TY - GEN

T1 - Increasing the spatial resolution of direct laser writing of diffractive structures on thin films of titanium group metals

AU - Korolkov, Victor P.

AU - Sedukhin, Andrey G.

AU - Belousov, Dmitry A.

AU - Shimansky, Ruslan V.

AU - Khomutov, Vladimir N.

AU - Mikerin, Sergey L.

AU - Spesivtsev, Evgeny V.

AU - Kutz, Roman I.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - The important effects, techniques, and factors are considered that aim to increase the spatial resolution of a scanning direct laser writing of diffractive structures on thin films of transition metals from titanium group (Ti, Zr, and Hf). The writing process is based on metal oxidation under the thermal action of a tightly focused laser beam. Scanning speed of the laser beam and film thickness were varied to get a regime of through oxidation (TO) of the metal film under laser heating. It results in strong increase of the film transmission in exposed area. TO ensures a strong threshold due to feedback connected with decreasing of laser power absorption near center of focused gaussian laser spot. To the best of our knowledge, the direct laser writing of amplitude diffractive structures on Zr and Hf films were performed for the first time. The new regime of direct laser writing on thin Zr films was revealed. It allows forming tracks with width of 100 nm and less at laser spot diameter of 700 nm and laser wavelength of 532 nm. In this work, the spectral dependence of the refractive index and extinction coefficient of hafnium films was first experimentally determined in the wavelength range of 250-1100 nm.

AB - The important effects, techniques, and factors are considered that aim to increase the spatial resolution of a scanning direct laser writing of diffractive structures on thin films of transition metals from titanium group (Ti, Zr, and Hf). The writing process is based on metal oxidation under the thermal action of a tightly focused laser beam. Scanning speed of the laser beam and film thickness were varied to get a regime of through oxidation (TO) of the metal film under laser heating. It results in strong increase of the film transmission in exposed area. TO ensures a strong threshold due to feedback connected with decreasing of laser power absorption near center of focused gaussian laser spot. To the best of our knowledge, the direct laser writing of amplitude diffractive structures on Zr and Hf films were performed for the first time. The new regime of direct laser writing on thin Zr films was revealed. It allows forming tracks with width of 100 nm and less at laser spot diameter of 700 nm and laser wavelength of 532 nm. In this work, the spectral dependence of the refractive index and extinction coefficient of hafnium films was first experimentally determined in the wavelength range of 250-1100 nm.

KW - direct laser writing

KW - thin metal films

KW - metal-oxide mask

KW - spatial resolution

KW - amplitude diffractive structures

KW - thermochemical laser writing

KW - through oxidation

KW - titanium group metals

KW - OPTICAL-CONSTANTS

KW - OXIDATION

KW - TI

UR - http://www.scopus.com/inward/record.url?scp=85073892503&partnerID=8YFLogxK

U2 - 10.1117/12.2520978

DO - 10.1117/12.2520978

M3 - Conference contribution

AN - SCOPUS:85073892503

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Holography

A2 - Fimia, Antonio

A2 - Hrabovsky, Miroslav

A2 - Sheridan, John T.

PB - SPIE

T2 - Holography: Advances and Modern Trends VI 2019

Y2 - 1 April 2019 through 4 April 2019

ER -