Abstract: Composite substrates are produced that include a strained III-nitride material seed layer on a support substrate. Methods of producing the composite substrate include developing a desired lattice strain in the III-nitride material to produce a lattice parameter substantially matching a lattice parameter of a device structure to be formed on the composite substrate. The III-nitride material may be formed with a Ga polarity or an N polarity. The desired lattice strain may be developed by forming a buffer layer between the III-nitride material and a growth substrate, implanting a dopant in the III-nitride material to modify its lattice parameter, or forming the III-nitride material with a coefficient of thermal expansion (CTE) on a growth substrate with a different CTE.

Abstract: A group 13 nitride crystal having a hexagonal crystal structure contains at least a nitrogen atom and at least one metal atom selected from a group consisting of B, Al, Ga, In and Tl. Dislocation density of basal plane dislocations in a cross section parallel to a c-axis is 104 cm?2 or more.

Abstract: There are provided a group III nitride semiconductor light emitting device which is constituted of a substrate, an intermediate layer formed thereon having a favorable level of orientation properties, and a group III nitride semiconductor formed thereon having a favorable level of crystallinity, and having excellent levels of light emitting properties and productivity; a production method thereof; and a lamp, the group III nitride semiconductor light emitting device configured so that at least an intermediate layer 12 composed of a group III nitride compound is laminated on a substrate 11, and an n-type semiconductor layer 14 having a base layer 14a, a light emitting layer 15 and a p-type semiconductor layer 16 are sequentially laminated on the intermediate layer 12, wherein when components are separated, based on a peak separation technique using an X-ray rocking curve of the intermediate layer 12, into a broad component having the full width at half maximum of 720 arcsec or more and a narrow component,

Abstract: Methods for integrating wide-gap semiconductors, and specifically, gallium nitride epilayers with synthetic diamond substrates are disclosed. Diamond substrates are created by depositing synthetic diamond onto a nucleating layer deposited or formed on a layered structure that comprises at least one layer made out of gallium nitride. Methods for manufacturing GaN-on-diamond wafers with low bow and high crystalline quality are disclosed along with preferred choices for manufacturing GaN-on-diamond wafers and chips tailored to specific applications.

Abstract: Objects of the present invention are to provide a method for producing a Group III nitride semiconductor single crystal, which method enables production of a Group III nitride semiconductor single crystal having a flat surface by means of a crucible having any inside diameter; to provide a self-standing substrate obtained from the Group III nitride semiconductor single crystal; and to provide a semiconductor device employing the self-standing substrate. The production method includes adding the template, a flux, and semiconductor raw materials to a crucible and growing a Group III nitride semiconductor single crystal while the crucible is rotated. In the growth of the semiconductor single crystal, the crucible having an inside diameter R (mm) is rotated at a maximum rotation speed ? (rpm) satisfying the following conditions: ?1?4????1+4; ?1=10z; and z=?0.78×log10(R)+3.1.

Abstract: A method of forming a semiconductor thin film structure and a semiconductor thin film structure formed using the same is provided. A sacrificial layer is formed on a substrate and then patterned through various methods, an inorganic thin film is formed on the sacrificial layer and then the sacrificial layer is selectively removed to form a cavity defined by the substrate and the inorganic thin film on the substrate.

Abstract: There is provided a group III nitride semiconductor crystal, containing a donor-type impurity and having a hydrogen concentration of 2.0E+16 cm?3 or less in a crystal.

Abstract: Films of III-nitride for semiconductor device growth are planarized using an etch-back method. The method includes coating a III-nitride surface having surface roughness features in the micron range with a sacrificial planarization material such as an appropriately chosen photoresist. The sacrificial planarization material is then etched together with the III-nitride roughness features using dry etch methods such as inductively coupled plasma reactive ion etching. By closely matching the etch rates of the sacrificial planarization material and the III-nitride material, a planarized III-nitride surface is achieved. The etch-back process together with a high temperature annealing process yields a planarized III-nitride surface with surface roughness features reduced to the nm range. Planarized III-nitride, e.g., GaN, substrates and devices containing them are also provided.

