JPS6435911A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To make it possible to form a groove of excellent controllability and having an impurity introduction layer on which a small area element can be isolated by a method wherein, after an impurity diffusion layer has been formed on the circumferential part of a crystal defect region, a crystal defect diffusion layer only is selectively removed, and then the surface layer of the impurity diffusion layer is removed. CONSTITUTION:After a crystal defect layer 2 has been formed on the desired region of a substrate 1, an impurity introduction layer 3 is formed on the surface of the crystal defect layer 2. Then, an impurity diffusion layer 4 is formed on the substrate 1 located on the circumference of the crystal defect layer 2 by conducting a heat treatment. Then, the crystal defect layer 2 only is selectively removed. Lastly, the surface of the impurity diffusion layer 4 is removed. As the impurity diffusion layer can be formed on the circumference of the processing groove uniformly in an excellent controllable manner, characteristic control can be conducted, and the irregularity in characteristics can also be reduced. Also, the stress of the processing groove can be reduced, and besides, as the impurity diffusion layer in the processing groove and on the circumference can be controlled by ion-implantation and a heat treatment subsequently conducted, the element isolation region can be made smaller in area in the amount of improvement in controllability.