Angle-resolved supersonic molecular beam study of the Cl sub 2 /GaAs l brace 110 r brace thermal etching reaction

Journal Article · Tue Jan 15 00:00:00 EST 1991 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.460011· OSTI ID:6039231

DeLouise, L A ^[1]

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1. Xerox Webster Research Center, 114-41D, Webster, New York 14580 (US)

Angle-resolved supersonic molecular beam scattering and time-of-flight techniques (TOF) are used to probe the dynamics of the Cl{sub 2}/GaAs{l brace}110{r brace} thermal etching reaction. TOF spectra are recorded for the unreacted Cl{sub 2} and the GaCl{sub 3} reaction product as a function of incident translational energy and surface temperature at various final scattering angles. Our results show that the reaction mechanism is precursor mediated. The weakly bound molecular (Cl{sub 2}){sub {ital ads}} species is a key reaction intermediate through which subsequent reaction steps occur. The reaction probability, determined by angle integration of the unreacted Cl{sub 2} flux, increases with surface temperature ({ital T}{sub {ital s}}) reaching a plateau and decreasing slightly between {ital T}{sub {ital s}}{similar to}425 K and 525 K before increasing sharply again beyond 525 K. This trend is nearly independent of incident kinetic energy. Detailed analysis of the TOF spectra reveal that the dynamical origin of this effect is due in part to a change in the reaction kinetics in which Cl{sub 2} desorption competes with product formation. The insights gained in this study are used to formulate plausible explanations for several discrepancies existing in the literature concerning the temperature dependence of the etch rate and of the high temperature product distribution.

• OSTI ID: 6039231
• Journal Information: Journal of Chemical Physics; (USA), Vol. 94:2; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHLORINE
MOLECULE COLLISIONS
GALLIUM ARSENIDES
ETCHING
ANGULAR DISTRIBUTION
HIGH TEMPERATURE
MOLECULAR BEAMS
SUPERSONIC FLOW
TEMPERATURE DEPENDENCE
TIME-OF-FLIGHT METHOD
ARSENIC COMPOUNDS
ARSENIDES
BEAMS
COLLISIONS
DISTRIBUTION
ELEMENTS
FLUID FLOW
GALLIUM COMPOUNDS
HALOGENS
NONMETALS
PNICTIDES
SURFACE FINISHING
656003* - Condensed Matter Physics- Interactions between Beams & Condensed Matter- (1987-)