Low-temperature growth and orientational control in RuO{sub 2} thin films by metal-organic chemical vapor deposition

For growth temperatures in the range of 275 C to 425 C, highly conductive RuO{sub 2} thin films with either (110)- or (101)-textured orientations have been grown by metal-organic chemical vapor deposition (MOCVD) on both SiO{sub 2}/Si(001) and Pt/Ti/SiO{sub 2}/Si(001) substrates. Both the growth temperature and growth rate were used to control the type and degree of orientational texture of the RuO{sub 2} films. In the upper part of this growth temperature range ({approximately} 350 C) and at a low growth rate (< 30 {angstrom}/min.), the RuO{sub 2} films favored a (110)-textured. In contrast, at the lower part of this growth temperature range ({approximately} 300 C) and at a high growth rate (> 30 {angstrom}/min.), the RuO{sub 2} films favored a (101)-textured. In contrast, a higher growth temperatures (> 425 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 {approximately} 3--10 nm. Four-probe electrical transport measurements showed that the films were highly conductive with resistivities of 34--40 {micro}{Omega}-cm ({at} 25 C)