Device and Method for Vaporizing Temperature Sensitive Materials

Abstract

A device vaporizes organic materials onto a substrate surface to form a film. The device includes a vaporization apparatus to receive a quantity of organic material that can have one or more components each having a different vaporization temperature, the vaporization apparatus having a first region and a second region spaced from the first region; a cooling unit to actively cool the organic material in the first region so that each of the one or more organic components is maintained well below its vaporization temperature to reduce degradation of the organic material; heating unit to heat the second region of the vaporization apparatus above the vaporization temperature of each of the one or more organic components; and a metering unit having a permeable member to meter organic material at a controlled rate from the first region into the second region so that a thin cross section of the organic material is heated at a desired rate-dependent vaporization temperature, whereby organic material vaporizes and forms a film on the substrate surface.

1 . A device for vaporizing organic materials onto a substrate surface to form a film, comprising:
 a vaporization apparatus to receive a quantity of organic material that can have one or more components each having a different vaporization temperature, the vaporization apparatus having a first region and a second region spaced from the first region;   a cooling unit to actively cool the organic material in the first region so that each of the one or more organic components is maintained well below its vaporization temperature to reduce degradation of the organic material;   heating unit to heat the second region of the vaporization apparatus above the vaporization temperature of each of the one or more organic components; and   a metering unit having a permeable member to meter organic material at a controlled rate from the first region into the second region so that a thin cross section of the organic material is heated at a desired rate-dependent vaporization temperature, whereby organic material vaporizes and forms a film on the substrate surface.   
     
     
         2 . The device according to  claim 1 , wherein the cooling unit includes a control passage, and a pumping device to pump a fluid through the passage, such fluid being adapted to absorb heat from the first region. 
     
     
         3 . The device according to  claim 1 , wherein the metering unit includes a chamber for receiving the organic material and a piston for raising the organic material in the chamber for metering such material. 
     
     
         4 . The device according to  claim 1 , wherein the cooling unit includes a cooling base block surrounding the organic material in the first region and providing a liquid between the cooling base block and the organic material in the first region to provide thermal contact and a vapor-tight seal between the organic material and the cooling block. 
     
     
         5 . The device according to  claim 1 , wherein the metering unit meters organic material into the second region at a controlled rate that varies linearly with vaporization rate. 
     
     
         6 . The device according to  claim 1 , further including a deposition chamber enclosing the substrate and for receiving vaporized organic material and wherein the second means includes means for interrupting heating so that the temperature falls below the vaporization temperature of the one or more organic components and thereby minimizes contamination of the deposition chamber walls and conserves the organic material when a substrate surface is not being coated. 
     
     
         7 . The device according to  claim 1 , wherein the heating unit provides a residence time at elevated temperature that permits heating to higher temperatures to achieve substantially higher vaporization rates without material degradation. 
     
     
         8 . The device according to  claim 1 , wherein the metering unit maintains a constant volume in the second region so as to establish and maintain a constant plume shape. 
     
     
         9 . The device according to  claim 1 , wherein the first region is maintained at a constant temperature as the organic material is consumed. 
     
     
         10 . A device for vaporizing organic materials onto a substrate surface to form a film, comprising:
 a) a vaporization apparatus for receiving a quantity of organic material that can have one or more components, each one having a different vaporization temperature, and defining a first region and a second region spaced from the first region;   b) first means for actively cooling the organic material in the first region so that each of the one or more organic components is maintained well below its vaporization temperature to reduce degradation of the organic material;   c) second means for heating the second region of the vaporization apparatus above the vaporization temperature of each of the one or more organic components; and   d) means for metering, including a permeable member, at a controlled rate, organic material from the first region into the second region so that a thin cross section of the organic material is heated at a desired rate-dependent vaporization temperature, whereby organic material vaporizes and forms a film on the substrate surface.