| 摘要 |
In a method for producing a recess-gate field effect transistor including a recess in a semiconductor substrate and a gate electrode disposed in the recess, a photoresist serving as a spacer film during lifting-off is applied onto the semiconductor substrate on which source and drain electrodes are formed, a first insulating film is formed on the entire surface of the device, a resist pattern, which has an opening for processing the first insulating film, is formed on the first insulating film, the first insulating film and the photoresist film serving as a spacer film are etched using the resist pattern as a mask to form an opening whose dimension increases downwards, a pair of side walls comprising second insulating film, which have thicknesses in a transverse direction at the lower end part thereof larger than the side etching amount of a recess achieved at a subsequent etching process, are formed on both side walls of the opening, the semiconductor substrate is etched using the opening narrowed by the pair of side walls as a mask to form a recess, the side walls are selectively removed by etching, gate metal is deposited on the entire surface of the device, and unnecessary gate metal is removed by lifting-off. <IMAGE> |