Abstract: A method and apparatus for depositing III-V material is provided. The apparatus includes a reactor partially enclosed by a selectively permeable membrane 12. A means is provided for generating source vapors, such as a vapor-phase halide of a group III element (IUPAC group 13) within the reactor volume 10, and an additional means is also provided for introducing a vapor-phase hydride of a group V element (IUPAC group 15) into the volume 10. The reaction of the group III halide and the group V hydride on a temperature-controlled substrate 18 within the reactor volume 10 produces crystalline III-V material and hydrogen gas. The hydrogen is preferentially removed from the reactor through the selectively permeable membrane 12, thus avoiding pressure buildup and reaction imbalance. Other gases within the reactor are unable to pass through the selectively permeable membrane.

Abstract: A nitride semiconductor light-emitting chip offers enhanced luminous efficacy as a result of an improved EL emission pattern. The nitride semiconductor laser chip (nitride semiconductor light-emitting chip) has a nitride semiconductor substrate having a principal growth plane, and nitride semiconductor layers grown on the principal growth plane of the nitride semiconductor substrate. The principal growth plane of the GaN substrate is a plane having off-angles in both the a- and c-axis directions relative to an m plane, and the off-angle in the a-axis direction is larger than the off-angle in the c-axis direction.

Abstract: A method of forming a group III nitride semiconductor comprises: preparing a group III nitride semiconductor which contains a p-type dopant or an n-type dopant; and performing a treatment of the group III nitride semiconductor by using a reducing gas and a nitrogen source gas to form a conductive group III nitride semiconductor. The treatment includes performing a first treatment of the group III nitride semiconductor by using a first treatment gas including the reducing gas and the nitrogen source gas, which are supplied to a treatment apparatus at a first flow rate and a second flow rate, respectively, and after the first treatment is performed, performing a second treatment of the group III nitride semiconductor by using a second treatment gas including the reducing gas and the nitrogen source gas, which are supplied to the treatment apparatus at a third flow rate and a fourth flow rate, respectively.

Abstract: A method of manufacturing a semiconductor layer with which inactivation of impurity is able to be inhibited by a simple method, a semiconductor layer in which inactivation of impurity is inhibited, a method of manufacturing a laser diode with which inactivation of impurity is able to be inhibited by a simple method, and a laser diode including a semiconductor layer in which inactivation of impurity is inhibited are provided. In the method of manufacturing a semiconductor layer, after a semiconductor layer is formed by epitaxial growth with the use of AsH3, supply of AsH3 is stopped without separately supplying new gas when process temperature is 500 deg C. or more.

Abstract: A complementary metal oxide semiconductor (CMOS) device in which a single InxGa1-xSb quantum well serves as both an n-channel and a p-channel in the same device and a method for making the same. The InxGa1-xSb layer is part of a heterostructure that includes a Te-delta doped AlyGa1-ySb layer above the InxGa1-xSb layer on a portion of the structure. The portion of the structure without the Te-delta doped AlyGa1-ySb barrier layer can be fabricated into a p-FET by the use of appropriate source, gate, and drain terminals, and the portion of the structure retaining the Te-delta doped AlyGa1-ySb layer can be fabricated into an n-FET so that the structure forms a CMOS device, wherein the single InxGa1-xSb quantum well serves as the transport channel for both the n-FET portion and the p-FET portion of the heterostructure.

Abstract: There is provided a method of forming a nitride semiconductor layer, including the steps of firstly providing a substrate on which a patterned epitaxy layer with a pier structure is formed. A protective layer is then formed on the patterned epitaxy layer, exposing a top surface of the pier structure. Next, a nitride semiconductor layer is formed over the patterned epitaxy layer connected to the nitride semiconductor layer through the pier structure, wherein the nitride semiconductor layer, the pier structure, and the patterned epitaxy layer together form a space exposing a bottom surface of the nitride semiconductor layer. Thereafter, a weakening process is performed to remove a portion of the bottom surface of the nitride semiconductor layer and to weaken a connection point between the top surface of the pier structure and the nitride semiconductor layer. Finally, the substrate is separated from the nitride semiconductor layer through the connection point.

Abstract: Provided is a high-quality Group III nitride crystal of excellent processability. A Group III nitride crystal is produced by forming a film is composed of an oxide, hydroxide and/or oxyhydroxide containing a Group III element by heat-treating a Group III nitride single crystal at 1000° C. or above, and removing the film.

