The invention provides a method of manufacturing a semiconductor device, an array substrate and a display apparatus. The method of manufacturing the semiconductor device comprises the following steps of depositing a first oxide semiconductor layer on a substrate and spraying an H2O2 solution on the first oxide semiconductor layer; using ultraviolet light to irradiate the H2O2 solution so as to promote H2O2 decomposition; and drying the H2O2 solution existing on the first oxide semiconductor layer and continuously depositing a second oxide semiconductor layer.