| 摘要 |
PURPOSE:To simplify the forming process of a contact layer and to improve the yield of good thin film transistor by adding an impurity to part of a semiconductor film formed on a substrate in a gas discharge atmosphere which contains compound of impurity element to form the contact layer. CONSTITUTION:A gate electrode 2, a gate insulating film 3, a semiconductor film 4 and a protective insulating film 5 are formed on a substrate 1. When the film 4 is formed, for example, of crystalline or polycrystalline silicon, it is discharged in a gas atmosphere which contains compound of any of or compounds of any several types of nitrogen, phosphorus, arsenic, antimony, boron, aluminum and gallium to form a contact layer 7 on a semiconductor film surface. In order to form the layer 7 to an N<+> type layer, phosphine of phosphorus compound or phosphine of gallium compound may be used, or in order to, on the contrary, form it to a P<+> type, compound of diborane or organic aluminum is used. Many steps from the coating of resist can be eliminated, and the film 5 is used as a mask at the time of forming the layer 7, and only one of discharging step may be sufficient. |