Abstract: A method for growing reduced defect density planar gallium nitride (GaN) films is disclosed. The method includes the steps of (a) growing at least one silicon nitride (SiNx) nanomask layer over a GaN template, and (b) growing a thickness of a GaN film on top of the SiNx nanomask layer.

Abstract: A nitride semiconductor substrate is provided in which leak current reduction and improvement in current collapse are effectively attained when using Si single crystal as a base substrate. The nitride semiconductor substrate is such that an active layer of a nitride semiconductor is formed on one principal plane of a Si single crystal substrate through a plurality of buffer layers made of a nitride, in the buffer layers, a carbon concentration of a layer which is in contact with at least the active layer is from 1×1018 to 1×1020 atoms/cm3, a ratio of a screw dislocation density to the total dislocation density is from 0.15 to 0.3 in an interface region between the buffer layer and the active layer, and the total dislocation density in the interface region is 15×109 cm?2 or less.

Abstract: III-N material grown on a silicon substrate includes a single crystal rare earth oxide layer positioned on a silicon substrate. The rare earth oxide is substantially crystal lattice matched to the surface of the silicon substrate. A first layer of III-N material is positioned on the surface of the rare earth oxide layer. An inter-layer of aluminum nitride (AlN) is positioned on the surface of the first layer of III-N material and an additional layer of III-N material is positioned on the surface of the inter-layer of aluminum nitride. The inter-layer of aluminum nitride and the additional layer of III-N material are repeated n-times to reduce or engineer strain in a final III-N layer.

Abstract: The purpose of the present invention is to provide a good ohmic contact for an n-type Group-III nitride semiconductor. An n-type GaN layer and a p-type GaN layer are aequentially formed on a lift-off layer (growth step). A p-side electrode is formed on the top face of the p-type GaN layer. A copper block is formed over the entire area of the top face through a cap metal. Then, the lift-off layer is removed by making a chemical treatment (lift-off step). Then, a laminate structure constituted by the n-type GaN layer, with which the surface of the N polar plane has been exposed, and the p-type GaN layer is subjected to anisotropic wet etching (surface etching step). The N-polar surface after the etching has irregularities constituted by {10-1-1} planes. Then, an n-side electrode is formed on the bottom face of the n-type GaN layer (electrode formation step).

Abstract: The present disclosure provides a semiconductor structure. The semiconductor structure includes a dielectric material layer on a silicon substrate, the dielectric material layer being patterned to define a plurality of regions separated by the dielectric material layer; a first buffer layer disposed on the silicon substrate; a heterogeneous buffer layer disposed on the first buffer layer; and a gallium nitride layer grown on the heterogeneous buffer layer only within the plurality of regions.

Abstract: A group III nitride semiconductor substrate production method includes preparing a bulk crystal formed of a group III nitride semiconductor single crystal. The group III nitride semiconductor single crystal has one crystalline plane and an other crystalline plane. Hardness of the other crystalline plane is smaller than hardness of the one crystalline plane. The prepared bulk crystal is cut from the other crystalline plane to the one crystalline plane of the bulk crystal.

Abstract: Embodiments are directed to glass-ceramic substrates with a III-V semiconductor layer, for example, a GaN layer that can be used in LED lighting devices. The glass-ceramics material is in the anorthite-rutile (CaAl2Si2O8+TiO2) family or in the cordierite-enstatite (SiO2—Al2O3—MgO—TiO2) family.

Abstract: An n-type GaN layer (3), a GaN layer (7) formed over the n-type GaN layer (3), an n-type AlGaN layer (9) formed over the GaN layer (7), a gate electrode (15) and a source electrode (13) formed over the n-type AlGaN layer (9), a drain electrode (14) formed below the n-type GaN layer (3), and a p-type GaN layer (4) formed between the GaN layer (7) and the drain electrode (14) are provided.

