Carrier gas effects on the SiGe quantum dots formation

C. H. Lee, C. Y. Yu, C. M. Lin, C. W. Liu*, H. Lin, Wen-Hao Chang

*Corresponding author for this work

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

SiGe quantum dots (QDs) grown by ultra-high vacuum chemical vapor deposition using H 2 and He carrier gases are investigated and compared. SiGe QDs using He carrier gas have smaller dot size with a better uniformity in terms of dot height and dot base as compared to the H 2 carrier gas. There is a higher Ge composition and less compressive strain in the SiGe QDs grown in He than in H 2 as measured by Raman spectroscopy. The Ge content is higher for He growth than H 2 growth due to hydrogen induced Si segregation and the lower interdiffusivity caused by the more strain relaxation in the He-grown SiGe dots. The photoluminescence also confirms more compressive strain for H 2 growth than He growth. Hydrogen passivation and Ge-H cluster formation play an important role in the QDs growth.

Original languageEnglish
Pages (from-to)6257-6260
Number of pages4
JournalApplied Surface Science
Volume254
Issue number19
DOIs
StatePublished - 30 Jul 2008

Keywords

  • Carrier gas effect
  • Hydrogen passivation
  • SiGe quantum dot
  • Surface mobility
  • UHVCVD

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