DEVICE ISOLATION METHOD OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A device isolation method of semiconductor device is provided which is capable of decreasing the thermal stress by decreasing time of diffusion process and of improving the degree of integration of device by decreasing lateral diffusion of impurity. CONSTITUTION: A method comprises steps of: forming the first cut-off layer having the first aperture exposing a certain portion of the semiconductor substrate(31) on the semiconductor substrate(31) and forming the first ion implantation region(37) of the first conductive type on the semiconductor substrate(31); removing the first cut-off layer and the epitaxial layer(39) of the second conductive type on the semiconductor substrate(31); forming the second cut-off layer(41) having the second aperture(43) exposing a certain portion corresponding to the first ion implantation region(37) on the epitaxial layer(39) and forming the second ion implantation region(45) of the first conductive type on the epitaxial layer(39); forming the impurity containing layer on the second cut-off layer(41) so that it is contacted to the exposed portion of the epitaxial layer(39) through the second aperture(43); and diffusing the impurity in the impurity containing layer(47) to the epitaxial layer(39), while activating the impurity ion in the first and second ion implantation regions(37, 45) to form the device isolation region at the epitaxial layer(39).