Electrical Conduction Mechanisms in Metal–Insulator–Metal (MIM) Structure with TiOxNy Thin Films Deposited with Different O/N Ratios

• Published in: Journal of electronic materials 2015-01, Vol.44 (1), p.103-109
• Main Authors: Libardi, Juliano, Grigorov, Korneli G., Moraes, Rodrigo S., Guerino, Marciel, Da Silva Sobrinho, Argemiro S., Massi, Marcos
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Electronics and Microelectronics; Instrumentation; Materials Science; Optical and Electronic Materials; Solid State Physics
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-014-3470-1

In this work, the current–voltage characteristics of titanium oxynitride thin films were measured and the charge carrier transport mechanisms established as a function of film composition. The films were deposited by magnetron sputtering, where the oxygen/nitrogen ratio was varied via a pulsing technique to enable the achievement of desired concentrations. Thus, the obtained films showed metallic titanium nitrate (TiN) or semiconductor titanium dioxide (TiO 2 ) character and were used to fabricate metal–insulator–metal structures. An ohmic conduction mechanism was identified in the films with higher nitrogen incorporation or presenting TiN-rich phase. Decrease in the nitrogen content resulted in films with TiO 2 -rich phase. In this case, Poole–Frenkel and space-charge-limited current conduction mechanisms were observed. The dielectric constants were calculated from the high-frequency capacitance–voltage dependences, with a reduction from 10 to 3 being observed due to the stoichiometric changes and probable incorporation of defects into the film structure. Finally, the film composition and structural characteristics of the films were revealed by Rutherford backscattering and x-ray diffraction techniques, respectively.