In this paper, the etching characteristic of diamond like nanocomposite thin films materials in hydrazine has been reported. The experiments have been carried out to explore the compatibility of hydrazine as a propellant with silicon based microthruster. In the reported work, 2″ N-type (100) silicon wafer with 4-6 Ω cm resistivity were used as base material. Diamond-like nanocomposite (DLN) films are deposited on silicon substrate by plasma enhanced chemical vapor deposition (PECVD) process using siloxane or silazane based precursors or their combinations. Thickness of deposited DLN thin films is around 1 µm. DLN samples are treated in 98% hydrazine at 25 °C, 70 °C and 90 °C for different time and etch rates and subsequently the change in refractive index of the DLN films if any has been measured.