Laser trimming of amorphous Ta42Si13N45 thin films with ultrashort pulses

We have studied experimentally the trimming of amorphous Ta42Si13N45 films of about 250 nm thickness deposited by reactive radiofrequency sputtering of a Ta5Si3 target on 3 inch Si〈100〉 wafers with infrared laser-generated pulses of 200 μs, 30 ns and 200 fs duration at fluencies of 250, 130 and 0.8 J/cm2, respectively. The optical characteristics obtained by ellipsometry reveal metal-like properties. Controlled ablation of the film has been achieved down to 20 nm per pulse with femtosecond pulses. In the microsecond and nanosecond regimes thermal effects dominate. Cracking and delamination were observed when ablating near the ablation threshold in these regimes.