Dislocation reduction in MOVPE grown GaN layers on (111)Si using SiN_xand AlGaN layers

Towards industrialisation of GaN‐on‐Si based high brightness blue LEDs

“…These dislocations can behave as a stress relaxation channel, making strain management more difficult [17]. The TDD can be reduced by involving epitaxial lateral overgrowth (ELOG) [18] or SiN x interlayer techniques [19].…”

“…The SiN interlayer growth time is typically ∼100 s, and a longer growth time can reduce TDD further but will also induce additional tensile strain. A 1.8 μm thick n-GaN layer doped up to 1x10 19 cm -3 is then grown on top until full coalescence is achieved. The epistructure is completed with a conventional LED structure comprising of a thick short-period superlattice (SPSL), thick InGaN/GaN multiple quantum wells (MQWs), p-electron blocking layer (EBL), p-doped GaN layer and a heavily doped p + -GaN contact layer.…”

Strain Relaxation via Misfit Dislocation in Step-Graded In GaN Heteroepitaxial Layers Grown on Semipolar (1122) and (1101) GaN

“…A high density of MD has been reported for uniform composition heteroepitaxial layer on mismatched substrate which degrades the performance of the device significantly [3]. Hence from the very beginning, the heterosructure researchers have been trying to find the way of improving performance of these devices by reducing the MDs.…”

“…Some experimental works have been carried out on step graded layer grown in different cubic material system such as SiGe/Si, InGaAs/GaAs and reported that this technology may be a promising solution for MD reduction during epitaxial growth [7]- [8]. A very few experimental works has been done on step graded wurtzite materials and they found strong evidence of MD reduction in InGaN epitaxial layer grown on GaN substrate [3], [9]. Though some mathematical model has been developed for cubic structure there is no such work on wurtzite materials for MD reduction via step grading.…”

High quality GaN epilayers grown on Si (111) with thin nonlinearly composition-graded AlxGa1−xN interlayers via metal-organic chemical vapor deposition

“…Some techniques originally used for the growth of III-nitrides on sapphire or SiC substrates, such as AlGaN interlayers [7], AlN/GaNor AlGaN/GaN-based superlattices [8,9], were applied for GaN epitaxy on Si substrates. Besides these routine techniques, several novel approaches showing excellent effects in strain control and dislocations reduction, for example, step-graded Al x Ga 1−x N interlayers [10][11][12]16], composition-graded Al x Ga 1−x N interlayer [13][14][15][16][17], AlInN interlayers [18], InN interlayers [19] and etc., have also been developed. For all these techniques, it has been noticed that the growth parameters of the buffer layer, such as growth temperature, thickness, and V/III ratio, affect the quality of GaN greatly, indicating the precise optimization of the growth parameters and detailed study of the stress relaxation mechanisms are essential.…”