Abstract: A radio frequency device includes a substrate, an epitaxial structure, a first electrode, a second electrode, a gate structure, a metal bulk, an auxiliary metal bulk, and a metal connection line. The first/second electrode includes a first/second electrode body and first/second electrode fingers. The gate structure includes a sub-gate having parallel portions and vertical portions alternately connected to one another in series to form a serpentine shape. The auxiliary metal bulk is arranged between corresponding adjacent two parallel portions and between a corresponding vertical portion and an end of a corresponding first electrode finger. The metal bulk is arranged between the auxiliary metal bulk and the vertical portion corresponding to the auxiliary metal bulk. The metal connection line connects the metal bulk to the second electrode body and is insulated from the sub-gate. A radio frequency front-end apparatus including the radio frequency device is also disclosed.

Abstract: A normally-off field effect transistor device includes a gate electrode structure having a first insulating film, a charge-accumulation gate electrode, a second insulating film and a gate electrode deposited one by one on a semiconductor, and a first capacitor formed by capacitive coupling between the charge-accumulation gate electrode and a source electrode. A charge is accumulated on the charge-accumulation gate electrode by a first current flowing through the first capacitor. The gate electrode structure further includes a stacked film having a third insulating film and a first semiconductor layer provided between the source electrode and the charge-accumulation gate electrode, with at least part of the first current flowing through the stacked film.

Abstract: A normally-off vertical nitride semiconductor transistor device with low threshold voltage variation includes a drift layer containing a nitride semiconductor, a channel region electrically connected to the drift layer, a source electrode, a drain electrode, a gate insulating film, and a gate electrode. The gate insulating film includes at least a first insulating film located at the channel region side, a second insulating film located at the gate electrode side, and a third insulating film between the second insulating film and the gate electrode, wherein the second insulating film has charge traps with energy levels located inside the band gaps of both the first and third insulating films, and the threshold voltage is adjusted by charges accumulated in the charge traps. The threshold voltage is used to block flowing current by substantially eliminating conduction carriers of the channel region by voltage applied to the gate electrode.

Abstract: A nitride semiconductor transistor device is disclosed. The device includes a first nitride semiconductor layer disposed over a substrate, and a second nitride semiconductor layer with a band gap larger than the first nitride semiconductor disposed over the first nitride semiconductor layer. Over the second nitride semiconductor layer, a first insulating film, a charge-storing gate electrode, a second insulating film, and a second gate electrode are formed in order thereon. A source electrode and a drain electrode are disposed over the second nitride semiconductor layer interposing the charge-storing gate electrode in a plane direction. The device further includes a first gate electrode capacitively coupling with the charge-storing gate electrode with an insulating film therebetween forming a first capacitor, and the charge-storing gate electrode is charged by an electron injection from the first gate electrode through the first capacitor.

Abstract: The invention provides a structure of an emitter layer and a base layer that reduces the influence of a conduction band energy barrier generated at an interface between the emitter layer and the base layer on power amplifier characteristics for a GaAs HBT using InGaAs grown by pseudomorphic growth in the base layer. In the first invention, InGaP having a CuPt-type ordering is used in the emitter layer. In the second invention, a p-type impurity concentration of an InGaAs base layer grown by pseudomorphic growth is less in an emitter layer side portion than in a collector layer side portion.

Abstract: A normally-off vertical nitride semiconductor transistor device with low threshold voltage variation includes a drift layer containing a nitride semiconductor, a channel region electrically connected to the drift layer, a source electrode, a drain electrode, a gate insulating film, and a gate electrode. The gate insulating film includes at least a first insulating film located at the channel region side, a second insulating film located at the gate electrode side, and a third insulating film between the second insulating film and the gate electrode, wherein the second insulating film has charge traps with energy levels located inside the band gaps of both the first and third insulating films, and the threshold voltage is adjusted by charges accumulated in the charge traps. The threshold voltage is used to block flowing current by substantially eliminating conduction carriers of the channel region by voltage applied to the gate electrode.

Abstract: The invention provides a structure of an emitter layer and a base layer that reduces the influence of a conduction band energy barrier generated at an interface between the emitter layer and the base layer on power amplifier characteristics for a GaAs HBT using InGaAs grown by pseudomorphic growth in the base layer. In the first invention, InGaP having a CuPt-type ordering is used in the emitter layer. In the second invention, a p-type impurity concentration of an InGaAs base layer grown by pseudomorphic growth is less in an emitter layer side portion than in a collector layer side portion.

