Effect of substrate misorientation on tear-drop-like hillock defect densities in InP and GaInAsP grown by metalorganic chemical vapor deposition

Abstract

Tear-drop-like hillock (TLH) defects in InP and GaInP layers grown by MOCVD have been systematically studied. It was found that the formation of TLH defects is caused both by dislocation and by substrate orientations. There is a critical misorientation angle for the appearance of TLH defects. TLH defects disappear above the critical angle. The angle, which is changed by the growth rate and the growth temperature, is 0.06° when the growth rate is 1 μ/h and the growth temperature is 625°C. When the angle is 0.25°, terraces appear on the surface of epitaxial layers. By using substrates with appropriate misorientation angles, smooth surfaces without any TLH defects or terraces could be obtained.