A method of forming a thin film includes forming an interface layer stack on a semiconductor substrate. Forming the interface layer stack may include performing a first surface treatment on the semiconductor substrate under a reducing atmosphere. Forming the interface layer stack may include performing a second surface treatment on the semiconductor substrate. The first surface treatment may be performed under a reducing atmosphere and the second surface treatment may be performed under a nitridation atmosphere. The first surface treatment may include forming a lower interface layer on a surface of the semiconductor substrate and the second surface treatment may include forming an upper interface layer. The first surface treatment may include selectively removing at least one oxide material from a native oxide film on the semiconductor substrate.