Low Power DC Magnetron Sputtering of Indium Thin Films

Indium thin films and coatings have a variety of applications such as fabrication of ohmic contacts for select semiconductors and reduction of UV transmission. Studies involving magnetron sputtering of elemental indium is not well documented due to experimental difficulties linked to the low melting point of indium, and the low power and operating costs make DC magnetron sputtering an attractive alternative to conventional thin film synthesis methods. An argon background gas was used to form an indium-rich plasma plume from an indium sputtering target. Applied voltage, sputtering power, and deposition time were varied to produce a series of indium films. Light transmittance was measured via absorption spectroscopy for each film, and x-ray diffraction (XRD) was performed to determine film crystallinity characteristics. Average crystallite size was determined via the Scherrer equation from XRD data.