Crack-free GaN grown on AlGaN∕(111)Si micropillar array fabricated by polystyrene microsphere lithography

Abstract

The authors report on the growth of GaN on AlGaN∕(111)Si micropillar array by metal-organic chemical vapor deposition. Using the substrates with micropillar array, 2-μm-thick GaN films without cracks can be achieved. Transmission electron microscopy, atomic force microscopy, and micro-Raman studies indicate that the dislocation density and residual stress of the GaN grown on micropillar array are also reduced. The results reveal the potential of this type of substrates for growing GaN-based devices as well as preparing GaN freestanding substrates.

Bottom‐Up Nano‐heteroepitaxy of Wafer‐Scale Semipolar GaN on (001) Si

“…It can be seen that the E 2 ‐high peak appears at 568.9 cm −1 after 20 min of the low‐temperature nucleation (Stage 1), corresponding to a stress‐free state . A minor peak at 549.3 cm −1 is also observed in the same spectra, which is ascribed to the signal from the ZnO nanorods .…”

“…The technique allows the strain energy in a heteroepitaxial layer to be released through lateral and vertical lattice deformation by performing the growth on the substrate patterned in nanoscale . The ultra­small contact area and 3D deformation dramatically extend the critical thickness of the epilayer and thereby defer the formation of crystal defects . Despite the tempting merits, most of the reported nano‐heteroepitaxy schemes find limited practical applications.…”

Correlation between ZnO nanorod growth and the dislocations in AlN-based substrates

“…The details of the AlN-based epilayers growth process are similar to our previous report [13]. For substrate B and C, a 1 m AlN epilayer was directly grown on sapphire, and the difference is that the substrate C was etched by 50 wt% KOH solution at 90 • C for 5 min to open up the etch pits [14]. All the substrates were cleaned by a standard procedure including a degreasing process.…”

Enhancement of Light Output Power from LEDs Based on Monolayer Colloidal Crystal

“…Apart from pattering sapphire substrate, it is noteworthy that MCC can also be used to pattern other substrates for epitaxial growth of GaN materials. Chen et al reported the growth of GaN on AlGaN/(111) Si micropillar array by metal‐organic chemical vapor deposition. The AlGaN/(111) Si micropillar array was prepared by ICP etching in the mixture of Cl 2 , BCl 3 , and Ar gases using a PS monolayer as an etching mask.…”