Patent ID: 9637838
Date: 2017-05-02
CPC Classifications: C01B,C23C,C30B,H01J

Claim:
1. A method of manufacturing synthetic CVD diamond material, the method comprising: providing a microwave plasma reactor comprising: a plasma chamber; one or more substrates disposed in the plasma chamber providing a growth surface area over which the synthetic CVD diamond material is to be deposited in use; a microwave coupling configuration for feeding microwaves from a microwave generator into the plasma chamber; and a gas flow system for feeding process gases into the plasma chamber and removing them therefrom, injecting process gases into the plasma chamber; feeding microwaves from the microwave generator into the plasma chamber through the microwave coupling configuration to form a plasma above the growth surface area or below the growth surface area if the microwave plasma reactor is in an inverted arrangement with process gases flowing in an upwards direction; and growing synthetic CVD diamond material over the growth surface area, wherein the gas flow system includes a gas inlet comprising one or more gas inlet nozzles disposed opposite the growth surface area and configured to inject process gases towards the growth surface area; wherein the microwave coupling configuration comprises a microwave window for feeding microwaves from the microwave generator into the plasma chamber, the microwave window being disposed at an opposite end of the plasma chamber to the growth surface area; wherein the process gases are injected into the plasma chamber through the one or more gas inlet nozzles with a Reynolds number in a range of 1 to 100; wherein the plasma chamber is configured to support a TM wherein the one or more gas inlet nozzles are integrally formed in a metallic wall of the plasma chamber disposed opposite the growth surface area; and wherein the microwave window is in the form of an annular dielectric window disposed around the metallic wall of the plasma chamber in which the one or more gas inlet nozzles are disposed; and wherein a power density delivered to the growth surface area is equal to or greater than 1 W/mm