Chemical investigation of the Al2O3 ultra-thin films

Ultra-thin layers of oluminum oxide (Al2O3) were deposited by ALD method. Atomic layer deposition provides precise thickness control down to a single atomic layer. The precursors used were trimethylaluminum (Sigma-Aldrich) and purified water. The deposition of the atomic layer was carried out at 200 °C. Samples with a thickness of 2 and 8 nm of alumina were selected for the XPS measurements. XPS tests were carried out at room temperature under ultrahigh vacuum conditions and pressures below 1.1 x 10-6 Pa using Omicron NanoScience equipment. Data analysis was performed with the CASA XPS software package using Shirley background subtraction and Gauss-Lorentz curve fitting algorithm by the least-squares method - GL (30). The resulting spectra were calibrated to obtain a binding energy of 285.00 eV for C 1s.