Abstract: A field effect transistor includes a nitride-based semiconductor multi-layer structure, a source electrode (108), a drain electrode (109), a protective film (110), and a gate electrode (112) that is provided in a recess structure, which is formed by etching, directly or with a gate insulating film interposed therebetween. The nitride-based semiconductor multi-layer structure includes at least a base layer (103) made of AlXGa1-XN (0?1), a channel layer (104) made of GaN or InGaN, a first electron supply layer (105), which is an undoped or n-type AlYGa1-YN layer, a threshold value control layer (106), which is an undoped AlZGa1-ZN layer, and a second electron supply layer (107), which is an undoped or n-type AlWGa1-WN layer, epitaxially grown in this order on a substrate (101) with a buffer layer (102) interposed therebetween. The Al composition of each layer in the nitride-based semiconductor multi-layer structure satisfies 0<X?Y?1 and 0<Z?Y?1.

Abstract: A method of forming a semiconductor device that includes providing a first strained layer of a first composition semiconductor material over a dielectric layer. A first portion of the layer of the first composition semiconductor material is etched or implanted to form relaxed islands of the first composition semiconductor material. A second composition semiconductor material is epitaxially formed over the relaxed island of the first composition semiconductor material. The second composition semiconductor material is intermixed with the relaxed islands of the first composition semiconductor material to provide a second strained layer having a different strain than the first strained layer.

Abstract: A stacking fault and twin blocking barrier for forming a III-V device layer on a silicon substrate and the method of manufacture is described. Embodiments of the present invention enable III-V InSb device layers with defect densities below 1×108 cm?2 to be formed on silicon substrates. In an embodiment of the present invention, a buffer layer is positioned between a III-V device layer and a silicon substrate to glide dislocations. In an embodiment of the present invention, GaSb buffer layer is selected on the basis of lattice constant, band gap, and melting point to prevent many lattice defects from propagating out of the buffer into the III-V device layer. In a specific embodiment, a III-V InSb device layer is formed directly on the GaSb buffer.

Abstract: Provided is a semiconductor wafer including a base wafer, a first insulating layer, and a semiconductor layer. Here, the base wafer, the first insulating layer and the semiconductor layer are arranged in an order of the base wafer, the first insulating layer and the semiconductor layer, the first insulating layer is made of an amorphous metal oxide or an amorphous metal nitride, the semiconductor layer includes a first crystal layer and a second crystal layer, the first crystal layer and the second crystal layer are arranged in an order of the first crystal layer and the second crystal layer in such a manner that the first crystal layer is positioned closer to the base wafer, and the electron affinity Ea1 of the first crystal layer is larger than the electron affinity Ea2 of the second crystal layer.

Abstract: Toward making available III nitride crystal substrates advantageously employed in light-emitting devices, and light-emitting devices incorporating the substrates, a III nitride crystal substrate has a major face whose surface area is not less than 10 cm2 and is characterized by: edge dislocations in the crystal being concentrated along propagation lines forming an angle of some 0° to 5° with a given {0001} plane of the crystal; screw dislocations in the crystal being concentrated along propagation lines forming an angle of some 45° to 60° with the given {0001} plane; and in a major-face principal region excluding the peripheral margin of the major face from its outer periphery to a 5 mm separation from its outer periphery, the total dislocation density being between 1×104 cm?2 to 3×106 cm?2 inclusive, and the ratio of screw-dislocation density to the total dislocation density being 0.5 or greater.

Abstract: Affords nitride semiconductor crystal manufacturing apparatuses that are durable and that are for manufacturing nitride semiconductor crystal in which the immixing of impurities from outside the crucible is kept under control, and makes methods for manufacturing such nitride semiconductor crystal, and the nitride semiconductor crystal itself, available. A nitride semiconductor crystal manufacturing apparatus (100) is furnished with a crucible (101), a heating unit (125), and a covering component (110). The crucible (101) is where, interiorly, source material (17) is disposed. The heating unit (125) is disposed about the outer periphery of the crucible (101), where it heats the crucible (101) interior. The covering component (110) is arranged in between the crucible (101) and the heating unit (125).

Abstract: Described herein is a method for growing indium nitride (InN) materials by growing hexagonal and/or cubic InN using a pulsed growth method at a temperature lower than 300° C. Also described is a material comprising InN in a face-centered cubic lattice crystalline structure having an NaCl type phase.

Abstract: In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

Abstract: A device includes providing a silicon substrate; annealing the silicon substrate at a first temperature higher than about 900° C.; and lowering a temperature of the silicon substrate from the first temperature to a second temperature. A temperature lowering rate during the step of lowering the temperature is greater than about 1° C./second. A III-V compound semiconductor region is epitaxially grown on a surface of the silicon substrate using metal organic chemical vapor deposition (MOCVD).

