Formation of Nano SiC Particles by Laser‐Assisted CVD

Nanocrystals of cubic silicon carbide (SiC) are formed using laser‐assisted gas‐phase synthesis. A CO2 laser beam is mechanically chopped to obtain pulsed infrared (IR) excitation. Silane (SiH4) and acetylene (C2H2) have been used as precursors. The SiC particles formed adopt the zinc blende crystal structure (β‐phase) with an average primary particle size of about 12 nm. Higher chopping frequencies yield smaller crystals. Oxidation and subsequent etching with HF removes the oxide shell, leading to further reduction of the particle size to 4 nm.