Thermal stability of tantalum nitride based thin film resistors

Abstract

Tantalum nitride thin films were deposited on Al2O3 substrates by the dc-magnetron sputtering technique. The nitrogen content in the argon/nitrogen flow varied from 5 to 50%. Structural properties were studied using X-ray diffraction. The ratio of Ar:N2 was 4:1; the ratio of Ta:N became 1:1. Sheet resistance depends on thickness and is in the range of 20 - 80 Ω/□ due to thickness 100 - 50 nm. The TaN films deposited at a nitrogen/argon ratio of 20% show the thermal stability of the resistance in the 25-400°C temperature range. Sheet resistance degradation was ∼ 5%. The TCR value was determined in the range of 25 - 300 C and was equal to - 21 ppm/K.