Abstract: The object of the invention is to provide a method for fabricating a semiconductor device having a peeled layer bonded to a base material with curvature. Particularly, the object is to provide a method for fabricating a display with curvature, more specifically, a light emitting device having an OLED bonded to a base material with curvature. An external force is applied to a support originally having curvature and elasticity, and the support is bonded to a peeled layer formed over a substrate. Then, when the substrate is peeled, the support returns into the original shape by the restoring force, and the peeled layer as well is curved along the shape of the support. Finally, a transfer object originally having curvature is bonded to the peeled layer, and then a device with a desired curvature is completed.

Abstract: Various embodiments provide methods for forming a diamond heat spreader and integrating the diamond heat spreader with a heat source without generating voids at the interface. In one embodiment, a semiconductor layer can be epitaxially formed on a diamond substrate having a desirably low surface root mean square (RMS) roughness. The semiconductor epi-layer can be used as an interface layer for bonding the diamond substrate to the heat source to provide efficient heat spreading.

Abstract: The method for producing a group III nitride semiconductor crystal comprises preparing a seed crystal having a non-polar plane followed by growing a group III nitride semiconductor from the non-polar plane in a vapor phase, wherein the growing includes growing the group III nitride semiconductor so as to extend in the +C-axis direction of the seed crystal. A group III-V nitride semiconductor crystal having high quality and a large-area non-polar plane can be obtained by the method.

Abstract: A GaN single crystal substrate has a main surface with an area of not less than 10 cm2, the main surface has a plane orientation inclined by not less than 65° and not more than 85° with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5×10?5, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25° C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

Abstract: A method of manufacturing is disclosed. An exemplary method includes providing a substrate and forming one or more layers over the substrate. The method further includes forming a surface layer over the one or more layers. The method further includes performing a patterning process on the surface layer thereby forming a pattern on the surface layer. The method further includes performing a cleaning process using a cleaning solution to clean a top surface of the substrate. The cleaning solution includes tetra methyl ammonium hydroxide (TMAH), hydrogen peroxide (H2O2) and water (H2O).

Abstract: According to one embodiment, a semiconductor light-emitting device includes: a first conductivity type first semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in a (0001) surface; a second conductivity type second semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in the (0001) surface; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, containing a nitride semiconductor crystal, and having an average lattice constant larger than the lattice constant of the first semiconductor layer; and a first stress application layer provided on a side opposite to the light emitting layer of the first semiconductor layer and applying a compressive stress to the first semiconductor layer.

Abstract: The present disclosure relates generally to semiconductor techniques. More specifically, embodiments of the present disclosure provide methods for efficiently dicing substrates containing gallium and nitrogen material. Additionally the present disclosure provide techniques resulting in a optical device comprising a substrate having three or more corners, where at least one of the corners is defined by a dislocation bundle characterized by a diameter of less than 100 microns, the gallium and nitrogen containing substrate having a predefined portion free from dislocation bundle centers, an active region containing one or more active layers, the active region being positioned within the predefined region; and a conductive region formed within the predefined region.

Abstract: Methods and apparatus for depositing thin films incorporating the use of a surfactant are described. Methods and apparatuses include a deposition process and system comprising multiple isolated processing regions which enables rapid repetition of sub-monolayer deposition of thin films. The use of surfactants allows the deposition of high quality epitaxial films at lower temperatures having low values of surface roughness. The deposition of Group III-V thin films such as GaN is used as an example.

Abstract: A gallium nitride based semiconductor device is provided which includes a gallium nitride based semiconductor film with a flat c-plane surface provided on a gallium oxide wafer. A light emitting diode LED includes a gallium oxide support base 32 having a primary surface 32a of monoclinic gallium oxide, and a laminate structure 33 of Group III nitride. A semiconductor mesa of the laminate structure 33 includes a low-temperature GaN buffer layer 35, an n-type GaN layer 37, an active layer 39 of a quantum well structure, and a p-type gallium nitride based semiconductor layer 37. The p-type gallium nitride based semiconductor layer 37 includes, for example, a p-type AlGaN electron block layer and a p-type GaN contact layer. The primary surface 32a of the gallium oxide support base 32 is inclined at an angle of not less than 2 degrees and not more than 4 degrees relative to a (100) plane of monoclinic gallium oxide.

