PRODUCTION OF LABORATORY-GROWN DIAMONDS Russian patent published in 2024 - IPC C30B25/12 C30B25/08 C30B29/04 C01B32/25 

FIELD: optics.

SUBSTANCE: invention can be used in semiconductor, optical and jewellery industry. Laboratory-grown diamond material is obtained by plasma-enhanced chemical vapor deposition (PECVD). Inside the plasma chamber there is substrate holder 510 with recessed pocket 512', 512'', in base 514 of which a substrate of monocrystalline diamond is placed, which performs the function of seed 502, 504. Then, process gases are introduced into plasma chamber and heated by means of electric energy, for example, electromagnetic energy in the micrometre range, to create a plasma containing carbon particles, and depositing carbon in form of monocrystalline diamond (SCD) 506, 508 on substrate and in form of polycrystalline diamond (PCD) 522 on surface 518 of holder 510. Relative growth rate of monocrystalline diamond 506, 508 and polycrystalline diamond 522 is set by controlling applied energy and/or cooling of holder 510 and/or chemical composition of process gases. As a result, monocrystalline diamond 506, 508 protrudes from recessed pocket 512', 512'', and the polycrystalline diamond layer 522 is grown on surrounding surface 518 of substrate holder 510 at such a rate that it is always located above the surface of recessed pocket 512', 512 ". Lateral growth of monocrystalline diamond 506, 508 is limited by a layer of polycrystalline diamond 522, completely surrounding its side faces so as to ensure reduction of cross-sectional area of part of monocrystalline diamond 506, 508 protruding from recessed pocket 512', 512'', as distance from substrate holder 510. Device for deposition of said laboratory-grown diamond material comprises a microwave generator; plasma chamber; microwave connection configuration for inputting microwaves from the microwave generator into the plasma chamber; system for supplying process gases and removing waste gases, equipped with a controller for controlling composition of process gases; a pressure control system for controlling pressure inside the plasma chamber and a cooling system for controlling temperature of holder 510. Laboratory-grown monocrystalline diamond material 506, 508 has a first shape, the cross-sectional area of which decreases with increasing distance from flat base 514 formed by the surface of seed 502, 504, or a second shape having the shape of two adjacent truncated conical shapes with a common base. Laboratory-grown monocrystalline diamond material 506, 508 is surrounded by polycrystalline diamond material 522 on all side ends.

EFFECT: invention enables to change the shape of the monocrystalline diamond material 506, 508 by controlling the growth rate of the polycrystalline diamond material 522.

16 cl, 14 dwg