TRIBOLOGICAL PROPERTIES OF CARBONIZED PHOTORESIST

AISI 52100 bearing steel samples were coated with 0.3 to 0.8-mu-m AZ 5210 photoresist by conventional spinning techniques. Ion bombardment with N, Al, and P ions in the dose range of 10(16) cm-2 and at an energy of 200 keV was conducted to carbonize the resist and to mix the carbonlike layer with the steel substrate. During irradiation, a rapid loss of volatile compounds occurred, which was accompanied by a densification of the polymer. A decrease of layer thickness of about 45% after ion bombardment was observed. The remaining layer shows a high Knoop microhardness of about 3900 HK (load: 0.01 N), much higher than that of the steel substrate, a friction coefficient lower than 0.2 and a drastically reduced wear rate of the layer and the counterpart, compared with the bare steel substrate. Raman spectroscopy and TEM investigations revealed that the layer consists of amorphous carbon. The Raman spectrum of carbonized photoresist is similar to the spectrum of hard, hydrogenated carbon films.