A method for manufacturing a sputtering target with which an oxide semiconductor film with a small amount of defects can be formed is provided. Alternatively, an oxide semiconductor film with a small amount of defects is formed. A method for manufacturing a sputtering target is provided, which includes the steps of: forming a polycrystalline In-M-Zn oxide (M represents a metal chosen among aluminum, titanium, gallium, yttrium, zirconium, lanthanum, cesium, neodymium, and hafnium) powder by mixing, sintering, and grinding indium oxide, an oxide of the metal, and zinc oxide; forming a mixture by mixing the polycrystalline In-M-Zn oxide powder and a zinc oxide powder; forming a compact by compacting the mixture; and sintering the compact.

The present disclosure describes epitaxial oxide high electron mobility transistors (HEMTs). In some embodiments, a HEMT comprises: a substrate; a template layer on the substrate; a first epitaxial semiconductor layer on the template layer; and a second epitaxial semiconductor layer on the first epitaxial semiconductor layer. The template layer can comprise crystalline metallic Al(111). The first epitaxial semiconductor layer can comprise (Al.sub.xGa.sub.1-x).sub.yO.sub.z, wherein 0≤x≤1, 1≤y≤3, and 2≤z≤4, wherein the (Al.sub.xGa.sub.1-x).sub.yO.sub.z comprises a Pna21 space group, and wherein the (Al.sub.xGa.sub.1-x).sub.yO.sub.z comprises a first conductivity type formed via polarization. The second epitaxial semiconductor layer can comprise a second oxide material.

A nitride laminate, in which contamination in the nitride layer is suppressed and crystallinity is improved, is provided. A nitride laminate includes a polymer substrate, and a nitride layer provided on at least one of the surfaces of the polymer substrate. The nitride layer has a wurtzite crystal structure. The atomic proportion of oxygen in the nitride layer is 2.5 atm. % or less, and the atomic proportion of hydrogen in the nitride layer is 2.0 atm. % or less. The FWHM of the X-ray rocking curve of the nitride layer is 8 degree or less.

A metal oxide thin film transistor is provided and includes a gate, a gate insulating layer, an active layer and a source-drain metal layer stacked on a side of a backplane, the active layer and the gate are provided on both sides of the gate insulating layer, the source-drain metal layer is provided on a side of the active layer away from the backplane, the active layer includes: a first metal oxide semiconductor layer provided on a side of the gate insulating layer away from the gate; a second metal oxide semiconductor layer provided on a surface of the first metal oxide semiconductor layer away from the gate.

A method includes forming a 2-D material semiconductor layer over a substrate; forming source/drain electrodes covering opposite sides of the 2-D material semiconductor layer, while leaving a portion of the 2-D material semiconductor layer exposed by the source/drain electrodes; forming a first gate dielectric layer over the portion of the 2-D material semiconductor layer by using a physical deposition process; forming a second gate dielectric layer over the first gate dielectric layer by using a chemical deposition process, in which a thickness of the first gate dielectric layer is less than a thickness of the second gate dielectric layer; and forming a gate electrode over the second gate dielectric layer.

A more convenient and highly reliable semiconductor device which has a transistor including an oxide semiconductor with higher impact resistance used for a variety of applications is provided. A semiconductor device has a bottom-gate transistor including a gate electrode layer, a gate insulating layer, and an oxide semiconductor layer over a substrate, an insulating layer over the transistor, and a conductive layer over the insulating layer. The insulating layer covers the oxide semiconductor layer and is in contact with the gate insulating layer. In a channel width direction of the oxide semiconductor layer, end portions of the gate insulating layer and the insulating layer are aligned with each other over the gate electrode layer, and the conductive layer covers a channel formation region of the oxide semiconductor layer and the end portions of the gate insulating layer and the insulating layer and is in contact with the gate electrode layer.

Disclosed herein are a method of forming a transition metal dichalcogenide thin film and a method of manufacturing a device including the same. The method of forming a transition metal dichalcogenide thin film includes: providing a substrate in a reaction chamber; depositing a transition metal dichalcogenide thin film on the substrate using a sputtering process that uses a transition metal precursor and a chalcogen precursor and is performed at a first temperature; and injecting the chalcogen precursor in a gas state and heat-treating the transition metal dichalcogenide thin film at a second temperature that is higher than the first temperature. The substrate may include a sapphire substrate, a silicon oxide (SiO.sub.2) substrate, a nanocrystalline graphene substrate, or a molybdenum disulfide (MoS.sub.2) substrate.

A semiconductor device with low parasitic capacitance is provided. The semiconductor device includes a first oxide insulator, an oxide semiconductor, a second oxide insulator, a gate insulating layer, a gate electrode layer, source and drain electrode layers and an insulating layer. The oxide semiconductor includes first to fifth regions. The first region overlaps with the source electrode layer. The second region overlaps with the drain electrode layer. The third region overlaps with the gate electrode layer. The fourth region is between the first region and the third region. The fifth region is between the second region and the third region. The fourth region and the fifth region each contain an element N (N is hydrogen, nitrogen, helium, neon, argon, krypton, or xenon). A top surface of the insulating layer is positioned at a lower level than top surfaces of the source and drain electrode layers.

A semiconductor device with a small variation in transistor characteristics is provided. The semiconductor device includes an oxide semiconductor film, a source electrode and a drain electrode over the oxide semiconductor film, an interlayer insulating film placed to cover the oxide semiconductor film, the source electrode, and the drain electrode, a first gate insulating film over the oxide semiconductor film, a second gate insulating film over the first gate insulating film, and a gate electrode over the second gate insulating film. The interlayer insulating film has an opening overlapping with a region between the source electrode and the drain electrode, the first gate insulating film, the second gate insulating film, and the gate electrode are placed in the opening of the interlayer insulating film, the first gate insulating film includes oxygen and aluminum, and the first gate insulating film includes a region thinner that is than the second gate insulating film.

An InN nanorod epitaxial wafer grown on an aluminum foil substrate (1) sequentially comprises the aluminum foil substrate (1), an amorphous aluminum oxide layer (2), an AlN layer (3) and an InN nanorod layer, (4) from bottom to top. The wafer can be prepared by pretreating the aluminum foil substrate with an oxidized surface and carrying out an in-situ annealing treatment; then, in a molecular beam epitaxial growth process, forming AlN nucleation sites on the annealed aluminum foil substrate, nucleating on the AlN and growing InN nanorods on the AlN, where the substrate temperature is 400-700° C., the pressure of a reaction chamber is 4.0-10.0×10.sup.−5 Torr and the beam ratio of V/III is 20-40.