Patents Represented by Attorney Patentability Associates
  • Patent number: 7983139
    Abstract: An optical data storage disc measuring 32 mm in diameter contains 1 GB of data per layer. The data is designed to be readable by a disc drive that contains a blue wavelength laser, an objective lens having a numerical aperture of 0.72 and conventional DVD controller electronics. This combination of elements allows a full-length movie or a video game to be displayed with DVD-quality on a cell phone or other portable hand held device.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: July 19, 2011
    Assignee: Vmedia Research, Inc.
    Inventors: Jerry E. Hurst, Jr., Neil Deeman, Steven B. Volk
  • Patent number: 7977927
    Abstract: A DC/DC voltage converter includes an inductive switching voltage regulator and a capacitive charge pump connected in series between the input and output terminals of the converter. The charge pump has a second input terminal connected to the input terminal of the converter. This reduces the series resistance in the current path by which charge is transferred from the capacitor in the charge pump to the output capacitor and thereby improves the ability of the converter to respond to rapid changes in current required by the load.
    Type: Grant
    Filed: July 31, 2008
    Date of Patent: July 12, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventor: Richard K. Williams
  • Patent number: 7977926
    Abstract: A freewheeling MOSFET is connected in parallel with the inductor in a switched DC/DC converter. When the freewheeling MOSFET is turned on during the switching operation of the converter, while the low-side and energy transfer MOSFETs are turned off, the inductor current circulates or “freewheels” through the freewheeling MOSFET. The frequency of the converter is thereby made independent of the lengths of the magnetizing and energy transfer stages, allowing far greater flexibility in operating and converter and overcoming numerous problems associated with conventional DC/DC converters. For example, the converter may operate in either step-up or step-down mode and may even transition for one mode to the other as the values of the input voltage and desired output voltage vary.
    Type: Grant
    Filed: April 21, 2008
    Date of Patent: July 12, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventor: Richard K. Williams
  • Patent number: 7960997
    Abstract: A cascode current sensor includes a main MOSFET and a sense MOSFET. The drain terminal of the main MOSFET is connected to a power device whose current is to be monitored, and the source and gate terminals of the main MOSFET are connected to the source and gate terminals, respectively, of the sense MOSFET. The drain voltages of the main and sense MOSFETs are equalized, in one embodiment by using a variable current source and negative feedback. The gate width of the main MOSFET is typically larger than the gate width of the sense MOSFET. Using the size ratio of the gate widths, the current in the main MOSFET is measured by sensing the magnitude of the current in the sense MOSFET. Inserting the relatively large MOSFET in the power circuit minimizes power loss.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: June 14, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventor: Richard K. Williams
  • Patent number: 7955947
    Abstract: Isolation regions for semiconductor substrates include dielectric-filled trenches and field oxide regions. Protective caps of dielectric materials dissimilar from the dielectric materials in the main portions of the trenches and field oxide regions may be used to protect the structures from erosion during later process steps. The top surfaces of the isolation structures are coplanar with the surface of the substrate. Field doping regions may be formed beneath the field oxide regions. To meet the demands of different devices, the isolation structures may have varying widths and depths.
    Type: Grant
    Filed: April 30, 2008
    Date of Patent: June 7, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventor: Richard K. Williams
  • Patent number: 7956391
    Abstract: Various integrated circuit devices, in particular a junction field-effect transistor (JFET), are formed inside an isolation structure which includes a floor isolation region and a trench extending from the surface of the substrate to the floor isolation region. The trench may be filled with a dielectric material or may have a conductive material in a central portion with a dielectric layer lining the walls of the trench. Various techniques for terminating the isolation structure by extending the floor isolation region beyond the trench, using a guard ring, and a forming a drift region are described.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: June 7, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventors: Donald R. Disney, Richard K. Williams
  • Patent number: 7956437
    Abstract: A variety of isolation structures for semiconductor substrates include a trench formed in the substrate that is filled with a dielectric material or filled with a conductive material and lined with a dielectric layer along the walls of the trench. The trench may be used in combination with doped sidewall isolation regions. Both the trench and the sidewall isolation regions may be annular and enclose an isolated pocket of the substrate. The isolation structures are formed by modular implant and etch processes that do not include significant thermal processing or diffusion of dopants so that the resulting structures are compact and may be tightly packed in the surface of the substrate.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: June 7, 2011
    Assignees: Advanced Analogic Technologies, Inc., Advanced Analogic Technologies (Hong Kong) Limited
    Inventors: Richard K. Williams, Donald Ray Disney, Jun-Wei Chen, Wai Tien Chan, HyungSik Ryu
  • Patent number: 7939420
    Abstract: Processes for forming isolation structures for semiconductor devices include forming a submerged floor isolation region and a filed trench which together enclose an isolated pocket of the substrate. One process aligns the trench to the floor isolation region. In another process a second, narrower trench is formed in the isolated pocket and filled with a dielectric material while the dielectric material is deposited so as to line the walls and floor of the first trench. The substrate does not contain an epitaxial layer, thereby overcoming the many problems associated with fabricating the same.
