Deposition of diamond films on SiO2 surfaces using a high power microwave enhanced chemical vapor deposition process

Abstract

Diamonds were successfully nucleated on SiO 2 -coated silicon substrates using a high power microwave plasma enhanced chemical vapor deposition process. Nucleation rates on SiO 2 surfaces ͑i.e., 0.5ϫ10 10 cm Ϫ2 ͒ were, however, still smaller than those on Si surfaces ͑i.e., 1.0ϫ10 10 cm Ϫ2 ͒. The major advantage in using high power microwaves was revealed by optical emission spectroscopy to be that the atomic C and H species produced are more abundant and energetic. Therefore, the negative bias effect is enabled and the formation of sp 3 bonds is enhanced. The nucleation of diamonds on SiO 2 surface is thus made possible. The growth of diamonds behaved similarly on the prenucleated surface, regardless of the nature of the substrates. Diamonds were of single grain columnar structure with random orientation when deposited without bias and were of multi-grain columnar structure with ͓111͔ or ͓001͔ preferred orientation when deposited under Ϫ100 V dc bias. Multi-grain columnar structure was ascribed to the induction of secondary nucleation at the presence of bias voltage.

Oxide Ceramic Functional Thin Layer Processing by Thermal and Laser Sintering of Green Layers

“…The term chemical vapor infiltration (CVI) refers to the internal coating of porous preforms. Well-known examples are CVD/CVI synthesis of SiC from SiCl 4 /CH 4 or CH 3 SiCl 3 , being used for example for the processing of large-scale high-temperature SiC matrix fiber composites or for CVD-coatings of diamond-like carbon (DLC) [11].…”

Novel Two-Step Method for Synthesis of High-Density Nanocrystalline Diamond Fibers

“…However, the difficulty in controlling the size, texture, and crystalline quality of the diamond grains and in achieving concrete coating is reflected in many of these works. There are many reports on growth of diamond films on a -SiO 2 surfaces using a high-power microwave plasma enhanced chemical vapor deposition (MPECVD) technique; – however, no method of coating nanocrystalline diamond (NCD) onto silica ( a -SiO 2 ) nanofibers has been reported.…”