Abstract
Scanning tunneling microscopy (STM) has been used to investigate nucleation and initial growth in the heteroepitaxies of calcium fluoride (CaF2) and barium fluoride (BaF2) on Si(111) surfaces in situ. The fluoride depositions and the STM measurements are performed at a substrate temperature of about 400°C. STM images clearly show that a BaF2-deposited surface has a different morphology from that of CaF2-deposited surface. Preferential nucleation and island growth of BaF2 only occur at steps and domain boundaries on a Si(111)-7 x 7 reconstructed surface. On the other hand, CaF2 islands nucleate not only at steps and domain boundaries but also in domain-boundary-free regions of a Si(111) surface. We attribute the difference in the morphologies to the much higher mobility and diffusion length of a BaF2 molecule in comparison to those of a CaF2 molecule on a Si(111) surface at 400°C. We also report the first STM measurement of a (CAF2 + BaF2)-coexisting surface at 480°C.
Original language | English |
---|---|
Pages (from-to) | L1077-L1080 |
Journal | Japanese Journal of Applied Physics, Part 2: Letters |
Volume | 35 |
Issue number | 8 SUPPL. B |
DOIs | |
Publication status | Published - 1996 Aug 15 |
Externally published | Yes |
Keywords
- Barium fluoride
- Calcium fluoride
- Heteroepitaxy
- Scanning tunneling microscopy
- Silicon
ASJC Scopus subject areas
- Engineering(all)
- Physics and Astronomy(all)