Surface chemistry of dimethylaluminum hydride and trimethylaluminum on polycrystalline aluminum

• Published in: Journal of physical chemistry (1952) Vol. 95; no. 3; pp. 1329 - 1333
• Main Authors: Strongin, Daniel R, Comita, Paul B
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.02.1991
• Subjects: 400102 - Chemical & Spectral Procedures; ALUMINIUM COMPOUNDS; ALUMINIUM HYDRIDES; Applied sciences; AUGER ELECTRON SPECTROSCOPY; Chemistry; DATA; ELECTRON SPECTROSCOPY; Exact sciences and technology; EXPERIMENTAL DATA; General and physical chemistry; HYDRIDES; HYDROGEN COMPOUNDS; INFORMATION; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; MASS SPECTROSCOPY; MEDIUM TEMPERATURE; Metals. Metallurgy; NUMERICAL DATA; Solid-gas interface; SPECTROSCOPY; Surface physical chemistry; SURFACE PROPERTIES; THIN FILMS; Surface reaction; Organic adsorbate; Polycrystal; Thermodesorption; Secondary ion mass spectrometry; Aluminium; Thermal desorption; Experimental study; Gas solid adsorption; Gas solid interface; Metallic adsorbent; Aluminium Organic compounds; Auger electron spectrometry; Physical method
• ISSN: 0022-3654; 1541-5740
• DOI: 10.1021/j100156a055

The surface chemistry of both dimethylaluminum hydride (DMAH)and trimethylaluminum (TMA) on a polycrystalline aluminum surface has been investigated with temperature-programmed desorption (TPD), secondary ion mass spectrometery (SIMS), and Auger electron spectroscopy (AES). Under the authors experimental conditions, DMAH adsorbs on the aluminum surface in its trimeric form and TMA adsorbs primarily in a dimeric form. DMAH desorbs from the atomically clean aluminum surface at 235 K, and TMA desorbs at 200 K. Both DMAH and TMA dissociate readily on the aluminum surface, and analysis by SIMS shows that this decomposition leaves a partially methylated aluminum surface at temperatures up to 500 K. DMAH desorbs from the carbon-contaminated aluminum surface at about 200 K. Both TMA and DMAH are found to produce methane product during the TPD experiments. The TPD experiments also suggest that the surface reactions of DMAH produce TMA as a reaction product. However, the reactions that form methane and TMA product occur in minor yield under their experimental conditions. By AES the surface is comprised of both aluminum and carbon after either DMAH-TPD or TMA-TPD.