TY - GEN A1 - Sioncke, Sonja A1 - Lin, Hang-Chu A1 - Brammertz, Guy A1 - Delabie, Annelies A1 - Conard, Thierry A1 - Franquet, Alexis A1 - Caymax, Matty A1 - Meuris, Marc A1 - Schmeißer, Dieter A1 - Tallarida, Massimo T1 - ALD on high mobility channels: engineering the proper gate stack passivation T2 - ECS Transactions KW - ALD KW - engineering KW - gate stack KW - passivation Y1 - 2010 SN - 1938-5862 VL - 33 IS - 2 SP - 9 EP - 23 ER - TY - GEN A1 - Tallarida, Massimo A1 - Adelmann, Christoph A1 - Delabie, Annelies A1 - Elshocht, Sven van A1 - Caymax, Matty A1 - Schmeißer, Dieter T1 - Surface chemistry and Fermi level movement during the self-cleaning of GaAs by trimethyl-aluminum T2 - Applied physics letters Y1 - 2011 U6 - https://doi.org/10.1063/1.3615784 SN - 1077-3118 VL - 99 IS - 4 SP - 042906-1 EP - 042906-3 ER - TY - GEN A1 - Tallarida, Massimo A1 - Adelmann, Christoph A1 - Delabie, Annelies A1 - van Elshocht, Sven A1 - Caymax, Matty A1 - Schmeißer, Dieter T1 - GaAs clean up studied with synchrotron radiation photoemission T2 - IOP Conference Series : Materials Science and Engineering N2 - In this contribution we describe the chemical changes at the surface of GaAs upon adsorption of tri-methyl-aluminum (TMA). TMA is used to grow Al2O3 with atomic layer deposition (ALD) usually using H2O as oxygen source. Recently, it was pointed out that the adsorption of TMA on various III-V surfaces reduces the native oxide, allowing the growth of an abrupt III-V/High-K interface with reduced density of defects. Synchrotron radiation photoemission spectroscopy (SR-PES) is a powerful method to characterize surfaces and interfaces of many materials, as it is capable todetermine their chemical composition as well as the electronic properties. We performed in-situ SR-PES measurements after exposing a GaAs surface to TMA pulses at about 250°C. Upon using the possibility of tuning the incident photon energy we compared the Ga3d spectra at 41 eV, 71 eV, 91 eV and 121 eV, as well as the As3d at 71 eV and 91 eV. Finally, we show that using SR-PES allows a further understanding of the surface composition, which is usually not accessible with other techniques. KW - photoemission spectroscopy KW - atomic layer deposition KW - GaAs Y1 - 2012 U6 - https://doi.org/10.1088/1757-899X/41/1/012003 SN - 1757-899X IS - 41 SP - 012003 ER - TY - GEN A1 - Tallarida, Massimo A1 - Adelmann, Christoph A1 - Delabie, Annelies A1 - Elshocht, Sven van A1 - Caymax, Matty A1 - Schmeißer, Dieter T1 - III-V/Oxide Interfaces Investigated with Synchrotron Radiation Photoemission Spectroscopy T2 - ECS Transactions N2 - We used synchrotron radiation photoemission spectroscopy (SR-PES) to investigate the surface of GaAs and other III-V semiconductors after tri-methyl-aluminum (TMA) pulses performed at 250{degree sign}C. We observed the removal of native oxide and the growth of Al-oxide upon measuring the As3d, Ga3d, Al2p and VB spectra. After seven TMA pulses we performed one water pulse. As3d and Ga3d peaks showed almost no lineshape change, but a decrease of intensity due to the water adsorption. The valence band shows a change in the secondary electron cut-off and the decrease of work function. We conclude that water mostly adsorbs molecularly and induces the work function decrease. The molecular absorption of water indicates that the seven TMA pulses produce a passivated surface only partially terminated with OH groups. KW - Interfaces KW - III/V KW - Synchrotron Photoemission Spectroscopy Y1 - 2013 U6 - https://doi.org/10.1149/05004.0123ecst SN - 1938-6737 VL - 50 IS - 4 SP - 123 EP - 128 ER - TY - GEN A1 - Adelmann, Christoph A1 - Cuypers, Daniel A1 - Tallarida, Massimo A1 - Rodriguez, Leonard A1 - De Clercq, Astrid A1 - Friedrich, Daniel A1 - Conard, Thierry A1 - Delabie, Annelies A1 - Seo, Jin Won A1 - Locquet, Jean-Pierre A1 - De Gendt, Stefan A1 - Schmeißer, Dieter A1 - Elshocht, Sven van A1 - Caymax, Matty T1 - Surface Chemistry and Interface Formation during the Atomic Layer Deposition of Alumina from Trimethylaluminum and Water on Indium Phosphide T2 - Chemistry of Materials N2 - The surface chemistry and the interface formation during the initial stages of the atomic layer deposition (ALD) of Al2O3 from trimethylaluminum (TMA) and H2O on InP(100)were studied by synchrotron radiation photoemission spectroscopy and scanning tunneling microscopy. The effect of the ex situ surface cleaning by either H2SO4 or (NH4)2S was examined. It is shown that the native oxide on the InP surface consisted mainly of indium hydrogen phosphates with a P enrichment at the interface with InP. After a (NH4)2S treatment, S was present on the surface as a sulfide in both surface and subsurface sites. Exposure to TMA led to the formation of a thin AlPO4 layer, irrespective of the surface cleaning. The surface Fermi level of p-type InP was found to be pinned close to midgap after H2SO4 cleaning and moved only slightly further toward the conduction band edge upon TMA exposure, indicating that the AlPO4/InP interface was rather defective. (NH4)2S passivation led to a Fermi level position of p-type InP close to the conduction band edge. Hence, the InP surface was weakly inverted, which can be attributed to surface doping by S donors. TMA exposure was found to remove surface S, which was accompanied by a shift of the Fermi level to midgap, consistent with the removal of (part of) the S donors in combination with a defective AlPO4/InP interface. Further TMA/H2O ALD did not lead to any detectable changes of the AlPO4/InP interface and suggested simple overgrowth with Al2O3. Y1 - 2013 U6 - https://doi.org/10.1021/cm304070h SN - 1520-5002 VL - 25 IS - 7 SP - 1078 EP - 1091 ER -