Current Transport and Maximum Dielectric Strength of Silicon Nitride Films

Measurements of current‐voltage characteristics have been performed on Au‐Si3N4‐Mo and Au‐Si3N4‐Si (degenerate substrate) structures of various nitride‐film thicknesses from 300 A to 3000 A and over a range of temperatures. The films are deposited by the process of reaction of SiCl4 with NH3. It is found that at any given temperature and electric field, the current transport is essentially independent of the substrate material, the film thickness, or the polarity of the electrodes.It is proposed that the current‐transport mechanisms are bulk controlled rather than electrode controlled. The conduction‐current density, J, is the sum of three contributions: J = J1+J2+J3, where J1∼E exp {−q[φ1 − (qE/πe0ed)½]/ kT}, J2∼E2 exp (−E2/E), and J3∼E exp (−qφ3/kT). At high fields and high temperatures J1 dominates the current conduction (the Poole‐Frenkel effect or internal Schottky effect); one obtains a barrier height of (1.3±0.2) V for φ1 and a value of 5.5±1 for the dynamic dielectric constant ed. At high fields a...