The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 19, 2005
Filed:
Jul. 20, 2001
Sven Lindfors, Espoo, FI;
Pekka T. Soininen, Helsinki, FI;
Sven Lindfors, Espoo, FI;
Pekka T. Soininen, Helsinki, FI;
ASM Microchemistry Oy, Espoo, FI;
Abstract
The present invention relates to the production of thin films. In particular, the invention concerns a method of growing a thin film onto a substrate, in which method the substrate is placed in a reaction chamber and is subjected to surface reactions of a plurality of vapor-phase reactants according to the ALD method. The present invention is based on replacing the mechanical valves conventionally used for regulating the pulsing of the reactants, which valves tend to wear and intrude metallic particles into the process flow, with an improved precursor dosing system. The invention is characterized by choking the reactant flow between the vapour-phase pulses while still allowing a minimum flow of said reactant, and redirecting the reactant at these times to an other destination than the reaction chamber. The redirection is performed with an inactive gas, which is also used for ventilating the reaction chamber between the vapour-phase pulses.