Effect of reaction pressure on the nucleation behaviour of diamond synthesized by hot-filament chemical vapour deposition

✍ Scribed by Dong -Gook Kim; Hwan -Chul Lee; Jai -Young Lee

• Publisher: Springer
• Year: 1993
• Tongue: English
• Weight: 835 KB
• Volume: 28
• Category: Article
• ISSN: 0022-2461
• DOI: 10.1007/bf00356418

✦ Synopsis

Synthetic diamond particles were deposited on a Si (1 0 0) substrate using a hot-filament chemical-vapour-deposition method in order to study the effect of the reaction pressure on the nucleation behaviour. The reaction pressure was controlled, as an experimental variable, from 2 to 50 torr under the following conditions: a filament temperature of 2200 ~ a substrate temperature of 850 ~ a total flow rate of 200 s.c.c.m, and a methane concentration of 0.8 vol %. Diamond deposits on the Si wafer were characterized by micro-Raman spectroscopy, scanning electron microscopy (SEM) and optical microscopy.

The maximum nucleation density of diamond particles on the unscratched Si substrate is shown at the reaction pressure of 5 torr. These phenomena can be explained by the competition effect between J3-SiC formation, which increases the diamond nucleation density, and atomic-hydrogen etching which decreases the nucleation sites.

A new fabrication method for a high-quality diamond film without any surface pretreatments is introduced using a combination process between diamond nucleation at low pressure (5 torr) and growth at high pressure (30 torr).