Investigation of the kinetics of digermane chemisorption and reaction product desorption in thin film growth of germanium

Journal Article · Wed Sep 01 00:00:00 EDT 1993 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578593· OSTI ID:6236750

Eres, G; Sharp, J W ^[1]

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1. Solid State Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6056 (United States)

The kinetics of the elementary reaction steps in surface-limited thin film growth of germanium from digermane was investigated by utilizing surface differential reflectance. Separation of the elementary reaction steps of chemisorption and reaction product desorption was achieved by using a pulsed molecular beam to modulate the digermane delivery to the heated substrate. Both elementary reaction steps were found to be single exponential first-order processes. The chemisorption reaction on Ge(100) was rapid ([ital k][sub 1]=500[plus minus]50 s[sup [minus]1]), and independent of the substrate temperature between 680 and 810 K. On the other hand the desorption step in the same substrate temperature range is strongly temperature dependent with an activation energy of 1.7[plus minus]0.1 eV and a prefactor of 2[times]10[sup 13[plus minus]1] s[sup [minus]1]. A simple kinetic model comprised of two opposing first-order elementary steps is found to be consistent with the experimental results. It is concluded that the kinetic data are compatible with the pairing mechanism for molecular hydrogen desorption, but no (thermal) decomposition mechanism of digermane is found to provide a unique interpretation for the first-order adsorption kinetics.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6236750
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 11:5; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISORPTION
DESORPTION
ELEMENTS
EPITAXY
FILMS
GERMANIUM
GERMANIUM COMPOUNDS
GERMANIUM HYDRIDES
HYDRIDES
HYDROGEN
HYDROGEN COMPOUNDS
KINETICS
METALS
MOLECULAR BEAM EPITAXY
NONMETALS
REACTION KINETICS
SEPARATION PROCESSES
SORPTION
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
THIN FILMS