MANUFACTURE OF SEMICONDUCTOR ELEMENT

摘要

PURPOSE:To eliminate both of the addition of impurity element of III-group or V-group and the high temperature heat treatment of a substrate by a method wherein the surface of a p-type silicon substrate is heated by a laser beam to form a p-n junction. CONSTITUTION:A silicon nitride film 2 is formed on the surface of a p-type silicon substrate 1 to improve a heating efficiency. Long time heat treatment at about 450 deg.C is carried out to create oxygen donors and convert the p-type silicon substrate 1 into the n-type silicon substrate. The substrate 1 is locally heated by a heating source 3 to create oxygen donors. The heated region 4 in which the oxygen donors are created becomes high concentration n-type. Short time heat treatment at about 650 deg.C is carried out to eliminate the oxygen donors and convert both of the heated region 4 and the silicon substrate 1 into p-type. Finally, short time heat treatment at about 450 deg.C is carried out to activate the oxygen donors in the heated region 4 and convert the heated region 4 into n-type. Thus, a p-n junction consisting of the n-type heated region 4 and the p-type silicon substrate 1 can be formed.