| Autor: |
Baron FA; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia., Mikhlin YL; Institute of Chemistry and Chemical Technology, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia., Molokeev MS; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.; Siberian Federal University, Krasnoyarsk 660041, Russia., Rautskiy MV; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia., Tarasov IA; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia., Volochaev MN; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.; Reshetnev Siberian State University of Science and Technology, Krasnoyarsk 660037, Russia., Shanidze LV; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia., Lukyanenko AV; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.; Siberian Federal University, Krasnoyarsk 660041, Russia., Smolyarova TE; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.; Siberian Federal University, Krasnoyarsk 660041, Russia., Konovalov SO; Reshetnev Siberian State University of Science and Technology, Krasnoyarsk 660037, Russia., Zelenov FV; Reshetnev Siberian State University of Science and Technology, Krasnoyarsk 660037, Russia., Tarasov AS; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.; Siberian Federal University, Krasnoyarsk 660041, Russia., Volkov NV; Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia. |
| Abstrakt: |
Copper-doped titanium oxynitride (TiN x O y ) thin films were grown by atomic layer deposition (ALD) using the TiCl 4 precursor, NH 3 , and O 2 at 420 °C. Forming gas was used to reduce the background oxygen concentration and to transfer the copper atoms in an ALD chamber prior to the growth initiation of Cu-doped TiN x O y . Such forming gas-mediated Cu-doping of TiN x O y films had a pronounced effect on their resistivity, which dropped from 484 ± 8 to 202 ± 4 μΩ cm, and also on the resistance temperature coefficient (TCR), which decreased from 1000 to 150 ppm °C -1 . We explored physical mechanisms causing this reduction by performing comparative analysis of atomic force microscopy, X-ray photoemission spectroscopy, X-ray diffraction, optical spectra, low-temperature transport, and Hall measurement data for the samples grown with and without forming gas doping. The difference in the oxygen concentration between the films did not exceed 6%. Copper segregated to the TiN x O y surface where its concentration reached 0.72%, but its penetration depth was less than 10 nm. Pronounced effects of the copper doping by forming gas included the TiN x O y film crystallite average size decrease from 57-59 to 32-34 nm, considerably finer surface granularity, electron concentration increase from 2.2(3) × 10 22 to 3.5(1) × 10 22 cm -3 , and the electron mobility improvement from 0.56(4) to 0.92(2) cm 2 V -1 s -1 . The DC resistivity versus temperature R ( T ) measurements from 4.2 to 300 K showed a Cu-induced phase transition from a disordered to semimetallic state. The resistivity of Cu-doped TiN x O y films decreased with the temperature increase at low temperatures and reached the minimum near T = 50 K revealing signatures of the quantum interference effects similar to 2D Cu thin films, and then, semimetallic behavior was observed at higher temperatures. In TiN x O y films grown without forming gas, the resistivity decreased with the temperature increase as R ( T ) = - 1.88 T 0.6 + 604 μΩ cm with no semimetallic behavior observed. The medium range resistivity and low TCR of Cu-doped TiN x O y make this material an attractive choice for improved matching resistors in RF analog circuits and Si complementary metal-oxide-semiconductor integrated circuits. |
