Thermochemical direct laser writing of amplitude diffractive structures on thin metal films (Zr, Ta, V, Mo, Cr) at different processing conditions with focused cw laser beam has been experimentally investigated. The study was aimed to select proper material and thickness range ensuring through oxidation, which helps to get higher resolution due to bleaching of the thin absorbing film near peak of intensity distribution of focused laser beam and stopping thermal trace widening. The resistless thermal writing process will be further used as base for developing high-resolution laser lithography system with 266 nm DPSS laser intended for nano-optics fabrication.
Experimental investigation of thermochemical laser-induced periodic surface structures (TLIPSS) formation on metal films (Ti, Cr, Ni, NiCr) at different processing conditions is presented. The hypothesis that the TLIPSS formation depends significantly on parabolic rate constant for oxide thin film growth is discussed. Evidently, low value of this parameter for Ni is the reason of TLIPSS absence on Ni and NiCr film with low Cr content. The effect of simultaneous ablative (with period ≈λ) and thermochemical (with period ≈λ) LIPSS formation was observed. The formation of structures after TLIPSS selective etching was demonstrated.