Abstract: An electronic assembly, comprising a carrier wafer having a top wafer surface and a bottom wafer surface; an electronic integrated circuit being formed in the carrier wafer and comprising a wafer contact pad on the top wafer surface; said carrier wafer comprising a through-wafer cavity joining the top and bottom wafer surfaces; a component chip having a component chip top surface, a component chip bottom surface and component chip side surfaces, the component chip being held in said through-wafer cavity by direct contact of at least a side surface of said first component chip with an attachment metal that fills at least a portion of said through-wafer cavity; said component chip comprising at least one component contact pad on said component chip top surface; a first conductor connecting said wafer contact pad and said component contact pad.

Abstract: A self-aligned GaN FinFET device and a method of fabricating the same are disclosed. This self-aligned process helps to fabricate GaN FinFET devices in a scalable manner. This work transforms the T-gate process to incorporate fins to further improve pinch-off and decrease leakage currents on highly scaled GaN HEMT structures. The GaN FinFET structure will also allow for integration of normally-off devices with normally-on devices by varying the fin width. The FinFET improvement combines the fin structure consisting of various fin pitches and widths, gate dielectric, self-aligned gate design, ultra-low ohmic contacts, and vertically scaled epitaxy into a single scalable process.

Abstract: An electronic assembly, comprising a carrier wafer having a top wafer surface and a bottom wafer surface; an electronic integrated circuit being formed in the carrier wafer and comprising a wafer contact pad on the top wafer surface; said carrier wafer comprising a through-wafer cavity joining the top and bottom wafer surfaces; a component chip having a component chip top surface, a component chip bottom surface and component chip side surfaces, the component chip being held in said through-wafer cavity by an attachment material attaching at least one wall of the through-wafer cavity to at least one of the component chip bottom surface and a component chip side surface; said component chip comprising at least one component contact pad on said component chip top substrate; a first conductor connecting said wafer contact pad and said component contact pad.

Abstract: Semiconductor devices, such as transistors, FETs and HEMTs having a non-linear gate foot region and non-linear channel width are disclosed as well as methods of making and using such devices and the operational benefits of the devices.

Abstract: Monolithic integration of high-frequency GaN-HEMTs and GaN-Schottky diodes. The integrated HEMTs/Schottky diodes are realized using an epitaxial structure and a fabrication process which reduces fabrication cost. Since the disclosed process preferably uses self-aligned technology, both devices show extremely high-frequency performance by minimizing device parasitic resistances and capacitances. Furthermore, since the Schottky contact of diodes is formed by making a direct contact of an anode metal to the 2DEG channel the resulting structure minimizes an intrinsic junction capacitance due to the very thin contact area size. The low resistance of high-mobility 2DEG channel and a low contact resistance realized by a n+GaN ohmic regrowth layer reduce a series resistance of diodes as well as access resistance of the HEMT.

Abstract: A self-aligned process for locating a stem of a T-shaped gate relative to source and drain contacts of a FET or HEMT. The gate stem is located asymmetrically in some embodiments and in such embodiments the stem of the T-shaped gate is located relative to drain and source contacts of the device by forming a plurality of sidewall spacers, with more sidewall spacers being formed on the drain side of the stem than are formed on the source side of the stem. Additionally the gate stem preferably has a high aspect ratio to improve the performance of the resulting FET or HEMT. Drain and source contacts are preferably formed of an n+ semiconductor material.

Abstract: A method of making a stepped field gate for an FET including forming a first set of layers having a passivation layer on a barrier layer of the FET and a first etch stop layer over the first passivation layer, forming additional sets of layers having alternating passivation layer and etch stop layers, successively removing portions of each set of layers using lithography and reactive ion etching to form stepped passivation layers and a gate foot, applying a mask having an opening defining an extent of a stepped field-plate gate, and forming the stepped field plate gate and the gate foot by plating through the opening in the mask.

Abstract: A method of making a stepped field gate for an FET including forming a first set of layers having a passivation layer on a barrier layer of the FET and a first etch stop layer over the first passivation layer, forming additional sets of layers having alternating passivation layer and etch stop layers, successively removing portions of each set of layers using lithography and reactive ion etching to form stepped passivation layers and a gate foot, applying a mask having an opening defining an extent of a stepped field-plate gate, and forming the stepped field plate gate and the gate foot by plating through the opening in the mask.

