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) = − 1.88T 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.

We fabricated Cu-doped TiNxOy thin film resistors by using atomic layer deposition, optical lithography, dry etching, Ti/Cu/Ti/Au e-beam evaporation and lift-off processes. The results of the measurements of the resistance temperature dependence, non-linearity, S-parameters at 0.01–26 GHz and details of the breakdown mechanism under high-voltage stress are reported. The devices’ sheet resistance is 220 ± 8 Ω/□ (480 ± 20 µΩ*cm); intrinsic resistance temperature coefficient (TCR) is ~400 ppm/°C in the T-range of 10–300 K; and S-parameters versus frequency are flat up to 2 GHz with maximum variation of 10% at 26 GHz. The resistors can sustain power and current densities up to ~5 kW*cm−2 and ~2 MA*cm−2, above which they switch to high-resistance state with the sheet resistance equal to ~200 kΩ/□ (~0.4 Ω*cm) caused by nitrogen and copper desorption from TiNxOy film. The Cu/Ti/TiNxOy contact is prone to ageing due to gradual titanium oxidation while the TiNxOy resistor body is stable. The resistors have strong potential for applications in high-frequency integrated and hybrid circuits that require small-footprint, medium-range resistors of 0.05–10 kΩ, with small TCR and high-power handling capability.

The temperature dependence of the resistivity of titanium oxynitride TiNxOy thin films with different oxygen and nitrogen content obtained by atomic layer deposition was investigated. We found that the resistance of all films monotonically decreased with increasing temperature and varied within a wide range depending on the chemical composition and thickness of the film. The technology for obtaining a compact temperature sensor of wide range from helium to room temperature based on 40 nm thick TiN0.87O0.97 is presented. Keywords: titanium oxide-nitride, temperature sensors, thin films, atomic layer deposition, integrated circuit components.

We demonstrate that a magnetic tunnel structure irradiated by microwaves can generate a significant voltage signal due to the rectification effect. The measurements were carried out using current-in-plane geometry with a current flowing parallel to the interfaces in the structure. A value of the microwave-induced voltage strongly depends on a bias current and can be driven by a magnetic field. The rectification effect is discussed both in classical terms of nonlinearity of the current-voltage characteristic and using a mechanism that involves the interplay between the spin-polarized current and magnetization dynamics in the magnetic tunnel structure.