| Alpha and Omega Semiconductor Incorporated Patent applications |
| Patent application number | Title | Published |
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| 20120126317 | ACCUFET WITH INTEGRATED CLAMPING CIRCUIT - The present invention features a field effect transistor that includes a semiconductor substrate having gate, source and drain regions; and a p-n junction formed on the semiconductor substrate and in electrical communication with the gate, drain and source regions to establish a desired breakdown voltage. In one embodiment, gate region further includes a plurality of spaced-apart trench gates with the p-n junction being defined by an interface between an epitaxial layer in which the trench gates are formed and the interface with a metallization layer. The breakdown voltage provided is defined, in part by the number of p-n junctions formed. In another embodiment, the p-n junctions are formed by generating a plurality of spaced-apart p-type regions in areas of the epitaxial layer located adjacent to the trench gates. | 05-24-2012 |
| 20120104580 | SUBSTRATELESS POWER DEVICE PACKAGES - A substrate-less composite power semiconductor device may include a thin substrate and a top metal layer located on a top surface of the substrate. A total thickness of the substrate and the epitaxial layer may be less than 25 microns. Solder bumps are formed on top of the top metal layer and molding compound surrounds the solder bumps and leaves the solder bumps at least partly exposed. | 05-03-2012 |
| 20120086499 | LOW LEAKAGE DYNAMIC BI-DIRECTIONAL BODY-SNATCHING (LLDBBS) SCHEME FOR HIGH SPEED ANALOG SWITCHES - A bidirectional switch device includes a main pass field effect transistor (FET) connected to an input node and an output node. A body region of the first main pass transistor is tied to a voltage substantially halfway between the voltage at the input node side of the first main pass transistor and the voltage at the output node side of the transistor when the first main pass transistor is in an ON state. | 04-12-2012 |
| 20120025298 | WAFER LEVEL CHIP SCALE PACKAGE - A semiconductor device, a method of manufacturing semiconductor devices and a circuit package assembly are described. A semiconductor device can have a semiconductor substrate with first and second surfaces and a sidewall between them. First and second conductive pads on the first and second surfaces are in electrical contact with corresponding first and second semiconductor device structures in the substrate. An insulator layer on the first surface and sidewall covers a portion of the first conductive pad on the first surface. An electrically conductive layer on part of the insulator layer on the first conductive pad and sidewall is in electrical contact with the second conductive pad. The insulator layer prevents the conductive layer from making electrical contact between the first and second conductive pads. | 02-02-2012 |
| 20110233667 | DUAL GATE OXIDE TRENCH MOSFET WITH CHANNEL STOP TRENCH AND THREE OR FOUR MASKS PROCESS - A semiconductor device and fabrication methods are disclosed. The device includes a plurality of gate electrodes formed in trenches located in an active region of a semiconductor substrate. A first gate runner is formed in the substrate and electrically connected to the gate electrodes, wherein the first gate runner surrounds the active region. A second gate runner is connected to the first gate runner and located between the active region and a termination region. A termination structure surrounds the first and second gate runners and the active region. The termination structure includes a conductive material in an insulator-lined trench in the substrate, wherein the termination structure is electrically shorted to a source or body layer of the substrate thereby forming a channel stop for the device. | 09-29-2011 |
| 20110233666 | OXIDE TERMINATED TRENCH MOSFET WITH THREE OR FOUR MASKS - An oxide termination semiconductor device may comprise a plurality of gate trenches, a gate runner, and an insulator termination trench. The gate trenches are located in an active region. Each gate trench includes a conductive gate electrode. The insulator termination trench is located in a termination region that surrounds the active region. The insulator termination trench is filled with an insulator material to form an insulator termination for the semiconductor device. The device can be made using a three-mask or four-mask process. | 09-29-2011 |
| 20110227207 | STACKED DUAL CHIP PACKAGE AND METHOD OF FABRICATION - The present invention is directed to a lead-frame having a stack of semiconductor dies with interposed metalized clip structure. Level projections extend from the clip structure to ensure that the clip structure remains level during fabrication. | 09-22-2011 |
