Patent ID: 6838324

Claim:
A method of fabricating an EL display device, said method comprising the steps of: forming a gate wiring on an insulating surface; forming a gate insulating film and an amorphous semiconductor film into a laminate sequentially without exposing them to an atmosphere on the gate wiring; irradiating the amorphous semiconductor film with at least a light selected from the group consisting of an infrared light and an ultraviolet light to crystallize the amorphous semiconductor film into a crystalline semiconductor film in an oxidizing atmosphere and to form an oxide film at a same time; covering a first portion of the crystalline semiconductor film with a first mask; providing an impurity element into second portions of the crystalline semiconductor film at a first concentration through the oxide film using the first mask; providing the impurity element into third portions of the crystalline semiconductor film at a second concentration through the oxide film using a second mask, wherein the second concentration is higher than the first concentration, wherein the first portion of the crystalline semiconductor film is a channel forming region while the third portions of the crystalline semiconductor film are source and drain regions, wherein fourth portions of the crystalline semiconductor film which are not provided with the impurity at the second concentration but only the first concentration are low concentration impurity regions.