Low pressure vapor phase deposition of organic thin films

Abstract

Methods for preparing organic thin films on substrates, the method comprising the steps of providing a plurality of organic precursors in the vapor phase, and reacting the plurality or organic precursors at a sub-atmospheric pressure. Also included are thin films made by such a method and apparatuses used to conduct such a method. The method is well-suited to the formation of organic light emitting devices and other display-related technologies.

What is claimed is:  
     
         1 . A method for preparing an organic thin film on a substrate, said method comprising the steps of: 
 providing a plurality of organic precursors, said organic precursors being in the vapor phase; and    reacting said plurality of organic precursors at a sub-atmospheric pressure in the presence of said substrate to form said thin film on said substrate.    
     
     
         2 . The method of    claim 1   , wherein said substrate is located in a reaction chamber.  
     
     
         3 . The method of    claim 2   , further comprising the step of transporting one of said plurality of organic precursors into said reaction chamber prior to said step of reacting.  
     
     
         4 . The method of    claim 3   , wherein said step of transporting includes the step of using an inert gas to carry said transported organic precursor into said reaction chamber.  
     
     
         5 . The method of    claim 4   , wherein said inert gas is selected from the group consisting of nitrogen, argon, helium, neon, krypton and xenon.  
     
     
         6 . The method of    claim 1   , wherein at least one of said plurality of organic precursors is selected from the group consisting of MT, DASI, MM, M f M, DASTh, MeOSI, DAS(Et)I, DAS(Et)OH, acetyl toluenesulfonate, MA f , TTF, TCNQ, DCM, Alq 3 , TPP, TPD, α-NPD, MTDATA, and (Alq 2 )′-OPh.  
     
     
         7 . The method of    claim 3   , further comprising the step of volatilizing said transported organic precursor prior to said step of transporting.  
     
     
         8 . The method of    claim 7   , wherein: 
 said step of volatilizing includes the step of loading said transported organic precursor into a bubbler; and    said step of transporting includes the step of passing an inert gas through said bubbler for carrying said transported organic precursor into said reaction chamber.    
     
     
         9 . The method of    claim 7   , wherein: 
 said step of volatilizing includes the steps of placing said transported organic precursor into an open container and heating said open container; and    said step of transporting includes the step of passing an inert gas over said open container for carrying said transported organic precursor into said reaction chamber.    
     
     
         10 . The method of    claim 7   , wherein said step of volatilizing includes the steps of: 
 loading said transported organic precursor into a Knudsen cell, said Knudsen cell extending into said reaction chamber; and    heating said Knudsen cell.    
     
     
         11 . The method of    claim 1   , wherein the substrate is mounted to a rotating sample holder.  
     
     
         12 . The method of    claim 1   , wherein said sub-atmospheric pressure is within the range of about 10 −11 -10 2  torr.  
     
     
         13 . An organic film produced by the method of    claim 1   .  
     
     
         14 . The organic film of    claim 13   , wherein said film comprises a light emitting material.  
     
     
         15 . The organic film of    claim 13   , wherein said film comprises an optically non-linear material.  
     
     
         16 . An apparatus for preparing an organic thin film on a substrate, said apparatus comprising: 
 a reaction chamber;    a heater substantially surrounding said reaction chamber;    tubing extending into said reaction chamber; and    a vacuum pump attached to said reaction chamber.    
     
     
         17 . The apparatus of    claim 16   , wherein said reaction chamber comprises a reactor tube.  
     
     
         18 . The apparatus of    claim 16   , wherein said heater is a multi-zone heater/cooler.  
     
     
         19 . The apparatus of    claim 16   , wherein said tubing comprises: 
 a tube having a first end and a second end, the second end of said tube extending into said reaction chamber; and    a gas source connected to the first end of said tube.    
     
     
         20 . The apparatus of    claim 19   , further comprising an open container located inside of said tube, said open container for holding organic precursor material.  
     
