Degradation of n+/p junction characteristics by aluminum contamination

Toshihiko Itoga*, Hisao Kojima, Atsushi Hiraiwa, Makoto Ohkura

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


This paper discusses the effects of Al contamination on n+/p junction characteristics. The Al contamination occurs during ion implantation and the level can be as high as one tenth of the implanted dose. The Al contamination leads to an increase in the n+/p junction leakage current and a decrease in breakdown voltage. This is due to the increase of SiO2/Si interface state density and fixed negative charge in SiO2 film. The contaminating Al is segregated in the SiO2 film and remains very close to the oxide surface even in nm-order SiO2 (less than 10 nm), and the influence of Al becomes greater as SiO2 thickness decreases. Since Al is, and will continue to be, the most widely used material for process equipment, Al contamination control might become one of the key issues in achieving highly reliable future giga-scale ULSIs.

Original languageEnglish
Pages (from-to)4431-4434
Number of pages4
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Issue number7 A
Publication statusPublished - 1997 Jul
Externally publishedYes


  • Aluminum
  • Contamination
  • Gate oxide
  • Interface state
  • Ion implantation
  • Junction leakage current
  • SiO/Si interface
  • ULSI

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)
  • General Engineering


Dive into the research topics of 'Degradation of n+/p junction characteristics by aluminum contamination'. Together they form a unique fingerprint.

Cite this