Growth and morphology of GaN

Synthesis of dense polycrystalline GaN of high purity by the chemical vapor reaction process

“…The reaction continues until the majority of the molten gallium is converted into dense polycrystalline GaN. By-products are captured in the recovery system downstream, consisting of a separation chamber to capture excess NH 4 Cl and other precipitants and a chamber containing water for scrubbing HCl, Cl 2 , and NH 3 .…”

“…Subsequently similar processes were developed to produce powder, polycrystalline, or single-crystal GaN using ammonia [2][3][4][5][6]. In 1999 we reported a new process called the chemical vapor reaction process (CVRP) to synthesize gallium nitride [7] and to manufacture nitride targets for use in sputtering and similar equipment [8].…”

Crystal growth and characterization of thick GaN layers grown by oxide vapor transport technique

“…HVPE is also a widely researched growth technique to produce bulk GaN crystals even though it falls behind sublimation in terms of the reported maximum growth rates. Freestanding GaN crystals were also prepared by reaction of Ga vapors with ammonia [11], Ga with ammonia [12], sublimation of GaN powder [13] and growth in sodium flux [14]. Out of the above-mentioned techniques, sublimation technique gave GaN crystals with the highest growth rates.…”

Bulk GaN growth by Gallium Vapor Transport technique

“…Recently, Hydride Vapor Phase Epitaxy (HVPE) [4], high pressure solution growth [5], and sublimation techniques [6][7][8] have been used to grow bulk GaN crystals. Free standing GaN crystals grown by sodium flux technique and ammonothermal technique have been also reported [9].…”