| 20110220990 | SHIELDED GATE TRENCH MOS WITH IMPROVED SOURCE PICKUP LAYOUT - A method for fabricating a semiconductor device includes forming a plurality of trenches using a first mask. The trenches include source pickup trenches located in outside a termination area and between two adjacent active areas. First and second conductive regions separated by an intermediate dielectric region are formed using a second mask. A first electrical contact to the first conductive region and a second electrical contact to the second conductive region are formed using a third mask and forming a source metal region. Contacts to a gate metal region are formed using a fourth mask. A semiconductor device includes a source pickup contact located outside a termination region and outside an active region of the device. | 09-15-2011 |
| 20110210390 | MOS DEVICE WITH VARYING TRENCH DEPTH - A semiconductor device includes a drain region comprising an epitaxial layer, a body disposed in the epitaxial layer, a source embedded in the body, a gate trench extending into the epitaxial layer, a gate disposed in the gate trench, an active region contact trench extending through the source, and an active region contact electrode disposed within the active region contact trench. The active region contact trench has a first width associated with a first region that is in proximity to a bottom portion of the body and a second width associated with a second region that is in proximity to a bottom portion of the source. The first width is substantially different from the second width. | 09-01-2011 |
| 20110204442 | CORNER LAYOUT FOR SUPERJUNCTION DEVICE - A superjunction device and methods for layout design and fabrication of a superjunction device are disclosed. A layout of active cell column structures can be configured so that a charge due to first conductivity type dopants balances out charge due to second conductivity type dopants in a doped layer in an active cell region. A layout of end portions of the active cell column structures proximate termination column structures can be configured so that a charge due to the first conductivity type dopants in the end portions and a charge due to the first conductivity type dopants in the termination column structures balances out charge due to the second conductivity type dopants in a portion of the doped layer between the termination column structures and the end portions. | 08-25-2011 |
| 20110147830 | METHOD OF FORMING A SELF-ALIGNED CHARGE BALANCED POWER DMOS - Self-aligned charge balanced semiconductor devices and methods for forming such devices are disclosed. One or more planar gates are formed over a semiconductor substrate of a first conductivity type. One or more deep trenches are etched in the semiconductor self-aligned to the planar gates. The trenches are filled with a semiconductor material of a second conductivity type such that the deep trenches are charge balanced with the adjacent regions of the semiconductor substrate This process can form self-aligned charge balanced devices with a cell pitch less than 12 microns. | 06-23-2011 |
| 20110133258 | SHIELDED GATE TRENCH MOSFET WITH INCREASED SOURCE-METAL CONTACT - A semiconductor device formed on a semiconductor substrate having a substrate top surface, includes: a gate trench extending from the substrate top surface into the semiconductor substrate; a gate electrode in the gate trench; a dielectric material disposed over the gate electrode; a body region adjacent to the gate trench; a source region embedded in the body region, at least a portion of the source region extending above the dielectric material; a contact trench that allows contact such as electrical contact between the source region and the body region; and a metal layer disposed over at least a portion of a gate trench opening, at least a portion of the source region, and at least a portion of the contact trench. | 06-09-2011 |
| 20110127602 | Dual Channel Trench LDMOS Transistors and BCD Process with Deep Trench Isolation - A dual channel trench LDMOS transistor includes a substrate of a first conductivity type; a semiconductor layer of a second conductivity type formed on the substrate; a first trench formed in the semiconductor layer where a trench gate is formed in an upper portion of the first trench; a body region of the first conductivity type formed in the semiconductor layer adjacent the first trench; a source region of the second conductivity type formed in the body region and adjacent the first trench; a planar gate overlying the body region; a drain region of the second conductivity type spaced apart from the body region by a drain drift region. The planar gate forms a lateral channel in the body region, and the trench gate in the first trench forms a vertical channel in the body region of the LDMOS transistor. | 06-02-2011 |
