Abstract: Tantalum nitride (TaN) and nichrome (NiCr) are the two most common materials used as thin film resistors (TFR) for monolithic microwave integrated circuits (MMIC) based on AlGaN/GaN high electron mobility transistors (HEMTs).In this study,we compare the reliability of the two materials used as TFRs on a semi-insulation 4H SiC substrate.Through the comparison between NiCr and TaN thin-film resistor materials,we find the square resistor (Rs) of TaN TFR increases as the annealing temperature increases.However,the Rs of NiCr TFR shows the opposite trend.We also find the change of the TaN Rs and contacted resistor (RC) is smaller than the NiCr.After O.2 plasma exposure in RIE,the TaN Rs only decreases 0.7Ω,or about 2.56%,and RC increases 0.1Ω,or about 6.6%,at an annealing temperature of 400℃.In contrast,the NiCr Rs and RC show large changes at different annealing temperatures after O.2 plasma exposure.In conclusion,TaN is more stable during plasma exposure after 400℃ annealing in N2 ambient.

Key words: TaN, NiCr, TFR, reliability, MMIC