Semiconductor device and production method thereof

This Application is intended to provide a method for effectively protecting paper or film-form media against forgery. This can be achieved by, for example, embedding in a paper or film-form medium a thin semiconductor chip up to 0.5 mm square, equipped with an antenna, and characterized in that the side walls of the semiconductor chip are formed using oxide films, and in that multiple such semiconductor chips are separated by etching. Limiting the size of these semiconductor chips to 0.5 mm or less enables improvement against bending and concentrated loads, and separating the semiconductor chips by etching results in semiconductor chips free from cracking and breakage. Also, the oxide films constituting the side walls of the semiconductor chips prevents short-circuiting at edges during connection to the respective antennas. Thus, simplified processes can be adopted.