The roles of argon addition in the hot filament chemical vapor deposition system

Nano-crystalline diamond films were successfully deposited using CH4/H-2/Ar gas mixture by hot filament chemical vapor deposition (HFCVD) method. The characterizations of the as-grown films are carried out by using field emis sion scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). The results show that the film consists of n ano-crystalline diamond grains with sizes ranging from 4 to 30 nm. High ren ucleation rates are found and attributed to the formation of these nano-dia mond grains. The roles that Ar plays in HFCVD system are discussed. (C) 200 1 Elsevier Science B.V. All rights reserved.