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

摘要

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. Four-probe electrical transport measurements showed that the films were highly conductive with resistivities of 34--40 (micro)(Omega)-cm ((at) 25 C).