Patent ID: 6057243
Filing Date: 2000-05-02
Classification: H01L

Abstract:
A method for producing a semiconductor device comprising the steps of:forming a conductive layer on a semiconductor substrate whereby said conductive layer has a sidewall surface adjacent to a top surface;forming a first diffusion layer containing a conductive impurity at a first concentration in the semiconductor substrate by ion implantation using the conductive layer as a mask;forming a sidewall mask layer containing silicon over the etching stopper film facing the sidewall surface of the conductive layer;forming a sidewall mask layer containing silicon over the etching stopper film facing the sidewall surface of the conductive layer;forming a second diffusion layer containing a conductive impurity at a second concentration and connecting to the first diffusion layer in the semiconductor substrate by ion implantation using the sidewall mask layer as a mask;removing the sidewall mask layer selectively by etch controlling the ratio of etching rate between the sidewall mask layer and the etching stopper film;forming an insulating film over the etching stopper film; andforming a contact hole reaching the second diffusion layer through the insulating film,wherein at least the step of forming a sidewall mask layer or the step of forming a second diffusion layer includes a step of introducing a conductive impurity into the sidewall mask layerand, a heat treatment step for activating the conductive impurity in the sidewall mask layer before the step of removing the sidewall mask layer.