Plasma Analysis Of Excimer Laser Ablated Novolak Photoresist

The excimer laser ablation of a chresol-novolak based photoresist is reported. The process is caracterised at low gas pressure by laser beam transmission, the emission from fluorescing radicals, and analysing material which is deposited on the wafer surface. The results suggest that a supersonic ejection of the ablated molecules occurs in addition to chemical reaction which take place in the gas phase at reduced kinetic energies. Some conclusions about the ejected particle condensation and the corresponding accumulation of debris are drawn. These results allow improved understanding of how the ambient gas effects the ejected chresol-novolak molecules produced by excimer laser ablation.