Adsorption Of Triethylgallium Research Articles

Adsorption and Thermal or Photodecomposition of Triethylgallium and Trimethylgallium on Si(111)-7×7

Adsorption and thermal or photodecomposition of triethylgallium (TEG) and trimethylgallium (TMG) on Si(111)-7×7 were investigated using a home-built scanning tunneling microscope (STM), Auger electron spectroscopy (AES), and thermal desorption spectroscopy (TDS). Adsorption of TEG and TMG at room temperature gave bright protrusions of Ga(C2H5)x (a) and Ga(CH3)x (a) (x=2, 3) on atop sites of Si adatoms with a slight preference for center adatoms over comer ones. The Ga(C2H5)x (a) and Ga(CH3)x (a) species were decomposed by UV irradiation probably due to absorption of UV photons by these adsorbates. Thermal decomposition of TEG on the 7×7 surface led to severe carbon deposition, particularly at low initial coverage of TEG, in contrast to the result reported on Si(100)-2×1.

In-situ reflection high-energy electron diffraction observation of laser-triggered GaP growth in chemical beam epitaxy

Surface reaction triggered by N 2 laser irradiation onto adsorbed triethylgallium (TEGa) and reaction with phosphorus in chemical beam epitaxy (CBE) was studied by growth experiment and intensity change of reflection high-energy electron diffraction (RHEED). The growth rate shows saturation with a high TEGa supply, which suggests that the adsorption of TEGa on a surface is saturated. The change of RHEED oscillation was different from that of a continuous reaction. The result showed that the decomposition of TEGa and formation of GaP occur alternately under continuous supply of TEGa and PH 3.

Comparative studies of the surface reactivity of triethylgallium on semiconductor and dielectric surfaces

The adsorption of triethylgallium (TEG) on GaAs in the presence of submonolayer quantities of Al or In has been investigated. It is found that these additives modify the reactivity patterns observed for TEG on the clean GaAs surface; the presence of Al suppresses the amount of diethylgallium (DEG) desorbing whereas In has the opposite effect. This arises since the kinetic parameters governing the desorption of DEG, which occurs in competition with its surface decomposition, are changed when Al or In are deposited on the surface. Comparative studies on the adsorption of TEG on Si3N4 have also been performed and the results are used to gain an insight into phenomena observed during the growth of III-V semiconductors by chemical beam epitaxy.

Surface chemical processes in metal organic molecular-beam epitaxy; Ga deposition from triethylgallium on GaAs(100)

The adsorption of triethylgallium on the GaAs (100) (4×1) surface has been studied using the techniques of low energy electron diffraction, x-ray photoelectron and Auger spectroscopies, high resolution electron energy loss spectroscopy and temperature-programmed desorption. Condensed multilayers of the organometallic compound formed following adsorption at 150 K desorb from the surface at ∼170 K to leave a chemisorbed molecular monolayer of triethylgallium. Upon further heating this layer partially desorbs and partially decomposes to form diethylgallium in two competing processes. The diethylgallium so formed can also desorb or otherwise decompose ultimately to adsorbed Ga atoms in a reaction which results in the formation of hydrogen, ethene, and ethane. The temperature-programmed desorption characteristics of these latter species are found to be similar to those observed for a dissociated layer of ethyl bromide. A reaction scheme is proposed to account for the observations and kinetic parameters are obtained from computer modeling of the temperature-programmed desorption results. The reaction scheme is also used to evaluate the temperature-dependent growth rate expected in metal organic molecular beam epitaxial growth of GaAs. Comparison with experimental results is made and the work is discussed in the light of the previous model which has been proposed for the epitaxial growth of GaAs by metal organic molecular-beam epitaxy.

The adsorption of triethylgallium on GaAs (100) at 300 K

The adsorption of a typical GaAs MOVPE precursor, triethylgallium (TEG) on an As-rich GaAs (100) surface at 300 K is confirmed via Auger and desorption measurements. Desorption data are consistent with the sequential decomposition of a diethylgallium species and indicate that both ethane and ethene are produced in the decomposition of the surface species over the temperature range 300–770 K. The formation of diethylgallium via 300 K adsorption is further supported by AES intensity data which reveal that the surface species has an apparent stoichiometry of 1 Ga to 4(±0.5) C. Carbon (1s VV) lineshapes suggest that the ethyl groups are not significantly perturbed via adsorption.