A fabrication method for a semiconductor device includes measuring a thickness of a semiconductor substrate in which a bulk donor of a first conductivity type is entirely distributed, adjusting an implantation condition in accordance with the thickness of the semiconductor substrate and implanting hydrogen ions from a lower surface of the semiconductor substrate to an upper surface side of the semiconductor substrate, and annealing the semiconductor substrate and forming, in a passage region through which the hydrogen ions have passed, a first high concentration region of the first conductivity type in which a donor concentration is higher than a doping concentration of the bulk donor.

A field effect transistor comprising: a first semiconductor structure, the first semiconductor structure having a channel layer; a second semiconductor structure, the second semiconductor structure is arranged on the first semiconductor structure, and the second semiconductor structure is stacked in sequence from bottom to top with a Schottky layer, a first etch stop layer, a wide recess layer, an ohmic contact layer, and a narrow recess, a wide recess is opened in the ohmic contact layer, so that the upper surface of the wide recess layer forms a wide recess area and the upper surface of the Schottky layer forms a narrow recess area; at least one delta-doped layer, a gate metal contact, the gate metal contact is formed inside the wide recess a source metal contact; and a drain metal contact, and the drain metal contact is located on the other side of the gate metal contact.

The present invention generally relates to nanoscale wires and, in particular, to nanoscale wires with heterojunctions, such as tip-localized homo- or heterojunctions. In one aspect, the nanoscale wire may include a core, an inner shell surrounding the core, and an outer shell surrounding the inner shell. The outer shell may also contact the core, e.g., at an end portion of the nanoscale wire. In some cases, such nanoscale wires may be used as electrical devices. For example a p-n junction may be created where the inner shell is electrically insulating, and the core and the outer shell are p-doped and n-doped. Other aspects of the present invention generally relate to methods of making or using such nanoscale wires, devices, or kits including such nanoscale wires, or the like.

A method of growing a conductive Ga.sub.2O.sub.3-based crystal film by MBE includes producing a Ga vapor and a Si-containing vapor and supplying the vapors as molecular beams onto a surface of a Ga.sub.2O.sub.3-based crystal substrate so as to grow the Ga.sub.2O.sub.3-based crystal film. The Ga.sub.2O.sub.3-based crystal film includes a Si-containing Ga.sub.2O.sub.3-based single crystal film. The Si-containing vapor is produced by heating Si or a Si compound and Ga while allowing the Si or a Si compound to contact with the Ga.

A semiconductor device includes a semiconductor body, an electrode provided on a surface of the semiconductor body. The semiconductor body includes a first semiconductor layer and a second semiconductor layer provided between the first semiconductor layer and the second electrode. The second semiconductor layer includes first and second regions arranged along the surface of the semiconductor body. The first region has a surface contacting the electrode, and the second region includes second conductivity type impurities with a concentration lower than a concentration of the second conductivity type impurities at the surface of the first region. The second semiconductor layer has a first concentration of second conductivity type impurities at a first position in the second region, and a second concentration of second conductivity type impurities at a second position between the first position and the electrode, the second concentration being lower than the first concentration.

A high-quality nitride crystal can be produced efficiently by charging a nitride crystal starting material that contains tertiary particles having a maximum diameter of from 1 to 120 mm and formed through aggregation of secondary particles having a maximum diameter of from 100 to 1000 μm, in the starting material charging region of a reactor, followed by crystal growth in the presence of a solvent in a supercritical state and/or a subcritical state in the reactor, wherein the nitride crystal starting material is charged in the starting material charging region in a bulk density of from 0.7 to 4.5 g/cm.sup.3 for the intended crystal growth.

A solar cell includes: a semiconductor substrate which includes a first principal surface and a second principal surface; a first semiconductor layer of the first conductivity type disposed above the first principal surface; and a second semiconductor layer of a second conductivity type disposed below the second principal surface. The semiconductor substrate includes: a first impurity region of the first conductivity type; a second impurity region of the first conductivity type disposed between the first impurity region and the first semiconductor layer; and a third impurity region of the first conductivity type disposed between the first impurity region and the second semiconductor layer. A concentration of an impurity in the second impurity region is higher than a concentration of the impurity in the third impurity region, and the concentration of the impurity in the third impurity region is higher than a concentration of the impurity in the first impurity region.

A semiconductor device having metamorphic high electron mobility transistor (HEMT)-heterojunction bipolar transistor (HBT) integration on a semiconductor substrate. An example semiconductor device generally includes a semiconductor substrate, a bipolar junction transistor (BJT) disposed above the semiconductor substrate and comprising indium, and a HEMT disposed above the semiconductor substrate and comprising indium.

A Group III-Nitride (III-N) device structure is presented comprising: a heterostructure having three or more layers comprising III-N material, a cathode comprising donor dopants, wherein the cathode is on a first layer of the heterostructure, an anode within a recess that extends through two or more of the layers of the heterostructure, wherein the anode comprises a first region wherein the anode is separated from the heterostructure by a high k dielectric material, and a second region wherein the anode is in direct contact with the heterostructure, and a conducting region in the first layer in direct contact to the cathode and conductively connected to the anode. Other embodiments are also disclosed and claimed.

A fabrication method for a semiconductor device includes measuring a thickness of a semiconductor substrate in which a bulk donor of a first conductivity type is entirely distributed, adjusting an implantation condition in accordance with the thickness of the semiconductor substrate and implanting hydrogen ions from a lower surface of the semiconductor substrate to an upper surface side of the semiconductor substrate, and annealing the semiconductor substrate and forming, in a passage region through which the hydrogen ions have passed, a first high concentration region of the first conductivity type in which a donor concentration is higher than a doping concentration of the bulk donor.