Method and device for plasma heating of the internal walls of a vacuum furnace
OwnerPierre VANDEN BRANDEinventor
Life of this patent
Estimating the term…
Abstract
Method and device for heating the walls (17) of a vacuum furnace (8,9,30), said walls (17) having an electric conductive surface (20), wherein a plasma is generated in a gas at a pressure lower than 1 mbar in the vacuum furnace (8,9,30) between said walls (17) and an anode (18). A voltage bias is generated between the plasma and said surface (20) of the walls (17) by polarising the surface (20) negatively with respect to the anode (18). The temperature of the walls (17), in particular of the conductive surface (20), is regulated by regulating the power transfer of the plasma to the walls (17) by controlling the electrical power supply through said voltage bias.
Claims25
A method for heating walls delimiting an internal volume in a vacuum furnace, said walls forming a thermal shield and having an electrically conductive surface directed towards said internal volume, wherein a plasma is generated in a gas at a pressure lower than 1 mbar in the internal volume between said walls and an anode present in the internal volume, wherein a voltage bias is generated between the plasma and said surface of the walls by polarizing said surface negatively with respect to the anode and wherein the temperature of said walls, in particular of said surface, is regulated by a controller by regulating power transfer of the plasma to the walls by controlling electrical power supply to the plasma through controlling said voltage bias.
A device for plasma treatment of a substrate, comprising a vacuum furnace having an internal volume delimited by walls forming a thermal shield and having a side directed towards said internal volume, said side having an electrically conductive surface, wherein an anode is provided in the internal volume permitting to generate a plasma in the internal volume, wherein said electrically conductive surface of the walls is adapted to be negatively polarized against said anode, wherein a power supply is provided permitting to apply voltage bias between the plasma and said electrically conductive surface of the walls by polarizing said electrically conductive surface negatively with respect to the anode and wherein a controller is provided for regulating the temperature of said surface by regulating power transfer of the plasma to the walls by controlling electrical power supply to the plasma through controlling said voltage bias.
The device according to claim 18, wherein the surface area of said anode in said internal volume is smaller than the total area of said side of the walls directed towards said internal volume.
Dependencies are inferred from the claim text.