Patents Represented by Attorney, Agent or Law Firm Douglas A. Sorensen
  • Patent number: 5079605
    Abstract: A silicon-on-insulator MOS transistor (100) is disclosed which has contact regions on both the source (6) and drain (8) sides of the gate electrode (10) for (36,38) potentially making contact to the body node (12) from either side. Each contact region (36,38) is of the same conductivity type as the body node (12), (for example, a p-type region for an n-channel transistor), and may be formed by blocking all source/drain implants from the contact regions (36,38), so that the contact region (36,38) remains substantially with the same doping concentration as the of the body region (12). A mask is provided prior to silicidation so that the contact regions (36,38) on either side of the gate electrode (12) are not connected by silicide to the adjacent source/drain doped regions (6,8).
    Type: Grant
    Filed: November 27, 1989
    Date of Patent: January 7, 1992
    Assignee: Texas Instruments Incorporated
    Inventor: Terence G. W. Blake
  • Patent number: 5077228
    Abstract: The described embodiments of the present invention provide structures and methods for fabricating the structures which provide compact contact from the surface of an integrated circuit to a buried layer formed in conjunction with a vertical gate extending from the buried layer to a doped layer at a surface of the integrated circuit. In one embodiment, trenches are simultaneously formed for providing the vertical gate and the contact to the buried layer. A thermal oxide layer is formed on the surface of the integrated circuit to provide an insulating layer on the surfaces of both the contact trench and the gate trench. A first layer of in situ doped polycrystalline silicon is deposited on the surface of the integrated circuit. The thickness of this polycrystalline silicon layer is chosen so as to not fill the gate and contact trenches. A masking layer is then provided to protect the gate trench and expose the contact trench.
    Type: Grant
    Filed: December 1, 1989
    Date of Patent: December 31, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: Robert H. Eklund, Roger Haken
  • Patent number: 5070297
    Abstract: A full wafer integrated circuit testing device (10) tests integrated circuits (15) formed as a wafer in conjunction with a test control unit (40). Probe units (14) associate with respective integrated circuits (15). Probe tips (16) on probe units (14) communicate with respective pads (19) with the integrated circuits (15). Interface circuitry (36) selectively communicates test data between the test control unit (40) and the integrated circuit (15). Test pins (16) have positions on probe units (14) associated with respective integrated circuit connection points (19) for testing associated integrated circuit (15) components. Interface circuitry (36) includes comparators (54 and 56) that compare signals between the integrated circuit (15) and the test control unit (40). Memory components (66 and 68) store data associated with signals from test control unit (40) and said integrated circuit (15).
    Type: Grant
    Filed: June 4, 1990
    Date of Patent: December 3, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: Oh-Kyong Kwon, Masashi Hashimoto, Satwinder Malhi, Eng C. Born
  • Patent number: 5070381
    Abstract: The described embodiments of the present invention provide a structure and method for easily incorporating a high voltage lateral bipolar transistor in an integrated circuit. A buried base contact is formed and the base itself is formed of a well region in the integrated circuit. An oppositely doped well region is formed surrounding the collector region in the lateral PNP transistor. This collector well is formed of the opposite conductivity type of the base well. Contact to the collector and a heavily doped emitter are then formed in the collector well and base well, respectively. The more lightly doped collector well provides a thick depletion region between the collector and base and thus provides higher voltage operation. The positioning of the base/collector junction to the collector well at base well junction also reduces the spacing between the collector and the emitter.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: December 3, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: David B. Scott, Hiep V. Tran
  • Patent number: 5068825
    Abstract: An improved memory cell 118 is provided utilizing transistor pairs 142, 144 ands 160, 162 as dual purpose transistor pairs for the two modes of operation of the cell. During the first or non-access mode of operation, the transistor pairs operate as switched capacitive elements in order to provide an equivalent resistance between bit line 140 and first node 26 and inverted bit line 158 and second node 130. Control circuit 119 maintains bit lines 140 and inverted bit line 158 high during this non-access mode. During the second or access mode of operation, each transistor pair operates as a respective pass transistor for connecting bit line 140 to first node 126 and inverted bit line 158 to second node 130 so that data may be read from, or written to, the cross-coupled transistors 120 and 122.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: November 26, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: Shivaling S. Mahant-Shetti, Mark G. Harward
