Vacuum‐Deposited Gold Films: II . Role of the Crystallographic Orientation of Oxide‐Covered Silicon Substrates

Abstract

The influence of the orientation of oxide-covered Si substrates on the morphology, overall surface roughness, and crystallographic texture of 35 nm thick evaporated gold films was investigated using scanning tunneling microscopy (STM), transmission electron microscopy (TEM), and cyclic voltammetry (CV). It is shown that gold films on Si (i00) are substantially different from gold films on Si (iii). The films deposited on Si (iii) contain larger grains than those on Si (I00). Annealed Au on Si (i i I) 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 (iii), whereas for nonannealed samples, the gold on Si (i00) is smoother. While very strong {iii} texture is obtained for gold on Si (III), the Au on Si (i00) is nontextured. Annealing of the gold films deposited on Si promotes grain enlargement, surface smoothness, and (for Si (Iii)) strong enhancement of the gold [Iii} texture. The different gold morphologies obtained on oxide-covered Si (iii) and Si (I00) are discussed in terms of the structural properties of the St/St oxide interface.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.100.58.76 Downloaded on 2015-06-07 to IP

Thermo-mechanical evolution of multilayer thin films: Part II. Microstructure evolution in Au/Cr/Si microcantilevers

“…The presence of a {001} sub-texture is also noted in some studies of gold [2,6]. For gold, the population of {111} grains has been seen to increase after subsequent thermal cycling at the expense of other crystallographic orientations [6]. A different study similarly notes an increase in the {111} texture at the expense of all other orientations, except {001}, which remained relatively constant [2].…”

“…That is, the {111} planes are parallel to the free surface, with random crystallographic orientation for the in-plane direction. This "{111} texture" has been observed for gold thin films grown on amorphous silicon dioxide [2], {0001} sapphire [3], {0001} highly oriented pyrolytic graphite [4], {0001} mica [5], {111} silicon [6], {111} NaCl [7,8], and {110} chromium [9,10]. The influence of surface energy increases as the thickness of the FCC metal film is decreased [1], resulting in very uniform {111} texture in ultra thin films.…”

“…In copper, it was noted that the population of {111} and {001} textures remains relatively constant even after multiple thermal cycles [12,13]. The presence of a {001} sub-texture is also noted in some studies of gold [2,6]. For gold, the population of {111} grains has been seen to increase after subsequent thermal cycling at the expense of other crystallographic orientations [6].…”

“…For example, the use of a {001} silicon substrate Thin Solid Films 515 (2007) 3224 -3240 www.elsevier.com/locate/tsf will result in random crystallographic orientation in gold films [6]. External influence may also affect the crystallographic texture.…”

Room temperature thermally evaporated thin Au film on Si suitable for application of thiol self-assembled monolayers in micro/nano-electro-mechanical-systems sensors

“…At lower deposition rates, the surface diffusion distance also increases and atoms can nucleate and bind to adjacent islands forming larger grains. At higher deposition rates, adatoms agglomerate at binding sites due to arrival of new atoms and so produce smaller grain sizes 28 . These effects are clearly seen in the images of Figure 4, where for the lower deposition rates there are large grains, and for the higher deposition rate, multigrain islands are observed.…”