Effects of initial conditions and growth temperature on the properties of nonpolar a ‐plane AlN grown by LP‐HVPE

Abstract

AlN was grown on r ‐ and c ‐plane sapphire substrates by low‐pressure hydride vapor phase epitaxy (LP‐HVPE). Nitridation and buffer methods were used and compared. Results show that the buffer method is appropriate for the growth of a‐plane AlN. In‐plane stresses were measured and found to be different in the two in‐plane directions parallel and perpendicular to the AlN c‐axis. In‐plane stress anisotropy is reduced at high temperature leading to a smoother surface, partly owing to a decreased difference in the growth rates between two in‐plane directions. However, too high a temperature decreases the crystal quality of a‐plane AlN. Thus, there exists an optimal temperature range for the growth of a‐plane AlN, in which improved crystal and surface qualities can both be obtained. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Growth and Characterization of Thick Polycrystalline AlN Layers by HTCVD

“…These results could have an important impact on the future investigations on the nonpolar epitaxial growth of ͑110͒ a-plane AlN layers at high temperature ͑T ജ 1500°C͒ and high growth rate on a-plane 4H or 6H SiC ͑Ref. 39͒ or r-plane sapphire [40][41][42] single crystals for UV LED applications.…”

Influence of off-cut angle of r-plane sapphire on the crystal quality of nonpolar a-plane AlN by LP-HVPE

“…We previously used a low-temperature (LT) buffer method to grow a-plane AlN by low-pressure LP-HVPE [9]. The use of off-cut sapphire has been found to be very effective in growing highquality a-plane GaN [10] and c-plane AlN [11] with a fairly flat surface.…”

Growth of non-polar a-plane AlN on r-plane sapphire

“…Thus, the growth of non-polar nitrides has been extensively studied with developing various techniques. [12][13][14][15][16][17][18][19] However, the target nitride has been mainly on GaN, and only a few studies were reported on AlN. Growth of nonpolar AlN is crucial to the realization of polarization-free LEDs in deep UV range.…”