Evolution of phosphorus-vacancy clusters in epitaxial germanium

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • KU Leuven
  • IMEC Vzw
  • University of Antwerp

Abstract

The E centers (dopant-vacancy pairs) play a significant role in dopant deactivation in semiconductors. In order to gain insight into dopant-defect interactions during epitaxial growth of in situ phosphorus doped Ge, positron annihilation spectroscopy, which is sensitive to open-volume defects, was performed on Ge layers grown by chemical vapor deposition with different concentrations of phosphorus (∼ 1 × 10 18- 1 × 10 20 cm - 3). Experimental results supported by first-principles calculations based on the two component density-functional theory gave evidence for the existence of mono-vacancies decorated by several phosphorus atoms as the dominant defect type in the epitaxial Ge. The concentration of vacancies increases with the amount of P-doping. The number of P atoms around the vacancy also increases, depending on the P concentration. The evolution of P n-V clusters in Ge contributes significantly to the dopant deactivation.

Details

Original languageEnglish
Article number025701
JournalJournal of Applied Physics
Volume125
Issue number2
Publication statusPublished - 14 Jan 2019
MoE publication typeA1 Journal article-refereed

ID: 31435293