Abstract: The present invention provides a substrate formed at a low cost and having a controlled plate shape, an epitaxial layer provided substrate obtained by forming an epitaxial layer on the substrate, and methods for producing them. The method for producing the substrate according to the present invention includes an ingot growing step serving as a step of preparing an ingot formed of gallium nitride (GaN); and a slicing step serving as a step of obtaining a substrate formed of gallium nitride, by slicing the ingot. In the slicing step, the substrate thus obtained by the slicing has a main surface with an arithmetic mean roughness Ra of not less than 0.05 ?m and not more than 1 ?m on a line of 10 mm.

Abstract: A nitride light emitting diode, on a patterned substrate, comprising a nitride interlayer having at least two periods of alternating layers of InxGa1-xN and InyGa1-yN where 0<x<1 and 0?y<1, and a nitride based active region having at least one quantum well structure on the nitride interlayer.

Abstract: A method for fabricating edge termination structures in gallium nitride (GaN) materials includes providing a n-type GaN substrate having a first surface and a second surface, forming an n-type GaN epitaxial layer coupled to the first surface of the n-type GaN substrate, and forming a growth mask coupled to the n-type GaN epitaxial layer. The method further includes patterning the growth mask to expose at least a portion of the n-type GaN epitaxial layer, and forming at least one p-type GaN epitaxial structure coupled to the at least a portion of the n-type GaN epitaxial layer. The at least one p-type GaN epitaxial structure comprises at least one portion of an edge termination structure. The method additionally includes forming a first metal structure electrically coupled to the second surface of the n-type GaN substrate.

Abstract: The invention relates to a free-standing semiconductor substrate as well as a process and a mask layer for the manufacture of a free-standing semiconductor substrate, wherein the material for forming the mask layer consists at least partially of tungsten silicide nitride or tungsten silicide and wherein the semiconductor substrate self-separates from the starting substrate without further process steps.

Abstract: A nitride semiconductor substrate includes two principal surfaces including an upper surface that is a growth face and a lower surface on its opposite side. An FWHM in a surface layer region at depths of from 0 to 250 nm from the upper surface is narrower than an FWHM in an inner region at depths exceeding 5 ?m from the upper surface, where the FWHMs are obtained by X-ray rocking curve measurement using diffraction off a particular asymmetric plane inclined relative to the upper surface.

Abstract: A compound semiconductor device is provided with a first nitride semiconductor layer of a first conductivity type, a second nitride semiconductor layer of the first conductivity type which is formed over the first nitride semiconctor layer and being in contact with the first nitride semiconductor layer, a third nitride semiconductor layer of a second conductivity type being in contact with the second nitride semiconductor layer, a fourth nitride semiconductor layer of the first conductivity type being in contact with the third nitride semiconductor layer, and an insulating film insulating the first nitride semiconductor layer and the fourth nitride, semiconductor layer from each other. A source electrode is positioned inside an Outer edge of the insulating film in planar view.

Abstract: A semiconductor device includes a semiconductor element having a substrate of GaAs, InP, or GaN, and an element securing member bonded to the semiconductor element by solder. The element securing member is a composite material of Cu and carbon or a composite of Al and carbon.

Abstract: A first AlGaN layer formed over a substrate, a second AlGaN layer formed over the first AlGaN layer, an electron transit layer formed over the second AlGaN layer, and an electron supply layer formed over the electron transit layer are provided. A relationship of “0?x1<x2?1” is found when a composition of the first AlGaN layer is represented by Alx1Ga1-x1N, and a composition of the second AlGaN layer is represented by Alx2Ga1-x2N. Negative charges exist at an upper surface of the AlGaN layer more than positive charges existing at a lower surface of the AlGaN layer.

Abstract: A semiconductor device includes a substrate having first main face having rectangular shape, a first electrode provided at the center on first main face of substrate, first electrode is made of conducting material harder than substrate, and a second electrode provided along at least a part of the periphery on first main face so as to surround first electrode, second electrode is integrated with first electrode by the same conducting material as that of the first electrode, and second electrode has a thinner film thickness than that of the first electrode.