Mattey, Nevil L. (1991) On the electrical and structural properties of boron delta layers in silicon. PhD thesis, University of Warwick.

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Abstract

This thesis describes the first successful growth of boron δ layers using
silicon MBE. SIMS has been used to demonstrate that the layer widths are
∽2nm as has been confirmed by TEM. This is probably an overestimate, an
average value of (0.3+-0.5)nm being obtained from XRD, suggesting that these
are the thinnest 6 layers produced to date.
Hall and XRD measurements indicate that the boron dopant is fully
activated up to sheet coverages of 1/2 monolayer, i. e. ∽3.5x10^14cm-2.
The CV profile obtained for a B δ layer of sheet density 2.5x10^12cm-2 has
FWHM ∽3nm, a result which is shown to be consisitent with δ doping in the
light of recent theoretical work.
Resistivity, magnetoresistance and the Hall effect have been measured at
temperatures down to 0.3K using magnetic fields of up to 12T on samples of
sheet density in the range 4x10^12cm-2 to 8x10^13cm-2.
2D weak localisation and
associated electron-electron interaction effects have been observed in samples of
sheet density above 1.8x10^13cm-2 with evidence of spin-orbit scattering. These
samples are shown to undergo a "metal-insulator" transition in high magnetic
fields with variable range hopping at 12T. Samples of sheet density ≤ 1x10^13cm-2,
show activated transport from which it is concluded that the critical acceptor
separation for the metal-insulator transition in this system is significantly less
than the value found in bulk, uniformly doped, Si:B. It is suggested that this may
be due to the splitting of the valence band degeneracy due to quantum
confinement.

Item Type:	Thesis or Dissertation (PhD)
Subjects:	Q Science > QC Physics
Library of Congress Subject Headings (LCSH):	Boron -- Synthesis, Boron -- Properties, Molecular beam epitaxy, Silicon, Doped semiconductors
Official Date:	September 1991
Dates:	Date Event September 1991 Submitted
Institution:	University of Warwick
Theses Department:	Department of Physics
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Whall, Terry
Extent:	vii, 107 p.
Language:	eng
URI:	http://wrap.warwick.ac.uk/id/eprint/4007

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