In plasma processing the efficient dissociation of molecules is the key element for producing the precursors for plasma deposition, surface modification, and molecule conversion. During these processes always molecules are generated, as e.g. H2 in deposition of hydrogenated carbon or molecules may be converted to new molecules. Measurement of molecules is thus a possible way to investigate the reactive pathways in plasma chemistry. It appears that the surface plays a pertinent role in the formation of molecules. This became clear from the study of several plasmas, including the remote plasma of an expanding thermal plasma. Measurements by mass spectrometry and infrared absorption indicate several dominant pathways as re-formation of N2 and O2 besides a small percentage of NO in N/O, the formation of ammonia in N/H, of water in H/O and CO and H2 in H/C/N/O containing plasmas. The presence of excited molecules presumably generated at the surface bordering the plasma indicates the presence of modified chemistry in a plasma environment.
|Journal||Journal of Optoelectronics and Advanced Materials|
|Publication status||Published - 2008|