Journal of Electronic Materials

, Volume 21, Issue 2, pp 173–179

Effects of S, Si, or Fe dopants on the diffusion of Zn in InP during MOCVD


  • C. Blaauw
    • Bell-Northern Research
  • B. Emmerstorfer
    • Bell-Northern Research
  • D. Kreller
    • Bell-Northern Research
  • L. Hobbs
    • Bell-Northern Research
  • A. J. Springthorpe
    • Bell-Northern Research

DOI: 10.1007/BF02655833

Cite this article as:
Blaauw, C., Emmerstorfer, B., Kreller, D. et al. JEM (1992) 21: 173. doi:10.1007/BF02655833


Diffusion of Zn in InP during growth of InP epitaxial layers has been investigated in layer structures consisting of Zn-InP epilayers grown on S-InP and Fe-InP substrates, and on undoped InP epilayers. The layers were grown by metalorganic chemical vapour deposition (MOCVD) atT = 625° C andP = 75 Torr. Dopant diffusion profiles were measured by secondary ion mass spectrometry (SIMS). At sufficiently high Zn doping levels ([Zn] ≥8 × 1017 cm−3) diffusion into S-InP substrates took place, with accumulation of Zn in the substrate at a concentration similar to [S]. Diffusion into undoped InP epilayers produced a diffusion tail at low [Zn] levels, probably associated with interstitial Zn diffusion. For diffusion into Fe-InP, this low level diffusion produced a region of constant Zn concentration at [Zn] ≈ 3 × 1016 cm−3, due to kick-out of the original Fe species from substitutional sites. We also investigated diffusion out of (Zn, Si) codoped InP epilayers grown on Fe-InP substates. The SIMS profiles were characterised by a sharp decrease in [Zn] at the epilayer-substrate interface; the magnitude of this decrease corresponded to that of the Si donor level in the epilayer. For [Si] ≫ [Zn] in the epilayer no Zn diffusion was observed; Hall measurements indicated that the donor and acceptor species in those samples were electrically active. All these results are consistent with the presence of donor-acceptor interactions in InP, resulting in the formation of ionised donor-acceptor pairs which are immobile, and do not contribute to the diffusion process.

Key words

InPMOCVDdopant diffusiondopant incorporation

Copyright information

© The Mineral, Metal & Materials Society,Inc. 1992