| 20110108896 | WAFER LEVEL CHIP SCALE PACKAGE AND PROCESS OF MANUFACTURE - Power wafer level chip scale package (CSP) and process of manufacture are enclosed. The power wafer level chip scale package includes all source, gate and drain electrodes located on one side of the device, which is convenient for mounting to a printed circuit board (PCB) with solder paste. | 05-12-2011 |
| 20110101446 | STAGGERED COLUMN SUPERJUNCTION - A staggered column superjunction semiconductor device may include a cell region having one or more device cells. One or more device cells in the cell region include a semiconductor substrate configured to act as a drain and a semiconductor layer formed on the substrate. A first doped column may be formed in the semiconductor layer to a first depth and a second doped column may be formed in the semiconductor layer to a second depth. The first depth is greater than the second depth. The first and second columns are doped with dopants of a same second conductivity type and extend along a portion of a thickness of the semiconductor layer and are separated from each by a portion of the semiconductor layer. | 05-05-2011 |
| 20110095833 | FLEXIBLE LOW CURRENT OSCILLATOR FOR MULTIPHASE OPERATIONS - A method for generating an oscillator signal uses a multiphase oscillator having a plurality of input stages and a reference stage. Each input stage produces an input stage voltage that represents a phase for the oscillator. The input stage voltages produced by each of the input stages are compared to a reference voltage produced by the reference stage. An input stage having a maximum input stage voltage is selected and an output of the selected input stage having the maximum input stage voltage is changed. A current need of the oscillator is detected with a negative feedback loop coupled to the reference stage. An appropriate supply current is provided to each input stage with the negative feedback loop. | 04-28-2011 |
| 20110073943 | TRUE CSP POWER MOSFET BASED ON BOTTOM-SOURCE LDMOS - A semiconductor package may comprise a semiconductor substrate, a MOSFET device having a plurality cells formed on the substrate, and a source region common to all cells disposed on a bottom of the substrate. Each cell comprises a drain region on a top of the semiconductor device, a gate to control a flow of electrical current between the source and drain regions, a source contact proximate the gate; and an electrical connection between the source contact and source region. At least one drain connection is electrically coupled to the drain region. Source, drain and gate pads are electrically connected to the source region, drain region and gates of the devices. The drain, source and gate pads are formed on one surface of the semiconductor package. The cells are distributed across the substrate, whereby the electrical connections between the source contact of each device and the source region are distributed across the substrate. | 03-31-2011 |
| 20110068395 | SUPER-SELF-ALIGNED TRENCH-DMOS STRUCTURE AND METHOD - A semiconductor device includes a P-body layer formed in an N-epitaxial layer; a gate electrode formed in a trench in the P-body and N-epitaxial layer; a top source region formed from the P-body layer next to the gate electrode; a gate insulator disposed along a sidewall of the gate electrode between the gate electrode and the source, between the gate electrode and the P-body and between the gate electrode and the N-epitaxial layer; a cap insulator disposed on top of the gate electrode; and an N+ doped spacer disposed along a sidewall of the source and a sidewall of the gate insulator. The source includes N+ dopants diffused from the spacer. A body contact region containing P-type dopants is formed from the N-epitaxial layer. The contact region touches one or more P-doped regions of the P-body layer and the source. Methods for manufacturing such a device are also disclosed. Embodiments of this invention may also be applied to P-channel devices. | 03-24-2011 |
| 20110018116 | CHIP SCALE SURFACE MOUNTED SEMICONDUCTOR DEVICE PACKAGE AND PROCESS OF MANUFACTURE - A semiconductor device package die and method of manufacture are disclosed. The device package die may comprise a device substrate having one or more front electrodes located on a front surface of the device substrate and electrically connected to one or more corresponding device regions formed within the device substrate proximate the front surface. A back conductive layer is formed on a back surface of the device substrate. The back conductive layer is electrically connected to a device region formed within the device substrate proximate a back surface of the device substrate. One or more conductive extensions are formed on one or more corresponding sidewalls of the device substrate in electrical contact with the back conductive layer, and extend to a portion of the front surface of the device substrate. A support substrate is bonded to the back surface of the device substrate. | 01-27-2011 |
