Distribution of the lateral correlation length in GaN epitaxial layers

Kozłowski, J.; Paszkiewicz, R.; Korbutowicz, R.; Tłaczała, M.

doi:10.1016/s0921-4526(01)00710-4

Cited by 3 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This suggests that the finite lateral size of the crystalline domains dominates the mosaic structure in our sample. We determined the density of lateral correlation length distribution [5] for two AlN layers grown with and without the initial nitridation step. The distributions obtained were similar, with most probable correlation length of ~80 nm.…”

Section: Resultsmentioning

confidence: 99%

“…It is seen that the FWHM values from φ-scan for lattice plane with low inclination angle could be much broader. As φ-scan and twist sensitive [5] ω-scan are essentially the same for lattice planes perpendicular to the substrate surface (0001), such as (10 10) , FWHMs plotted vs. inclination angle from φ-scans and ω-scans will converge at 90°. Therefore, extrapolation of FWHMs to the 90° inclination angle would be necessary for the calculation using either φ-scans or ω-scans.…”

Section: Introductionmentioning

confidence: 99%

“…This spreading contributes to the broadening of the width of the X-ray diffraction peaks. The methods reported in the literature to characterize such twist, however, vary from group to group: some use rocking curves of a quasi-symmetric or a symmetric reflection [4,5], while others …”

mentioning

confidence: 99%

See 2 more Smart Citations

X‐ray characterization of high quality AlN epitaxial layers: effect of growth condition on layer structural properties

Paduano

Drehman

Weyburne

et al. 2003

phys. stat. sol. (c)

View full text Add to dashboard Cite

.72. Dd, 68.55.Jk AlN layers were deposited directly on (0001) sapphire by a MOCVD two-step pressure process. The best (0002) and (10 12) rocking curves had FWHM values of ~360 arcsec and ~580 arcsec respectively. A detailed X-ray diffraction study was carried out to investigate the effect of growth condition on the layer structural properties. In-plane twist was estimated from the FWHM values of both ω-scans and φ-scans as functions of inclination angle, using the quasi-symmetrical reflection from a group of lattice planes with inclination angle ranging from 0 to 75°. The range of twist spread was found to be sensitive to the substrate nitridation condition. The lowest spread angle obtained with optimized nitridation was ~770 arcsec. As expected, the edge-type threading dislocation density estimated from twist spreading was found to correlate well with the dislocation density measured by TEM. The tilt spreading was found to be sensitive to the growth pressure. By reducing growth pressure to 40 Torr, we obtained layers with tilt spreading less than 120 arcsec. 1 Introduction There is increasing interest in the growth of high quality AlN because of its high temperature stability, high electrical resistivity, high thermal conductivity, UV transparency, and good lattice match with GaN. These properties make AlN a promising substrate for various high power, high temperature electronic and opto-electronic applications. Indeed, recent reports have shown that InGaN based LEDs [1] and GaN HEMTs [2] grown on AlN/sapphire template have substantially improved device performance. Since AlN substrates are not available, heteroepitaxial AlN films are usually deposited on foreign substrates. These AlN films often contain high densities of structural defects. Recently, we reported the development of a two-step pressure process for AlN growth on sapphire substrates [3]. With an optimum nitridation condition, we showed that the new process was effective for the improvement of crystalline quality of AlN films.To understand the effect of growth conditions on the layer structural properties, we undertook a detailed X-ray diffraction study. AlN films usually exhibit a high degree of mosaicity; i.e. the films consist of sub-grains slightly misoriented with respect to each other and the underlying substrate. Such structure is usually described by a spread of tilt angles with respect to substrate normal and a range of twist angles in the basal plane. This spreading contributes to the broadening of the width of the X-ray diffraction peaks. The methods reported in the literature to characterize such twist, however, vary from group to group: some use rocking curves of a quasi-symmetric or a symmetric reflection [4,5], while others

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

X‐ray characterization of high quality AlN epitaxial layers: effect of growth condition on layer structural properties

Paduano

Drehman

Weyburne

et al. 2003

phys. stat. sol. (c)

View full text Add to dashboard Cite

show abstract

“…• The distribution of lateral size of crystallographic blocks is assumed as a log-normal, e.g. [4]. • The Gaussian distribution is established for the gradient lattice parameters.…”

Section: The Model Of the Disordered Epitaxial Layermentioning

confidence: 99%

Structure modelling and reciprocal space maps simulation of the (Ga,Al)N epitaxial layers deposited on the sapphire substrate

Kozłowski

Serafińczuk

2005

Journal of Alloys and Compounds

View full text Add to dashboard Cite

“…Characterization process of such structures, possesses many problems and the appointment of the value of these undesirable attributes in some cases is difficult. Various methods of characterization of such structures can be carried out in different ways [5][6][7][8][9][10][11][12][13][14][15], e.g. by measuring a number of diffraction reflections [5][6][7], by analyzing the shape of the diffraction reflections or reciprocal lattice points (RLP) [8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Determination of lateral block size and mosaicity of crystals using X‐ray diffraction from the edge of the sample

Serafińczuk

2016

Crystal Research and Technology

View full text Add to dashboard Cite

In this paper a novel lateral block size characterization method based on X‐ray diffractometry (XRD) is presented. The developed method based on scans of plans perpendicular to the surface visible from the edge of the sample and subconsequent numerical analysis based on Scherrer equation. In presented investigations as a reference sample bulk GaN substrate fabricated by AMMONO Ltd. was used. The GaN layers deposited on sapphire substrate were investigated as a case of study. Moreover, a method of analyzing the magnitude of the tilt and twist mosaicity based on the scans of rocking curves and reciprocal lattice maps (RLM) from the edge of sample is presented. As an example for this methodology highly mosaicited SiC crystal was used. Presented approach allows to directly determine the value of the angular deviation of mosaicity in a direction perpendicular and parallel to the sample surface.

show abstract

Distribution of the lateral correlation length in GaN epitaxial layers

Cited by 3 publications

References 3 publications

X‐ray characterization of high quality AlN epitaxial layers: effect of growth condition on layer structural properties

X‐ray characterization of high quality AlN epitaxial layers: effect of growth condition on layer structural properties

Structure modelling and reciprocal space maps simulation of the (Ga,Al)N epitaxial layers deposited on the sapphire substrate

Determination of lateral block size and mosaicity of crystals using X‐ray diffraction from the edge of the sample

Contact Info

Product

Resources

About