SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

The invention discloses a semiconductor device and a manufacturing method of the semiconductor device. The invention relates to a semiconductor device and a manufacturing method of the semiconductor device. The invention provides a highly reliable semiconductor device and a method for manufacturing the semiconductor device. In a semiconductor device having a transistor having a bottom gate structure in which an insulating layer serving as a channel protection film is provided over an oxide semiconductor film, an impurity removal process is performed after the insulating layer and/or a source electrode layer and a drain electrode layer provided so as to be in contact with the oxide semiconductor film is formed. Elements in the etching gas can be prevented from remaining on the surface of the oxide semiconductor film as impurities. The impurity concentration in the surface of the oxide semiconductor film is 5 * 10 < 18 > atoms/cm < 3 > or less, preferably 1 * 10 < 18 > atoms/cm < 3 > or less. 本公开的发明名称是"半导体装置以及半