Positive-Negative Inversion of Silicon Based Resist Materials: Poly(di-n-hexylsilane) for Ion Beam Irradiation

The present paper describes radiation induced solubility changes and emission spectra of poly(di-n-hexylsilane) and their temperature dependence on. Poly(di-n-hexylsilane) has a clear phase transition temperature at around 312 K with change of the silicon skeleton structure. Radiation induced reactions differed greatly above and below this temperature, showing large emission spectral changes. High LET (linear energy transfer; energy deposition rate of incident particles per 100 Å ion beams induced main chain crosslinking in the polymer. PDHS behaved as a negative-type resist material below 312 K, although it had been previously confirmed that PDHS had shown positive-type resist properties for UV light, electron beams, X-rays, low LET proton beams at any temperature range and for higher LET He ion beams at a temperature above 312 K.