The influence of surface structure on the reaction of dimethylzinc on GaAs(100)

Growth Mechanism and Electronic Structure of Zn3P2 on the Ga-Rich GaAs(001) Surface

“…Figure shows high-resolution STM images (top), cross-sectional line profiles (center), and proposed structure models (bottom) of a clean GaAs(001)-(6 × 6) surface and submonolayer Zn 3 P 2 layers grown on the clean (6 × 6) surface at high temperatures (300, 490, and 560 °C). Our XPS data showed that the films grown at >400 °C did not contain Zn, which is supported by previous reports of Zn desorption occurring below 323 °C, depending on the coverage and surface properties. , Thus, we expect that the films grown at high temperatures are effectively the same as those formed using only an elemental P 4 source. Figure a displays the clean GaAs(001)-(6 × 6) surface reconstruction.…”

“…Upon exposure of the clean (6 × 6) surface to a Zn 3 P 2 source, any additional feature whose number density increased as the amount of Zn 3 P 2 exposure increased was associated with either Zn or P atoms. However, since the peanut-shaped features were also observed on the films grown at temperatures higher than the Zn desorption temperature, 21,22 Zn was not associated with this surface reconstruction. In addition, since Zn and Ga are cations in II−V and III−V materials, one would expect to observe only the group-V atoms and not the metal atoms in the filled-state STM image under a negative sample voltage.…”

“…Our XPS data showed that the films grown at >400 °C did not contain Zn, which is supported by previous reports of Zn desorption occurring below 323 °C, depending on the coverage and surface properties. 21,22 Thus, we expect that the films grown at high temperatures are effectively the same as those formed using only an elemental P 4 source. Figure 2a 2a).…”

Reaction Chemistry of ZnTe Metalorganic Vapor-Phase Epitaxy

“…The surface hydrogenation of methyl groups into methane is contrary to current understanding of compound semiconductor surface chemistry. Vohs and co-workers have investigated the decomposition of DMZn on GaAs(001) and have only detected methyl radicals and zinc atoms with the mass spectrometer during temperature-programmed desorption. Furthermore, it is generally agreed that trimethylgallium decomposes by desorption of methyl radicals on GaAs(001) surfaces. , The discrepancy between our observations and the surface science studies may be due to the drastically different conditions under which the experiments are performed.…”

Surface Chemistry of Prototypical Bulk II−VI and III−V Semiconductors and Implications for Chemical Sensing

“…A number of metal alkyls have been studied at GaAs surfaces owing to their importance in metal organic chemical vapor deposition (MOCVD) processes used in the growth of semiconductor thin films. Most commonly investigated have been the reactions on GaAs surfaces of trialkylgallium and dialkylzinc compounds used in the growth of GaAs and ZnSe overlayers, respectively. − In a study comparing the Ga-rich (4 × 2) and As-rich (2 × 4) and c(4 × 4) GaAs(100) surfaces for adsorption of diethylzinc, using HREELS and TPD, Lam et al report that diethylzinc undergoes dissociative adsorption at room temperature on all three faces, forming surface ethyl and Zn as adsorbates. Surface Zn is found to desorb at 560 K on the Ga-rich surface and at 585 K on the As-rich surfaces, indicating that the Zn−As interaction is stronger …”