Heterogeneous Crystallinity of Atomic-Layer-Deposited Zinc Oxide Thin Film Using Resonance Raman Scattering Analysis

High-performance transistors with high electron mobility and reliability are prerequisites to the design of next-generation displays. This has inspired many researchers to focus on oxide thin film transistors having excellent electrical and optical characteristics. Among popular materials used, ZnO belongs to the family of compound semiconductors with a wide band gap of about 3.4 eV. ZnO is transparent to visible light, and serves as a suitable material for devices such as lasers and LEDs. In addition, ZnO thin films have the advantage of possessing high mobilities even at low temperatures. In this study, thin films of ZnO with various thicknesses were deposited using atomic layer deposition below 130celcius. Atomic force microscopic analysis was performed to elicit information on the interface states and bonding stress within the silicon substrate as also data on surface morphology of the ZnO thin film. The phase of each deposited sample was analyzed by X-ray diffraction. Unlike X-ray diffraction, Raman spectroscopy is a technique that measures the inelastic scattering of photons, and probe the surface and molecular structure. In this study, resonant Raman spectroscopy was resorted to facilitate characterization of ultra-thin (< 100 nm) films of ZnO. Graphic

Automated summary

High-performance transistors with high electron mobility and reliability are essential for next-generation displays. Researchers focus on oxide thin film transistors, with ZnO being a popular choice due to its wide band gap and transparency to visible light. In this study, ZnO thin films were deposited using atomic layer deposition at low temperatures, and analyzed using X-ray diffraction and resonant Raman spectroscopy for structural characterization.