In this study, we focused on the electrical and reliability characteristics of a ferroelectric diode (FE diode) composed of an InGaZnO (IGZO)/Hf<inline-formula> <tex-math notation="LaTeX">_{\text{x}}</tex-math> </inline-formula>Zr<inline-formula> <tex-math notation="LaTeX">_{\text{1-\text{x}}}</tex-math> </inline-formula>O<inline-formula> <tex-math notation="LaTeX">_{\text{2}}</tex-math> </inline-formula> (HZO) stack by controlling the bulk and interface defect of IGZO. Initially, to achieve the high ON/OFF ratio, we reduced the bulk defects in the IGZO film during deposition by adjusting the oxygen partial pressure. This strategy effectively reduced the OFF-state leakage current in the high-resistance state (HRS), as demonstrated by current-voltage ( I -<inline-formula> <tex-math notation="LaTeX">\textit{V}\text{)}</tex-math> </inline-formula> characteristics and x -ray photoelectron spectroscopy (XPS) analysis. Subsequently, to enhance the endurance characteristics, we considered the application of microwave annealing (MWA) as an alternative to the conventional rapid thermal annealing (RTA) to decrease interface traps. Upon assessing interface trap densities, we confirmed an improved interface quality within double-layered structure. Consequently, the IGZO/HZO FE diode device exhibited a remarkable ON/OFF ratio of 4 <inline-formula> <tex-math notation="LaTeX">\times</tex-math> </inline-formula> 10<inline-formula> <tex-math notation="LaTeX">^{\text{5}}</tex-math> </inline-formula> and cycling endurance of 10<inline-formula> <tex-math notation="LaTeX">^{\text{10}}</tex-math> </inline-formula>, underlining the importance of defect management in device performance.