Method of manufacturing silicon on insulator substrate

A method of manufacturing a silicon on insulator substrate, comprising:

• (a) preparing a semiconductor substrate including a rear side semiconductor layer, an insulating layer, and a front side semiconductor layer, a first surface of the insulating layer being in contact with a surface of the rear side semiconductor layer, and a first surface of the front side semiconductor layer being in contact with a second surface of the insulating layer;
• (b) forming a high concentration region in the front side semiconductor layer, including a plurality of regions arranged in a lateral direction of the front side semiconductor layer, in which an impurity concentration is increased, by repeatedly injecting impurities into the front side semiconductor layer while changing an area of the front side semiconductor layer into which the impurities are injected, one of the plurality of regions having a different impurity concentration than another of the plurality of regions, and the impurities being n-type impurities or p-type impurities;
• (c) heating the semiconductor substrate having the high concentration region;
• and
• (d) epitaxially growing an additional semiconductor layer on a second surface of the front side semiconductor layer of the heated semiconductor substrate, the additional semiconductor layer having a lower impurity concentration than the high concentration region;
• wherein, in step (c), an average diffusion length of impurities in the front side semiconductor layer is twice a thickness of the front side semiconductor layer or more.