Abstract: In a manufacturing method of a thin film transistor (1), the oxide film forming step is performed whereby: a process-target substrate (2) having a surface on which a gate oxide film (4) should be formed is immersed in an oxidizing solution containing a; active oxidizing species; and a gate oxide film (4) is formed through direct oxidation of polycrystalline silicon (51) on the process-target substrate (2). With this step, a silicon dioxide film (42) is formed while growing a silicon dioxide film (41) on the process-target substrate 2. Accordingly, the interface between the polycrystalline silicon (51) and the gate oxide film (4) is kept clean. The gate oxide film (4) is uniformly formed with excellent quality in insulation tolerance and other properties. Therefore, the thin film transistor (1) contains a high quality oxide film with excellent insulation tolerance and other properties which can be formed at low temperature.

Abstract: In a manufacturing method of a thin film transistor (1), the oxide film forming step is performed whereby: a process-target substrate (2) having a surface on which a gate oxide film (4) should be formed is immersed in an oxidizing solution containing an active oxidizing species; and a gate oxide film (4) is formed through direct oxidation of polycrystalline silicon (51) on the process-target substrate (2). With this step, a silicon dioxide film (42) is formed while growing a silicon dioxide film (41) on the process-target substrate 2. Accordingly, the interface between the polycrystalline silicon (51) and the gate oxide film (4) is kept clean. The gate oxide film (4) is uniformly formed with excellent quality in insulation tolerance and other properties. Therefore, the thin film transistor (1) contains a high quality oxide film with excellent insulation tolerance and other properties which can be formed at low temperature.

Abstract: The semiconductor of the present invention comprises at least an oxide film and a metal thin film on the surface of the semiconductor. The metal thin film includes a metal serving as an oxidation catalyst and has a thickness in the range of 0.5-30 nm. The oxide film comprises a metal serving as an oxidation catalyst and having a thickness in the range of 1-20 nm. Thus, a high-quality oxide film can be formed on the surface of the semiconductor substrate with high controllability without conducting a high temperature heat treatment. The invention employs the method of manufacturing the semiconductor has a steps of forming the first oxidation film having thickness in the range of 0.1-2.5 nm on the semiconductor substrate; forming the metal thin film (for example platinum film) serving as an oxide catalyst to the thickness in the range of 0.5-30 nm on the first oxide thin film; and then forming the second oxide film by heat treating in an oxidizing atmosphere at temperatures from 25 to 600° C.