Effect of dislocations on electrical and electron transport properties of InN thin films. I. Strain relief and formation of a dislocation network

Abstract

Articles you may be interested inImpact of varying buffer thickness generated strain and threading dislocations on the formation of plasma assisted MBE grown ultra-thin AlGaN/GaN heterostructure on silicon AIP Advances 5, 057149 (2015); 10.1063/1.4921757 Improved electron mobility in InSb epilayers and quantum wells on off-axis Ge (001) substratesThe strain-relaxation phenomena and the formation of a dislocation network in 2H-InN epilayers during molecular beam epitaxy are reported. Plastic and elastic strain relaxations were studied by reflection high-energy electron diffraction, transmission electron microscopy, and high resolution x-ray diffraction. Characterization of the surface properties has been performed using atomic force microscopy and photoelectron spectroscopy. In the framework of the growth model the following stages of the strain relief have been proposed: plastic relaxation of strain by the introduction of geometric misfit dislocations, elastic strain relief during island growth, formation of threading dislocations induced by the coalescence of the islands, and relaxation of elastic strain by the introduction of secondary misfit dislocations. The model emphasizes the determining role of the coalescence process in the formation of a dislocation network in heteroepitaxially grown 2H-InN. Edge-type threading dislocations and dislocations of mixed character have been found to be dominating defects in the wurtzite InN layers. It has been shown that the threading dislocation density decreases exponentially during the film growth due to recombination and, hence, annihilation of dislocations, reaching ϳ10 9 cm −2 for ϳ2200 nm thick InN films.

Effect of charged dislocation scattering on electrical and electrothermal transport inn-type InN

“…Prior work has found that the dislocation density is often nonuniform through the thickness of InN films. 17 Typically, the dislocation density drops rapidly within the first few hundred nanometers of the film/buffer interface before reaching a constant value. Sample A is sufficiently thin such that the dislocation density has not reached the typical asymptotic value.…”

“…Because InN growth is exclusively heteroepitaxial, usually on GaN, threading dislocation (TD) densities in InN are very high, typically in the range of 10 9 − 10 11 cm −2 . [15][16][17] It is clear at least qualitatively that dislocations play a role in limiting electron transport in n-type InN. For example, studies of non-radiative recombination 18 and of electron transport (mobility) 14,19,20 have found deleterious effects which are attributed to charged dislocations.…”

Low-temperature self-limiting atomic layer deposition of wurtzite InN on Si(100)

“…35 Any form of N-O bonding will appear in the spectra at higher binding energy with respect to the main peak (396.4 eV), i.e., the shoulder peak can be attributed to the presence of In-O bond. 36,37 XPS-measured valence band spectrum of HCPA-ALD grown sample was obtained in order to extract information about electronic structure of the InN sample (Fig. 6).…”

Hole transport and photoluminescence in Mg-doped InN

“…There is evidence that dislocations act as donors and may indeed act as junction shunts in these materials as well, providing a plausible explanation for why the depletion region fails to fully isolate the p-type bulk from the n-type surface layer [17,27,[49][50][51][52][53][54][55][56][57].…”