Evaporation apparatus, vapor deposition apparatus, and evaporation method

Abstract

An evaporation apparatus (100) is described, particularly for evaporating a reactive material such as lithium. The evaporation apparatus (100) includes an evaporation crucible (110) for evaporating a liquid material (105), a material conduit (120) for supplying the liquid material (105) to the evaporation crucible (110), and a valve (150) configured to close the material conduit (120) by solidifying a part of the liquid material (105) in the material conduit (120) with a cooling device (152). The valve (150) may include a cooling gas supply (154) for a cooling gas (106), and the cooling device (152) may be configured to cool the liquid material (105) with the cooling gas (106). Further described are a vapor deposition apparatus (200) for coating a substrate as well as an evaporation method.

1 . An evaporation apparatus, comprising:
 an evaporation crucible for evaporating a liquid material;   a material conduit for supplying the liquid material into the evaporation crucible; and   a valve configured to close the material conduit by solidifying a part of the liquid material in the material conduit with a cooling device.   
     
     
         2 . The evaporation apparatus according to  claim 1 , wherein the valve further comprises a cooling gas supply for guiding a cooling gas to the cooling device, the cooling device configured to cool the liquid material with the cooling gas. 
     
     
         3 . The evaporation apparatus according to  claim 2 , wherein the cooling gas supply is a noble gas supply, particularly an argon supply. 
     
     
         4 . The evaporation apparatus according to  claim 2 , wherein the cooling gas supply is configured to guide the cooling gas through a cooling passage of the cooling device with at least one or more of: (i) a gas pressure in a range from 2 bar to 20 bar, (ii) a gas velocity in a range from 15 m/s to 50 m/s, and (iii) a mass flow in a range from 10 slm to 50 slm. 
     
     
         5 . The evaporation apparatus according to  claim 1 , wherein the cooling device comprises a cooling passage that surrounds a section of the material conduit and is in thermal contact with the material conduit. 
     
     
         6 . The evaporation apparatus according to  claim 5 , wherein the cooling passage extends helically or spirally around the material conduit. 
     
     
         7 . The evaporation apparatus according to  claim 1 , wherein a distance between the cooling device and the evaporation crucible is 20 cm or less. 
     
     
         8 . The evaporation apparatus according to  claim 1 , further comprising a heatable enclosure or chamber through which the material conduit extends, wherein the cooling device is arranged at the material conduit inside the heatable enclosure or chamber. 
     
     
         9 . The evaporation apparatus according to  claim 8 , further comprising a thermal insulation arrangement that at least partially or entirely encloses the cooling device for thermally insulating the cooling device and a section of the material conduit surrounded by the cooling device from a hot environment inside the heatable enclosure or chamber. 
     
     
         10 . The evaporation apparatus according to  claim 9 , wherein the thermal insulation arrangement comprises one or more heat shields that coaxially extend around the material conduit. 
     
     
         11 . The evaporation apparatus according to  claim 1 , wherein the evaporation crucible is configured to evaporate a reactive material, particularly lithium. 
     
     
         12 . An evaporation apparatus, comprising:
 an evaporation crucible;   a material conduit connected to the evaporation crucible; and   a valve configured to close the material conduit by cooling the material conduit with a cooling gas.   
     
     
         13 . A vapor deposition apparatus for coating a substrate, comprising:
 the evaporation apparatus according to  claim 1 ;   a vapor distributor with a plurality of nozzles for directing material evaporated in the evaporation crucible toward the substrate; and   a movable substrate support for moving the substrate past the vapor distributor.   
     
     
         14 . An evaporation method, comprising:
 guiding a liquid material through a material conduit into an evaporation crucible;   evaporating the liquid material in the evaporation crucible; and   closing the material conduit by solidifying a part of the liquid material in the material conduit.   
     
     
         15 . The method according to  claim 14 , wherein the part of the liquid material is solidified through cooling with a cooling gas. 
     
     
         16 . The method according to  claim 15 , wherein the cooling gas is argon. 
     
     
         17 . The method according to  claim 15 , wherein the cooling gas is guided through a cooling passage of a cooling device that surrounds a section of the material conduit. 
     
     
         18 . The method according to  claim 17 , wherein the cooling gas in the cooling device has at least one of (i) a temperature of |5° C. or more and |50° C. or less at a position upstream of the cooling passage, (ii) a gas pressure in a range from 2 bar to 20 bar, (iii) a gas velocity in a range from 15 m/s to 50 m/s, and (iv) a mass flow in a range from 10 slm to 50 slm. 
     
     
         19 . The method according to  claim 17 , further comprising re-opening the material conduit by stopping a supply of the cooling gas through the cooling passage. 
     
     
         20 . The method according to  claim 14 , wherein the liquid material is an alkali metal or an alkaline earth metal. 
     
     
         21 . The method according to  claim 14 , further comprising:
 guiding evaporated material from the evaporation crucible into a vapor distributor; and   directing the evaporated material from the vapor distributor through a plurality of vapor nozzles toward a substrate for coating the substrate in a vacuum chamber.