LED sapphire substrate with groups of three projections on the surface

A sapphire substrate having a principle surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device, the sapphire substrate comprising:

• a plurality of groupings of projections, each grouping including exactly three sub-groupings, each sub-grouping being discontinuous from each other sub-grouping, the plurality of sub-groupings including:
• a first sub-grouping on a first side of the grouping, the first sub-grouping comprising a first projection,
• a second sub-grouping on a second side of the grouping, the second sub-grouping comprising a second projection, and
• a third sub-grouping on a third side of the grouping, the third sub-grouping comprising a third projection,
• wherein each of the first, second, and third projections has a width, and a length that is greater than the width,
• wherein the first projection extends lengthwise in a first direction,
• wherein the second projection extends lengthwise in a second direction that is different from the first direction, and
• wherein the third projection extends lengthwise in a third direction that is different from the first and second directions.