A method for forming a semiconductor device with a group-III oxide active layer including at least two group-III materials is provided. A group-III oxide substrate is provided and a group-III oxide active layer including at least one group-III material on the group-III oxide substrate is formed on the group-III oxide substrate. A group-III material in the group-III oxide substrate is different from the at least one group-III material in the group-III oxide active layer. The group-III oxide active layer including at least one group-III material and the group-III oxide substrate are annealed at a temperature greater than or equal to 1,000° C. so that the group-III material in the group-III oxide substrate diffuses into the group-III oxide active layer to form the group-III oxide active layer including the at least two group-III materials.

A film formation apparatus is configured to supply mist of a solution to a surface of a substrate so as to epitaxially grow a film on the surface of the substrate. The film formation apparatus may be provided with: a furnace configured to house and heat the substrate; a reservoir configured to store the solution; a heater configured to heat the solution in the reservoir; an ultrasonic transducer configured to apply ultrasound to the solution in the reservoir so as to generate the mist of the solution in the reservoir; and a mist supply path configured to carry the mist from the reservoir to the furnace.

A high-quality crystalline film having less impurity of Si and the like and useful in semiconductor devices is provided. A crystalline film containing a crystalline metallic oxide including gallium as a main component, wherein the crystalline film includes a Si in a content of 2×10.sup.15 cm.sup.−3 or less.

To provide a gallium oxide-based semiconductor with its bandgap being sufficiently reduced, and a manufacturing method thereof.

A gallium oxide-based semiconductor containing a mixed crystal having a composition represented by (Ga.sub.(1-x)Fe.sub.x).sub.2yO.sub.3, wherein 0.10≤x≤0.40 and 0.85≤y≤1.2, wherein the mixed crystal has a beta-gallia structure, is provided. Also, a method for manufacturing the gallium oxide-based semiconductor, including depositing a mixed crystal having a composition represented by (Ga.sub.(1-x)Fe.sub.x).sub.2yO.sub.3, wherein 0.10≤x≤0.40 and 0.85≤y≤1.2 on a substrate surface by a pulsed laser deposition method, wherein denoting the temperature of the substrate as PC, x and T satisfy the relationship represented by 500x+800≤T<1,000, is provided.

A crystalline oxide semiconductor with excellent crystalline qualities that is useful for semiconductors requiring heat dissipation is provided. A crystalline oxide semiconductor including a first crystal axis, a second crystal axis, a first side, and a second side that is shorter than the first side, a linear thermal expansion coefficient of the first crystal axis is smaller than a linear thermal expansion coefficient of the second crystal axis, a direction of the first side is parallel and/or substantially parallel to a direction of the first crystal axis, and a direction of the second side is parallel and/or substantially parallel to a direction of the second crystal axis.

A semiconductor device with enhanced semiconductor characteristics that is useful for power devices. A semiconductor device, including: an n-type semiconductor layer; one or more p-type semiconductors; an electrode, the one or more p-type semiconductors that are provided between the n-type semiconductor layer and the electrode, and at least a part of the one or more p-type semiconductors is protruded in the electrode.

A semiconductor device with enhanced semiconductor characteristics that is useful for power devices. A semiconductor device, including: an n-type semiconductor layer; an electrode; two or more p-type semiconductors that is provided between the n-type semiconductor layer and the electrode, the n-type semiconductor layer containing gallium, a number of the two or more p-type semiconductors that is equal to or more than three, and the two or more p-type semiconductors that are embedded in the n-type semiconductor layer.

A semiconductor substrate includes a gallium oxide-based semiconductor single crystal and a chamfered portion at an outer periphery portion. The chamfered portion includes a first inclined surface located on the outer side of a first principal surface of the semiconductor substrate and being linear at an edge in a vertical cross section of the semiconductor substrate, a second inclined surface located on the outer side of a second principal surface on the opposite side to the first principal surface and being linear at an edge in the vertical cross section, and an end face located between the first inclined surface and the second inclined surface at a leading end of the chamfered portion. A width of the end face in a thickness direction of the semiconductor substrate is within the range of not less than 50% and not more than 97% of a thickness of the semiconductor substrate.

A semiconductor film, a sheet like object, and a semiconductor device are provided that have inhibited semiconductor properties, particularly leakage current, and excellent withstand voltage and heat dissipation. A crystalline semiconductor film or a sheet like object includes a corundum structured oxide semiconductor as a major component, wherein the film has a film thickness of 1 μm or more. Particularly, the semiconductor film or the object includes a semiconductor component of oxide of one or more selected from gallium, indium, and aluminum as a major component. A semiconductor device has a semiconductor structure including the semiconductor film or the object.

The disclosure provides a crystalline oxide film that has reduced defects such as dislocations due to a reduced facet growth. Also, the disclosure provides a crystalline oxide film that is useful for semiconductor devices and has an enhanced crystal quality. A crystalline oxide film, including: an epitaxial layer having a corundum structure, the lateral growth area is substantially free from a facet growth area, a growth direction of the lateral growth area that is c-axis direction or substantially c-axis direction, the lateral growth area including a dislocation line extending to the c-axis direction or substantially c-axis direction, a first crystal oxide and a second crystal oxide bonded to each other, that are crystal-grown in a direction parallel or approximately parallel to the x-axis.