Abstract: The disclosed method of making a compound semiconductor single-crystalline substrate for liquid phase epitaxial growth has a relatively low cost and excellent practicality. The compound semiconductor single-crystalline substrate is prepared to have a surface roughness of at least 1 .mu.m and not more than 10 .mu.m as measured over a line of 1 mm length. This substrate is employed as a substrate for an epitaxial wafer for an infrared- or visible light-emitting diode. Due to its particular roughness, the substrate can be prevented from slipping or falling while it is transported during processing. Furthermore, no lapping and polishing are required for manufacturing the substrate. Thus, the substrate for liquid phase epitaxial growth can be provided at a relatively low cost.

Abstract: The disclosed compound semiconductor single-crystalline substrate for liquid phase epitaxial growth has a relatively low cost and excellent practicality. This compound semiconductor single-crystalline substrate has a surface roughness of at least 1 .mu.m and not more than 10 .mu.m as measured over a line of 1 mm length. This substrate is employed as a substrate for an epitaxial wafer for an infrared- or visible light-emitting diode. Due to its particular roughness, the substrate can be prevented from slipping or falling while it is transported during processing. Furthermore, no lapping and polishing are required for manufacturing the substrate. Thus, the substrate for liquid phase epitaxial growth can be provided at a relatively low cost.