Abstract: A novel integration scheme for forming power MOSFET, particularly forming salicides for both gate and mesa contact regions, as well as using multiple energy contact implants through the salicided layer to form conductive body contacts which short to the source region by the salicides.
Abstract: A semiconductor device wafer includes a test structure. The test structure includes a layer of material having an angle-shaped test portion disposed on at least a portion of a surface of the semiconductor wafer. A ruler marking on the surface of the semiconductor wafer proximate the test portion is adapted to facilitate measurement of a change in length of the test portion.
Abstract: A TSOP (Thin Small Outline Package) contains a MOSFET and a Schottky diode. The MOSFET has a source terminal a gate terminal and a drain terminal. The Schottky diode has a cathode terminal, a anode terminal. The TSOP contains the MOSFET and the Schottky diode with a special configuration by placing the drain terminal of the MOSFET and the anode terminal of the Schottky diode on a same side. Specifically, the TSOP implements a leadframe that comprises a plurality of leads. The drain terminal of the MOSFET and the anode terminal extends outside of the TSOP separate on the same side of the package.
Abstract: A boost converter for high power and high output voltage applications includes a low voltage controller integrated circuit and a high voltage, vertical, discrete field effect transistor, both of which are packed in a single package on separate electrically isolated die pads.
Abstract: This invention discloses a method for manufacturing a one-time programmable (OTP) memory includes a first and second MOS transistors connected in parallel and controlled by a common gate formed with a single polysilicon stripe. The method further comprises a step of implanting a drift region in a substrate region below a drain and source of the first and second MOS transistors counter doping a lightly dope drain (LDD) encompassing and surrounding a drain and a source of the first MOS transistor having a different threshold voltage than the second MOS transistor not reached by the drift region.
Abstract: High-mobility vertical trench DMOSFETs and methods for manufacturing are disclosed. A source region, a drain region or a channel region of a high-mobility vertical trench DMOSFET may comprise silicon germanium (SiGe) that increases the mobility of the charge carriers in the channel region. In some embodiments the channel region may be strained to increase channel charge carriers mobility.
Abstract: This invention discloses a trenched metal oxide semiconductor field effect transistor (MOSFET) cell. The trenched MOSFET cell includes a trenched gate opened from a top surface of the semiconductor substrate surrounded by a source region encompassed in a body region above a drain region disposed on a bottom surface of a substrate. The trenched gate further includes at least two mutually insulated trench-filling segments each filled with materials of different work functions. In an exemplary embodiment, the trenched gate includes a polysilicon segment at a bottom portion of the trenched gate and a metal segment at a top portion of the trenched gate.
Abstract: This invention discloses an improved semiconductor power device includes a plurality of power transistor cells wherein each cell further includes a planar gate padded by a gate oxide layer disposed on top of a drift layer constituting an upper layer of a semiconductor substrate wherein the planar gate further constituting a split gate including a gap opened in a gate layer whereby the a total surface area of the gate is reduced. The transistor cell further includes a JFET (junction field effect transistor) diffusion region disposed in the drift layer below the gap of the gate layer wherein the JFET diffusion region having a higher dopant concentration than the drift region for reducing a channel resistance of the semiconductor power device.
Type:
Grant
Filed:
March 16, 2009
Date of Patent:
November 8, 2011
Assignee:
Alpha & Omega Semiconductor Ltd.
Inventors:
Anup Bhalla, Francois Hebert, Daniel S. Ng
Abstract: A semiconductor power device supported on a semiconductor substrate includes a plurality of transistor cells each having a source and a drain with a gate to control an electric current transmitted between the source and the drain. The semiconductor further includes a source metal connected to the source region, and a gate metal configured as a metal stripe surrounding a peripheral region of the substrate connected to a gate pad wherein the gate metal and the gate pad are separated from the source metal by a metal gap. The semiconductor power device further includes an ESD protection circuit includes a plurality of doped polysilicon regions of opposite conductivity types constituting ESD diodes extending across the metal gap and connected between the gate metal and the source metal on the peripheral region of the substrate.
Type:
Grant
Filed:
May 21, 2007
Date of Patent:
November 8, 2011
Assignee:
Alpha & Omega Semiconductor, Ltd.
Inventors:
Yi Su, Anup Bhalla, Daniel Ng, Wei Wang, Ji Pan
Abstract: This invention discloses a method of manufacturing a trenched semiconductor power device with split gate filling a trench opened in a semiconductor substrate wherein the split gate is separated by an inter-poly insulation layer disposed between a top and a bottom gate segments. The method further includes a step of forming the inter-poly layer by applying a RTP process after a HDP oxide deposition process to bring an etch rate of the HDP oxide layer close to an etch rate of a thermal oxide.
Type:
Grant
Filed:
October 16, 2009
Date of Patent:
November 8, 2011
Assignee:
Alpha & Omega Semiconductor, LTD
Inventors:
Sung-Shan Tai, Yong-Zhong Hu, François Hébert, Hong Chang, Mengyu Pan, Yingying Lou, Yu Wang
Abstract: A semiconductor package assembly may include a lead frame having a die bonding pad and plurality of leads coupled to the first die bonding pad. A vertical semiconductor device may be bonded to the die bonding pad. The device may have a conductive pad electrically connected to one lead through a first bond wire. An electrically isolated conductive trace may be formed from a layer of conductive material of the first semiconductor device. The conductive trace provides an electrically conductive path between the first bond wire and a second bond wire. The conductive path may either pass underneath a third bond wire thereby avoiding the third bond wire crossing another bond wire, or the conductive path may result in a reduced length for the first and second bond wires that is less than a predetermined maximum length.
