Class 257/E29.247 - With inverted single heterostructure (i.e., with active layer formed on top of wide bandgap layer (e.g., IHEMT)) (EPO)

Subclass of Class 257 - Active solid-state devices (e.g., transistors, solid-state diodes)
Definition: This subclass is indented under subclass E29.246. This subclass
No. of patents: 21
Last issue date: 10/07/2008

Number	Title	Issue Date
7432538	Field-effect transistor A field-effect transistor includes a channel layer having a channel and a carrier supply layer, disposed on the channel layer, containing a semiconductor represented by the formula AlxGa1-xN, wherein x is greater than 0.04 and less than 0.45. T...	10/07/2008
7361536	Method of fabrication of a field effect transistor with materialistically different two etch stop layers in an enhanced mode transistor and an depletion mode transistor A semiconductor structure a structure with an enhancement mode transistor device disposed in a first region and depletion mode transistor device disposed in a laterally displaced second region. The structure has a channel layer for the depletion mode and enhancement...	04/22/2008
7268375	Inverted nitride-based semiconductor structure A nitride-based semiconductor structure is provided. The structure includes an active layer that comprises an inverted quantum well structure that includes Indium and Nitrogen. The structure can be used to create a field effect transistor. In this case, the active l...	09/11/2007
7199408	Semiconductor multilayer structure, semiconductor device and HEMT device A semiconductor device includes an underlying layer made of a group-III nitride containing at least Al and formed on a substrate, and a group of stacked semiconductor layers including a first semiconductor layer made of a group-III nitride, preferably GaN, a second ...	04/03/2007
6147370	Field effect transistor with first and second drain electrodes To enhance a drain current voltage characteristics of a compound semiconductor field effect transistor, an n-GaAs substrate is used. After forming an n- -GaAs layer and an i-AlGaAs layer successively on the substrate, an n-type transistor is fo...	11/14/2000
5932889	Semiconductor device with floating quantum box An undoped Al0.22 Ga0.78 As spacer layer having a large forbidden bandgap and an N-Al0.22 Ga0.78 As electron-supplying layer having a large forbidden bandgap are formed in order on an undoped GaAs buffer layer h...	08/03/1999
5698868	High-speed heterojunction transistor A high-speed heterojunction transistor includes a first region for controlling current, and a second region for receiving carriers which have passed the first region. An energy level difference between a lowermost valley of energy and an upper valley of e...	12/16/1997
5322808	Method of fabricating inverted modulation-doped heterostructure A donor layer (17) including an undoped wide bandgap material (14) and an n-type dopant (16) is deposited on a substrate (12) by molecular beam epitaxy (MBE) at a first temperature which is high enough for optimal growth of the donor layer (17). The dopan...	06/21/1994
5285088	High electron mobility transistor A semiconductor device capable of reducing element sizes exceedingly and a mask alignment accuracy in lithography is provided. This device has a pair of semiconductor layers for source/drain electrodes formed on the field insulating film so as to be respe...	02/08/1994
5272365	Silicon transistor device with silicon-germanium electron gas hetero structure channel A metal oxide semiconductor field effect transistor with heterostructure has a silicon substrate. Heavily-doped source and drain layers which are different in conductivity type from the substrate are spaced apart from each other in the surface portion of ...	12/21/1993
5266506	Method of making substantially linear field-effect transistor An FET with multiple channels to provide a substantially linear transfer characteristic. The widths and carrier concentrations of the channels, and the depths of the channels below the gate of the FET, are adjusted such that a substantially linear gate vo...	11/30/1993
5223724	Multiple channel high electron mobility transistor An FET with multiple channels to provide a substantially linear transfer characteristic. The widths and carrier concentrations of the channels, and the depths of the channels below the gate of the FET, are adjusted such that a substantially linear gate vo...	06/29/1993
4885614	Semiconductor device with crystalline silicon-germanium-carbon alloy The present invention discloses a semiconductor device comprising a semiconductor layer being made of monocrystalline silicon or silicon-germanium alloy and a semiconductor layer being made of silicon-germanium-carbon alloy formed thereon, wherein the two...	12/05/1989
4792832	Superlattice semiconductor having high carrier density The superlattice type semiconductor material has a multilayered structure of first layers of semiconductor containing impurities and having a thickness thinner than electron or hole wavelength and second layers of semiconductor free from impurities or ins...	12/20/1988
4755857	Heterostructure semiconductor device A heterostructure semiconductor device as a Schottky gate field-effect tristor comprises a semiconductor body including first and second layers made of different semiconductor materials, as gallium arsenide and aluminium gallium arsenide. A narrow hetero...	07/05/1988
4714948	HEMT with epitaxial narrow bandgap source/drain contacts isolated from wide bandgap layer The present invention is related to an improvement of a high-electron mobility transistor (HEMT) which has an undoped GaAs layer and an N-doped AlGaAs layer a heterojunction formed between the undoped GaAs layer and the N-doped AlGaAs layer, respectively ...	12/22/1987
4695857	Superlattice semiconductor having high carrier density The superlattice type semiconductor material has a multilayered structure of first layers of semiconductor containing impurities and having a thickness thinner than electron or hole wavelength and second layers of semiconductor free from impurities or ins...	09/22/1987
4673959	Heterojunction FET with doubly-doped channel There is disclosed a semiconductor device comprising at least first and second semiconductor layers positioned to form a hetero-junction therebetween, such a hetero-junction being adapted to form a channel, means for controlling carriers, and source and d...	06/16/1987
4499481	Heterojunction Schottky gate MESFET with lower channel ridge barrier An FET with an extremely short channel formed by the apex of a substrate ridge structure protruding upward through the channel layer toward a Schottky-barrier gate contact. The device is formed by etching a modulation-doped substrate to form an upwardly p...	02/12/1985
4455564	Field effect transistor with a high cut-off frequency The invention relates to semiconductor devices of the transistor type operating at high frequencies. In order to make the drain/source current characteristic linear with the voltage applied to the grid and in order to retain a construction technology whic...	06/19/1984
4424525	High electron mobility single heterojunction semiconductor devices A thin electron accumulation layer is generated along a heterojunction between two kinds of semiconductors each of which has a different electron affinity. This electron accumulation layer suffers less ionized-impurity scattering, because the thickness do...	01/03/1984

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Class 257/E29.247 - With inverted single heterostructure (i.e., with active layer formed on top of wide bandgap layer (e.g., IHEMT)) (EPO)