VACUUM-DEPOSITED GOLD-FILMS .2. ROLE OF THE CRYSTALLOGRAPHIC ORIENTATION OF OXIDE-COVERED SILICON SUBSTRATES

The influence of the orientation of oxide-covered Si substrates on the morphology, overall surface roughness, and crystallographic texture o f 35 nm thick evaporated gold films was investigated using scanning tu nneling microscopy (STM), transmission electron microscopy (TEM), and cyclic voltammetry (CV). It is shown that gold films on Si (100) are s ubstantially different from gold films on Si (111). The films deposite d on Si (111) contain larger grains than those on Si (100). Annealed A u on Si (111) contains large atomically flat terraces which enable STM imaging at atomic resolution. The overall surface roughness measured by CV is smaller for annealed gold on Si (111), whereas for nonanneale d samples, the gold on Si (100) is smoother. While very strong {111} t exture is obtained for gold on Si (111), the Au on Si (100) is nontext ured. Annealing of the gold films deposited on Si promotes grain enlar gement, surface smoothness, and (for Si (111)) strong enhancement of t he gold {111} texture. The different gold morphologies obtained on oxi de-covered Si (111) and Si (100) are discussed in terms of the structu ral properties of the Si/Si oxide interface.