Atomic layer deposition of zirconium oxide thin films

In this work, we studied an atomic layer deposition (ALD) process of ZrO2 with the precursors of tetrakis(dimethylamido)zirconium(IV) and water. We investigated the growth characteristics and mechanism of the ALD ZrO2 in the temperature range of 50-275 degrees C. Furthermore, the evolutions of film thickness and morphology were studied and discussed. It was found that the growth rate of ZrO2 decreased almost linearly with the increasing temperature from similar to 1.81 angstrom/cycle at 50 degrees C to similar to 0.8 angstrom/cycle at 225 degrees C. Interestingly, it was revealed that the growth of ZrO2 films ceased after a certain number of ALD cycles at a temperature higher than 250 degrees C. We also verified that the crystallinity of ZrO2 evolved with deposition temperature from amorphous to crystalline phase. In addition, the wettability of ZrO2 films was studied, showing a hydrophobic nature.