Hydride vapor phase epitaxy of semipolar gallium nitride

Conventional c-plane nitride optoelectronic devices suffer from deleterious polarization effects. These polarization effects can be reduced or eliminated by growing devices on semipolar planes. Semipolar films have the GaN [0001] direction neither normal to or parallel to the surface plane of the film. We have calculated the polarization normal to the surface for all possible semipolar orientations and find that significant reductions in polarization are achieved with semipolar planes.; We have recently discovered certain epitaxial relationships with GaN and foreign substrates that allow planar and fully coalesced films of GaN to be grown in semipolar orientations. The relationships are (101¯1¯) GaN on (100) spinel, (101¯3¯) GaN on (110) spinel, and both (101¯3¯) and (112¯2) GaN on m-plane sapphire. This dissertation describes the morphology and crystal quality of these semipolar films as grown by hydride vapor phase epitaxy. Lateral epitaxial overgrowth was performed on (112¯2) films to reduce the dislocation density.; MOCVD device growths on HVPE-grown templates and bare substrate wafers have demonstrated the feasibility of optoelectronic devices in all of these orientations. The devices exhibited a reduced blue shifting with increasing drive current as compared to c-plane devices, which is evidence of the reduced polarization effects. This dissertation will discuss research to enable fabrication of semipolar GaN templates that can be utilized to make nitride LEDs and LDs with reduced polarization than conventional nitride devices.