Abstract: A nitride semiconductor transistor device is disclosed. The device includes a first nitride semiconductor layer disposed over a substrate, and a second nitride semiconductor layer with a band gap larger than the first nitride semiconductor disposed over the first nitride semiconductor layer. Over the second nitride semiconductor layer, a first insulating film, a charge-storing gate electrode, a second insulating film, and a second gate electrode are formed in order thereon. A source electrode and a drain electrode are disposed over the second nitride semiconductor layer interposing the charge-storing gate electrode in a plane direction. The device further includes a first gate electrode capacitively coupling with the charge-storing gate electrode with an insulating film therebetween forming a first capacitor, and the charge-storing gate electrode is charged by an electron injection from the first gate electrode through the first capacitor.

Abstract: A HBT on a GaAs substrate is presented, wherein its base comprises a first base layer comprising IniGa1-iAs with an Indium content i with a slope s1 and a second base layer on the emitter side comprising InjGa1-jAs with an Indium content j with a slope s2, and an average of s1 is half of the average of s2 or smaller; or the base comprises a first base layer comprising InmGa1-mAs with an Indium content m and a second base layer on the emitter side comprising InnGa1-nAs with an Indium content n, and an average of n is larger than the m at a second base layer side; or the base comprises a first base layer pseudomorphic to GaAs with a bulk lattice constant larger than GaAs, and the emitter comprises a first emitter layer pseudomorphic to GaAs with a bulk lattice constant smaller than GaAs.

Abstract: The present invention relates to a compound semiconductor integrated circuit chip having a front and/or back surface metal layer used for electrical connection to an external circuit. The compound semiconductor integrated circuit chip (first chip) comprises a substrate, an electronic device layer, and a dielectric layer. A first metal layer is formed on the front side of the dielectric layer, and a third metal layer is formed on the back side of the substrate. The first and third metal layer are made essentially of Cu and used for the connection to other electronic circuits. A second chip may be mounted on the first chip with electrical connection made with the first or the third metal layer that extends over the electronic device in the first chip in the three-dimensional manner to make the electrical connection between the two chips having connection nodes away from each other.

Abstract: A nitride semiconductor transistor device provides a normally-off nitride semiconductor transistor device which is excellent in switching properties with less dispersion of the properties. The nitride semiconductor transistor device has a buffer layer, a GaN layer, and an AlGaN layer in turn grown on a substrate. A first insulating film, a charge storage layer, a second insulating film, and a control electrode are in turn grown on the AlGaN layer. A source electrode and a drain electrode are formed to sandwich the charge storage layer over the AlGaN layer. A threshold voltage to shut off an electric current flowing between the source and drain electrodes through a conductive channel induced at an interface of the AlGaN layer and the GaN layer is made positive by adjusting the charge stored in the charge storage layer.

Abstract: A nitride semiconductor transistor device is disclosed to provide a normally-off nitride semiconductor transistor device which is excellent in switching properties with less dispersion of the properties. The nitride semiconductor transistor device has a buffer layer, a GaN layer, and an AlGaN layer in turn grown on a substrate. A first insulating film, a charge storage layer, a second insulating film, and a control electrode are in turn grown on the AlGaN layer. A source electrode and a drain electrode are formed to sandwich the charge storage layer over the AlGaN layer. A threshold voltage to shut off an electric current flowing between the source and drain electrodes through a conductive channel induced at an interface of the AlGaN layer and the GaN layer is made positive by adjusting charge stored in the charge storage layer.

Abstract: The present invention relates to a compound semiconductor integrated circuit chip having a front and/or back surface metal layer used for electrical connection to an external circuit. The compound semiconductor integrated circuit chip (first chip) comprises a substrate, an electronic device layer, and a dielectric layer. A first metal layer is formed on the front side of the dielectric layer, and a third metal layer is formed on the back side of the substrate. The first and third metal layer are made essentially of Cu and used for the connection to other electronic circuits. A second chip may be mounted on the first chip with electrical connection made with the first or the third metal layer that extends over the electronic device in the first chip in the three-dimensional manner to make the electrical connection between the two chips having connection nodes away from each other.

