Papers by Keyword: Temperature Programmed Desorption

Abstract: Incorporating substrates with higher charge mobilities than Si and Ge in metal-oxide-semiconductor field-effect transistors (MOSFETs) would extend the scaling of this device architecture. III-V semiconductors are candidates, and etching and passivation processes are needed that are selective and yield smooth surfaces. The (100) face of III-V compounds contains both electron-deficient group III (Ga, In) atoms and electron-rich group V (P, As, Sb) atoms. Etching InP(100) in a mixture of HCl and H₂O₂ chlorinates the In (group III) atom forming a soluble product [1,2], yet the P (group V) atom is more reactive and is depleted from the surface [3]. α-Hydroxy acids (lactic, citric, malic, and tartaric) have been shown to bind to the group III atom [3] and could promote more uniform etching. This paper compares the surface chemistry of GaAs and InAs after etching in HCl and H₂O₂ mixtures with and without tartaric acid.

Abstract: Surface science studies of photochemistry on titanium dioxide (TiO2) were reviewed. In the studies, photochemical processes were investigated in relation to atomic-scale surface structures by applying surface-sensitive analytical methods to single crystal TiO2 surfaces with well-defined structures. It is demonstrated that a surface science approach is promising for full description of the photochemical processes on TiO2.

Abstract: Hydrogen sorption-desorption properties of Ti/B and Ti/C nanocomposites prepared under ball-milling of the corresponding powders in H2 flow were studied using kinetic, microscopic and spectroscopic techniques. Amorphous boron was found to be more effective in spurring Ti – H2 interaction than carbon because of the following properties: (1) significant fragmentation of Ti powder by preventing agglomeration of the particles; (2) unhindered hydrogen access to the surface of Ti nanoparticles through the boron matrix; (3) appearance of new occupation sites available for H atoms, which are characterized by low H2 desorption temperature. The dynamics of the formation of these sites and the H2 distribution between different occupation sites in dependence on phase composition and morphology were studied for the Ti/B system.