Growth of Aluminum Molybdenum Oxide Films by Atomic Layer Deposition with Using Trimethylaluminum, Molybdenum Oxytetrachloride, and Water

— In this paper, we report on the growth of aluminum molybdenum oxide (Al x Mo y O z ) films via atomic layer deposition (ALD) with the use of trimethylaluminum (TMA) (Al(CH 3 ) 3 ), molybdenum oxytetrachloride (MoOCl 4 ), and water. The film growth process was studied in situ using a quartz crystal microbalance and ex situ using various X-ray techniques. Al x Mo y O z ALD was performed using supercycles consisting of TMA/H 2 O and MoOCl 4 /H 2 O subcycles. We obtained two types of films, with the subcycles in the ratio 1 : 1 (1Al1MoO) and 1 : 7 (1Al7MoO). Film growth at 150°C was shown to be a linear process, with growth rate of 3.0 and 5.7 Å/supercycle for 1Al1MoO and 1Al7MoO, respectively. The density of the 1Al1MoO and 1Al7MoO films were 3.7 and 3.9 g/cm 3 , respectively, and their surface roughness did not exceed 20 Å. The oxidation state of the molybdenum in the films found to be 6+, 5+, and 4+. X-ray diffraction characterization showed that the films had an amorphous structure.