An electron paramagnetic resonance study of the Si(100)/Al2O3 interface defects

The defects at abrupt and ultrathin thermal silicon dioxide mediated Si( 100)/a-Al 2 O 3 interfaces have been studied by X-band electron paramagnetic resonance spectroscopy. Amorphous Al 2 O 3 films of 40 A thickness were deposited by atomic layer deposition at 300 °C. Different deposition conditions and post deposition annealing have been investigated. In all cases the main interface defects are found to be the two Pb centers (P b0 , P b1 ) known from previous Si/SiO 2 interface studies. The P b0 center is dominating in concentration with P b0 /P b1 ratios higher than 5. The concentrations are in the 10 12 -10 13 cm -3 range. Forming gas annealing at 450 °C did reduce the Pb center concentrations only by 50%.