Effect of anneal temperature on GaN nucleation layer transformation

Modeling of laser reflectance evolution during metalorganic vapor phase epitaxy growth of GaN using SiN treatment

“…The surface normal to the incident laser increases and constructive interferences overcome the signal loss due to roughening. In addition, the basal plane sizes of these islands increase sufficiently to induce a coalescence process as reported by Lada et al [8]. Regular oscillations with constant intensity maximum were obtained when the coalescence process is achieved.…”

In‐situ reflectivity observation of GaN layers grown directly on sapphire by HVPE using low‐temperature nucleation layers

“…The reflectivity signal exhibits large differences as a function of the gas composition used during this step. In the MOVPE re-crystallization step, the reflectivity increases slightly due to the variation of the refractive index with temperature and then the signal drops sharply due to coarsening [2]. In our experiments, no such signal drop is observed.…”

“…It is suggested that during the re-crystallization step, the Ga rich nucleation layer partially dissociates and Ga diffuses on the surface to nearby growing islands and is incorporated as GaN. This process can be compared with mass transport observed in HVPE [3] and MOVPE [2] on annealed GaN layers under NH 3 atmosphere. The presence of metallic particles on the surface of the sample can increase the reflectivity signal as observed at around 1030 °C during the re-crystallization under pure N 2 .…”

GaN property evolution at all stages of MOVPE Si/N treatment growth

“…Similar morphological evolutions were reported in ref. [2,10,14]. But these studies deal with only the buffer layer transformation and/or the GaN epilayer growth without the SiN treatment.…”

“…The defects are found to be related to the density and size of islands in the low temperature buffer layer. The density of these islands can be controlled (depending on growth parameters) by using a 3D growth mode in the first stage of the deposition [1][2][3][4]. Another way to induce the 3D growth mode is the use of the so-called "Si/N treatment" growth method [5].…”