Patents Assigned to RFHIC CORPORATION
  • Patent number: 11521957
    Abstract: In one embodiment, a semiconductor device includes a first substrate with a transistor formed in a first active are, a first bonding pad electrically connected to the transistor and a first metal pad surrounding the first active area. A second substrate of a type that is different from the first substrate includes a passive circuit element in a second active area on a front surface, a second bonding pad electrically connected to the passive circuit element, a second metal pad surrounding the second active area, and a mounting pad on a back surface of the second substrate with a through-via electrically connecting the second bonding pad to the mounting pad. A first interconnection extends from the first bonding pad to the second bonding pad, and a second interconnection extends from the first metal pad to the second metal pad and surrounds the region through which the first interconnection extends.
    Type: Grant
    Filed: July 8, 2021
    Date of Patent: December 6, 2022
    Assignee: RFHIC CORPORATION
    Inventor: Won Sang Lee
  • Patent number: 10861947
    Abstract: Methods for processing a semiconductor transistor are provided, where the semiconductor transistor includes a substrate, an epitaxial layer, and transistor components that are formed on the epitaxial layer. The method includes: removing a portion of the substrate that is disposed below a portion of the transistor components, to thereby expose a portion of a bottom surface of the epitaxial layer; forming an electrically insulating layer on the exposed portion of the bottom surface of the epitaxial layer; forming a via that extends from a bottom surface of the insulating layer to a bottom surface of one of the transistor components; depositing at least one metal layer on the bottom surface of the insulating layer, on a side wall of the via and on the bottom surface of one of the transistor components; and applying a solder paste to a bottom surface of the at least one metal layer.
    Type: Grant
    Filed: May 26, 2020
    Date of Patent: December 8, 2020
    Assignee: RFHIC CORPORATION
    Inventor: Won Sang Lee
  • Patent number: 10707311
    Abstract: HEMT having a drain field plate is provided. The drain field plate is formed in the area between the gate and drain of a HEMT. The drain field plate includes a metal pad that has a larger projection area than the drain pad. The drain field plate and semiconductor layer disposed beneath the drain field plate form a metal-semiconductor (M-S) Schottky structure. The capacitance of the M-S Schottky structure generates capacitance in the semiconductor area, which increases the breakdown voltage of the transistor components of the HEMT. A portion of the substrate under the active area may be removed to thereby increase the heat conductivity and reduce the junction temperature of the transistor components of the HEMT.
    Type: Grant
    Filed: December 1, 2018
    Date of Patent: July 7, 2020
    Assignee: RFHIC CORPORATION
    Inventor: Won Sang Lee
  • Patent number: 10699896
    Abstract: A method of fabricating a semiconductor device structure includes: providing a substrate comprising a layer of compound semiconductor material; forming a seed layer of nano-crystalline diamond having a layer thickness in a range 5 to 50 nm on the layer of compound semiconductor material; and growing a layer of polycrystalline CVD diamond on the seed layer using a chemical vapour deposition (CVD) technique. An effective thermal boundary resistance (TBReff) at an interface between the layer of compound semiconductor material and the layer of polycrystalline CVD diamond material is no more than 50 m2K/GW.
    Type: Grant
    Filed: April 14, 2019
    Date of Patent: June 30, 2020
    Assignee: RFHIC CORPORATION
    Inventors: Firooz Nasser-Faili, Daniel Francis, Frank Yantis Lowe, Daniel James Twitchen
  • Patent number: 10446468
    Abstract: Methods of fabricating compound semiconductor device structures having polycrystalline CVD diamond. The method includes: providing a substrate that has a layer of single crystal compound semiconductor material; forming a bonding layer on a surface of the substrate, the bonding layer having a thickness of less than 25 nm and a thickness variation of no more than 15 nm; and growing a layer of polycrystalline diamond on the bonding layer using a chemical vapor deposition technique. The effective thermal boundary resistance at the interface between the layer of single crystal compound semiconductor material and the layer of polycrystalline CVD diamond material is less than 25 m2K/GW. The layer of single crystal compound semiconductor material has one or both of the following characteristics: a charge mobility of at least 1200 cm2V?1s?1; and a sheet resistance of no more than 700 ?/square.
    Type: Grant
    Filed: February 24, 2019
    Date of Patent: October 15, 2019
    Assignee: RFHIC CORPORATION
    Inventors: Frank Yantis Lowe, Daniel Francis, Firooz Nasser-Faili, Daniel James Twitchen
  • Patent number: 10319580
    Abstract: A semiconductor device structure comprising: a layer of compound semiconductor material; and a layer of polycrystalline CVD diamond material, wherein the layer of polycrystalline CVD diamond material is bonded to the layer of compound semiconductor material via a layer of nano-crystalline diamond which is directly bonded to the layer of compound semiconductor material, the layer of nano-crystalline diamond having a thickness in a range 5 to 50 nm and configured such that an effective thermal boundary resistance (TBReff) as measured by transient thermoreflectance at an interface between the layer of compound semiconductor material and the layer of polycrystalline CVD diamond material is no more than 50 m2K/GW.
