Disordering of the ordered structure in MOCVD-grown GaInP and AlGaInP by impurity diffusion and thermal annealing

Gavrilovic, P., Dabkowski, F. P., Meehan, K., Williams, J. E., Stutius, W., Hsieh, K. C., Holonyak, N., Shahid, M. A. and Mahajan, S. (1988) Disordering of the ordered structure in MOCVD-grown GaInP and AlGaInP by impurity diffusion and thermal annealing. Journal of Crystal Growth, 93(1), pp. 426-433. (doi: 10.1016/0022-0248(88)90563-5)

Abstract

Ga0.5In0.5P and (AlxGa1−x)0.5In0.5P grown by metal-organic chemical vapor deposition (MOCVD) at temperatures below 700 °C show an ordered arrangement of the group III atoms on the column III sublattice. A periodic compositional modulation along the growth direction is also observed under certain growth conditions. This paper presents data showing that epitaxial layers of both Ga0.5In0.5P and (AlxGa1−x)0.5In0.5P grown on (001) GaAs substrates and containing the ordered phase can be converted to disordered alloys by thermal annealing under a variety of conditions at temperatures not exceeding the growth temperature. The disappearance of the ordered phase, as determined by TEM, is accompanied by a sift of the bandgap to higher energy by ≈90 meV. Ga0.5In0.5P and (AlxGa1−x)0.5In0.5P have been annealed in sealed ampoules under the following conditions: (1) thermal anneal with P4 overpressure, (2) Zn diffusion with Zn3P2 only, and (3) Zn diffusion with both Zn3P2 and P4. Similar bandgap shifts are obtained under all three conditions. It is further shown that selective disordering with either Zn or P4 can be achieved by using a patterned dielectric mask. The relative stabilities of the random and the ordered alloys are discussed in light of these disordering data.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Meehan, Professor Kathleen
• Authors: Gavrilovic, P., Dabkowski, F. P., Meehan, K., Williams, J. E., Stutius, W., Hsieh, K. C., Holonyak, N., Shahid, M. A., and Mahajan, S.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Journal of Crystal Growth
• Publisher: Elsevier
• ISSN: 0022-0248
• ISSN (Online): 1873-5002