CC BY
10LM-I-21 ALT,22
LASER-MATTER INTERACTION
Laser synthesis of thin-film memristor structures based on tantalum
and niobium oxides
O. Novodvorsky, O. Khramova, L. Parshina, D. Gusev*, A. Polyakov, V. Mikhalevsky, E. Cherebilo
1- Institute on Laser and Information Technologies of Russian Academy of Sciences — Branch of Federal Scientific Research Center "Crystallography and Photonics" of Russian Academy of Sciences, Svyatoozerskaya 1,
140700, Shatura, Moscow Region.
.* Corresponding author.
E-mail address:dagiet04@gmail.com (D.Gusev).
In the present work, thin films of niobium and tantalum oxides are obtained and investigated [1,2]. The effect of the O2 gas pressure and the laser radiation energy on the target on the composition, structure, and optical properties of the deposited NbOx and TaOx films is considered. It was found that, at different oxygen pressures, NbOx films are formed by various nanocrystallites, the size and structure of which depend on the wavelength of the ablating radiation. In this case, the band gap of NbOx films depends on the energy of particles deposited by PLD. The behavior of bifurcations and at-tractor type in the transmission curves of NbOx films was found as a function of the oxygen pressure, which is associated with the formation of NbO2 nanocrystallites. Switching of memristor devices based on tantalum oxides is associated, in particular, with a change in the degree of oxidation in a TaOx thin film, which affects its structural and electrical characteristics. In this work, we investigate the possibility of tuning the resistive switching of the Pt/TaOx/Ta2O5/Pt/c-Al2O3 memristors in crossbar geometry by changing the oxygen pressure from 0.5 to 50 mTorr during the low-temperature laser synthesis. X-ray diffraction studies of the TaOx films with high resolution made it possible to determine the conditions for obtaining the active region of the memristor with the formation of certain size nanocrystallites. The Pt/TaOx/ Ta2O5/Pt/c-Al2O3 memristor showed very reliable resistive switching performance over 100 DC cycles with the memory window performance of RON/ROFF ~ 103 at RESET operating voltage of ~ 2.3 V. Memristors Me/NbOx/Me with a lower electrode of a noble metal and an upper one of a noble or reactive metal have been obtained and investigated. Volatile memristors of Nb/NbOx/Nb2O5/Pt/c-Al2O3 (x <2.5) in cross-bar geometry were created demonstrating long-term stability of operation for 60 DC cycles with ARhrs/Rhrs < 8% at an operating switching voltage of ~ 0.5 V. All memristor layers were deposited by PLD in a drop-free mode using an excimer KrF laser or a second harmonic of a YAG:Nd3+ laser. The influence of the energy of deposited particles on the characteristics of memristors with different types of upper electrode and different compositions of the oxide NbOx layer is investigated.
[1] L. Parshina, O. Novodvorsky, O. Khramova, D. Gusev, A. Polyakov, V. Mikhalevsky, E. Cherebilo Laser synthesis of nonvolatile memristor structures based on tantalum oxide thin films Chaos, Solitons and Fractals vol.142, pp. 110460-5, (2021).
[2] O. Novodvorsky, L. Parshina, O. Khramova, D. Gusev, A. Polyakov, V. Mikhalevsky, E. Cherebilo Laser synthesis of volatile
memristors based on niobium oxide thin films Surfaces and Interfaces vol. 30, pp101891-7, (2022).
