Electrical Properties Of Low Pressure Chemical Vapor Deposited Silicon Nitride Thin Films For Temperatures Up To 650 ℃

摘要

The results of a study on electrical conduction in low pressure chemical vapor deposited silicon nitride thin films for temperatures up to 650 ℃ are described. Current density versus electrical field characteristics are measured as a function of temperature for 100 and 200 nm thick stoichiometric (Si_3N_4) and low stress silicon-rich (SiRN) films. For high E-fields and temperatures up to 500 ℃ conduction through Si_3N_4 can be described well by Frenkel-Poole transport with a barrier height of ～1.10 eV, whereas for SiRN films Frenkel-Poole conduction prevails up to 350 ℃ with a barrier height of ～0.92 eV. For higher temperatures, dielectric breakdown of the Si_3N_4 and SiRN films occurred before the E-field was reached above which Frenkel-Poole conduction dominates. A design graph is given that describes the maximum E-field that can be applied over silicon nitride films at high temperatures before electrical breakdown occurs.