US Patent 6958500 Semiconductor device having low resistivity source and drain electrodes

A dummy gate crossing an active area having ends in contact with an isolation area is formed. A low area lower than a dummy gate is formed in the isolation area. Side walls are formed in the active area except the dummy gate. A semiconductor film having the same height as that of the dummy gate is formed in the low area. An oxide film is formed on the semiconductor film. The dummy gate is removed by the oxide film as a mask. The oxide film is removed by the semiconductor film as a stopper.