Eliminating stacking faults in semi-polar GaN by AlN interlayers

Abstract

We report on the elimination of stacking faults by the insertion of low-temperature AlN interlayers in nearly (1016) and (11¯04) oriented semi-polar GaN grown by metalorganic vapor phase epitaxy on Si(112) and Si(113), respectively. The elimination of these defects is visualized by cathodoluminescence (CL) as well as scanning transmission electron microscopy (STEM) and STEM-CL. A possible annihilation mechanism is discussed which leads to the conclusion that the elimination mechanism is most likely valid for all layers with (11¯01) surfaces, enabling heteroepitaxial semi- and non-polar GaN free from stacking faults.

Charge transport in non-polar and semi-polar III-V nitride heterostructures

“…Stacking fault-free high-quality semi-polar and non-polar nitrides and related compounds are currently under development [59][60][61]. It is apparent that with decreasing BSF density, transport anisotropy will decrease and eventually vanishes for BSF-free non-polar and semi-polar GaN films.…”

Single-crystalline semipolar GaN on Si(001) using a directional sputtered AlN intermediate layer

“…We investigated the structure of GaN (1.2 μm)/LT (low temperature)-AlN (12 nm)/GaN (1.5 μm)/sputtered AlN/Si(001) to observe the defect in (1013)GaN [19,20]. Fig.…”

Semipolar (10-11) GaN growth on silicon-on-insulator substrates: Defect reduction and meltback etching suppression

“…10 In situ low temperature (LT)-AlN interlayers have been used to block basal stacking faults (BSFs), but this method is not always efficient, particularly on semipolar orientations with high inclination angles with respect to the c-axis. 11 Hence, there is a clear interest in finding a way that leads to low dislocation and BSF densities in heteroepitaxial semipolar layers.…”

“…In their approach, the growth takes place on inclined v-shaped (111) facets etched on the silicon substrate, 12 the inclination of which determines the orientation of the GaN semipolar epilayer grown thereon. Accordingly, various semipolar orientations were achieved, including (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN layer on the r-plane patterned sapphire substrate (PSS), 13,14 (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN on the patterned (113) Si substrate, 15 and (20-21) GaN on the (114) 1°off patterned Si substrate. 16 In the case of sapphire substrates, several methods have been implemented to reduce the dislocation density in the semipolar GaN layers; in particular, the so-called 3-steps growth on PSS 13 results in a record threading dislocation density in the mid-10 7 cm 2 range and a BSF density of around 100 cm −1 , establishing the current state of the art.…”

“…(20)(21) semipolar GaN and InGaN quantum well were also demonstrated on similarly patterned sapphire substrates. 17 Recently, semipolar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) 550 nm yellow/green 18 and 444 nm blue InGaN light-emitting diodes (LEDs) 19 and semipolar (20)(21) GaN and InGaN LEDs 20 were demonstrated on sapphire templates using this defect filtering method.…”