Patents by Inventor Pradeep L. Shah

Pradeep L. Shah 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: 5508544
    Abstract: Memory cell transistors are provided in which column structures (12a, 14a) are formed at the face of a semiconductor substrate (10). Floating gates (46) and control gates (52) are formed adjacent to the column structures (12a, 14a). The floating gates (46) and control gates (52) are insulatively disposed by gate oxide layer (42) and insulating layer (50). Source regions (36) are implanted in the semiconductor substrate. Drain regions (38) are also implanted in the column structures (12a, 14a).
    Type: Grant
    Filed: September 27, 1994
    Date of Patent: April 16, 1996
    Assignee: Texas Instruments Incorporated
    Inventor: Pradeep L. Shah
  • Patent number: 5469383
    Abstract: A CMOS memory cell array and a method of forming it, which avoids problems caused by field oxide corner-rounding. A moat pattern defines alternating columns of active areas and field oxide regions. A source line pattern defines rows of source lines. Silicon dopant is implanted in areas not covered by the source line pattern to form buried n+ source lines. The field oxide regions are formed in areas not covered by the moat pattern. Subsequent fabrication steps may be in accordance with conventional CMOS fabrication techniques.
    Type: Grant
    Filed: June 24, 1994
    Date of Patent: November 21, 1995
    Assignee: Texas Instruments Incorporated
    Inventors: Dave J. McElroy, Manzur Gill, Pradeep L. Shah
  • Patent number: 5379255
    Abstract: Memory cell transistors are provided in which pillar structures or column structures (12, 12a, 14, and 14a) are formed at the face of a semiconductor substrate (10). Floating gates (46) and control gates (52) are formed adjacent to the pillar structures or column structures (12, 12a, 14, and 14a). The floating gates (46) and control gates (52) are insulatively disposed by gate oxide layer (42) and insulating layer (50). Source regions (36, 40, and 48) are implanted in the semiconductor substrate (10). Drain regions (38) are also implanted in the pillar structures or column structures (12, 12a, 14 and 14a).
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: January 3, 1995
    Assignee: Texas Instruments Incorporated
    Inventor: Pradeep L. Shah
  • Patent number: 5365082
    Abstract: A CMOS memory cell array, and a process for making it, that avoids problems caused by LOCOS isolation of cells. Moats are formed by etching away columns of a thick field oxide layer. The moats have two-tiered sidewalls, such that an upper tier is sloped, and a lower tier is more vertical. This approach provides the advantages of sloped sidewalls, but avoids filament problems. After the moats are formed, subsequent fabrication steps may be in accordance with conventional fabrication techniques for CMOS arrays.
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: November 15, 1994
    Assignee: Texas Instruments Incorporated
    Inventors: Manzur Gill, Pradeep L. Shah, Dave J. McElroy
  • Patent number: 5350706
    Abstract: A CMOS memory cell array and a method of forming it, which avoids problems caused by field oxide corner-rounding. A moat pattern defines alternating columns of active areas and field oxide regions. A source line pattern defines rows of source lines. Silicon dopant is implanted in areas not covered by the source line pattern to form buried n+ source lines. The field oxide regions are formed in areas not covered by the moat pattern. Subsequent fabrication steps may be in accordance with conventional CMOS fabrication techniques.
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: September 27, 1994
    Assignee: Texas Instruments Incorporated
    Inventors: Dave J. McElroy, Manzur Gill, Pradeep L. Shah
  • Patent number: 5313427
    Abstract: A nonvolatile memory has pairs of cells in which each cell includes a control gate, a floating gate and a source/drain diffusion. A first cell in each of the pairs is producible to have one value of floating-gate to diffusion capacitance. A second cell in each of the pairs is producible to have a second value of floating-gate to diffusion capacitance different from the first value. The memory includes a first circuit for applying a first erasing pulse to the control gates and the diffusions of the first cells of the pairs and includes a second circuit for applying a second erasing pulse to the control gates and the diffusions of the second cells of the pairs. The first erasing pulse is adjustable to have a different magnitude than the second erasing pulse in order to narrow the margin of erased threshold voltages and thereby compensate for misalignment.
    Type: Grant
    Filed: September 20, 1991
    Date of Patent: May 17, 1994
    Assignee: Texas Instruments Incorporated
    Inventors: John F. Schreck, David J. McElroy, Pradeep L. Shah
  • Patent number: 4101351
    Abstract: Silicon solar cells may be made from either "P" type substrates with "N" type dopants to form the geometries or with "N" type substrates and "P" type dopants forming the junction. This invention relates to the dopant species employed, the improved method of application and junction formation, formation of insitu anti-reflective coatings, and improved metallization processing for silicon solar cells. The invention does not affect preparation of the silicon substrate prior to diffusion steps, and is applicable both to planar solar cells and to vertical-multijunction cells. This invention discloses an alternate process of junction formation using arsenic as dopant. The process is uniquely different in the fact that it simplifies the number of process steps by using the doped oxide for junction formation, metallization mask and as an anti-reflection surface layer.
    Type: Grant
    Filed: November 15, 1976
    Date of Patent: July 18, 1978
    Assignee: Texas Instruments Incorporated
    Inventors: Pradeep L. Shah, Clyde R. Fuller