Partner: Jarosław Domagała

Institute of Physics, Polish Academy of Sciences (PL)

Recent publications
1.Domagała J.Z., Morelhão S.L., Sarzyński M., Maździarz M., Dłużewski P., Leszczyński M., Hybrid reciprocal lattice: application to layer stress determination in GaAlN/GaN(0001) systems with patterned substrates, JOURNAL OF APPLIED CRYSTALLOGRAPHY, ISSN: 1600-5767, DOI: 10.1107/S1600576716004441, Vol.49, No.3, pp.798-805, 2016
Abstract:

Epitaxy of semiconductors is a process of tremendous importance in applied science and in the optoelectronics industry. The control of defects introduced during epitaxial growth is a key point in manufacturing devices of high efficiency and durability. In this work, it is demonstrated how useful hybrid reflections are for the study of epitaxial structures with anisotropic strain gradients due to patterned substrates. High accuracy in detecting and distinguishing elastic and plastic relaxations is one of the greatest advantages of measuring this type of reflection, as well as the fact that the method can be exploited in a symmetric reflection geometry on a commercial high-resolution diffractometer.

Keywords:

optoelectronics, Group III-nitride semiconductors, epitaxial growth, X-ray multiple diffraction, interface defects

Affiliations:
Domagała J.Z.-Institute of Physics, Polish Academy of Sciences (PL)
Morelhão S.L.-University of Sao Paulo (BR)
Sarzyński M.-other affiliation
Maździarz M.-IPPT PAN
Dłużewski P.-IPPT PAN
Leszczyński M.-other affiliation
2.Czyżak A., Domagała J.Z., Maciejewski G., Żytkiewicz Z.R., X-ray diffraction micro-imaging of strain in laterally overgrown GaAs layers. Part I: analysis of a single GaAs stripe, APPLIED PHYSICS A-MATERIALS SCIENCE AND PROCESSING, ISSN: 0947-8396, DOI: 10.1007/s00339-008-4511-5, Vol.91, No.4, pp.601-607, 2008
Abstract:

Spatially resolved X-ray diffraction (SRXRD) is used for micro-imaging of strain in GaAs:Si layers grown by liquid phase epitaxial lateral overgrowth (ELO) on SiO2-masked GaAs substrates. We show that laterally overgrown parts of the layers (wings) are tilted towards the underlying mask. By SRXRD mapping local wing tilt is easily distinguished from macroscopic sample curvature. The direction of the tilt and distribution of tilt magnitude across the width of each layer can also be readily determined. This allows measuring of the shape of the lattice planes in individual ELO stripes. Downward wing tilt disappears completely when the mask is removed by selective etching. Then residual strain in ELO layers is exposed. In particular, upward tilt is found in free-standing ELO wings. Numerical simulations show that this phenomenon is caused by different concentrations of silicon dopant in vertically and laterally grown parts of the layer.

Affiliations:
Czyżak A.-other affiliation
Domagała J.Z.-Institute of Physics, Polish Academy of Sciences (PL)
Maciejewski G.-IPPT PAN
Żytkiewicz Z.R.-other affiliation

Conference papers
1.Maciejewski G., Sarzyński M., Domagała J.Z., Leszczyński M., A new method of strain determination in partially relaxed thin films, EDS 2006, International Conference on Extended Defects in Semiconductors, 2006-09-17/09-22, Halle (GE), DOI: 10.1002/pssc.200675497, Vol.4, No.8, pp.3048-3055, 2007
Abstract:

It is well known that classical Stoney's formula for radius of thin film bowing fails when thin film is dislocated. Thereby, a method of determination lattice parameters for each of heterostructure epilayers is needed when inelastic relaxation takes place. In this article, we have developed a method of determination lattice parameters of a heterostructure from radius curvature measurement data. Description of deformation when dislocations are nucleated is carefully analyzed. It is shown that in order to take into account nucleated dislocations in thin film an additional term responsible for increased volume of layers should be included in the analysis. The proposed method is based on the finite deformation elasticity and uses the finite element method and bowing radius measurement by the laser beam reflection method. As an example the nitride alloy heterostructure with GaN as a substrate is analyzed. The verification is performed using X-ray measurement of lattice parameters. A very good correspondence between numerically determined lattice parameters and XRD measurements data are observed.

Affiliations:
Maciejewski G.-IPPT PAN
Sarzyński M.-other affiliation
Domagała J.Z.-Institute of Physics, Polish Academy of Sciences (PL)
Leszczyński M.-other affiliation