Growth of copper–phthalocyanine thin films on mica using a two-stage deposition technique

Abstract

We have developed a two-stage deposition technique to fabricate copper–phthalocyanine (Cu–Pc) thin films with good crystallinity and a molecularly flat surface. The Cu–Pc thin films were grown on mica substrates using an ionized cluster beam (ICB) system, and examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) techniques. In the two-stage deposition technique, a thin layer (2 nm) of Cu–Pc film was deposited at a temperature below 338 K in the first stage, and a Cu–Pc film of designed thickness (10 nm) was deposited at a temperature near 473 K in the second stage. These thin films had a well developed (002) texture showing good crystallinity, and unidirectionally aligned, elongated crystallites with the root mean square (rms) surface roughness of 1.8 nm, which is less than the 2 molecular diameter of Cu–Pc. Various factors affecting the growth of Cu–Pc films during the two-stage deposition are examined to elucidate the controlling mechanisms.