Si spreading in lattice-matched In0.53Ga0.47As grown by molecular-beam epitaxy
Φόρτωση...
Ημερομηνία
Συγγραφείς
Skuras, E.
Long, A. R.
Vogele, B.
Holland, M. C.
Stanley, C. R.
Johnson, E. A.
van der Burgt, M.
Yaguchi, H.
Singleton, J.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
American Physical Society
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Physical Review B
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
A detailed study is reported of Si spreading in slab- and delta-doped In0.53Ga0.47As grown lattice matched to InP substrates by molecular beam epitaxy at temperatures from approximate to 420 to approximate to 520 degrees C and doping concentrations From 2 X 10(12) to 1.5 X 10(13) cm(-2). The spreading is deduced by comparing the individual subband densities calculated from a fast Fourier transform analysis of Shubnikov-de Haas measurements with those derived from self-consistent calculations for which the doping profile width is used as a fitting parameter. The growth conditions for the epitaxial layers were designed to differentiate between surface segregation and thermal diffusion of the dopant atoms. Surface segregation is found to be the dominant mechanism causing Si spreading at growth temperatures higher than approximate to 470 degrees C. An ideal S-doping profile in In0.53Ga0.47As requires only the growth of a thin cap layer of undoped material at temperatures less than approximate to 470 degrees C over the delta doping. Holding the substrate temperature at values up to approximate to 520 degrees C during delta doping or the subsequent deposition of material over the cap does not produce any spreading. The three-band Kane model is found to provide an adequate description of the electronic properties of narrow Si doping profiles with carrier concentrations as high as 1.5 X 10(13) cm(-2) and Fermi energies close to 550 meV, the separation between the Gamma- and L-conduction band minima in In0.53Ga0.47As. The free electron concentrations from low magnetic field Hall measurements are consistently less than the sums of the individual subband densities derived from the Shubnikov-de Haas effect. In addition, for the same total Si doping density, the apparent electron concentration from Hall measurements is lower when the Si dopants are more confined compared with the case where the dopants are significantly spread. These apparent discrepancies are shown to follow from the different subband mobilities expected in these structures. From the data a direct measure of the standard deviation of carrier mobilities over subbands for a given structure is obtained. [S0163-1829(99)04515-4].
Περιγραφή
Λέξεις-κλειδιά
delta-doped semiconductor, electron-concentration, transport-properties, surface segregation, doping layers, gaas, mobility, silicon, mbe, quantum
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000080114800050
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Μηχανικών Επιστήμης Υλικών