Photoelectrochemical etching measurement of defect density in GaN grown by nanoheteroepitaxy

Abstract

The density of dislocations in n-type GaN was measured by photoelectrochemical etching. A 10× reduction in dislocation density was observed compared to planar GaN grown at the same time. Cross-sectional transmission electron microscopy studies indicate that defect reduction is due to the mutual cancellation of dislocations with equal and opposite Burger’s vectors. The nanoheteroepitaxy sample exhibited significantly higher photoluminescence intensity and higher electron mobility than the planar reference sample.

Microstructure and origin of dislocation etch pits in GaN epilayers grown by metal organic chemical vapor deposition

“…1- 16 The shapes of etch pits are well correlated with types of defects, and the etch pits density ͑EPD͒ may correspond to the density of defects. However, for GaN, the density, types, and distribution of defects vary significantly due to growth-related conditions, which makes it difficult to reach an agreement about the origin of the etch pits, and it can be even more difficult for test techniques.…”

Effect of threading defects on InGaN∕GaN multiple quantum well light emitting diodes

“…The defect density was accurately determined by counting the number of whiskers within a known area within the mesa of the LED. 10 PEC etching is only effective for n-type GaN as it requires hole accumulation at the semiconductor surface to raise the oxidation state and reactivity of the surface atoms. 8,9 The diameter of the PEC etched whiskers was also shown to increase when multiple threading defects agglomerated.…”

Influence of Defects on Low Temperature Diffusion of Boron in SiC

“…And application of the electrical current can make a significant impact in the electrolytic etching mechanism [15]. The light if it is generate a surface holes is also can be used for stimulation of etching [20]. As is known, [21] for etching of semiconductors can play an important role excitation of surface states, when a surface holes or two-hole state are created.…”