We report room-temperature pseudodielectric function spectra 〈ε (ω) 〉 = 〈 ε1 (ω) 〉 +i 〈 ε2 (ω) 〉 from 1.5 to 6.0 eV of a series of (GaSb)3n (AlSb)n (1≤n≤5) short-period superlattices (SLs) and the corresponding ternary alloy, Al0.3 Ga0.7 Sb, as determined by spectroscopic ellipsometry. An in situ chemical etching procedure was performed to minimize the effect of surface oxides and other overlayers. For small periods (n≤2), the dielectric responses of the SLs are similar to those of the random alloy. For larger n, structures due to the E1, E1 + Δ1, E0′, E2, and E1′ interband transitions can be seen, with the E1, E1 + Δ1, and E0′ structures showing a clear SL-period dependence. Two additional features were also observed near the E1 + Δ1 structure for n≥4.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures|
|State||Published - 2005|
ASJC Scopus subject areas
- Condensed Matter Physics
- Electrical and Electronic Engineering