Low temperature atomic layer deposition of noble metals using ozone and molecular hydrogen as reactants

Abstract

Atomic layer deposition (ALD) of noble metals by thermal processes has relied mostly on the use of molecular oxygen as a reactant at temperatures of 200°C and above. In this study, the concept of using consecutive ozone and molecular hydrogen pulses with noble metal precursors in ALD is introduced for palladium, rhodium, and platinum metals. This approach facilitates the growth of noble metal thin films below 200°C. Also the ALD of palladium oxide thin films is demonstrated by the ozone-based chemistry. The growth rates, resistivities, crystallinities, surface roughnesses, impurity contents, and adhesion of the films to the underlying Al2O3 starting surface are reported and the results are compared with the most common noble metal ALD processes.