Method for forming p-type semiconductor region, and semiconductor element

Abstract

A substrateis set in a film-forming apparatus, such as a metal organic vapor phase epitaxy system, and a GaN buffer film, an undoped GaN film, and a GaN filmcontaining a p-type dopant are successively grown on the substrateto form an epitaxial substrate E. The semiconductor filmalso contains hydrogen, which was included in a source gas, in addition to the p-type dopant. Then the epitaxial substrate Eis placed in a short pulsed laser beam emitter. A laser beam Lis applied to a part or the whole of a surface of the epitaxial substrate Eto activate the p-type dopant by making use of a multiphoton absorption process. When the substrate is irradiated with the pulsed laser beam Lwhich can induce multiphoton absorption, a p-type GaN filmis formed. There is thus provided a method of optically activating the p-type dopant in the semiconductor film to form the p-type semiconductor region, without use of thermal annealing.