Au and Al Schottky barrier formation on GaAs (100) surfaces prepared by thermal desorption of a protective arsenic coating

Journal Article · Mon Jul 01 00:00:00 EDT 1991 · Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States)

DOI:https://doi.org/10.1116/1.585780· OSTI ID:5360909

Spindt, C J; Yamada, M; Meissner, P L; Miyano, K E; Herrera, A; Spicer, W E ^[1]; Arko, A J ^[2]

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1. Stanford Electronics Laboratories, Stanford University, Stanford, California 94305-4055 (US)
2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (US)

Soft x-ray photoemission spectroscopy has been used to investigate the initial stages of Schottky barrier formation on GaAs (100) surfaces prepared by the thermal desorption of an As cap. This work was motivated by a previous study (Brillson {ital et} {ital al}., J. Vac. Sci. Technol. B {bold 6}, 1263 (1988)) of identically grown and capped samples which reported unpinned'' Schottky barrier formation, with barrier heights falling over a wide range (0.75 eV) of energies. This large energy range is a striking result, as a considerable number of prior studies on both (110) and (100) surfaces have found that all metals will pin in a narrow (0.25 eV) range near midgap. Since Au and Al are the extremes of the larger 0.75 eV span of Schottky barriers, we have studied the deposition of these two metals. We found that the barrier height measurements on the low doped {ital n}-type samples used in this work and in the paper referenced above are affected by photovoltaic effects, even at room temperature. These photovoltaic effects cause shifts in the band bending, which are an artifact of the measurement. We also performed measurements on more heavily doped samples, and the photovoltaic effects were removed. In addition, we point out that Au--Ga alloying makes the case of Au potentially misleading. With the photovoltaic effects removed, and the Au--Ga alloying carefully accounted for, we found that the barriers heights for Au and Al differ by only 0.25 eV.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5360909
• Journal Information: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States), Vol. 9:4; ISSN 0734-211X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
PHOTOVOLTAIC EFFECT
GALLIUM ARSENIDES
GOLD
SCHOTTKY BARRIER DIODES
ARSENIC
DESORPTION
PHOTOELECTRON SPECTROSCOPY
SOFT X RADIATION
SYNTHESIS
ARSENIC COMPOUNDS
ARSENIDES
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
GALLIUM COMPOUNDS
IONIZING RADIATIONS
METALS
PHOTOELECTROMAGNETIC EFFECTS
PNICTIDES
RADIATIONS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMIMETALS
SPECTROSCOPY
TRANSITION ELEMENTS
X RADIATION
360603* - Materials- Properties