A method for forming a film, including: atomizing a raw material solution into a mist to form raw material mist; mixing raw material mist and a carrier gas to form gas mixture; placing a substrate on a placement section of susceptor; supplying gas mixture from an atomizer to the substrate to perform film formation by thermal reaction on substrate; and discharging gas mixture after the film formation through an exhaust unit, wherein in the step of supplying the gas mixture from atomizer to substrate to perform film formation by thermal reaction on the substrate, at least a part of gas mixture is supplied from a smooth section adjacent to placement section to a surface of substrate, the smooth section having a surface roughness of 200 m or less. A method for forming a film capable of uniformly and stably producing a high-quality film on a surface of a large-diameter substrate.

Provided are a substrate for epitaxially growing a diamond crystal, having at least a surface made of a metal, in which the above surface made of the metal is a plane having an off angle of more than 0, and the full width at half maximum of the X-ray diffraction peak from the (002) plane by the X-ray rocking curve measurement at the above surface made of the metal is 300 seconds or less; and a method of manufacturing a diamond crystal, including epitaxially growing a diamond crystal on the above surface made of the metal of the above substrate.

A semiconductor device according to some embodiments includes: a transfer substrate, a semiconductor layer, and an adhesive layer between the transfer substrate and the semiconductor layer. The adhesive layer includes a lower portion and first and second protrusions, and the semiconductor layer comprises an upper portion and first and second protrusions. The first and second protrusions of the adhesive layer are in contact with the upper portion of the semiconductor layer, the first and second protrusions of the semiconductor layer are in contact with the lower portion of the adhesive layer, the first protrusion of the adhesive layer is disposed between the first and second protrusions of the semiconductor layer, and the second protrusion of the semiconductor layer is disposed between the first and second protrusions of the semiconductor layer.

A preparation method of an aluminum nitride (AlN) composite structure based on a two-dimensional (2D) crystal transition layer is provided. The preparation method includes: transferring the 2D crystal transition layer on a first periodic groove of an epitaxial substrate; forming a second periodic groove staggered with the first periodic groove on the 2D crystal transition layer; depositing a supporting protective layer; depositing a functional layer of a required AlN-based material; and removing the 2D crystal transition layer through thermal oxidation to obtain a semi-suspended AlN composite structure. The preparation method has low difficulty and is suitable for large-scale industrial production. Design windows of the periodic grooves and the AlN functional layer are large and can meet the material requirements of deep ultraviolet light-emitting diodes (DUV-LEDs) and radio frequency (RF) electronic devices for different purposes, resulting in a wide application range.

An object of the present invention is to provide a novel technique capable of suppressing the occurrence of cracks in the growth layer. The present invention is a method for manufacturing a semiconductor substrate, which includes: an embrittlement processing step S10 of reducing strength of an underlying substrate 10; and a crystal growth step S20 of forming the growth layer 20 on the underlying substrate 10. In addition, the present invention is a method for suppressing the occurrence of cracks in the growth layer 20, and this method includes an embrittlement processing step S10 of reducing the strength of the underlying substrate 10 before forming the growth layer 20 on the underlying substrate 10.

A semiconductor substrate comprising a first epitaxial silicon carbide layer and a second silicon carbide epitaxial layer. At least one semiconductor device is formed in or on the second silicon carbide epitaxial layer. The semiconductor substrate is formed overlying a silicon carbide substrate having a surface comprising silicon carbide and carbon. An exfoliation process is used to remove the semiconductor substrate from the silicon carbide substrate. The carbon on the surface of the silicon carbide substrate supports separation. A portion of the silicon carbide substrate on the semiconductor substrate is removed after the exfoliation process. The surface of the silicon carbide substrate is prepared for reuse in subsequent formation of semiconductor substrates.