Wafer and method of producing same

A wafer comprising;

• a single crystal substrate being made of a semiconductor, a metal or a non-diamond insulator;
• a diamond film being deposited on the substrate and having single-orientation parts in which more than 90% of diamond grains have orientations similar to the substrate with a deviation less than ten degrees and cavities;
• an interface between the substrate and the diamond film and;
• a surface of the diamond film being polished to a roughness less than Rmax100 nm and Ra50 nm;
• wherein the single-orientation parts occupy more than 60% of the surface and the cavities occupy 0.1% to 50% of the whole area on a horizontal section taken in parallel to the interface in the vicinity of the the interface.

A wafer comprising;

• a single crystal substrate being made of a semiconductor, a metal or a non-diamond insulator;
• a diamond film being deposited on the substrate and having single-orientation parts in which more than 90% of diamond grains have orientations similar to the substrate with a deviation less than ten degrees and random-oriented parts in which diamond grains have randomly distributed directions;
• an interface between the substrate and the diamond film and;
• a surface of the diamond film being polished to a roughness less than Rmax100 nm and Ra50 nm;
• wherein the single-orientation parts occupy more than 60% of the surface and the random-oriented parts exist at the periphery of the wafer and occupy 1% to 50% of the whole area on a horizontal section taken in parallel to the interface in the vicinity of the the interface.

A wafer comprising;

• a single crystal substrate being made of a semiconductor, a metal or a non-diamond insulator;
• a diamond film being deposited on the substrate and having single-orientation parts in which more than 90% of diamond grains have orientations similar to the substrate with a deviation less than ten degrees and non-diamond carbon parts in which amorphous carbon or graphitic carbon makes films;
• an interface between the substrate and the diamond film and;
• a surface of the diamond film being polished to a roughness less than Rmax100 nm and Ra50 nm;
• wherein the single-orientation parts occupy more than 60% of the surface and the non-diamond carbon parts occupy 0.1% to 50% of the whole area on a horizontal section taken in parallel to the interface in the vicinity of the the interface.

A method of producing a wafer comprising the steps of;

• preparing a non-diamond single crystal substrate having two surfaces;
• scratching parts of the surface;
• making scratched parts and unscratched parts on the surface;
• growing random-oriented diamond islands only on the scratched parts by a vapor phase method using a material gas including at least hydrogen gas and a hydrocarbon gas;
• growing single-oriented diamond films on the unscratched parts;
• sticking the substrate to a holder which can incline to a holder shaft;
• pushing the diamond film on a turn-table coated with diamond powder of a polishing machine and;
• polishing the convex distorted diamond film till a roughness less than Rmax100 nm and Ra50 nm by inclining the holder to the turn-table.

A method of producing a wafer comprising the steps of;

• preparing a non-diamond single crystal substrate having two surfaces, digging grooves or holes;
• making cavity parts defined by the grooves or holes and flat parts on the surface;
• growing single-oriented diamond films orientation-aligning to the substrate only on the flat parts by a vapor phase epitaxy method using a material gas including at least hydrogen gas and a hydrocarbon gas;
• making holes on the cavity parts by preventing diamond from growing on the cavity parts;
• sticking the substrate to a holder which can incline to a holder shaft;
• pushing the diamond film on a turn-table coated with diamond powder of a polishing machine and;
• polishing the convex distorted diamond film till a roughness less than Rmax100 nm and Ra50 nm by inclining the holder to the turn-table.

A method of producing a wafer comprising the steps of;

• preparing a non-diamond single crystal substrate having two surfaces;
• scratching parts of the surface;
• making scratched areas and unscratched areas on the surface;
• growing random-oriented diamond films only on the scratched areas by a vapor phase deposition method using a material gas including at least hydrogen gas and a hydrocarbon gas;
• growing single-oriented diamond films on the unscratched parts;
• sticking the substrate to a holder which can incline to a holder shaft;
• pushing the diamond film on a turn-table coated with diamond powder of a polishing machine;
• polishing the convex distorted diamond film till a roughness less than Rmax100 nm and Ra50 nm by inclining the holder to the turn-table;
• eliminating the substrate and;
• obtaining a freestanding diamond wafer.

A method of producing a wafer comprising the steps of;

• preparing a non-diamond single crystal substrate having two surfaces;
• scratching parts of the surface;
• covering some parts on the substrate with photoresist films;
• sandblasting the substrate by diamond powder;
• making scratched parts and unscratched parts on the substrate;
• growing non-diamond carbon films only on the scratched parts by a vapor phase deposition method using a material gas including at least hydrogen gas and a hydrocarbon gas;
• growing single-oriented diamond films on the unscratched parts;
• sticking the substrate to a holder which can incline to a holder shaft;
• pushing the diamond film on a turn-table coated with diamond powder of a polishing machine and;
• polishing the convex distorted diamond film till a roughness less than Rmax100 nm and Ra50 nm by inclining the holder to the turn-table.