Suppression of quantum well intermixing in GaAs/AlGaAs laser structures using phosphorus-doped SiO2 encapsulant layer

P. Cusumano*, B. S. Ooi, A. Saher Helmy, S. G. Ayling, A. C. Bryce, J. H. Marsh, B. Voegele, M. J. Rose

*Corresponding author for this work

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Abstract

A phosphorus-doped silica (SiO2:P) cap containing 5 wt% P has been demonstrated to inhibit the bandgap shifts of p-i-n and n-i-p GaAs/AlGaAs quantum well laser structures after rapid thermal processing. The intermixing suppression has been attributed to the fact that SiO2:P is more dense and void free compared with standard SiO2 together with a strain relaxation effect of the cap layer during annealing. Band gap shift differences as large as 100 meV have been observed from samples capped with SiO2 and with SiO2:P. The n-i-p structure showed a higher degree of intermixing compared to p-i-n structure. This behaviour has been attributed to the rise of Fermi level in the n doped structure, through which the formation energy of Ga vacancies is reduced compared to the p doped structure.

Original languageEnglish (US)
Pages (from-to)2445-2447
Number of pages3
JournalJournal of Applied Physics
Volume81
Issue number5
StatePublished - Mar 1 1997
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physics and Astronomy (miscellaneous)

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