Ballistic electron emission microscopy studies of inhomogeneity in Au/CaF2/n-Si(111) interfaces

Touru Sumiya, Haruko Fujinuma, Tadao Miura, Shun Ichiro Tanaka

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


We have performed ballistic electron emission microscopy (BEEM) measurements on the Au/CaF2/n-Si(111) system in which calcium fluoride (CaF2) (about 2 monolayers (ML)) was introduced at the Au/Si interface. A BEEM image clearly shows the coexistence of two types of terrace for each of which the BEEM I-V spectrum has a different shape. A typical threshold voltage of the BEEM current for one type is about 0.75 V. In contrast, the second type shows a threshold voltage of about 3.5 V, which is much higher than the value of the first type. Furthermore, the BEEM current on the second type is significantly reduced and saturates above about 6 V. We attribute the coexistence of the two types of terrace in the BEEM image to the different degrees of coverage of the CaF2 intralayers between them. At the second type of terrace, a Au/2 ML CaF2/1 ML CaF/Si(111) interface exists, although the first type has a Au/1 ML CaF/Si(111) interface without a CaF2 intralayer.

Original languageEnglish
Pages (from-to)L996-L999
JournalJapanese Journal of Applied Physics, Part 2: Letters
Issue number8 PART A
Publication statusPublished - 1997 Aug 1
Externally publishedYes


  • BEEM
  • Ballistic electron emission microscopy
  • Calcium fluoride
  • Interface
  • Silicon

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)


Dive into the research topics of 'Ballistic electron emission microscopy studies of inhomogeneity in Au/CaF2/n-Si(111) interfaces'. Together they form a unique fingerprint.

Cite this