Atomic layer deposition of ZrO2 thin films using dichlorobis [bis-(trimethylsilyl)amido] zirconium and water

Abstract

A new zirconium precursor, (ZrCl2[N(SiMe3)(2)](2)), and H2O oxidant were used to deposit ZrO2 films on a Si substrate, for alternative gate dielectrics, via atomic layer deposition (ALD) in the temperature range 150-350 degreesC. The film growth showed the self-limiting characteristic of ALD, with a maximum growth rate of 1.6 Angstrom per cycle at 175 degreesC. The compositions of as-deposited films were analyzed by Rutherford backscattering spectroscopy (RBS), X-ray photoelectron spectroscopy (XPS), and secondary ion mass spectroscopy (SIMS), and it was found that the amount of silicon in ZrO2 films was uniformly distributed throughout the film in the range of 1.1 at.-% to 5.4 at.-% as the deposition temperature was increased. After rapid thermal annealing in an Ar atmosphere at 700-900 degreesC, the amorphous as-deposited film was crystallized mainly in the cubic phase, and no significant change in surface morphology was observed.