Resonant and nonresonant vibrational excitation of ammonia molecules in the growth of gallium nitride using laser-assisted metal organic chemical vapour deposition

Abstract

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Fast Growth of GaN Epilayers via Laser-Assisted Metal–Organic Chemical Vapor Deposition for Ultraviolet Photodetector Applications

“…16,[22][23][24][25][26][27][28][29][30] For instance, Iwanaga et al 22 reported the deposition of large-area amorphous silicon films using CO2 laser LMOCVD with a high growth rate of > 60 µm/h in a relatively low laser power and low substrate temperatures. Recently, we have demonstrated the fast growth of GaN films with (0002) preferential orientation using CO2 laser LMOCVD with a growth rate up to 84 µm/h at low temperatures, 26 where the experiments were designed to elucidate the GaN growth mechanism via CO2 laser LMOCVD rather than to optimize the material crystalline quality. The high GaN growth rate is due to the mixed photolysis/pyrolysis reactions of the precursors and the photo-induced effects, as has been evidenced by wavelength dependence of GaN growth rates.…”

“…The high GaN growth rate is due to the mixed photolysis/pyrolysis reactions of the precursors and the photo-induced effects, as has been evidenced by wavelength dependence of GaN growth rates. [25][26][27] However, the low-temperature deposition resulted in films with broad XRD peaks and low crystalline quality. 22,25 The growth of high-quality GaN films suitable for device application were usually realized at high deposition temperatures.…”

Laser‐Assisted Metal–Organic Chemical Vapor Deposition of Gallium Nitride

“…[19] Previously, carbon dioxide (CO 2 ) laser was also utilized in GaN MOCVD growth. [20][21][22] At the resonant wavelength of 9.219 μm, strong emissions from NH 2 radicals were observed in the optical emission spectra (OES) from the resonantly excited NH 3 flows, together with other emission peaks from NH, N, N þ , and H, which exhibited an effective dissociation of NH 3 molecules with CO 2 laser irradiation. [22] It demonstrated GaN growth on (0001) sapphire substrate at a very low temperature of 250 C in a custom-designed system.…”

“…[20][21][22] At the resonant wavelength of 9.219 μm, strong emissions from NH 2 radicals were observed in the optical emission spectra (OES) from the resonantly excited NH 3 flows, together with other emission peaks from NH, N, N þ , and H, which exhibited an effective dissociation of NH 3 molecules with CO 2 laser irradiation. [22] It demonstrated GaN growth on (0001) sapphire substrate at a very low temperature of 250 C in a custom-designed system. Fast GaN GRs of 12 [21] and 84 μm h À1 [22] were demonstrated using CO 2 laser at the growth temperature of 600 and 750 C, respectively.…”

“…[22] It demonstrated GaN growth on (0001) sapphire substrate at a very low temperature of 250 C in a custom-designed system. Fast GaN GRs of 12 [21] and 84 μm h À1 [22] were demonstrated using CO 2 laser at the growth temperature of 600 and 750 C, respectively. However, characterization of these materials indicates relatively low crystalline quality.…”