New approach to the ALD of bismuth silicates:: Bi(CH2SiMe3)3 acting as a precursor for both bismuth and silicon

Bismuth silicate thin films were deposited using atomic layer deposition (ALD) with a novel precursor, Bi(CH2SiMe3)(3), serving as both bismuth and silicon source. Precursor synthesis, analysis, and crystal structure are also reported. Bi(CH2SiMe3)(3) forms hexagonal crystals with a = 10.7110(11) angstrom, b = 10.7110(11) angstrom, c = 10.2500(7) angstrom; space group P6(3). The deposition temperature of thin films was 200-450 degrees C, where a constant growth rate of 0.4 angstrom per cycle was obtained between 250 degrees C and 350 degrees C. Impurity levels of bismuth silicate films deposited at 250 degrees C were below 0.2 at.- % and 0.1 at.- % for carbon and hydrogen, respectively. The as-deposited films were amorphous, and post-synthetic annealing in an atmosphere of N-2 or O-2 at 400-1000 degrees C was applied.