Patent ID: 7294201

Claim:
A method of manufacturing a crystal of a III-V compound of a nitride system, the method comprising: growing a crystal of a III-V compound of the nitride system having a predetermined thickness on a surface selected from a group of surfaces consisting of a surface of a basal body and a surface of a base layer; wherein the growth step comprises: forming a first III-V nitride pattern in one position in the crystal in a direction of a thickness of the crystal, the first pattern including a plurality of first elements distributed in a lateral direction with respect to the crystal at a pitch, each of the first elements forming an elongate stripe extending in a longitudinal direction that is substantially orthogonal to said lateral direction and each of the first elements having at least one width measured in the lateral direction; depositing an intermediate layer directly on a surface of the first pattern; and forming a second III-V nitride pattern in another position in the crystal in the direction of the thickness of the crystal directly on a surface of said intermediate layer, the second pattern including a plurality of second elements distributed in the lateral direction with respect to the crystal at a pitch, each of the second elements forming an elongate stripe extending in the longitudinal direction and each of the second elements having at least one width measured in the lateral direction; wherein the pitch of said first pattern and the pitch of said second pattern are different; and wherein the second pattern partly overlies and partly does not overlie said first pattern in the direction of the thickness of the crystal due at least in part to the different pitches of the first pattern and the second pattern.