Method for manufacturing semiconductor device

摘要

The present invention provides a manufacturing method of a semiconductor device at low cost and with high reliability. According to one feature of a method for manufacturing a semiconductor device includes the steps of forming a metal film over a substrate; forming a metal oxide film over the surface of the metal film by performing plasma treatment to the metal film in an atmosphere containing oxygen; forming a base film over the metal oxide film; forming an element layer having a thin film transistor over the base film; forming a protective layer over the element layer; forming an opening after selectively removing the metal film, the metal oxide film, the base film, the element layer, and the protective layer; separating the base film, the element layer, and the protective layer from the substrate; and sealing the base film, the element layer, and the protective layer by using flexible first and second films, in which an electron density of plasma around the substrate is 1x10¹¹ cm^-3 or more and 1x10¹³ cm^-3 or less and an electron temperature of the plasma treatment is 0.5 eV or more and 1.5 eV or less.