Low dislocation buffer and process for production thereof as well as device provided with low dislocation buffer

摘要

To provide a low dislocation buffer, which can be formed by a simple process for a short period of time, and there is no fear of producing cracks, a first layer made of a nitride semiconductor containing an impurity at a concentration exceeding its doping level is laminated a predetermined number of times alternately with a second layer made of a nitride semiconductor containing no impurity on a substrate to form a superlattice structure in a low dislocation buffer formed between the substrate and a nitride semiconductor as a device material to be formed for constituting a device structure on the substrate.