     
         21 . The apparatus of    claim 20   , wherein said tube includes a pressure regulator and a valve.  
     
     
         22 . The apparatus of    claim 16   , wherein said tubing comprises: 
 a first tube having a first end and a second end, said second end of said first tube extending into said reaction chamber;    a bubbler connected to the first end of said first tube, said bubbler for containing organic precursor material;    a second tube having a first end and a second end, said second end of said second tube connected to said bubbler; and    a gas source connected to the first end of said second tube.    
     
     
         23 . The apparatus of    claim 22   , wherein said second tube includes a pressure regulator and a valve.  
     
     
         24 . The apparatus of    claim 16   , further comprising a temperature-control block in contact with the substrate, said temperature-control block having a channel therein.  
     
     
         25 . The apparatus of    claim 16   , further comprising a trap attached to said reaction chamber.  
     
     
         26 . The apparatus of    claim 16   , further comprising a first roll and a second roll in said reaction chamber for passing the substrate between said first and second rolls.  
     
     
         27 . An apparatus for preparing an organic thin film on a substrate, said apparatus comprising: 
 a reaction chamber;    a Knudsen cell extending into said reaction chamber;    a sample holder connected to the substrate; said sample holder being rotatable; and    a vacuum pump attached to said reaction chamber.    
     
     
         28 . The apparatus of    claim 27   , further comprising tubing extending into said reaction chamber, said tubing comprising: 
 a first tube having a first end and a second end, said second end of said first tube extending into said reaction chamber;    a bubbler connected to the first end of said first tube, said bubbler for containing organic precursor material;    a second tube having a first end and a second end, said second end of said second tube connected to said bubbler; and    a gas source connected to the first end of said second tube.    
     
     
         29 . The apparatus of    claim 27   , wherein said first tube is heated.  
     
     
         30 . The apparatus of    claim 27   , further comprising a cooled shroud in said reaction chamber.  
     
     
         31 . The apparatus of    claim 27   , further comprising a sensor for detecting the thickness of the thin firm.  
     
     
         32 . The apparatus of    claim 31   , wherein said sensor is a quartz crystal.  
     
     
         33 . The apparatus of    claim 27   , further comprising a load-lock connected to said reaction chamber.  
     
     
         34 . The apparatus of    claim 27   , wherein said vacuum pump is a turbomolecular pump.  
     
     
         35 . The apparatus of    claim 27   , further comprising a first roll and a second roll in said reaction chamber for passing the substrate between said first and second rolls.  
     
     
         36 . An apparatus for preparing an organic thin film on a substrate, said apparatus comprising: 
 a plurality of vacuum chambers, said plurality of vacuum chambers including a loading chamber and an organic layer deposition chamber; and    a conveyor belt passing through said plurality of vacuum chambers, said conveyor belt having a substrate thereon.    
     
     
         37 . The apparatus of    claim 36   , wherein said organic layer deposition chamber includes a reactant gas distributor.  
     
     
         38 . The apparatus of    claim 36   , wherein said organic layer deposition chamber includes a heater.  
     
     
         39 . The apparatus of    claim 36   , further comprising a contact deposition chamber.  
     
     
         40 . An apparatus for preparing an organic thin film on a substrate, said apparatus comprising: 
 a reaction chamber;    means for heating said reaction chamber;    means for introducing vapors of organic precursor materials into said reaction chamber; and    means for reducing the pressure in said reaction chamber to below atmospheric pressure.    
     
     
         41 . A method for preparing an OLED, said method comprising the steps of: 
 providing a plurality of organic precursors, said organic precursors being in the vapor phase; and    reacting said plurality of organic precursors at a sub-atmospheric pressure.    
     
     
         42 . The method of    claim 41   , wherein said organic precursors are light emitting materials.  
     
     
         43 . The method of    claim 41   , wherein said step of reacting results in the formation of a light emitting material.