  • Patent number: 5057886
    Abstract: A non-volatile memory is provided which provides a floating gate (42) disposed over control gate (38) in order to increase the coupling therebetween. The degree of coupling may be varied by adjusting the area of the floating gate formed over the control gate relative to the area of the floating gate over the substrate.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: October 15, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: Bert R. Riemenschneider, Howard L. Tigelaar
  • Patent number: 5055423
    Abstract: In an improved selection tungsten metallization system, a plurality of orifices (20) are cut into a first level dielectric layer (18). A nucleation layer (52), preferably Ti-W alloy, is then formed in each orifice (20) and on the outer surface of the first dielectric layer (18) in a second-level metallization pattern. A second dielectric layer (30) is deposited over the first dielectric layer (18) and the nucleation layer (52), and a reverse second level metallization pattern is used to etch slots (58) back down to the nucleation layers (52) and into orifices (20). Thereafter, tungsten is deposited by selective CVD to fill the first level orifices (20) and the second level slots (58) until the upper surfaces (62) of the tungsten conductors (60) are substantially coplanar with the upper surface (38) of the second dielectric layer (30).
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: October 8, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: Gregory C. Smith, Thomas D. Bonifield
  • Patent number: 5053839
    Abstract: One embodiment of the invention provides an EPROM and a method of fabricating an EPROM with enhanced capacitive coupling. Trenched memory cells each comprise a pleat-shaped floating gate with the control gate nested in a fold of the floating gate to increase the coupling ratio with the control gate. As a result higher programming speed and improved cell density may be obtained for a given programming voltage. Formation of bit lines along trench walls results in lower bit line resistivity for a given cell density.
    Type: Grant
    Filed: August 21, 1990
    Date of Patent: October 1, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: Agerico L. Esquivel, Allan T. Mitchell, Howard L. Tigelaar
  • Patent number: 5028980
    Abstract: A trench capacitor (10) has a center portion (26) formed from the substrate (14) by a tubular trench (24). A conducting layer (32) is deposed within the tubular trench (24) and is separated from the substrate (14) and center portion (26) by a dielectric layer (30). Since the charge storage area and the trench capacitor (10) includes both the inside and outside of the trench (24), a greater surface area is obtained, thereby increasing the capacitance of the device. A memory cell (34) may be implemented using the capacitor (10).
    Type: Grant
    Filed: April 27, 1990
    Date of Patent: July 2, 1991
    Assignee: Texas Instruments Incorporated
    Inventor: Clarence W. Teng
  • Patent number: 5023206
    Abstract: A semiconductor device is disclosed in which a deposited non-oxide layer (44) overlies and physically contacts another non-oxide layer (38) so that no intervening oxide layer is present. The device is fabricated by performing an insitu etch and deposition process. In one embodiment, the device (36) is sealed in a LPCVD chamber (10) and etched using gaseous anhydrous hydrofluoric acid to remove an oxide (40) from one non-oxide layer (38). Then, without exposing the device to a water rinse or to the atmosphere, a chemical vapor deposition process applies the deposited layer (44) upon the other layer (38).
    Type: Grant
    Filed: December 16, 1987
    Date of Patent: June 11, 1991
    Assignee: Texas Instruments Incorporated
    Inventor: Dean W. Freeman
  • Patent number: 5017506
    Abstract: The described embodiments of the present invention provide DRAM cells, structures and manufacturing methods. A DRAM cell with a trench capacitor having a first plate formed as a diffusion on the outside surface of a trench formed in the substrate and a second plate having a conductive region formed inside the trench is fabricated. The transfer transistor is formed using a field plate isolation structure which includes a self-aligned moat area for the transfer transistor. The moat area slightly overlaps the capacitor area and allows for increased misalignment tolerance thus foregoing the requirement for misalignment tolerances built into the layout of the DRAM cell. The field plate itself is etched so that it has sloped sidewalls to avoid the formation of conductive filaments from subsequent conductive layers formed on the integrated circuit.