Abstract: A semiconductor device comprises one or more transistors and two or more layers of dielectric material encapsulating a front side of said one or more transistors. The gate of each of said one or more transistors is located within a cavity, or air-box, in at least one of the dielectric layers, so that the gate terminal is physically separated from said dielectric material. Such an arrangement may reduce parasitic capacitance. In another arrangement, a semiconductor device comprises one or more gallium nitride high electron mobility transistors and one or more dielectric layers encapsulating a front side of said one or more transistors, wherein the gate terminal of each of said one or more transistors is located within a cavity in at least one of the one or more dielectric layers, separated from said dielectric material.

Abstract: A method of forming a slanted field plate including forming epitaxy for a FET on a substrate, forming a wall near a drain of the FET, the wall comprising a first negative tone electron-beam resist (NTEBR), depositing a dielectric over the epitaxy and the wall, the wall causing the dielectric to have a step near the drain of the FET, depositing a second NTEBR over the dielectric, wherein surface tension causes the deposited second NTEBR to have a slanted top surface between the step and a source of the FET, etching anisotropically vertically the second NTEBR and the dielectric to remove the second NTEBR and to transfer a shape of the slanted top surface to the dielectric, and forming a gatehead comprising metal on the dielectric between the step and the source of the FET, wherein the gatehead forms a slanted field plate.

Abstract: Monolithic integration of high-frequency GaN-HEMTs and GaN-Schottky diodes. The integrated HEMTs/Schottky diodes are realized using an epitaxial structure and a fabrication process which reduces fabrication cost. Since the disclosed process preferably uses self-aligned technology, both devices show extremely high-frequency performance by minimizing device parasitic resistances and capacitances. Furthermore, since the Schottky contact of diodes is formed by making a direct contact of an anode metal to the 2DEG channel the resulting structure minimizes an intrinsic junction capacitance due to the very thin contact area size. The low resistance of high-mobility 2DEG channel and a low contact resistance realized by a n+GaN ohmic regrowth layer reduce a series resistance of diodes as well as access resistance of the HEMT.

Abstract: A method of fabricating a GaN HEMT includes growing a first epitaxial layer on a substrate, growing a second epitaxial layer on the first epitaxial layer, growing a third epitaxial layer on the second epitaxial layer, depositing a first dielectric film on the third epitaxial layer, using dielectric films to form a first sidewall dielectric spacer, forming a sidewall gate adjacent the first sidewall dielectric spacer. The sidewall gate may be made to be less than 50 nm in length.

Abstract: A method for fabricating a gate structure for a field effect transistor having a buffer layer on a substrate, a channel layer and a barrier layer over the channel layer includes forming a gate of a first dielectric, forming first sidewalls of a second dielectric on either side and adjacent to the gate, selectively etching into the buffer layer to form a mesa for the field effect transistor, depositing a dielectric layer over the mesa, planarizing the dielectric layer over the mesa to form a planarized surface such that a top of the gate, tops of the first sidewalls, and a top of the dielectric layer over the mesa are on the same planarized surface, depositing metal on the planzarized surface, annealing to form the gate into a metal silicided gate, and etching to remove excess non-silicided metal.

Abstract: A method for fabricating a gate structure for a field effect transistor having a buffer layer on a substrate, a channel layer and a barrier layer over the channel layer includes forming a gate including silicon, forming first sidewalls of a first material on either side and adjacent to the gate, selectively etching into the buffer layer to form a mesa for the field effect transistor, depositing a material layer over the mesa, planarizing the material layer over the mesa to form a planarized surface such that a top of the gate, tops of the first sidewalls, and a top of the material layer over the mesa are on the same planarized surface, depositing metal on the planzarized surface, annealing to form the gate into a metal silicided gate, and etching to remove excess non-silicided metal.

Abstract: A method of fabricating a GaN HEMT includes growing a first epitaxial layer on a substrate, growing a second epitaxial layer on the first epitaxial layer, growing a third epitaxial layer on the second epitaxial layer, depositing a first dielectric film on the third epitaxial layer, using dielectric films to form a first sidewall dielectric spacer, forming a sidewall gate adjacent the first sidewall dielectric spacer. The sidewall gate may be made to be less than 50 nm in length.