Structure and morphology characteristics of copper gallium oxide sputtered on different substrates

Transparent p-type semiconductor thin films exhibiting significant optical and electrical represent a promising material for applications in semiconductor devices. The quality of the films’ structures also critically influences the performance of this transparent semiconductor. Thus, this study investigates the structure and morphology of p-type semiconductor of CuGaO2 thin films fabricated onto different substrates such as the ITO, glass and quartz using RF Sputtering technique. From the X-Ray Diffraction (XRD) analysis, the CuGaO2 thin film on the ITO substrate has the most noticeable crystalline with the significant peaks have been observed at around 20 = 30. In contrast, the CuGaO2 on the glass and quartz substrates, both the XRD profiles demonstrated broad hump around 20 = 15 to 30. The absence of distinct peaks for both substrates confirming a poor crystalline of CuGaO2 thin films. Meanwhile, the morphology of the CuGaO2 thin films examined by the Atomic Force Microscopy (AFM) shows that films deposited on the ITO substrate had the rougher surface (Ra = 2.920 nm; Rq = 3.670 nm) as compared to the films on the glass and quartz substrate. From these findings, it indicates that the crystalline structure of the CuGaO2 is strongly influenced by the substrate material. These results provide the role of substrate selection in dictating the crystalline quality of CuGaO₂ thin films, suggesting that ITO substrates promote better crystallinity, which may enhance the films' electrical and optical functionalities.