CHLORINE CONTAINING PLASMA ETCH METHOD WITH ENHANCED SIDEWALL PASSIVATION AND ATTENUATED MICROLOADING EFFECT

摘要

A method for forming a patterned layer within a microelectronics fabrication.There is first provided a substrate. There is then formed over the substrate a blanket chlorinecontaining plasma etchable layer. There is then formed upon the blanket chlorine containingplasma etchable layer a blanket hard mask layer. There is then formed upon the blanket hardmask layer a patterned photoresist layer. There is then etched the blanket hard mask layer to forma patterned hard mask layer while employing a first plasma etch method in conjunction with thepatterned photoresist layer as a first etch mask layer. There is then etched the blanket chlorinecontaining plasma etchable layer to form a patterned chlorine containing plasma etchable layerwhile employing a second plasma etch method in conjunction with at least the patterned hardmask layer as a second etch mask layer. The second plasma etch method employs a secondetchant gas composition which upon plasma activation forms a chlorine containing etchant speciesand a sidewall passivation layer forming species. The patterned chlorine containing plasmaetchable layer has incident to the second plasma etch method a sidewall passivation layer formedupon a sidewall of the patterned chlorine containing plasma etchable layer. Finally, there is thenstripped from the sidewall of the patterned chlorine containing plasma etchable layer the sidewallpassivation layer while sequentially oxidizing the sidewall of the patterned chlorine containingplasma etchable layer to form an oxidized chlorine containing plasma etchable material sidewalllayer upon a partially oxidized patterned chlorine containing plasma etchable layer whileemploying a third plasma etch method. The third plasma etch method employs a third etchant gascomposition which upon plasma activation forms an oxygen containing oxidizing species.