A silicon carbide seed is provided, including a first seed layer and a second seed layer. The first seed layer includes a polycrystalline silicon carbide material. The second seed layer is directly attached to the first seed layer, where the second seed layer includes a single crystal silicon carbide material, and a thickness ratio (T2/T1) of a thickness T1 of the first seed layer to a thickness T2 of the second seed layer is in a range of 10% to 50%.

A silicon carbide seed is provided, including a first seed layer and a second seed layer. The first seed layer includes a polycrystalline silicon carbide material. The second seed layer is directly attached to the first seed layer, where the second seed layer includes a single crystal silicon carbide material, and a thickness ratio (T2/T1) of a thickness T1 of the first seed layer to a thickness T2 of the second seed layer is in a range of 10% to 50%.

A semiconductor processing method includes the following steps. A semiconductor ingot is cut to obtain a semiconductor wafer, in which the semiconductor wafer includes a first side and a second side opposite to the first side. A double-sided grinding process is performed to simultaneously grind the first side and the second side of the semiconductor wafer using diamond grinding fluid. The diamond grinding fluid contains diamond particles with a median particle diameter of 0.1 m to 3 m.

A method for manufacturing a crystal layer includes using a substrate having a surface film made of a dichalcogenide of a transition metal, designated MX.sub.2, where M denotes a transition metal and X denotes a chalcogen, the surface film including a set of monolayers bonded together by van der Waals bonds; forming a polycrystalline aluminium nitride AlN film, having grain boundaries, on the surface film; and diffusing metal elements into the surface film, through the grain boundaries of the polycrystalline aluminium nitride AlN film, the metal elements being chosen to react chemically with MX.sub.2 by a redox reaction so as to convert the van der Waals bonds into covalent bonds, A crystalline layer is formed on the polycrystalline aluminium nitride AlN film after the diffusing.

A method for manufacturing a crystal layer includes using a substrate having a surface film made of a dichalcogenide of a transition metal, designated MX.sub.2, where M denotes a transition metal and X denotes a chalcogen, the surface film including a set of monolayers bonded together by van der Waals bonds; forming a polycrystalline aluminium nitride AlN film, having grain boundaries, on the surface film; and diffusing metal elements into the surface film, through the grain boundaries of the polycrystalline aluminium nitride AlN film, the metal elements being chosen to react chemically with MX.sub.2 by a redox reaction so as to convert the van der Waals bonds into covalent bonds, A crystalline layer is formed on the polycrystalline aluminium nitride AlN film after the diffusing.

There is provided a diamond film-deposited substrate, including: a substrate comprising niobium metal; a niobium carbide layer on at least one main surface of the substrate; and a conductive diamond film on the niobium carbide layer,

wherein when a surface of the conductive diamond film was observed using a scanning electron microscope, no pinholes reaching the substrate or the niobium carbide layer are present within a field of view of 20 m20 m.

There is provided a diamond film-deposited substrate, including: a substrate comprising niobium metal; a niobium carbide layer on at least one main surface of the substrate; and a conductive diamond film on the niobium carbide layer,

wherein when a surface of the conductive diamond film was observed using a scanning electron microscope, no pinholes reaching the substrate or the niobium carbide layer are present within a field of view of 20 m20 m.

A method is disclosed comprising providing a carbonaceous substrate; performing a chemical vapor deposition process on the carbonaceous substrate using a mixture of precursor gasses comprising a silicon precursor gas comprising trichlorosilane, and a carbon precursor gas selected from carbon-carbon double bond hydrocarbons and carbon-carbon triple bond hydrocarbons; and via said chemical vapor deposition process, forming a polycrystalline cubic silicon carbide layer with crystallographic orientation.

A SiC carrier wafer has a diameter of at least 7.5 cm and a height between 200 m and 500 m. The wafer includes an inner section and an outer section. The outer section surrounds the inner section and the inner section includes a part of a SiC growth substrate. The inner section is formed by a crystal structure that is predominantly formed by a 3C crystal structure. The outer section is formed by a crystal structure predominantly formed by a 3C crystal structure and includes crystallites extending in length direction of the individual crystallite of more than 5 m. A bow of the wafer is less than 50 m and a warp of the wafer is less than 50 m. The crystal structure of the inner section and the crystal structure of the outer section are Nitrogen doped and have an electric resistivity less than 0.03 Ohm-cm.

A SiC carrier wafer has a diameter of at least 7.5 cm and a height between 200 m and 500 m. The wafer includes an inner section and an outer section. The outer section surrounds the inner section and the inner section includes a part of a SiC growth substrate. The inner section is formed by a crystal structure that is predominantly formed by a 3C crystal structure. The outer section is formed by a crystal structure predominantly formed by a 3C crystal structure and includes crystallites extending in length direction of the individual crystallite of more than 5 m. A bow of the wafer is less than 50 m and a warp of the wafer is less than 50 m. The crystal structure of the inner section and the crystal structure of the outer section are Nitrogen doped and have an electric resistivity less than 0.03 Ohm-cm.