The effect of substrate temperature on structural and morphological properties of Au/Si(1 1 1) thin films

We report here the effects of substrate temperature on the orientation and surface morphology of 100 nm thick gold films, using scanning tunneling microscopy and X-ray diffraction. The gold films were deposited using molecular beam epitaxy technique onto Si(1 1 1) 7 × 7 substrates. Ex situ characterizations are performed using scanning tunneling microscope at room temperature. X-ray diffraction measurements reveal the (1 1 1) orientation of the film deposited at 580 °C. We present data showing the evolution of the RMS roughness amplitude of the gold films as a function of substrate temperature during deposition. For our purposes, the best compromise between roughness and grain size is found to occur for a substrate temperature maintained at 580 °C.