Semiconductor device and method of manufacturing 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 thesemiconductor device. In a semiconductor device including a transistor having a bottom gate structure in which an insulating layer serving as a channel protection film is provided on an oxide semiconductor film, an impurity removal process is performed after forming 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. Elements in the etching gas can be prevented from remaining as impurities on the surface of the oxide semiconductor film. The impurity concentration in the surface of the oxide semiconductor film is 5 * 10 atoms/cm or less, preferably 1 * 10 atoms/cm or less. 本公开涉及半导体装置以及半导体装置的制造方法。本发明提供一种高可靠性的半导体装置以及该半导体装置的制造方法。在具有在氧化物半导体膜上设置有用作沟道保护膜的绝缘层的底栅结构的晶体管的半导体装置中，通过在形成以接触于氧化物半导体膜的方式设置的绝缘层及/或源电极层及漏电极层之后，进行杂质去除处理，可以防