Electrical properties of Si-N films deposited on silicon from reactive plasma

Because reactive-plasma-deposited Si-N films might offer certain advantages in silicon integrated-circuit technology, we have evaluated their electrical properties and compared them with those of CVD Si3N4. Various films with compositions in the range 0.75?Si/N?1.9 were studied using C-V and I-V measurements, the latter at temperatures up to 200 °C. The dominant conduction mode appears to be Frenkel-Poole emission; this is consistent with the observed linear I-vs-V1/2 relationship and magnitudes of various parameters. The resistivities (range 104–1021 Ω cm at 2×106 V/cm) and dielectric strengths (range 0.8×106 to 8×106 V/cm) are found to depend upon the film composition and on an as yet undefined structural parameter (for Si/N?0.75). The interface between Si-N and Si is associated with a high density of surface charge (≳1012 cm−2) and a large trapping instability.