Abstract: A method for forming semiconductor devices from a semiconductor wafer includes cutting a first surface of a semiconductor wafer to form a first region that extends partially through the semiconductor wafer and the first region has a bottom portion. The method further includes directing a beam of laser light to the semiconductor wafer such that the beam of laser light is focused within the semiconductor wafer between the first surface and the second surface thereof and the beam of laser light further cuts the semiconductor wafer by material ablation to form a second region aligned with the first region. A resulting semiconductor device is disclosed as well.
Abstract: A system configured to increase a reliability of electrical connections in a device. The system including a lead configured to electrically connect a pad of at least one support structure to a pad of at least one electrical component. The lead includes an upper portion that includes a lower surface arranged on a lower surface thereof. The lower surface of the upper portion is arranged vertically above a first upper surface of a first pad connection portion; and the lower surface of the upper portion is arranged vertically above a second upper surface of the second pad connection portion. A process configured to increase a reliability of electrical connections in a device is also disclosed.
Type:
Grant
Filed:
October 9, 2019
Date of Patent:
March 29, 2022
Assignee:
WOLFSPEED, INC.
Inventors:
Sung Chul Joo, Jack Powell, Donald Farrell, Bradley Millon
Abstract: A radio frequency (“RF”) power device includes a RF power transistor, and a bias circuit coupled between a reference voltage input and an input terminal of the RF power transistor. The bias circuit includes an impedance control circuit that is configured to vary an impedance of the bias circuit at the input terminal of the RF power transistor responsive to a RF input signal provided to the input terminal, and/or a current control circuit that is configured to control a bias current provided to the input terminal of the RF power transistor responsive to variations in operating characteristics of the RF power transistor. Related RF power amplifiers and device packages are also discussed.
Abstract: A semiconductor device includes a semiconductor layer structure comprising a source/drain region, a gate dielectric layer on the semiconductor layer structure, and a gate electrode on the gate dielectric layer. The source/drain region comprises a first portion comprising a first dopant concentration and a second portion comprising a second dopant concentration. The second portion is closer to a center of the gate electrode than the first portion.
Type:
Grant
Filed:
June 4, 2020
Date of Patent:
March 22, 2022
Assignee:
Wolfspeed, Inc.
Inventors:
Philipp Steinmann, Edward Van Brunt, Jae Hyung Park, Vaishno Dasika
Abstract: A semiconductor device includes a semiconductor layer structure, a gate insulating pattern on the semiconductor layer structure, a gate electrode on the gate insulating pattern, and an interface layer between the gate insulating pattern and the semiconductor layer structure, the interface layer having a first segment and a second segment with a gap therebetween.
Abstract: A HEMT comprises a composite channel, made up of a plurality of channel/barrier layer heterojunctions. That is, two or more channel/barrier layer pairs are deposited on a substrate, under a gate contact. A separate 2DEG is formed in each channel layer at the heterojunction with the barrier layer. The HEMT channel is effectively divided among a plurality of parallel 2DEGs. A high total charge density—required for high power operation—is divided among the plurality of 2DEGs. Since each 2DEG does not have a large charge density, it can sustain the high saturated electron velocity required for very high frequency operation. The composite-channel HEMT thus operates with high gain, at high power levels, and at high frequencies.
Abstract: A device includes: a surface mount device carrier configured to be mounted to a metal submount of a transistor package, said surface mount device carrier includes an insulating substrate includes a top surface and a bottom surface and a first pad and a second pad arranged on a top surface of said surface mount device carrier; at least one surface mount device includes a first terminal and a second terminal, said first terminal of said surface mount device mounted to said first pad and said second terminal mounted to said second pad; and at least one of the first terminal and the second terminal being configured to be isolated from the metal submount by said insulating substrate, where at least one of the first pad and the second pad are configured as wire bond pads.
Type:
Grant
Filed:
February 21, 2020
Date of Patent:
February 22, 2022
Assignee:
WOLFSPEED, INC.
Inventors:
Alexander Komposch, Simon Ward, Madhu Chidurala
Abstract: A transistor device is provided. The transistor device includes a substrate, a channel layer on the substrate, the channel layer including a GaN material, a barrier layer that is on the channel layer and that includes an AlGaN material, a drain electrode that is on the barrier layer in a drain region of the device, a source ohmic structure that is at least partially recessed into the barrier layer in a source region of the device, a source electrode that is on the source ohmic structure and a gate contact that is on the barrier layer and that is in a gate region of the device that is between the drain region and the source region.
Abstract: Gallium nitride based RF transistor amplifiers include a semiconductor structure having a gallium nitride based channel layer and a gallium nitride based barrier layer thereon, and are configured to operate at a specific direct current drain-to-source bias voltage. These amplifiers are configured to have a normalized drain-to-gate capacitance at the direct current drain-to-source bias voltage, and to have a second normalized drain-to-gate capacitance at two-thirds the direct current drain-to-source bias voltage, where the second normalized drain-to-gate capacitance is less than twice the first normalized drain-to-gate capacitance.
Type:
Grant
Filed:
October 2, 2019
Date of Patent:
February 1, 2022
Assignee:
Wolfspeed, Inc.
Inventors:
Qianli Mu, Zulhazmi Mokhti, Jia Guo, Scott Sheppard
Abstract: A semiconductor device includes a semiconductor layer structure that includes silicon carbide, a gate dielectric layer on the semiconductor layer structure, and a gate electrode on the gate dielectric layer opposite the semiconductor layer structure. In some embodiments, a periphery of a portion of the gate dielectric layer that underlies the gate electrode is thicker than a central portion of the gate dielectric layer, and a lower surface of the gate electrode has recessed outer edges such as rounded and/or beveled outer edges.
Type:
Grant
Filed:
April 22, 2020
Date of Patent:
January 11, 2022
Assignee:
Wolfspeed, Inc.
Inventors:
Daniel Jenner Lichtenwalner, Brett Hull, Edward Robert Van Brunt, Shadi Sabri, Matt N. McCain
Abstract: A crystalline material processing method includes forming subsurface laser damage at a first average depth position to form cracks in the substrate interior propagating outward from at least one subsurface laser damage pattern, followed by imaging the substrate top surface, analyzing the image to identify a condition indicative of presence of uncracked regions within the substrate, and taking one or more actions responsive to the analyzing. One potential action includes changing an instruction set for producing subsequent laser damage formation (at second or subsequent average depth positions), without necessarily forming additional damage at the first depth position. Another potential action includes forming additional subsurface laser damage at the first depth position.
Type:
Grant
Filed:
February 16, 2020
Date of Patent:
January 11, 2022
Assignee:
WOLFSPEED, INC.
Inventors:
Matthew Donofrio, John Edmond, Harshad Golakia, Eric Mayer