Low temperature deposition of silicon nitride using Si3Cl8

• We deposited SiN by atomic layer deposition using Si3Cl8 and NH3.
• The films show a step coverage > 80% in high aspect ratio structures.
• The films show a significant C–V-hysteresis, as required for charge trap based memories.

We demonstrate the deposition of SixNy thin films using octachlorotrisilane (Si3Cl8) and ammonia between 300 and 500 °C by an atomic layer deposition-like growth mechanism. Although there are chemical vapor deposition growth mechanisms present, which lead to an incomplete saturation, a step coverage > 80% in high aspect ratio (> 60:1) trenches could be achieved. The deposited films oxidize after contact with ambient air leading to substoichiometric N/Si ratios. Increasing the deposition temperature diminishes this oxidation. At temperatures > 390 °C a bulk N/Si ratio of ~ 1.3 is achieved. The capacitance–voltage (C–V) measurements of these films yield a k value of ~ 6 and a strong C–V hysteresis indicates significant charge trapping.