielectric layer (260) from, a channel-zone portion (244) of body material of a semiconductor body. Semiconductor dopant is introduced into the body material to define a more heavily doped pocket portion (250) using the gate electrode as a dopant-blocking shield. A spacer (264T) is provided along the gate electrode. The spacer includes (i) a dielectric portion situated along the gate electrode, (ii) a dielectric portion situated along the semiconductor body, and (iii) a filler portion (SC) largely occupying the space between the other two spacer portions. Semiconductor dopant is introduced into the semiconductor body to define a pair of main source/drain portions (240M and 240E) using the gate electrode and the spacer as a dopant-blocking shield. The filler spacer portion is removed to convert the spacer to an L shape (264).
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventors: D. Courtney Parker, Donald M. Archer, Sandeep R. Bahl, Constantin Bulucea, William D. French, Peter B. Johnson, Jeng-Jiun Yang
  • Publication number: 20100244152
    Abstract: An extended-drain insulated-gate field-effect transistor (104 or 106) contains first and second source/drain zones 324 and 184B or 364 and 186B) laterally separated by a channel (322 or 362) zone constituted by part of a first well region (184A or 186A). A gate dielectric layer (344 or 384) overlies the channel zone. A gate electrode (346 or 386) overlies the gate dielectric layer above the channel zone. The first source/drain zone is normally the source. The second S/D zone, normally the drain, is constituted with a second well region (184B or 186B). A well-separating portion 186A or 186B/212U) of the semiconductor body extends between the well regions and is more lightly doped than each well region. The configuration of the well regions cause the maximum electric field in the IGFET's portion of the semiconductor body to occur well below the upper semiconductor surface, typically at or close to where the well regions are closest to each other.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventors: Sandeep R. Bahl, Constantin Bulucea, William D. French
  • Publication number: 20100244151
    Abstract: An insulated-gate field-effect transistor (100W) has a source (980) and a drain (242) laterally separated by a channel zone (244) of body material (180) of a semiconductor body. A gate electrode (262) overlies a gate dielectric layer (260) above the channel zone. A more heavily doped pocket portion (250) of the body material normally extends largely along only the source so that the IGFET is an asymmetric device. The source has a main source portion (980M) and a more lightly doped lateral source extension (980E). The semiconductor dopant which defines the source reaches multiple local concentration maxima in defining the source extension. The procedure involved in defining the source extension with semiconductor dopant that reaches two such local concentration maxima enables source/drain extensions of mutually different characteristics for three insulated-gate field-effect transistors to be defined in only two source/drain-extension doping operations.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventors: William D. French, Constantin Bulucea
  • Publication number: 20100244149
    Abstract: A group of high-performance like-polarity insulated-gate field-effect transistors (100, 108, 112, 116, 120, and 124 or 102, 110, 114, 118, 122, and 126) have selectably different configurations of lateral source/drain extensions, halo pockets, and gate dielectric thicknesses suitable for a semiconductor fabrication platform that provides a wide variety of transistors for analog and/or digital applications. Each transistor has a pair of source/drain zones, a gate dielectric layer, and a gate electrode. Each source/drain zone includes a main portion and a more lightly doped lateral extension. The lateral extension of one of the source/drain zones of one of the transistors is more heavily doped or/and extends less deeply below the upper semiconductor surface than the lateral extension of one of the source/drain zones of another of the transistors.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventors: Constantin Bulucea, William D. French, Donald M. Archer, Jeng-Jiun Yang, Sandeep R. Bahl, D. Courtney Parker