Amorphous/Nanocrystalline High-Entropy CoCrFeNiTix Thin Films with Low Thermal Coefficient of Resistivity Obtained via Magnetron Deposition

High-entropy alloys are promising materials for novel thin-film resistors since they have high resistivity and a low-temperature coefficient of resistivity (TCR). In this work, a new high-entropy thin-film CoCrFeNiTix was deposited on a Si/SiO2 substrate by means of magnetron sputtering of the multi-component target produced by hot pressing of the powder mixture. The samples possessed a thickness of 130-230 nm and an amorphous atomic structure with nanocrystallite traces. This structure persisted after being annealed up to 400 & DEG;C, which was confirmed using X-ray and electron diffraction. The film had a single-phase structure with a smooth surface and a uniform distribution of all elements. The obtained film served for microresistor elaboration, which was produced using the lithography technique and tested in a temperature range from -60 & DEG;C up to 200 & DEG;C. Resistivity at room temperature was estimated as 2.37 & mu;Ohm & BULL;m. The results have demonstrated that TCR depends on temperature according to the simple linear law in a range from -60 & DEG;C up to 130 & DEG;C, changing its value from -78 ppm/& DEG;C at low temperatures to -6.6 ppm/& DEG;C at 130 & DEG;C. Such characteristics show the possibility of using these high-entropy alloy films for resistive elements in contemporary and future micro-electronic devices.

Automated summary

In this work, a high-entropy thin-film CoCrFeNiTix was deposited on a Si/SiO2 substrate using magnetron sputtering. The film had an amorphous atomic structure and retained this structure after annealing up to 400°C. It showed a single-phase structure, a smooth surface, and a uniform distribution of elements. This study demonstrates the potential use of high-entropy alloy films as resistive elements in contemporary and future microelectronic devices.