A method for forming impurity junction regions of a semiconductor device wherein impurity junction regions with a small depth are formed by selectively forming defecting regions and amorphous regions in a semiconductor substrate by an implantation of impurity ions with a large molecular weight, thereby achieving an improvement in the characteristics of the semiconductor device. The method includes the steps of forming a first photoresist film pattern on an active region portion of a semiconductor substrate, implanting first impurity ions in exposed portions of said semiconductor substrate using said first photoresist film pattern as a mask, thereby forming defecting regions, removing said first photoresist film pattern, forming a second photoresist film pattern on the exposed semiconductor surface portions except for the portion which was covered with said first photoresist film pattern, implanting second impurity ions in exposed portions of said semiconductor substrate using said second photoresist film pattern as a mask, thereby forming amorphous regions, removing said second photoresist film pattern, and implanting third impurity ions in said active region portion of said semiconductor substrate, thereby forming impurity junction regions.