SELF-DEVELOPMENT MECHANISM OF NITROCELLULOSE RESIST - ELECTRON-BEAM IRRADIATION

The decomposition mechanism of a nitrocellulose film induced by irradiation of an electron beam and He+ ion beam was investigated by monitoring the changes of the infrared spectra. With irradiation of the electron beam, it was found that the electronic stopping power caused the decomposition of the nitrocellulose resist by breaking the R-O-NO2 bond. In addition, it was found that oxidation due to oxygen supplied from NO2 enhanced the decomposition, and finally, a residue was formed. This is almost the same result as obtained by heat treatment. In the case of He+ ion irradiation, the electronic stopping power caused the same decomposition process as did irradiation of the electron beam. However, the residue formed was sputtered off due to the nuclear stopping power.