Large-area atomic layer deposition and characterization of Al2O3 film grown using AlCl3 and H2O

The atomic layer deposition (ALD) process of Al2O3 films in a large area traveling wave reactor was studied as well as the materials and electrical characteristics of the films. The precursors used in the deposition of Al2O3 were AlCl3 and H2O. The dependence of growth rate and Cl content of Al2O3 films on the growth temperature was investigated at the reactor temperature ranging from 300 .deg. C to 500 .deg. C. The growth rate decreased from 0.66 to 0.45 A/cycle as the reactor temperature increased from 330 .deg. C to 500 .deg. C. The etch rate of the films and the annealing effect on the crystallinity of Al2O3 films were also studied. The dependence of characteristics of Al2O3 on the growth conditions was discussed according to the growth mechanism. The electrical characteristics including breakdown electric field and leakage current of the Al2O3 films were measured to determine the effect of growth temperature on electrical properties. The breakdown electric field of Al2O3 films grown at 300 .deg. C and 500 .deg. C were 5.7 and 4.5 MV/cm, respectively. The 500 A thick-Al2O3 film revealed the leakage current density in the order of 10-8 A/cm2 with 3 MV/cm electric field