Electrical properties of electron cyclotron resonance plasma-deposited silicon dioxide: Effect of the oxygen to silane flow ratio

Silicon dioxide layers have been deposited at 150 degrees C from electron cyclotron resonance plasma using pure oxygen and argon-diluted silane. The sign of the oxide charge depends on the flow ratio and also on the post-deposition processing. In the post-metallization annealed layers, net negative charge densities as low as 1 x 10(10) q cm(-2) have been obtained in the best conditions. Most of the charge seems to be trapped at oxide centres and the measured mobile charge is negligible. Post-oxidation treatments did not anneal out the oxide traps but released additional positive charge in the oxide.