Abstract
A structure of brittle material substrate and the fabricating process thereof are described. The structure of brittle material substrate comprises a first substrate with a plurality of formed cracks and a second substrate made of brittle material conjoint with the first substrate. The crack grows up in a predetermined direction to dice the first substrate and the second substrate into designed dimensions under power waves acting thereupon. In light emitting diode application, the first substrate is made of silicon and the second substrate is made of sapphire. Furthermore, the cracks with stress concentration upon the first substrate are formed by a power beam. Guide opens facing the cracks on the other side of the first substrate enhance the crack growth control capacity.