Morphology control of diamond films in the region of α=1-1.5 using a 60-kW microwave plasma CVD reactor

摘要

The present study focuses on controlling the diamond film morphology in the range of a < 1.5 using a 60-kW microwave plasma reactor. To this end, it is found that the addition of CO{sub}2 gas to a CH{sub}4 + H{sub}2 gas mixture was effective. By choosing both an appropriate composition of the CO{sub}2 + CH{sub}4 + H{sub}2 gas mixture and a proper substrate temperature, a diamond growth for α = 1 - 1.5 was achieved. Also, it is demonstrated that under the growth conditions of α = 1, diamond cubes or {100}-faceted crystals can be almost uniformly deposited over a 150 mmφ Si substrate. Thus, the control of diamond film morphology is now possible using a CH{sub}4 + H{sub}4 or a CH{sub}4 + CO{sub}2 + H{sub}2 gas mixture in the full range of 1 ≤ α ≤ 3.