Thin Film Deposition
Thin film deposition is a critical process for creating advanced materials with tailored properties, and I’ve used it to deposit refractory multi-principal element alloy (RMPEA) thin films, such as CrMoNbTaW and AlxCrFeCoNi, on substrates like sapphire and SiO2/Si. The setup, an AJA Orion DC magnetron co-sputtering system, enables precise deposition by simultaneously sputtering individual metal targets (Al, Cr, Mo, Nb, Ta, W, Fe, Co, Ni) onto a substrate. Before deposition, substrates are cleaned using Ar ion pre-sputtering to remove contaminants, ensuring strong film adhesion. The system operates at a low base pressure (e.g., 1.2 × 10⁻⁷ torr) and controlled working pressure, with substrate rotation to achieve uniform film thickness and composition. For my projects, I tuned the power for each target—ranging from 50W to 127W—to control the deposition rate and composition, resulting in films approximately 1.05 µm thick, with some featuring a 35 nm Al protective layer.
Magnetron sputtering works by generating a plasma in a low-pressure chamber, where argon gas is ionized and accelerated toward metal targets. These high-energy ions dislodge atoms from the target surfaces, which then deposit onto the substrate to form a thin film. The magnetron enhances efficiency by using magnetic fields to confine the plasma near the target, increasing the sputtering rate. This method allows precise control over film composition and thickness, making it ideal for creating complex alloys like RMPEAs. In my work, this technique enabled the deposition of uniform, high-quality films, which I later characterized to study their mechanical and structural properties for applications in extreme environments.
Read more on projects I’ve used magnetron sputtered thin films:
a. Oxidation of Refractory Multi Principal Element Alloy Thin Film