Nucleation and growth of copper oxide films in MOCVD processes using the beta-ketoiminate precursor 4,4 '-(1,2-ethanediyldinitrilo)bis(2-pentanonate) copper(II)

MOCVD of copper(I) and copper(II) oxides has been studied in a horizontal, low-pressure reactor using the beta-ketoiminate copper(II) complex of 4,4'-(1,2-ethanediyldinitrilo)bis(2-pentanone) as precursor (Cu(acen)). Film morphologies and growth kinetics are strongly influenced by the nature of the substrate. On glass, no deposition occurs below 460 degrees C, whilst significant rates have been measured on CuO in the 300 degrees C-500 degrees C temperature range. Sizeable rates have been observed on SiO2/Si only above 360 degrees C. SEM investigations show that morphologies of films grown on CuO are little affected by the substrate temperature and precursor partial pressure (P-Cu(acen)). In contrast, morphologies of films on SiO2/Si depend upon deposition temperature and P-Cu(acen) since smaller grains can be grown either by decreasing temperature or increasing P-Cu(acen). The dependence of these properties upon the nature of the substrates suggests that nucleation processes play a determinant role in the film quality.