    Type: Grant
    Filed: February 14, 2008
    Date of Patent: May 10, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventors: Donald R. Disney, Richard K. Williams
  • Patent number: 7923821
    Abstract: Isolation regions for semiconductor substrates include dielectric-filled trenches and field oxide regions. Protective caps of dielectric materials dissimilar from the dielectric materials in the main portions of the trenches and field oxide regions may be used to protect the structures from erosion during later process steps. The top surfaces of the isolation structures are coplanar with the surface of the substrate. Field doping regions may be formed beneath the field oxide regions. To meet the demands of different devices, the isolation structures may have varying widths and depths.
    Type: Grant
    Filed: April 30, 2008
    Date of Patent: April 12, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventor: Richard K. Williams
  • Patent number: 7915137
    Abstract: Isolation regions for semiconductor substrates include dielectric-filled trenches and field oxide regions. Protective caps of dielectric materials dissimilar from the dielectric materials in the main portions of the trenches and field oxide regions may be used to protect the structures from erosion during later process steps. The top surfaces of the isolation structures are coplanar with the surface of the substrate. Field doping regions may be formed beneath the field oxide regions. To meet the demands of different devices, the isolation structures may have varying widths and depths.
    Type: Grant
    Filed: April 30, 2008
    Date of Patent: March 29, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventor: Richard K. Williams
  • Patent number: 7902630
    Abstract: An isolated bipolar transistor formed in a P-type semiconductor substrate includes an N-type submerged floor isolation region and a filled trench extending downward from the surface of the substrate to the floor isolation region. Together the floor isolation region and the filled trench form an isolated pocket of the substrate which contains the bipolar transistor. The collector of the bipolar transistor may comprise the floor isolation region. The substrate does not contain an epitaxial layer, thereby overcoming the many problems associated with fabricating the same.
    Type: Grant
    Filed: February 14, 2008
    Date of Patent: March 8, 2011
    Assignee: Advanced Analogic Technologies, Inc.
    Inventors: Donald R. Disney, Richard K. Williams
  • Patent number: 7898060
    Abstract: A variety of isolation structures for semiconductor substrates include a trench formed in the substrate that is filled with a dielectric material or filled with a conductive material and lined with a dielectric layer along the walls of the trench. The trench may be used in combination with doped sidewall isolation regions. Both the trench and the sidewall isolation regions may be annular and enclose an isolated pocket of the substrate. The isolation structures are formed by modular implant and etch processes that do not include significant thermal processing or diffusion of dopants so that the resulting structures are compact and may be tightly packed in the surface of the substrate.
    Type: Grant
    Filed: July 30, 2008
    Date of Patent: March 1, 2011
    Assignees: Advanced Analogic Technologies, Inc., Advanced Analogic Technologies (Hong Kong) Limited
    Inventors: Richard K. Williams, Donald Ray Disney, Wai Tien Chan
  • Patent number: 7868414
    Abstract: A bipolar transistor is formed in an isolation structure comprising a floor isolation region, a dielectric filled trench above the floor isolation region and a sidewall isolation region extending downward from the bottom of the trench to the floor isolation region. This structure provides a relatively deep isolated pocket in a semiconductor substrate while limiting the depth of the trench that must be etched in the substrate.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: January 11, 2011
    Assignees: Advanced Analogic Technologies, Inc., Advanced Analogic Technologies (Hong Kong) Limited
    Inventors: Richard K. Williams, Donald Ray Disney, Wai Tien Chan
  • Patent number: 7834416
    Abstract: A semiconductor substrate includes a pair of trenches filled with a dielectric material. Dopant introduced into the mesa between the trenches is limited from diffusing laterally when the substrate is subjected to thermal processing. Therefore, semiconductor devices can be spaced more closely together on the substrate, and the packing density of the devices can be increased. Also trench constrained doped region diffuse faster and deeper than unconstrained diffusions, thereby reducing the time and temperature needed to complete a desired depth diffusion. The technique may be used for semiconductor devices such as bipolar transistors as well as isolation regions that electrically isolate the devices from each other. In one group of embodiments, a buried layer is formed at an interface between an epitaxial layer and a substrate, at a location generally below the dopant in the mesa.