    Type: Grant
    Filed: July 25, 1989
    Date of Patent: May 21, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: Bing-Whey Shen, Randy McKee, Gishi Chung
  • Patent number: 4989002
    Abstract: There is disclosed a fully differential converter (10) having a very high common mode rejection ratio. The capacitive parasitics (CP) are accounted for by a strategic placement of error correction capacitances (20). The actual value of the capacitance is calculated from time to time by successively making comparative circuit operations and by adding and subtracting capacitance automatically under logic control (62) until the circuit is in near balance. The final value of the added capacitance for any given calculation set is stored in a memory (61). In this manner the circuit become self-calibrating and common mode rejection ratios over 90 db are possible.
    Type: Grant
    Filed: February 12, 1990
    Date of Patent: January 29, 1991
    Assignee: Texas Instruments Incorporated
    Inventor: Khen-Sang Tan
  • Patent number: 4987462
    Abstract: Preferred embodiments include a microwave power MISFET (30) with a thin GaAS channel (54) bounded by an undoped Al.sub.x Ga.sub.1-x As gate insulator (44) and a doped Al.sub.y Ga.sub.1-y As barrier (40). Under forward bias the channel (54) forms a quantum well which accumulates electrons and thereby increase maximum current and power handling without degrading breakdown voltage of the heterostructure MISFET An additional active layer (36) can be included on the other side of the barrier (40) to further increase power handling. Other embodiments include use of a strained layer In.sub.z Ga.sub.1-z As channel.
    Type: Grant
    Filed: January 6, 1987
    Date of Patent: January 22, 1991
    Assignee: Texas Instruments Incorporated
    Inventors: Bumman Kim, Hua Q. Tserng
  • Patent number: 4962365
    Abstract: A resistor (10) includes a resistive filling (28) formed within a trench (12) and separated therefrom by an insulating layer (26). Resistive filling (28) is of the same type of semiconductor material as that of second layer (22), but of an opposite extreme of dopant concentration. A head region (32) may be formed below interface (30) within second layer (22) to more clearly delineate the edge of resistive filling (28) from second layer (22). Where resistive filling (28) is of a low dopant concentration, low resistance contact region (34) is formed of a high dopant concentration in order to provide a minimum resistance contact to resistive filling (28).
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: October 9, 1990
    Assignee: Texas Instruments Incorporated
    Inventors: Robert H. Havemann, Robert H. Eklund
  • Patent number: 4956538
    Abstract: A first and second pyrometer (26-28) are optically coupled by a light pipe (24) to a wafer (30) in an apparatus (10). The light pipe (24) passes through a shroud (16) of a heating lamp module (14). A computer (74) is interconnected to the pyrometers (26-28) and a lamp module power supply (80). A laser (48) emits a laser beam (50) through a power meter (86) onto an infrared mirror (56) over the light pipe (24). The mirror (56) directs the beam onto wafer (30) which reflects a portion of the beam back to the infrared mirror (56). The beam is then guided to an infrared photo-detector (58) which provides, in combination with the incident laser beam power meter (86), reflectance of the wafer surface for the laser beam which is related to wafer emissivity.
    Type: Grant
    Filed: September 9, 1988
    Date of Patent: September 11, 1990
    Assignee: Texas Instruments, Incorporated
    Inventor: Mehrdad M. Moslehi
  • Patent number: 4956307
    Abstract: A silicon-over-insulator transistor is provided having a semiconductor mesa (40) overlying a buried oxide (42). Insulating regions (50) are formed at the sides of the semiconductor mesa (40). An oxidizable layer (56) is formed over the mesa's insulating region (46). This oxidizable layer (56) is then anisotropically etched, resulting in oxidizable sidewalls (60). An optional foot (70) may be formed at the bottom edge of the oxidizable sidewalls (76). These oxidizable sidewalls (76) are then oxidized, resulting in a pure oxide sidewall (64). The gate (66) is then formed over the pure oxide sidewalls (64) and a gate oxide (62).
