Epitaxial wafer and manufacturing method thereof as well as light-emitting diode with enhanced luminance

An epitaxial semiconductor device with rear-surface reflection structure, said device comprising:

• a first compound semiconductor clad layer of a first type of conductivity;
• a multilayer lamination on the first clad layer, said lamination including a compound semiconductor active layer of the first conductivity type and a second compound semiconductor clad layer of a second type of conductivity;
• said first clad layer and said active layer having a first interface as defined therebetween;
• said active layer and the second clad layer having a second interface therebetween;
• and
• each of the first and second interfaces being less than or equal to 1.times.10.sup.17 cm.sup.-3 in oxygen concentration.

A light-emitting diode making use of an epitaxial wafer of a rear-surface reflection type, said wafer comprising:

• a first compound semiconductor clad layer of a first conductivity type;
• a multilayer lamination on the first clad layer, said lamination including a compound semiconductor active layer of the first conductivity type and a second compound semiconductor clad layer of a second conductivity type;
• said first clad layer and said active layer having a first interface as therebetween;
• said active layer and the second clad layer having
• a second interface therebetween;
• each of the first and second interfaces being less than or equal to 1.times.10.sup.17 cm.sup.-3 in oxygen concentration;
• an anode electrode on said first clad layer;
• and
• a cathode electrode on said second clad layer.