Development of a plate-to-plate MPCVD reactor configuration for diamond synthesis

Abstract

The design and performance of a microwave plasma chemical vapor deposition (MPCVD) reactor based on compressed microwave waveguides and plate-to-plate substrate holders are described. This reactor can be operated at pressures from 10 to 40kPa with microwave power of 0.4–1.2kW, and a high plasma power density up to 500W/cm3 can be obtained. The single-crystal diamond (lower substrate holder) and polycrystalline diamond (upper substrate holder) have been grown by the plate-to-plate MPCVD reactor using high pressure CH4-H2 mixture gases. Experimental results show that high quality single-crystal diamond and polycrystalline diamond were simultaneously synthesized at a growth rate of 25μm/h and 12μm/h, respectively. The results indicate that our MPCVD reactor is unique for the synthesis of diamond with high efficiency.