A method for producing a mos - transistor with ldd - structure

摘要

A process for producing a MOS transistor with the following steps is specified: - forming a gate oxide film on a substrate; - forming a p+ polysilicon film, doped with p-type ions of another material, on the gate oxide film; - applying an insulation film and a photoresist film in sequence on the p+ polysilicon film; - subjecting the resultant structure to a pattern-formation process, in order to expose a part of the insulation film; - using an etching process on the exposed insulation film, the photoresist film being used as mask; - implanting fluorine ions in the p+ polysilicon film, the remaining insulation film being used as mask; - removing the residual photoresist films; - forming an annealing step to form p--type source/drain regions; - using an etching step on the p+ polysilicon film, in order to produce a gate, the remaining insulation film being used as mask; - removing the residual insulation film; - depositing an oxide film over the entire resultant structure; - anisotropic etching of the oxide film, in order to form spacers in the lateral walls of the gate; - implanting p-type ions of other materials in the substrate with high density, in order to form p+-type source/drain regions in addition to the p--type source/drain regions