Qorvo Us, Inc.

Triquint Semiconductor Corporation

Xing Gu

Jinqiao Xie

Edward A Beam, Iii

Cathy Lee

Andrew Arthur Ketterson

Xing Chen

Yongjie Cui

Deep C Dumka

Cathy C Lee

Integration of self-biased magnetic circulators with microwave devices is disclosed herein. In microwave and other high-frequency radio frequency (RF) applications, a magnetic circulator can be implemented with a smaller permanent magnet. Aspects disclosed herein include a process flow for producing a self-biased circulator in an integrated circuit chip. In this regard, a magnetic circulator junction can be fabricated on an active layer of a semiconductor wafer. A deep pocket or cavity is formed in an insulating substrate under the active layer. This cavity is then filled with a ferromagnetic material such that the circulator junction is self-biased within the integrated circuit chip, eliminating the need for an external magnet. The self-biased circulator provides high isolation between ports in a smaller integrated circuit.

Integration of self-biased magnetic circulators with microwave devices

A passive magnetic device (PMD) has a base electrode, a multi-port signal structure (MPSS), and a substrate therebetween. The MPSS has a central plate residing in a second plane and at least two port tabs spaced apart from one another and extending from the central plate. The substrate has a central portion that defines a mesh structure between the base electrode and the central plate of the multi-port signal structure. A plurality of magnetic pillars are provided within the mesh structure, wherein each of the plurality of the magnetic pillars are spaced apart from one another and surrounded by a corresponding portion of the mesh structure. The PMD may provide a magnetically self-biased device that may be used as a radio frequency (RF) circulator, an RF isolator, and the like.

Passive magnetic devices

Fabricating high efficiency, high linearity N-polar gallium-nitride (GaN) transistors by selective area regrowth is disclosed. A demand for high efficiency components with highly linear performance characteristics for radio frequency (RF) systems has increased development of GaN transistors and, in particular, aluminum-gallium-nitride (AlGaN)/GaN high electron mobility transistor (HEMT) devices. A method of fabricating a high efficiency, high linearity N-polar HEMT device includes employing a selective area regrowth method for forming a HEMT structure on the Nitrogen-face (N-face) of a GaN buffer, a natural high composition AlGaN/AlN back barrier for carrier confinement, a thick undoped GaN layer on the access areas to eliminate surface dispersion, and a high access area width to channel width ratio for improved linearity. A problem of impurities on the GaN buffer surface prior to regrowth creating a leakage path is avoided by intentional silicon (Si) doping in the HEMT structure.

Process of fabricating high efficiency, high linearity N-polar gallium-nitride (GaN) transistors

A precursor cell for a transistor having a foundation structure, a mask structure, and a gallium nitride (GaN) PN structure is provided. The mask structure is provided over the foundation structure to expose a first area of a top surface of the foundation structure. The GaN PN structure resides over the first area and at least a portion of the mask structure and has a continuous crystalline structure with no internal regrowth interfaces. The GaN PN structure comprises a drift region over the first area, a control region laterally adjacent the drift region, and a PN junction formed between the drift region and the control region. Since the drift region and the control region form the PN junction having no internal regrowth interfaces, the GaN PN structure has a continuous crystalline structure with reduced regrowth related defects at the interface of the drift region and the control region.

Continuous crystalline gallium nitride (GaN) PN structure with no internal regrowth interfaces

The present disclosure relates to a process of forming a semiconductor device with a high thermal conductivity substrate. According to an exemplary process, a semiconductor precursor including a substrate structure, a buffer structure over the substrate structure, and a channel structure over the buffer structure is provided. The channel structure has a first channel surface and a second channel surface, which is opposite the first channel surface, adjacent to the buffer structure, and has a first polarity. Next, a high thermal conductivity substrate with a thermal conductivity greater than 400 W/mK is formed over the first channel surface. A heat sink carrier is then provided over the high thermal conductivity substrate. Next, the substrate structure and the buffer structure are removed to provide a thermally enhanced semiconductor device with an exposed surface, which has the first polarity.

Semiconductor device with high thermal conductivity substrate and process for making the same

The present disclosure relates to a process of forming a high thermal conductivity substrate for an Aluminum/Gallium/Indium (III)-Nitride semiconductor device. According to an exemplary process, a semiconductor precursor including a substrate structure and a buffer structure is provided. The buffer structure is formed over the substrate structure and has a first buffer surface and a second buffer surface. Herein, the second buffer surface is adjacent to the substrate structure and the first buffer surface is opposite the second buffer surface. Next, a high thermal conductivity substrate with a thermal conductivity greater than 400 W/mK is formed over the first buffer surface. A heat sink carrier is then provided over the high thermal conductivity substrate. The substrate structure is then substantially removed to provide a thermally enhanced precursor for the III-Nitride semiconductor device.

A semiconductor device includes a substrate, a relaxation layer, a channel layer, a polarization compensation layer, and a barrier layer. The relaxation layer is over the substrate and configured to reduce a total strain of the semiconductor device. The channel layer is over the relaxation layer. The polarization compensation layer is between the relaxation layer and the channel layer and configured to reduce a polarization between the relaxation layer and the channel layer. The barrier layer is over the relaxation layer and configured to polarize a junction between the barrier layer and the channel layer to induce a two-dimensional electron gas in the channel layer.

Double heterojunction field effect transistor with polarization compensated layer

Embodiments include but are not limited to semiconductor devices including a barrier layer, a gallium nitride channel layer having a Ga-face coupled with the barrier layer, and a thermoconductive layer having a thermal conductivity of at least 500 W/(m&#xb7;K) within 1000 nanometers of a Ga-face of the gallium nitride channel layer. The semiconductor device may be a high-electron-mobility transistor or a semiconductor wafer. Methods for making the same also are described.

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Allen, TX, United States of America

Xing Gu