Surface Modification of Positive Photoresist Mask during Reactive Ion Etching of Si and W in SF 6 Plasma

This paper reports the results of a preliminary study concerning the surface modification of a diazoquinone‐novolak photoresist (HPR 204) 1 during reactive ion etching of Si and W in plasmas. X‐ray photoelectron spectroscopy analyses provide the following information: the spectrum reveals various bonding states of carbon with fluorine such as , , and which proves the fluorination of the carbon network. The existence of and species is also most probable. A loss in the oxygen content is the main degradation observed. Sulfur residues are present and discussed in relation to the nature of the cathode material. In the case of a W cathode, the identification of tungsten fluorides on the photoresist surface is correlated with the etching of the cathode. Ion bombardment‐induced effects are investigated, in particular concerning the presence of metallic tungsten sputtered from the cathode.