Electric field involved transport at elevated temperature in nanocrystalline silicon carbide nitride (nc-SiCN) thin films for harsh environment applications

Abstract

The present study represents a systematic temperature dependent charge transport and dielectric properties of nanocrystalline silicon carbide nitride (nc-SiCN) thin films grown on Pt/Ti/SiO2/Si substrate. A large negative temperature coefficient of resistance (TCR) ranging from 6200 to 2300 ppmK-1 in the temperature range 300–773 K, suggests that the nc-SiCN thin films could be useful for futuristic thermal-based sensors. The current density vs. electric field (J-E) characteristics was measured at different temperatures (300–673 K). Detailed J-E analysis revealed an ohmic conduction at the low applied electric field (<65 kV/cm) within the entire temperature range. However, at high electric field (>65 kV/cm), space charge limited conduction (SCLC) mechanism was found to be dominating in low measurement temperature (300–473K), whereas, a transition from SCLC mechanism to Poole-Frenkel mechanism was observed with further increment in the temperature beyond 473 K. The temperature invariant dielectric tunability (nr ∼10%) and low zero electric field leakage current density (J ∼10−7A/cm2) at 673 K temperature, demonstrates the feasibility of nc-SiCN thin films for tunable device applications in the high-temperature and harsh environment.