Programmed substrate temperature ramping to increase nucleation density and decrease surface roughness during metalorganic chemical vapor deposition of aluminum

We discuss substrate temperature ramping effects during chemical vapor deposition of aluminum on nucleation density, texture, surface roughness, and resistivity of the resulting films. Results from three different process protocols are presented. Ramping the temperature down during the deposition from 673 K resulted in a larger fraction of small nuclei compared to deposition at a constant temperature of 573 K. From among the protocols studied, the lowest surface roughness was obtained by initially depositing for a short time while ramping the temperature down from 673 K, followed by deposition at 573 K, compared to all the other films. The same process protocol resulted in the highest Al(111) texturing, highest reflectivity, and lowest resistivity.