IMPACT OF RADIO FREQUENCY POWER AND DEPOSITION TIME ON SPUTTERED GOLD THIN FILM GROWTH

Abstract

The viability of Au thin film systems is decided by the growth parameters related diffusion mechanism where the gold layers can be made extremely thin without sacrificing their reliability. Controlling the characteristics of this process for Au over the various one- and two-layer base metal systems is challenging. Furthermore, Au acts as an important catalytic component in nanostructured material fabrication. Conventionally, catalyst assisted vapor-liquid-solid (VLS) process is used to synthesize semiconductors nanowire. In the VLS process, growth catalysts such as Au, Sn and In are exploited as energetically effective site for vapor-phase elements adsorption. Moreover, they require low eutectic temperatures where Au is highly suited. Thus, the size control of the metal catalyst is essential for semiconductors nanostructures growth. Selection of right deposition time and optimum RF power is very crucial to achieving the high quality Au catalyst thin film. The RF power and deposition time dependent morphological evolution of magnetron sputtered gold thin film is reported. Samples are prepared on a Si(100) substrate with varying deposition time (5 s, 10 s, and 20 s) and RF power (20 W, 30 W and 50 W). FESEM micrograps clearly manifested the formation of gold droplet, where the density of these droplets is found to increase with increasing deposition time. RF power of 50 W and 20 s deposition time produced smooth Au thin film surface devoid of droplets. Results suggest that for high quality Au catalyst thin film formation RF power and deposition time must be optimized.