| 20110014766 | BOTTOM-DRAIN LDMOS POWER MOSFET STRUCTURE HAVING A TOP DRAIN STRAP - Lateral DMOS devices having improved drain contact structures and methods for making the devices are disclosed. A semiconductor device comprises a semiconductor substrate; an epitaxial layer on top of the substrate; a drift region at a top surface of the epitaxial layer; a source region at a top surface of the epitaxial layer; a channel region between the source and drift regions; a gate positioned over a gate dielectric on top of the channel region; and a drain contact trench that electrically connects the drift layer and substrate. The contact trench includes a trench formed vertically from the drift region, through the epitaxial layer to the substrate and filled with an electrically conductive drain plug; electrically insulating spacers along sidewalls of the trench; and an electrically conductive drain strap on top of the drain contact trench that electrically connects the drain contact trench to the drift region. | 01-20-2011 |
| 20100320461 | INTEGRATION OF SENSE FET INTO DISCRETE POWER MOSFET - A semiconductor device includes a main field effect transistor (FET) and one or more sense FETs. A transistor portion of the sense FET is surrounded by transistors of the main FET. An electrical isolation structure that surrounds the main FET is configured to electrically isolate source and body regions of the main FET from source and body regions of the sense FET. A sense FET source pad is located at an edge of the main FET and spaced apart from the transistor portion of the sense FET. The sense FET source pad is connected to the transistor portion of the sense FET by a sense FET probe metal. The isolation structure is configured such that the transistor portion of the sense FET and the sense FET source pad are located outside an active area of the main FET. | 12-23-2010 |
| 20100314693 | INTEGRATION OF A SENSE FET INTO A DISCRETE POWER MOSFET - A semiconductor device includes a main field effect transistor (FET) and one or more sense FETs, and a common gate pad. The main FET and the one or more sense FETs are formed in a common substrate. The main FET and each of the sense FETs include a source terminal, a gate terminal and a drain terminal. The common gate pad connects the gate terminals of the main FET and the one or more sense FETs. An electrical isolation is disposed between the gate terminals of the main FET and the one or more sense FETs. Embodiments of this invention may be applied to both N-channel and P-channel MOSFET devices. | 12-16-2010 |
| 20100291744 | HIGH DENSITY TRENCH MOSFET WITH SINGLE MASK PRE-DEFINED GATE AND CONTACT TRENCHES - Trench gate MOSFET devices may be formed using a single mask to define gate trenches and body contact trenches. A hard mask is formed on a surface of a semiconductor substrate. A trench mask is applied on the hard mask to predefine a body contact trench and a gate trench. These predefined trenches are simultaneously etched into the substrate to a first predetermined depth. A gate trench mask is next applied on top of the hard mask. The gate trench mask covers the body contact trenches and has openings at the gate trenches. The gate trench, but not the body contact trench, is etched to a second predetermined depth. Conductive material of a first kind may fill the gate trench to form a gate. Conductive material of a second kind may fill the body contact trench to form a body contact. | 11-18-2010 |
| 20100225296 | HIGH VOLTAGE AND HIGH POWER BOOST CONVETER WITH CO-PACKAGED SCHOTTKY DIODE - A high voltage and high power boost converter is disclosed. The boost converter includes a boost converter IC and a discrete Schottky diode, both of which are co-packaged on a standard single common die pad. | 09-09-2010 |
| 20100032751 | SUPER-SELF-ALIGNED TRENCH-DMOS STRUCTURE AND METHOD - A semiconductor device includes a P-body layer formed in an N-epitaxial layer; a gate electrode formed in a trench in the P-body and N-epitaxial layer; a top source region formed from the P-body layer next to the gate electrode; a gate insulator disposed along a sidewall of the gate electrode between the gate electrode and the source, between the gate electrode and the P-body and between the gate electrode and the N-epitaxial layer; a cap insulator disposed on top of the gate electrode; and an N+ doped spacer disposed along a sidewall of the source and a sidewall of the gate insulator. The source includes N+ dopants diffused from the spacer. A body contact region containing P-type dopants is formed from the N-epitaxial layer. The contact region touches one or more P-doped regions of the P-body layer and the source. Methods for manufacturing such a device are also disclosed. Embodiments of this invention may also be applied to P-channel devices. | 02-11-2010 |
