Electrical study of Schottky-barrier heights on atomically clean p-type InP(110) surfaces

Nathan Newman, M. Van Schilfgaarde, W. E. Spicer

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

We report here a systematic study of the electrical properties of a large number of metal (Ag, Cr, Cu, Au, Pd, Mn, Al, Ni) on p-type InP diodes. Schottky-barrier diodes were fabricated by in situ metal deposition on atomically clean InP(110) surfaces in ultrahigh vacuum. Schottky-barrier heights were determined from current-voltage (I-V) and capacitance-voltage (C-V) measurements. A small, but finite, range in barrier heights (0.760.98 eV) is found for the metalp-type InP systems investigated. When a comparison is made to our earlier work on n-type surfaces, we find that the interface Fermi level of n-type and p-type samples pins at the same position within the band gap for each of the metal InP systems studied. Our experimental results indicate that models that use metal-independent surface states (energy and density) and potential normalization conditions (i.e., natural band lineups) can predict the general trends in the interface Fermi-level pinning behavior. They cannot, however, successfully predict the details of this behavior to within measurement error. A theoretical method to determine the natural band lineups at the interface (using a scheme developed by Anderson) is presented within this context. Also investigated was the effect of air exposure on the electrical characteristics of diodes. For in situ I-V measurements, the metal semiconductor systems were characterized by a near-unity (1.031.10) ideality factor n. Upon exposure to air, a large increase in the current and ideality factor n was found for several (Cu, Au, Pd, Mn, Ni) metalp-type InP systems at all measured biases. A detailed investigation of the Pdp-type InP system indicated that the excess current pathway which results from exposure to air is at the periphery and can be eliminated by mesa etching.

Original languageEnglish (US)
Pages (from-to)6298-6304
Number of pages7
JournalPhysical Review B
Volume35
Issue number12
DOIs
StatePublished - 1987
Externally publishedYes

Fingerprint

Metals
metals
Fermi level
air
Diodes
Air
diodes
Schottky barrier diodes
Capacitance measurement
Voltage measurement
Surface states
Ultrahigh vacuum
mesas
Schottky diodes
Measurement errors
electrical measurement
ultrahigh vacuum
unity
Etching
Electric properties

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Electrical study of Schottky-barrier heights on atomically clean p-type InP(110) surfaces. / Newman, Nathan; Van Schilfgaarde, M.; Spicer, W. E.

In: Physical Review B, Vol. 35, No. 12, 1987, p. 6298-6304.

Research output: Contribution to journalArticle

Newman, Nathan ; Van Schilfgaarde, M. ; Spicer, W. E. / Electrical study of Schottky-barrier heights on atomically clean p-type InP(110) surfaces. In: Physical Review B. 1987 ; Vol. 35, No. 12. pp. 6298-6304.
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