Al2O3 formation on si by catalytic chemical vapor deposition

Catalytic chemical vapor deposition (Cat-CVD) has been developed to deposit Al2O3 thin films on Si crystals using N2 bubbled tri-methyl aluminum [Al(CH3)3, TMA] and molecular O2 as source species and tungsten wires as a catalyzer. The catalyzer dissociated TMA at approximately 600 C. The maximum deposition rate was 18 nm min-1 at a catalyzer temperature of 1000 C and substrate temperature of 800 C. MOS diodes were fabricated using gates composed of 32.5-nm-thick alumina film deposited at a substrate temperature of 400 C. The capacitance measurements resulted in a relative dielectric constant of 7.4, fixed charge density of 1.74 x 1012 cm-2, small hysteresis voltage of 0.12 V, and very few interface trapping charges. The leakage current was 5.01 x 10-7 A cm-2 at a gate bias of 1 V. 16 refs.