Effect of rapid thermal annealing on structural and electrical characteristics of Ni-Al-O gate dielectrics

The high-k Ni-Al-O gate dielectric films were deposited on Si (100) and platinized Si (111) substrates by reactive pulsed-laser deposition (PLD) at 400 degrees C, and then annealed in a rapid thermal annealing furnace at various temperatures ranging from 600 degrees C to 750 degrees C. The structural and electrical properties of the Ni-Al-O films were investigated. It is found that Ni-Al-O thin film annealed up to 750 degrees C is amorphous and the root-mean-square roughness of the film is less than 0.5 nm. The dielectric constant of the film measured at the frequency of 1 MHz is determined to be 9.9 with Pt/Ni-Al-O/Pt structure. The capacitance and leakage current density of the film annealed above 700 degrees C are 135 pF and 7.0x10(-7) A/cm(2), respectively. The results indicate that the amorphous Ni-Al-O film is a promising candidate for high-k gate dielectric.