Post-growth process relaxation properties of strained Cd0.92Zn0.08Te/Cd0.83Zn0.17Te quantum well heterostructures grown by molecular beam epitaxy

Abstract

Articles you may be interested inNear infrared intersubband absorption of CdSe/MgSe quantum wells grown on InP substrate with an InAlAs buffer layer J. Vac. Sci. Technol. B 32, 02C105 (2014); 10.1116/1.4863496Study of intersubband transitions of Zn x Cd 1 − x Se ∕ Zn x ′ Cd y ′ Mg 1 − x ′ − y ′ Se multiple quantum wells grown by molecular beam epitaxy for midinfrared device applications Determination of the indices of refraction of molecular-beam-epitaxy-grown ZnSe/ZnCdSe multiple-quantum-well structures J. Molecular-beam epitaxy growth and nitrogen doping of hexagonal ZnSe and ZnCdSe/ZnSe quantum well structures on hexagonal ZnMgSSe bulk substratesInvestigation of e-h pair compression in molecular beam epitaxy grown ZnCdSe/ZnSe multiquantum wells at volume excitation by electron beamThe post-growth structural stability regarding relaxation and defect propagation in Cd 0.83 Zn 0.17 Te/Cd 0.92 Zn 0.08 Te/Cd 0.83 Zn 0.17 Te quantum well ͑QW͒ heterostructures grown on ͓001͔ oriented Cd 0.88 Zn 0.12 Te substrates at 300°C by molecular beam epitaxy is investigated. The investigated heterostructures were subjected to post-growth thermal treatment in an ambient atmosphere in a temperature range between 280 and 550°C for 3 h each. We have used high-resolution x-ray diffraction as the main characterization tool. High-resolution rocking curves as well as the powerful two-dimensional reciprocal space mapping were employed in both symmetrical as well as asymmetrical reflections. The results indicate that at a post-growth temperature cycle of 350°C for 3 h slight modification of the Cd 0.83 Zn 0.17 Te/Cd 0.92 Zn 0.08 Te barrier/QW heterointerface smoothness is affected. This indicates the onset of migration of Zn atoms at this post-growth temperature time cycle. At 450°C, this effect is more pronounced and seen as the complete disappearance of thickness fringes. For higher post-growth thermal treatment at 550°C for 3 h, a high relaxation level accompanied by Zn content reduction is observed. A reduction of the Zn content down to 0.11 fractional value in the thick Cd 0.83 Zn 0.17 Te barrier is attributed to Zn out diffusion and/or Zn precipitation.