    Type: Grant
    Filed: December 9, 2015
    Date of Patent: June 11, 2019
    Assignee: RFHIC CORPORATION
    Inventors: Firooz Nasser-Faili, Daniel Francis, Frank Yantis Lowe, Daniel James Twitchen
  • Patent number: 10297526
    Abstract: A semiconductor device structure includes a layer of single crystal compound semiconductor material; and a layer of polycrystalline CVD diamond material. The layer of polycrystalline CVD diamond material is bonded to the layer of single crystal compound semiconductor material via a bonding layer having a thickness of less than 25 nm and a thickness variation of no more than 15 nm. The effective thermal boundary resistance as measured by transient thermoreflectance at an interface between the layer of single crystal compound semiconductor material and the layer of polycrystalline CVD diamond material is less than 25 m2K/GW with a variation of no more than 12 m2K/GW as measured across the semiconductor device structure. The layer of single crystal compound semiconductor material has one or both of the following characteristics: a charge mobility of at least 1200 cm2V?1s?1; and a sheet resistance of no more than 700 ?/square.
    Type: Grant
    Filed: December 9, 2015
    Date of Patent: May 21, 2019
    Assignee: RFHIC CORPORATION
    Inventors: Frank Yantis Lowe, Daniel Francis, Firooz Nasser-Faili, Daneil James Twitchen
  • Patent number: 10128107
    Abstract: Wafers including a diamond layer and a semiconductor layer having III-Nitride compounds and methods for fabricating the wafers are provided. A first SiC layer is formed on a silicon substrate, and using a carbon containing gas, a surface of the first SiC layer is carbonized to form carbon particles on the SiC layer. Then, a diamond layer is grown on the carbonized surface, where the carbon atoms act as seed particles for growing the diamond layer. A second SiC layer is formed on the diamond layer and a semiconductor layer having III-Nitride compounds is formed on the second SiC layer. Then, the silicon substrate and the first SiC layer are removed.
    Type: Grant
    Filed: August 31, 2017
    Date of Patent: November 13, 2018
    Assignee: RFHIC CORPORATION
    Inventors: Sam Yul Cho, Won Sang Lee
  • Patent number: 10043700
    Abstract: A method of fabricating a semiconductor-on-diamond composite substrate, the method comprising: (i) starting with a native semiconductor wafer comprising a native silicon carbide substrate on which a compound semiconductor is disposed; (ii) bonding a silicon carbide carrier substrate to the compound semiconductor; (iii) removing the native silicon carbide substrate; (iv) forming a nucleation layer over the compound semiconductor; (v) growing polycrystalline chemical vapor deposited (CVD) diamond on the nucleation layer to form a composite diamond-compound semiconductor-silicon carbide wafer, and (vi) removing the silicon carbide carrier substrate y laser lift-off to achieve a layered structure comprising the compound semiconductor bonded to the polycrystalline CVD diamond via the nucleation layer, wherein in step (ii) the silicon carbide carrier substrate is bonded to the compound semiconductor via a laser absorption material which absorbs laser light, wherein the laser has a coherence length shorter than a th
    Type: Grant
    Filed: May 11, 2016
    Date of Patent: August 7, 2018
    Assignee: RFHIC CORPORATION
    Inventor: Daniel Francis
  • Patent number: 9859107
    Abstract: Provided is an electrodeless lighting system including a solid state power amplifier (SSPA) configured to generate a microwave having a predetermined frequency, a resonator having a shielding structure configured to shield the microwave having a predetermined frequency so as to prevent the microwave from being discharged to the outside of the resonator, a connector configured to connect the SSPA to the resonator, an antenna configured to discharge the microwave having the predetermined frequency, which is generated in the SSPA, to the resonator, a bulb disposed in the resonator and including a light emitting material that is excited by the microwave having the predetermined frequency to emit light, and a support configured to support the bulb. Here, the antenna is a conductor introduced into the resonator through the connector.
    Type: Grant
    Filed: November 21, 2016
    Date of Patent: January 2, 2018
    Assignee: RFHIC CORPORATION
    Inventor: Cheol Jun Kim
  • Patent number: 9548257
    Abstract: A semiconductor device structure includes a layer of III-V compound semiconductor material, a layer of polycrystalline CVD diamond material, and an interface region with a diamond nucleation layer. A Raman signal of the diamond nucleation layer exhibits an sp3 carbon peak at 1332 cm?1 having a full width half maximum of no more than 5.0 cm?1, and one or both of: (i) an sp2 carbon peak at 1550 cm?1 having a height which is no more than 20% of a height of the sp3 carbon peak at 1332 cm?1 after background subtraction when using a Raman excitation source at 633 nm; and (ii) the sp3 carbon peak at 1332 cm?1 is no less than 10% of local background intensity in a Raman spectrum using a Raman excitation source at 785 nm. An average nucleation density at a nucleation surface is no less than 1×108 cm?2 and no more than 1×1012 cm?2.
    Type: Grant
    Filed: August 29, 2014
    Date of Patent: January 17, 2017
    Assignee: RFHIC CORPORATION
    Inventor: Firooz Nasser-Faili