The present disclosure describes epitaxial oxide field effect transistors (FETs). In some embodiments, a FET comprises: a substrate comprising an oxide material; an epitaxial semiconductor layer on the substrate; a gate layer on the epitaxial semiconductor layer; and electrical contacts. In some cases, the epitaxial semiconductor layer can comprise a superlattice comprising a first and a second set of layers comprising oxide materials with a first and second bandgap. The gate layer can comprise an oxide material with a third bandgap, wherein the third bandgap is wider than the first bandgap. In some cases, the epitaxial semiconductor layer can comprise a second oxide material with a first bandgap, wherein the second oxide material comprises single crystal A.sub.xB.sub.1-xO.sub.n, wherein 0<x<1.0, wherein A is Al and/or Ga, wherein B is Mg, Ni, a rare earth, Er, Gd, Ir, Bi, or Li.

A semiconductor device includes semiconductor nanostructures disposed over a substrate, a source/drain epitaxial layer in contact with the semiconductor nanostructures, a gate dielectric layer disposed on and wrapping around each channel region of the semiconductor nanostructures, a gate electrode layer disposed on the gate dielectric layer and wrapping around each channel region, and insulating spacers disposed in spaces, respectively. The spaces are defined by adjacent semiconductor nanostructures, the gate electrode layer and the source/drain region. The source/drain epitaxial layer includes multiple doped SiGe layers having different Ge contents and at least one of the source/drain epitaxial layers is non-doped SiGe or Si.

A wafer includes a substrate and at least one intermediate layer formed on a surface of the substrate. The at least one intermediate layer covers the surface of the substrate at least partially. An outer surface of the at least one intermediate layer is directed away from the surface of the substrate. The wafer further includes nanostructures grown on the outer surface of the at least one intermediate layer. The at least one intermediate layer is formed in such a way that positions of growth of the nanostructures are predetermined on the outer surface of the at least one intermediate layer. At least one nanostructure material of the nanostructures is assembled at the positions of growth of the nanostructures.

Disclosed is a method for preparing a graphyne including: supplying a precursor represented by the following Chemical Formula 1 to a chamber including a first zone and a second zone; vaporizing or subliming the precursor in the first zone; and depositing the precursor vaporized or sublimed in the second zone on a metal substrate to form the graphyne:

##STR00001## (in Chemical Formula 1, X is carbon or nitrogen, and R.sub.1 to R.sub.3 may be selected from the group consisting of hydrogen, bromine, fluorine, chlorine, and iodine, respectively).

A method for forming a layer includes following operations. A workpiece is received in an apparatus for deposition. The apparatus for deposition includes a chamber, a pedestal disposed in the chamber to accommodate the workpiece, and a ring disposed on the pedestal. The ring includes a ring body having a first top surface and a second top surface and a barrier structure disposed between the first top surface and the second top surface. A vertical distance is defined by a top surface of the barrier structure and a top surface of the workpiece. The vertical distance is between approximately 0 mm and approximately 50 mm. A target disposed in the apparatus for deposition is sputtered. A sputtered material is deposited onto a top surface of the workpiece to form a layer. The barrier structure alters an electrical density distribution during the depositing the sputter material.

Energy bands of a thin film containing molecular clusters are tuned by controlling the size and the charge of the clusters during thin film deposition. Using atomic layer deposition, an ionic cluster film is formed in the gate region of a nanometer-scale transistor to adjust the threshold voltage, and a neutral cluster film is formed in the source and drain regions to adjust contact resistance. A work function semiconductor material such as a silver bromide or a lanthanum oxide is deposited so as to include clusters of different sizes such as dimers, trimers, and tetramers, formed from isolated monomers. A type of Atomic Layer Deposition system is used to deposit on semiconductor wafers molecular clusters to form thin film junctions having selected energy gaps. A beam of ions contains different ionic clusters which are then selected for deposition by passing the beam through a filter in which different apertures select clusters based on size and orientation.

A novel oxide semiconductor, a novel oxynitride semiconductor, a transistor including them, or a novel sputtering target is provided. A composite target includes a first region and a second region. The first region includes an insulating material and the second region includes a conductive material. The first region and the second region each include a microcrystal whose diameter is greater than or equal to 0.5 nm and less than or equal to 3 nm or a value in the neighborhood thereof. A semiconductor film is formed using the composite target.

A self-aligned short-channel SASC electronic device includes a first semiconductor layer formed on a substrate; a first metal layer formed on a first portion of the first semiconductor layer; a first dielectric layer formed on the first metal layer and extended with a dielectric extension on a second portion of the first semiconductor layer that extends from the first portion of the first semiconductor layer, the dielectric extension defining a channel length of a channel in the first semiconductor layer; and a gate electrode formed on the substrate and capacitively coupled with the channel. The dielectric extension is conformally grown on the first semiconductor layer in a self-aligned manner. The channel length is less than about 800 nm, preferably, less than about 200 nm, more preferably, about 135 nm.

A layer of amorphous Ge is formed on a substrate using electron-beam evaporation. The evaporation is performed at room temperature. The layer of amorphous Ge has a thickness of at least 50 nm and a purity of at least 90% Ge. The substrate is complementary metal-oxide-semiconductor (CMOS) compatible and is transparent at Long-Wave Infrared (LWIR) wavelengths. The layer of amorphous Ge can be used as a waveguide in chemical sensing and data communication applications. The amorphous Ge waveguide has a transmission loss in the LWIR of 11 dB/cm or less at 8 μm.

An object is to provide a display device which operates stably with use of a transistor having stable electric characteristics. In manufacture of a display device using transistors in which an oxide semiconductor layer is used for a channel formation region, a gate electrode is further provided over at least a transistor which is applied to a driver circuit. In manufacture of a transistor in which an oxide semiconductor layer is used for a channel formation region, the oxide semiconductor layer is subjected to heat treatment so as to be dehydrated or dehydrogenated; thus, impurities such as moisture existing in an interface between the oxide semiconductor layer and the gate insulating layer provided below and in contact with the oxide semiconductor layer and an interface between the oxide semiconductor layer and a protective insulating layer provided on and in contact with the oxide semiconductor layer can be reduced.