MOCVD-Epitaxy on Free-Standing HVPE-GaN Substrates

Surface Planarization of GaN-on-Sapphire Template by Chemical Mechanical Polishing for Subsequent GaN Homoepitaxy

“…By replacing the bare sapphire with a GaN template, we can exclude some initial growth steps such as low-temperature buffer growth, nucleation, and the growth of a few micrometers of undoped/n-GaN layers and start immediately with MOCVD growth from the active layers to create the LED structures. 5,6 HVPE growth rates are up to 100 times faster than those of MOCVD, and as only elemental metal sources are used, 7 it is possible to reduce the cost of growing the initial growth layers. In addition, the total processing time for the LED device film fabrication by a combination of HVPE and subsequent MOCVD can be minimized as compared to the conventional MOCVD-only growth process, which also contributes to cost reductions.…”

Homoepitaxy on GaN substrate with various treatments by metalorganic vapor phase epitaxy

“…We suggest that the scratches or slight indentations of the treated surfaces were the favored nucleation positions for GaN overgrowth and replicated in the epilayers, resulting in the remarkable variation of the morphologies of these samples after MOVPE overgrowth. Weyher et al [11] and Miskys et al [13] also observed the residual work damage is replicated in the epitaxial layer. Fig.…”

Effective reduction of bowing in free-standing GaN by N-face regrowth with hydride vapor-phase epitaxy

“…Gallium nitride substrate is the most suitable substrate for manufacturing high-performance nitride-based devices due to its homogeneity of lattice constant and thermal expansion coefficient with the overgrown device epitaxial layers [1,2]. It is highly favored as the substrate for making UV light-emitting diodes (LED), laser diodes (LD) and high-power devices [3,4].…”