Method for manufacturing semiconductor device with film transistor

The invention provides a manufacturing method of a semiconductor device, which comprises the following steps: a semiconductor film comprising silicon is formed on the substrate; the semiconductor filmcomprises at least a high-resistivity first region and a drain second region; a gate insulating film is formed on the semiconductor film, where gate electrodes are formed; the gate insulating film isarranged between the gate electrodes; the second region of the semiconductor film exposes from the gate insulating film to form a metal film which covers the semiconductor film, the gate insulating film and the gate electrodes and contacts with the second region of the semiconductor film; a conductive type is produced by adding impurity with a first concentration into the first region to form thehigh-resistivity region; the conductive type is produced by adding impurity with a second concentration higher than the first concentration into the second region to form a drain region; wherein, a metal silicide layer is not