Reconstruction of lattice structure of ion-implanted near-surface regions of HgCdTe epitaxial layers
|Wojciech Maziarz 1, Andrij P. Vlasov 2, Oleksandr Y. Bonchyk 3, Stepan Kiyak 3, Igor M. Fodchuk 4, Ruslan M. Zaplitnyy 4, Taras Kazemyrskyy 4, Adam Barcz 5, Zbigniew Swiatek 1, Pawel S. Zieba 1|
1. Polish Academy of Sciences, Institute of Metallurgy and Materials Sciences (IMIM PAN), Reymonta 25, Kraków 30-059, Poland
It has been presented the results of AFM, SEM, X-ray and SIMS studies of near-surface regions of HgCdTe graded-gap epitaxial layers obtained by high-temperature annealing of them in the vapour of the main components. We used grown on CdTe substrates the ISOVPE layers of HgCdTe whose surface was implanted by arsenic ions. The AFM investigation has showed that the morphology of surfaces of HgCdTe structures obtained at the same conditions is significantly influenced by the crystal orientation of the initial substrates of CdTe. By means of SIMS and SЕМ analysises it has been observed a substantial increase of the molar content of HgCdTe solid solution on the surface of ion-implanted epitaxial layers after high-temperature annealing. For X-ray investigation we used the technique of two-crystal spectrometry at skew-asymmetrical setup of the sample under study. On the basis of the observed structural changes taking place at different angles of azimuth scanning it has been made comparison of the calculated profiles of deformations and the experimental SIMS distribution of the main components of HgCdTe solid solution in the near-surface regions of the structure. Large gradients of composition HgCdTe solid solution have been shown to be formed in the near-surface regions of the epitaxial layers due to small changes in the thermodynamically equilibrium conditions of the process of high-temperature annealing. These gradients are the cause of formation of graded-band-gap structure in which strains of lattice crystal are present. The influence of these factors on the diffusion of an electrically active impurity is analyzed.
Presentation: Poster at E-MRS Fall Meeting 2007, Symposium H, by Wojciech Maziarz
See On-line Journal of E-MRS Fall Meeting 2007
Submitted: 2007-05-14 12:09 Revised: 2009-06-07 00:44