    Type: Grant
    Filed: July 31, 2008
    Date of Patent: November 16, 2010
    Assignees: Advanced Analogic Technologies, Inc., Advanced Analogic Technologies (Hong Kong) Limited
    Inventors: Richard K. Williams, Michael E. Cornell, Wai Tien Chan
  • Patent number: 7834421
    Abstract: Various integrated circuit devices, in particular a diode, are formed inside an isolation structure which includes a floor isolation region and a trench extending from the surface of the substrate to the floor isolation region. The trench may be filled with a dielectric material or may have a conductive material in a central portion with a dielectric layer lining the walls of the trench. Various techniques for terminating the isolation structure by extending the floor isolation region beyond the trench, using a guard ring, and a forming a drift region are described.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: November 16, 2010
    Assignee: Advanced Analogic Technologies, Inc.
    Inventors: Donald R. Disney, Richard K. Williams
  • Patent number: 7825488
    Abstract: A variety of isolation structures for semiconductor substrates include a trench formed in the substrate that is filled with a dielectric material or filled with a conductive material and lined with a dielectric layer along the walls of the trench. The trench may be used in combination with doped sidewall isolation regions. Both the trench and the sidewall isolation regions may be annular and enclose an isolated pocket of the substrate. The isolation structures are formed by modular implant and etch processes that do not include significant thermal processing or diffusion of dopants so that the resulting structures are compact and may be tightly packed in the surface of the substrate.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: November 2, 2010
    Assignees: Advanced Analogic Technologies, Inc., Advanced Analogic Technologies (Hong Kong) Limited
    Inventors: Richard K. Williams, Donald Ray Disney, Wai Tien Chan
  • Patent number: 7812579
    Abstract: A DC/DC converter includes a pre-converter stage, which may include a charge pump, and a post-regulator stage, which may include a boost converter. The duty factor of the post-regulator stage is controlled by a feedback path that extends from the output terminal of the DC/DC converter to an input terminal in the post-regulator stage. The pre-converter steps the input DC voltage up or down by a positive or negative integral or fractional value, and the post-regulator steps the voltage up by a variable amount depending on the duty factor at which the post-regulator is driven. The converter overcomes the problems of noise glitches, poor regulation, and instability, even near unity input-to-output voltage conversion ratios.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: October 12, 2010
    Assignee: Advanced Analogic Technologies, Inc.
    Inventor: Richard K. Williams
  • Patent number: 7812647
    Abstract: A gate driver for a power MOSFET in, for example, a DC-DC converter switches the MOSFET between a fully-on condition and a low-current condition instead of switching the MOSFET between fully-on and fully-off conditions. The amount of charge that must be transferred to charge and discharge the gate of the MOSFET is thereby reduced, and the efficiency of the MOSFET is improved. A feedback circuit may be used to assure that the magnitude of current in the power MOSFET in its low-current condition is correct. Alternatively, a trimming process may be used to correct the magnitude of the voltage supplied by the gate driver to the gate of the power MOSFET in the low-current condition.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: October 12, 2010
    Assignee: Advanced Analogic Technologies, Inc.
    Inventor: Richard K. Williams
  • Patent number: 7812403
    Abstract: An isolated CMOS pair of transistors formed in a P-type semiconductor substrate includes an N-type submerged floor isolation region and a filled trench extending downward from the surface of the substrate to the floor isolation region. Together the floor isolation region and the filled trench form an isolated pocket of the substrate which contains a P-channel MOSFET in an N-well and an N-channel MOSFET in a P-well. The substrate does not contain an epitaxial layer, thereby overcoming the many problems associated with fabricating the same.
    Type: Grant
    Filed: February 14, 2008
    Date of Patent: October 12, 2010
    Assignee: Advanced Analogic Technologies, Inc.
    Inventors: Donald R. Disney, Richard K. Williams
  • Patent number: 7812393
    Abstract: All low-temperature processes are used to fabricate a variety of semiconductor devices in a substrate the does not include an epitaxial layer. The devices include a non-isolated lateral DMOS, a non-isolated extended drain or drifted MOS device, a lateral trench DMOS, an isolated lateral DMOS, JFET and depletion-mode devices, and P-N diode clamps and rectifiers and junction terminations. Since the processes eliminate the need for high temperature processing and employ “as-implanted” dopant profiles, they constitute a modular architecture which allows devices to be added or omitted to the IC without the necessity of altering the processes used to produce the remaining devices.
    Type: Grant
    Filed: November 5, 2007
    Date of Patent: October 12, 2010
    Assignee: Advanced Analogic Technologies, Inc.
    Inventors: Richard K. Williams, Donald Ray Disney, Jun-Wei Chen, Wai Tien Chan, HyungSik Ryu