Method for forming ohmic contact

摘要

A method for forming ohmic contact has the steps of a) a process for forming an insulating film having a predetermined thickness on a diffusive layer formed on a semiconductor substrate; b) a process for forming a mask on the insulating film; the mask having a small selective ratio with respect to the insulating film and having an opening portion for a contact hole; c) a process for implanting ions into the diffusive layer through the opening portion; d) a process for taking heat treatment to electrically activate the implanted ions; e) a process for completely removing the mask and forming the contact hole by simultaneously etching the mask and the insulating film exposed through the opening portion of the mask; and f) a process for making an electrode come in ohmic contact with the semiconductor substrate exposed from the formed contact hole. In this method, the ohmic contact is formed with high accuracy with respect to a fine contact hole.