Paper
15 January 2008 Deposition of films and layers for sensors with PLD and LIFT method
S. A. Mulenko, Y. V. Kudryavtsev, N. T. Gorbachuk, A. Luches, A. P. Caricato, V. P. Veiko, V. A. Chuiko, A. A. Petrov
Author Affiliations +
Proceedings Volume 6985, Fundamentals of Laser Assisted Micro- and Nanotechnologies; 69850J (2008) https://doi.org/10.1117/12.786988
Event: Fundamentals of Laser Assisted Micro- and Nanotechnologies, 2007, St. Petersburg, Russian Federation
Abstract
Two methods were used for the deposition of thin films and layers: pulsed laser deposition (PLD) and laser-induced film transfer (LIFT). The first one was based on using KrF laser radiation. Thin films and layers were deposited by KrF laser ablation of CrSi2 and β-FeSi2 targets with the aim to obtain silicide layers with narrow band gap for sensor applications. The CrSi2-based films display both semiconductor and metal properties, depending on the deposition parameters. Thus, the film d ≅ 40 nm thick, deposited on Si at 740 K, presents a band gap Eg ≅ 0.18 eV, a thermo e.m.f. coefficient α ≅ 1.0-1.4 mV/K for 300≤T≤340 K and a coefficient of tensosensitivity (R-R0)/R) ≅ 5. The film with the same thickness, but deposited on SiO2 at 740 K, presents a metal behavior in the range 125≤T≤296 K and a semiconductor one for 77≤T≤125 K. Its α coefficient changes in the range 5.0 - 7.5 μV/K for 300≤T≤340 K. The 750 nm thick film deposited on SiO2 at 740 K displays only semiconductor behavior in the range 296-77 K with Eg ≅ 0.013 eV and α ≅ 10-15 μV/K for 293≤T≤340 K. The coefficient of tensosensitivity for these films is changing in the range 2-5. The β-FeSi2-based films deposited on SiO2 at 295≤T≤740 K show only semiconductor behavior. The thicker the film, the higher Eg: d ≅ 150 nm, Eg ≅ 0.032 eV; d ≅ 70 nm, Eg ≅ 0.027 eV; d ≅ 60 nm, Eg ≅ 0.023 eV. The thermo e.m.f coefficient α ≅ 10 μV/K for the 150 nm thick film and α 8 μV/K for the 60 nm thick film at 293≤T≤340 K. The coefficient of tensosensitivity for these films varies in the range 2.3-4.7. The second one was based on LIFT of CrSi2 and β-FeSi2 targets, using a Q-switched Nd: YAG laser. The α coefficient for the deposited layer from β-FeSi2 is about 2.2 μV/K with Eg ≅ 0.05 eV. While decreasing the average power density of the Q-switched Nd: YAG laser, the band gap decreases down to 0.005 eV. For this film we found α ≅ 2.0 μV/K. The α coefficient for the deposited layer from CrSi2 is about 36 μV/K with Eg ≅ 0.09 eV. Coefficient of thermo e.m.f. for layers obtained by LIFT method was measured at 300≤T≤350 K. The coefficient of tensosensitivity for layers obtained by LIFT varied in the range 1.5-4.2. The higher the semiconductor phase content in the deposited films and layers obtained by PLD and LIFT methods, the higher are the values of α and (R-R0)/R0ε.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
S. A. Mulenko, Y. V. Kudryavtsev, N. T. Gorbachuk, A. Luches, A. P. Caricato, V. P. Veiko, V. A. Chuiko, and A. A. Petrov "Deposition of films and layers for sensors with PLD and LIFT method", Proc. SPIE 6985, Fundamentals of Laser Assisted Micro- and Nanotechnologies, 69850J (15 January 2008); https://doi.org/10.1117/12.786988
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KEYWORDS
Silica

Semiconductors

Silicon

Metals

Sensors

Pulsed laser deposition

Thin films

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