Berlin 2008 – scientific programme
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O: Fachverband Oberflächenphysik
O 55: Poster Session III - MA 141/144 (Methods: Atomic and Electronic Structure; Particles and Clusters; Heterogeneous Catalysis; Semiconductor Substrates: Epitaxy and Growth+Adsorption+Clean Surfaces+Solid-Liquid Interfaces; Oxides and Insulators: Solid-Liquid Interfaces+Epitaxy and Growth; Phase Transitions; Metal Substrates: Adsorption of Inorganic Molecules+Epitaxy and Growth; Surface Chemical Reactions; Bimetallic Nanosystems: Tuning Physical and Chemical Properties; Oxides and insulators: Adsorption; Organic, polymeric, biomolecular films; etc.)
O 55.40: Poster
Wednesday, February 27, 2008, 18:30–19:30, Poster F
Laser Activated Vapour Phase Processes for Silicon Substrate Cleaning — •Ulrich Abelein, Andreas Assmuth, Torsten Sulima, and Ignaz Eisele — Universität der Bundeswehr München, Institut für Physik, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany
One of the most important issues in today’s nanoelectronics fabrication is the in situ cleaning of silicon substrates, i. e. the removal of organic impurities and SiO2, before epitaxial growth.
The currently used vapour phase methods, like the hydrogen bake, require high process temperatures above 800 ∘C to activate the chemical reaction which leads to the desired effect. To avoid the diffusion of dopands or the formation of SiC clusters during the cleaning process a reduction of the necessary temperature below 700 ∘C is desirable.
Possible solutions to achieve this aim are the activation of the gas molecules by a plasma source or by laser light. As plasma processes cause damages to insulating layers and roughen the surface the use of a laser to provide the energy is more suitable.
We have integrated a process chamber, equipped with a 193 nm ArF Excimer Laser and up to four gases, in an UHV cluster tool. The laser beam is guided parallel to the substrate to ensure that only the gas molecules are affected and not the silicon. An RTP lamp heater can be used to adjust the substrate temperature independent from the laser energy. The efficiency of this approach will by demonstrated by the results achieved with a cleaning process using laser activated GeH4 to remove carbon and SiO2.