| Autor: |
de Frésart, E., Wang, K. L., Rhee, S. S. |
| Předmět: |
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| Zdroj: |
Applied Physics Letters; 7/4/1988, Vol. 53 Issue 1, p48, 3p |
| Abstrakt: |
Boron surface segregation in Si molecular beam epitaxy has been measured on Si(111) substrate as a function of the growth temperature (400 °C≤Ts≤900 °C) by Auger electron spectroscopy. Boron oxide (B2O3) was used as dopant material to achieve a boron concentration level of about 1×1019 cm-3. Three temperature regions are observed for the behavior of the ratio rd=Is/Ib of the surface (Is) to the bulk (Ib) dopant atomic fractions. At low temperature, Ts=400–570 °C the ratio maintains at the value rd[bar_over_tilde:_approx._equal_to]1.5. For 570 °C≤Ts≤720 °C, rd increases to a plateau rd[bar_over_tilde:_approx._equal_to]5.5, and then jumps to rd=42 in the 720–750 °C region. At higher temperature, Ts≥750 °C, rd decreases according to a relation which can be approximated by the classical equilibrium segregation theory. In that region, the boron Gibbs free energy of surface segregation is calculated from data to be ΔGS=-0.33±0.02 eV. Evolution of rd is closely correlated to the etch pit count and electron channeling results revealing amorphous, polycrystalline, and epitaxial growth, when going from low to high growth temperature. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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