A device includes a semiconductor substrate containing gallium nitride and having a crystal face inclined from 0.05° to 15° inclusive with respect to the c-plane. The semiconductor substrate includes an irregular portion on the crystal face, and the contact angle of pure water having a specific resistance of 18 MΩ.Math.cm or more on the surface of the irregular portion is 10° or less.

A method for fabricating thin-film optoelectronic devices (100), the method comprising: providing a alkali-nondiffusing substrate (110), forming a back-contact layer (120); forming at least one absorber layer (130) made of an ABC chalcogenide material, adding least one and advantageously at least two different alkali metals, and forming at least one front-contact layer (150) wherein one of said alkali metals comprise Rb and/or Cs and where, following forming said front-contact layer, in the interval of layers (470) from back-contact layer (120), exclusive, to front-contact layer (150), inclusive, the comprised amounts resulting from adding alkali metals are, for Rb and/or Cs, in the range of 500 to 10000 ppm and, for the other alkali metals, typically Na or K, in the range of 5 to 2000 ppm and at most ½ and at least 1/2000 of the comprised amount of Rb and/or Cs. The method (200) is advantageous for more environmentally-friendly production of photovoltaic devices on flexible substrates with high photovoltaic conversion efficiency and faster production rate.

A stacked body includes: a substrate made of silicon carbide and having a first main surface forming an angle of 20° or less with a silicon plane; and a graphene film disposed on the first main surface and having an atomic arrangement oriented in relation to an atomic arrangement of silicon carbide forming the substrate. In an exposed surface of the graphene film which is a main surface opposite to the substrate, an area ratio of a region having a full width at half maximum of G′ of 40 cm.sup.−1 or less under Raman spectroscopy analysis is 50% or more. Accordingly, the stacked body is provided that enables a high mobility to be stably ensured in an electronic device manufactured to include the graphene film forming an electrically conductive portion.

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.

A non-planar semiconductor structure includes raised semiconductor structures, e.g., fins, having epitaxial structures grown on top surfaces thereof, for example, epitaxial silicon naturally growing into a diamond shape. The surface area of the epitaxial structure may be increased by removing portion(s) thereof. The removal may create a multi-head (e.g., dual-head) epitaxial structure, together with the neck of the raised structure resembling a Y-shape. Raised structures that are not intended to include an epitaxial structure will be masked during epitaxial structure creation and modification. In addition, in order to have a uniform height, the filler material surrounding the raised structures is recessed around those to receive epitaxial structures.

It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region using an oxide semiconductor layer, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer.

Methods for reducing surface roughness of germanium are described herein. In some embodiments, the surface roughness is reduced by thermal oxidation of germanium. In some embodiments, the surface roughness is further reduced by controlling a rate of the thermal oxidation. In some embodiments, the surface roughness is reduced by thermal annealing.

This disclosure provides apparatuses and methods of manufacturing apparatuses including thin film transistors (TFTs) and storage capacitors. An apparatus can include a substrate, a TFT, a storage capacitor adjacent to the TFT, and a common electrode. The storage capacitor can be substantially transparent to increase aperture ratio of a display device. The storage capacitor can include an insulating layer between a first transparent electrode and a second transparent electrode. The TFT can include a gate electrode, a gate insulating layer, an oxide semiconductor, source and drain electrodes, and a dielectric layer. The oxide semiconductor can be formed out of the same layer as the first transparent electrode, and the common electrode can be formed out of the same layer as the oxide semiconductor or the source and drain electrodes.

A nitride semiconductor free-standing substrate includes a diameter of not less than 40 mm, a thickness of not less than 100 μm, a dislocation density of not more than 5×10.sup.6/cm.sup.2, an impurity concentration of not more than 4×10.sup.19/cm.sup.3, and a nanoindentation hardness of not less than 19.0 GPa at a maximum load in a range of not less than 1 mN and not more than 50 mN.

Disclosed is a plasma processing method including: growing a polycrystalline silicon layer on a processing target base body; and exposing the polycrystalline silicon layer to hydrogen radicals by supplying a processing gas containing hydrogen into a processing container that accommodates the processing target base body including the polycrystalline silicon layer grown thereon and radiating microwaves within the processing container to generate the hydrogen radicals.