Low-temperature growth and orientational control in RuO2 thin films by metal-organic chemical vapor deposition

For growth temperatures in the range of 275 degrees C to 425 degrees C, highly conductive RuO2 thin films with either (110)- or (101)-textured orientations have been grown by metal-organic chemical vapor deposition (MOCVD) on both SiO2/Si(001) and Pt/Ti/SiO2/Si(001) substrates. Both the growth temperature and growth rate were used to control the type and degree of orientational texture of the RuO2 films. In the upper part of this growth temperature range (similar to 350 degrees C) and at a low growth rate (< 3.0 nm/min.), the RuO2 films favored a (110)-textured orientation. In contrast, at the lower part of this growth temperature range (similar to 300 degrees C) and at a high growth rate (> 3.0 nm/min.), the RuO, films favored a (101)-textured orientation. In contrast, higher growth temperatures (> 425 degrees C) always produced randomly-oriented polycrystalline films. For either of these low-temperature growth processes, the films produced were crack-free, well-adhered to the substrates, and had smooth, specular surfaces. Atomic force microscopy showed that the films had a dense microstructure with an average grain size of 50-80 nm and a rms. surface roughness of similar to 3-10 nm. Four-probe electrical transport measurements showed that the films were highly conductive with resistivities of 34-40 mu Omega-cm (at 25 degrees C). Published by Elsevier Science S.A.