Adsorption and decomposition of tert-butylacetylacetate (tBAA) on Si(100) have been investigated using static secondary ion mass spectrometry and temperature-programmed desorption. At low doses, all tBAA molecules dissociate readily upon adsorption on the surface at temperatures as low as -160 °C. The dissociation may occur through tBAA bonding via the ester oxygen or the carbonyl group to the surface. The bond scission occurring at the tBuO-CO bond leads to the formation of surface tert-butoxide. Further dehydrogenation can take place to yield isobutene and surface hydroxyl species. Subsequent heating of the substrate causes the hydroxyl to decompose, and the resulting substoichiometric silicon oxide sublimes as SiO. The surfaceinduced bond scission also occurs at the OC-CCO bond of the tBAA diketo moiety to produce isobutene. In addition, the OC-CCO bond scission induced by tBAA surface bonding, mainly via its carboxylic keto oxygen, affords acetaldehyde radical, whereas that induced mainly via the aceto oxygen yields carbon dioxide and isopropenoxy species. An enol-keto conversion takes place when isopropenoxy species acquire surface hydrogen to yield acetone, even at low substrate temperature of less than -126 °C. The aceto oxygen pathway dominates the cleavage of the OC-CCO bond. Increasing substrate temperature also causes the surface tertbutyl fragments to further react through different β-hydride elimination pathways, forming isobutene, which is either in the gaseous state or bound to the surface in a di-σ configuration.

The adsorption, reaction, growth, and the bonding configuration of a trinuclear linear metal atom chain complex, tetrakis(2,2′-dipyridylamino)chromium(VI) chloride (DPCC, Cr 3 (µ 3 -dpa) 4 Cl 2 ), on the GaN(0001) surface at 110 K were studied using synchrotron-induced X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectrometry (SIMS). XPS studies revealed three Cr chemical states of equal surface population present on the sample surface exposed to DPCC of low doses. The SIMS spectra showed main signals contributed from the sputter desorption of pyridine and the dipyridylamino ligand. Studies on small model molecules, such as pyridine and dipyridylamine (Hdpa), exposed to the sample surface showed that upon adsorption at 110 K, these small molecules were present on the sample surface in the molecular form only. They yielded the molecule-Ga adducts formed during SIMS detection. The absence of these adduct signals in the SIMS spectra taken from the DPCC-exposed surface indicated that DPCC chelates were not disintegrated upon adsorption. Instead, DPCC chelates of low doses reacted with the surface via bond rupture of one of the two terminal Cr-Cl bonds on their central Cr atom chains, leaving the Cl atom separated from DPCC to bond on the Ga site of the surface. The resulting chemisorbed DPCC chelate bonded to the surface via the terminal Cr atom of its trinuclear metal chain, resulting in one end of the chain anchored to the surface and the other oriented away from it. There was a change in the DPCC adsorption behavior as the exposure was increased to high doses. The DPCC layer grew molecularly by physisorption at high exposures and the chelates were present on the surface in an inclined configuration. The chelate effect from the presence of four chelating groups in DPCC may provide the chelate its large stability and chemical inertness.

The power of the angle‐resolved ion desorption technique for straightforward characterization of surfaces is demonstrated. The structural sensitivity of secondary ion desorption has led to a successful application of angle‐resolved ion sputtering yield measurements to the determination of the Cl chemical bonding structure on the Ag {100} surface. Angular distributions of the sputtered Cl− ions show that chlorine dissociates at the surface to yield a bonding state of atomic form at the room temperature. Both the polar and the azimuthal angle dependencies of the sputter intensity for Ag+ and Cl− ions reveal that the Cl adatom is chemi‐sorbed high above the topmost substrate layer of Ag atoms. At all Cl exposures, the Ag‐Cl bond is oriented along the <100> azimuth with the adsorbate occupying a C4 symmetry site, not an a‐top, a bridge, or a high symmetry site. Shadow‐cone enhanced ion desorption spectra show that die geometrical structure of the Cl chemisorbed surface changes slightly as the exposure is increased.

Better understanding about the chemistry of the organometallic chain complexes reacting on the solid surface can foster concepts of nanowire fabrication which are central to the continued advance of the electronic and optoelectronic industries. In this study, the adsorption and thermal reactivity of a trinuclear chromium chain complex, tetrakis (2,2′-dipyridylamino)chromium(VI) chloride, on the GaN(0001) surface were investigated using x-ray photoelectron spectroscopy, temperature-programmed desorption, and static secondary ion mass spectrometry in order to obtain some insight into the bonding changes involved in the reaction of the linear metal chain complex on the compound semiconductor surface. One of the two terminal Cr–Cl bonds of the complex may be cleaved upon adsorption at 110K, leading to the formation of the Ga–Cl bonds on the surface, although some complexes remained intact upon adsorption and bonded strongly to the surface. No ligand was dissociated from the chromium chain complex during the adsorption. The Cl-cleaved complex residue preserved its original chemical configuration. Both the Cl-cleaved and the intact complexes in the first layer were stable on the surface in the substrate temperature range between 110 and 260K. A partial decomposition in which some ligands were dissociated from the adsorbed complex took place before the substrate temperature reaching 400K. Additional Cr–Cl bonds were disrupted, resulting in a larger population of Ga–Cl bonds on the surface. Further thermal reaction at higher temperatures led to the dominance of the Ga–Cl bonding for the Cl presence on the surface. Surface etching of Ga by the dissociated Cl atoms started at a substrate temperature of ∼525K and the etching rate reached its maximum at ∼590K.