A group III-V nitride-based semiconductor substrate having a group III-V nitride-based semiconductor thick film with a same composition in the entire film. The thick film has a first region with a predetermined impurity concentration and a second region with an impurity concentration lower than the first...http://www.google.fr/patents/US7271404?utm_source=gb-gplus-shareBrevet US7271404 - Group III-V nitride-based semiconductor substrate and method of making same
Group III-V nitride-based semiconductor substrate and method of making same
