Nitrogen doped indium oxide (InON) and indium tin oxide (ITON) thin films have been fabricated with reactive sputtering in nitrogen-rich plasmas for high temperature thin film thermocouples (TFTCs). Different content of nitrogen was introduced into InON film electrode in order to improve the thermoelectric properties of the thin film thermocouples. XRD, XPS and SEM were used to reveal the chemistry and microstructure of InON films and high temperature static calibration was used to characterize the thermoelectric properties of InON-ITON TFTCs. The relationship between the thermoelectric properties of TFTC and the microstructures of the films was investigated. TFTCs with high linearity and excellent stability were realized. (C) 2017 Elsevier B.V. All rights reserved.