Gallium arsenide phosphide epitaxial wafer - has low probability of crack formation during LED mfr.

摘要

In a GaAsP epitaxial wafer, obtd. by producing a first GaAsP mixed crystal layer with varying mixed crystal ratio on a GaP single crystal substrate and then producing a second GaAsP mixed crystal layer with constant mixed crystal ratio, a difference in the mixed crystal ratio of the second layer is produced so that the mixed crystal ratio of the layer facing the substrate is 0.01-0.05 less than that of the surface side. USE/ADVANTAGE - The wafer is used esp. in LED mfr.. It has reduced residual stress level, and thus reduced probability of crack formation during processing to mfr. LEDs. The substrate has a crystallographic surface orientation along the (100) plane or at an angle of 2-100 deg. in the 110 direction relative to the (100) plane. The second layer is produced by gas phase epitaxy and consists of two sub-layers with different mixed crystal ratios.