Abstract: The present invention relates to a compound semiconductor integrated circuit chip having a front and/or back surface metal layer used for electrical connection to an external circuit. The compound semiconductor integrated circuit chip (first chip) comprises a substrate, an electronic device layer, and a dielectric layer. A first metal layer is formed on the front side of the dielectric layer, and a third metal layer is formed on the back side of the substrate. The first and third metal layer are made essentially of Cu and used for the connection to other electronic circuits. A second chip may be mounted on the first chip with electrical connection made with the first or the third metal layer that extends over the electronic device in the first chip in the three-dimensional manner to make the electrical connection between the two chips having connection nodes away from each other.

Abstract: A HBT on a GaAs substrate is presented, wherein its base comprises a first base layer comprising IniGa1-iAs with an Indium content i with a slope s1 and a second base layer on the emitter side comprising IniGa1-jAs with an Indium content j with a slope s2, and an average of s1 is half of the average of s2 or smaller; or the base comprises a first base layer comprising InmGa1-mAs with an Indium content m and a second base layer on the emitter side comprising InnGa1-nAs with an Indium content n, and an average of n is larger than the m at a second base layer side; or the base comprises a first base layer pseudomorphic to GaAs with a bulk lattice constant larger than GaAs, and the emitter comprises a first emitter layer pseudomorphic to GaAs with a bulk lattice constant smaller than GaAs.

Abstract: A layout structure of HBTs comprising one or more HBTs, each of which comprises a base electrode, an emitter electrode, and a collector electrode. A passive layer, a first dielectric layer, a collector redistribution layers, one or more emitter copper pillars, and one or more collector copper pillars are formed above the one or more HBTs. The passive layer comprises a collector and an emitter pads. The first dielectric layer has one or more emitter and collector via holes. The emitter copper pillar is disposed on the emitter via hole and forms an electrical connection to the emitter electrode. The collector copper pillar is disposed on the collector redistribution layer and forms electrical connection to the collector electrode. The layout design of the emitter and collector copper pillars is therefore flexible, and the heat dissipation efficiency is improved.

Abstract: A layout structure of HBTs comprising one or more HBTs, each of which comprises a base electrode, an emitter electrode, and a collector electrode. A passive layer, a first dielectric layer, a collector redistribution layers, one or more emitter copper pillars, and one or more collector copper pillars are formed above the one or more HBTs. The passive layer comprises a collector and an emitter pads. The first dielectric layer has one or more emitter and collector via holes. The emitter copper pillar is disposed on the emitter via hole and forms an electrical connection to the emitter electrode. The collector copper pillar is disposed on the collector redistribution layer and forms electrical connection to the collector electrode. The layout design of the emitter and collector copper pillars is therefore flexible, and the heat dissipation efficiency is improved.

Abstract: A compound semiconductor integrated circuit with three-dimensionally formed components, such as three-dimensionally formed bond pads or inductors, positioned above an electronic device. The dielectric layer inserted between the electronic device and the bond pads or inductors thereon has a thickness between 10 to 30 microns, so that it can effectively mitigate the effect of the structure on the device performance. A SiN protection layer can be disposed to cover the electronic devices to prevent contamination from the bond pad or inductor material to the electronic device, and therefore the lower cost copper can be used as the bond pad and inductor material. The three-dimensional bond pad can be used in wire bonding or bump bonding technology.

Abstract: The present invention relates to a compound semiconductor integrated circuit chip having a front and/or back surface metal layer used for electrical connection to an external circuit. The compound semiconductor integrated circuit chip (first chip) comprises a substrate, an electronic device layer, and a dielectric layer. A first metal layer is formed on the front side of the dielectric layer, and a third metal layer is formed on the back side of the substrate. The first and third metal layer are made essentially of Cu and used for the connection to other electronic circuits. A second chip may be mounted on the first chip with electrical connection made with the first or the third metal layer that extends over the electronic device in the first chip in the three-dimensional manner to make the electrical connection between the two chips having connection nodes away from each other.

Abstract: A compound semiconductor integrated circuit is provided, comprising a substrate, at least one compound semiconductor electronic device, a first metal layer, a protection layer, a plurality of second metal layers, and at least one dielectric layer. The first metal layer contains Au but does not contain Cu, and is at least partly electrically connected to the compound semiconductor electronic device. The protection layer covers the compound semiconductor electronic device and at least part of the first metal layer. Each of the plurality of second metal layers contains at least a Cu layer, and at least one of the plurality of second metal layers is partly electrically connected to the first metal layer described above. The at least one dielectric layer separates each pair of adjacent second metal layers. The second metal layers are used to form passive electronic components.