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: September 11, 1990
    Assignee: Texas Instruments, Incorporated
    Inventors: Gordon P. Pollack, Mishel Matloubian, Ravishankar Sundaresan
  • Patent number: 4951103
    Abstract: A non-volatie cross-point memory cell array comprises a trench isolated cross-point array of memory cells (10), which are electrically programmable and electrically FLASH eraseable, having diffused regions (28) operable as bitlines, each diffused region (28) traversed by a plurality of control gates (54) operable as wordlines. The diffused regions (28) undergo a silicidation process to decrease their resistivity, and thereby increase the speed of the memory cell array. A tunnel oxide (18) is provided for electrical erasing and programming. Planarized, high quality insulating regions (40, 36), such as dichlorosilane oxide, buttress the floating gate (20) to isolate the bitlines form the wordlines and to improve isolation between the pass gate and the floating gate. A planar structure of the memory cell (10) provides flat topography ideal for three dimensional stacked structures. Trench isolation regions (56) reduce bitline capacitance, thereby increasing programming speed.
    Type: Grant
    Filed: June 3, 1988
    Date of Patent: August 21, 1990
    Assignee: Texas Instruments, Incorporated
    Inventors: Agerico L. Esquivel, Allan T. Mitchell
  • Patent number: 4950618
    Abstract: An improved masking stack (63) comprises a pad oxide (58), polysilicon (60) and nitride (62). After forming a photoresist pattern (64) over the stack (63), an anisotropic etch is performed to remove the nitride (62) and a portion of the polysilicon (60) not covered by the pattern (64). Another etch is performed to remove the remaining polysilicon (60) to leave at least a portion of the pad oxide (58). A boron implant (66) is conducted to form implant areas (68 and 70) within the unmasked silicon active device layer (56). A portion of the implant areas (68 and 70) is masked with nitride (72), and the unmasked silicon layer (56) is then etched. The masking stack (63) and the nitride (72) is removed and unprotected silicon layer (56) and implant areas (68 and 70) are covered with an oxide forming the silicon dioxide mesa (78).
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: August 21, 1990
    Assignee: Texas Instruments, Incorporated
    Inventors: Ravishankar Sundaresan, Mishel Matloubian
  • Patent number: 4949154
    Abstract: The present invention teaches a new method for formation of thin dielectrics over polysilicon. This technique permits the fabrication of poly-to-poly capacitors with high specific capacitance (capacitance per unit area). This technique is completely compatible with standard MOS dual poly regrown gate oxide processes. The high value of specific capacitance is achieved by using a composite dielectric which has high dielectric integrity and whose thickness is completely independent of the formation of the regular gate oxide under the second poly. No extra mask steps are required. The composite dielectric is formed as a grown or deposited oxide followed by a deposited nitride which is then reoxidized. Optionally, a second oxide is deposited before reoxidation performed.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: August 14, 1990
    Assignee: Texas Instruments, Incorporated
    Inventor: Roger A. Haken
  • Patent number: 4947227
    Abstract: A latch-up free CMOS structure and method of fabrication thereof is disclosed. A P-type substrate (40) is appropriately masked to form a plurality of sites in which isolated wells (50) are formed. A thermal oxide layer (56) is grown on the surface of each well (50), and a boron channel stop (62) implanted therearound. Polysilicon semiconductor material (68) is formed within each well, and implant doped to form an N-well (76) of material. The P-substrate (40) is planarized. PMOS transistors are formed within the oxide isolated N-wells (76), while NMOS transistors are formed in the P-substrate (40) outside the wells.
    Type: Grant
    Filed: September 16, 1985
    Date of Patent: August 7, 1990
    Assignee: Texas Instruments, Incorporated
    Inventor: Clarence W. Teng