Study the passivation characteristics of microwave annealing applied to APALD deposited Al₂O₃ thin film

In this study, a self-developed atmospheric pressure atomic layer deposition (APALD) system is used to deposit Al₂ O₃ passivation film, along with the use of precursor combinations of Al(CH₃)₃ /H₂ O to improve its passivation characteristics through a short-time microwave post-annealing process. Comparing the unannealed and microwave-annealed samples whose temperature is controlled at 200–500^◦ C, APALD non-vacuum deposited film can be realized with a higher film deposition rate, which is beneficial for increasing the production throughput while at the same time reducing the operating cost of vacuum equipment at hand. Since the microwave has a greater penetration depth during the process, the resultant thermal energy provided can be spread out evenly to the entire wafer, thereby achieving the effect of rapid annealing. The film thickness is subsequently analyzed by TEM, whereas the chemical composition is verified by EDS and XPS. The negative fixed charge and interface trap density are analyzed by the C-V measurement method. Finally, the three major indicators of τ_eff, SRV, and IVoc are analyzed by QSSPC to duly verify the excellent passivation performance.