Electronic transport in low-temperature silicon nitride

Abstract

Perpendicular current transport through thin silicon nitride films deposited at 100 degreesC by radio frequency chemical vapor deposition (RF) is measured between patterned square contacts with side lengths between 5 and 200 mum. Hydrogen dilution, silane-to-ammonia ratio, and total gas flow were varied to achieve control of film properties. The dependence of the current on the applied field and measurement temperature are correlated to structural parameters such as the index of refraction, etching rate in buffered hydrofluoric acid and infrared vibrational band strengths. Using the appropriate deposition parameters, it is possible to prepare, at 100 degreesC, silicon nitride dielectric films with electronic properties compatible with use as gate dielectrics of thin-film transistors.