Resonant CO2 laser induced breakdown in polyatomic molecules

The onset of CO2 laser induced breakdown has been observed by irradiating several polyatomic species (SiH4, NH3, hydrocarbons, fluorohydrocarbons) at a wavelength resonant with an IR active vibration. Primary fragmentation and subsequent ion and radical secondary reactions have been monitored detecting the spontaneous luminescenue with a gateable Optical Multichannel Analyzer. The resonant laser induced processes can be of importance in etching reactors were hydrocarbons and fluoro-hydrocarbons are commonly used, as well as in laser chemical vapour deposition reactors for the productions of sinterable Si3N4 and SiC powders