Type:
Grant
Filed:
January 14, 2011
Date of Patent:
November 1, 2011
Assignee:
Alpha & Omega Semiconductors, Ltd.
Inventors:
Jun Lu, Anup Bhalla, Xiaobin Wang, Allen Chang, Kenny Man Sheng Hu, Xiaotian Zhang
Abstract: This invention discloses a semiconductor power device. The trenched semiconductor power device includes a trenched gate, opened from a top surface of a semiconductor substrate, surrounded by a source region encompassed in a body region near the top surface above a drain region disposed on a bottom surface of a substrate. The semiconductor power device further includes an implanting-ion block disposed above the top surface on a mesa area next to the body region having a thickness substantially larger than 0.3 micron for blocking body implanting ions and source ions from entering into the substrate under the mesa area whereby masks for manufacturing the semiconductor power device can be reduced.
Type:
Grant
Filed:
April 30, 2007
Date of Patent:
October 11, 2011
Assignee:
Alpha & Omega Semiconductor, Ltd.
Inventors:
Anup Bhalla, François Hébert, Sung-Shan Tai, Sik K Lui
Abstract: A main FET and one or more sense FETs are formed in a common substrate. The main FET and sense FET(s) include a source terminal, a gate terminal and a drain terminal. The common gate pad connects the gate terminals of the main FET and sense FET(s). An electrical isolation may be between the gate terminals of the main FET and the sense FET(s). A sense pad in electrical contact with the source of the one or more sense FETs does not overlap an area of the device containing the sense FET(s). It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
Abstract: A method for determining the depth etch, a method of forming a shielded gate trench (SGT) structure and a semiconductor device wafer are disclosed. A material layer is formed over part of a substrate having a trench. The material fills the trench. A resist mask is placed over a test portion of the layer of material. The resist mask does not cover the trench. The layer of material is isotropically etched. An etch depth may be determined from a characteristic of etching of the material underneath the mask. Such a method may be used for forming SGT structures. The wafer may comprise a layer of material disposed on at least a portion of a surface of semiconductor wafer; a resist mask comprising an angle-shaped test portion disposed over a portion of the layer of material; and a ruler marking on the surface of the substrate proximate the test portion.
Abstract: A trenched semiconductor power device includes a trenched gate insulated by a gate insulation layer and surrounded by a source region encompassed in a body region above a drain region disposed on a bottom surface of a semiconductor substrate. The source region surrounding the trenched gate includes a metal of low barrier height to function as a Schottky source. The metal of low barrier height further may include a PtSi or ErSi layer. In a preferred embodiment, the metal of low barrier height further includes an ErSi layer. The metal of low barrier height further may be a metal silicide layer having the low barrier height. A top oxide layer is disposed under a silicon nitride spacer on top of the trenched gate for insulating the trenched gate from the source region. A source contact disposed in a trench opened into the body region for contacting a body-contact dopant region and covering with a conductive metal layer such as a Ti/TiN layer.
Abstract: A boost converter for high power and high output voltage applications includes a low voltage controller integrated circuit and a high voltage, vertical, discrete field effect transistor, both of which are packed in a single package.
Abstract: This invention discloses bottom-source lateral diffusion MOS (BS-LDMOS) device. The device has a source region disposed laterally opposite a drain region near a top surface of a semiconductor substrate supporting a gate thereon between the source region and a drain region. The BS-LDMOS device further has a combined sinker-channel region disposed at a depth in the semiconductor substrate entirely below a body region disposed adjacent to the source region near the top surface wherein the combined sinker-channel region functioning as a buried source-body contact for electrically connecting the body region and the source region to a bottom of the substrate functioning as a source electrode. A drift region is disposed near the top surface under the gate and at a distance away from the source region and extending to and encompassing the drain region.
Type:
Grant
Filed:
September 17, 2006
Date of Patent:
August 30, 2011
Assignee:
Alpha & Omega Semiconductor, Ltd
Inventors:
Sik K Lui, François Hébert, Anup Bhalla
Abstract: This invention discloses a semiconductor power device disposed on a semiconductor substrate supporting an epitaxial layer as a drift region composed of an epitaxial layer. The semiconductor power device further includes a super-junction structure includes a plurality of doped sidewall columns disposed in a multiple of epitaxial layers. The epitaxial layer have a plurality of trenches opened and filled with the multiple epitaxial layer therein with the doped columns disposed along sidewalls of the trenches disposed in the multiple of epitaxial layers.
Abstract: A symmetrical blocking transient voltage suppressing (TVS) circuit for suppressing a transient voltage includes an NPN transistor having a base electrically connected to a common source of two transistors whereby the base is tied to a terminal of a low potential in either a positive or a negative voltage transient. The two transistors are two substantially identical transistors for carrying out a substantially symmetrical bi-directional clamping a transient voltage. These two transistors further include a first and second MOSFET transistors having an electrically interconnected source. The first MOSFET transistor further includes a drain connected to a high potential terminal and a gate connected to the terminal of a low potential and the second MOSFET transistor further includes a drain connected to the terminal of a low potential terminal and a gate connected to the high potential terminal.
Abstract: A resetable over-current self-protecting semiconductor power device comprises a vertical power semiconductor chip and an over-current protection layer composed of current limiting material such as a PTC material. The over-current protection layer may be sandwiched between the vertical power semiconductor chip and a conductive plate, which could be a leadframe, a metal plate, a PCB plate or a PCB that the device is mounted on.