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.

1 . An apparatus for the physical vapor deposition of an organic small molecule material on a substrate, said apparatus comprising:
 (a) a deposition chamber;   (b) at least one flow path in fluid communication with said deposition chamber, said flow path comprising:
 (i) a carrier gas source, 
 (ii) an organic small molecule material source containing a non-polymeric organic small molecule material that forms a non-polymeric organic thin film of the organic small molecule material, and 
 (iii) a flow controller; 
   (c) a substrate holder disposed within said deposition chamber; and   (d) a vacuum pump in fluid communication with said deposition chamber and adapted to provide a pressure ranging from 0.001 torr to 100 torr within said deposition chamber;   wherein the deposition chamber has walls that may be heated to a temperature sufficiently high to avoid re-condensation of volatilized organic small molecule material, without decomposing the volatilized organic small molecule material, and   wherein the non-polymeric organic thin film remains non-polymeric after deposition.   
   
   
       2 . The apparatus of  claim 1 , further comprising a roll-to-roll substrate delivery system. 
   
   
       3 . The apparatus of  claim 1 , wherein the non-polymeric organic small molecule material forms a uniform non-polymeric organic thin film. 
   
   
       4 . The apparatus of  claim 1 , wherein the organic small molecule material comprises Alq 3 . 
   
   
       5 . The apparatus of  claim 1 , wherein said flow controller includes a pressure regulator. 
   
   
       6 . The apparatus of  claim 1 , wherein said flow controller includes a flow meter. 
   
   
       7 . The apparatus of  claim 1 , wherein said flow controller includes a switching valve. 
   
   
       8 . The apparatus of  claim 1 , wherein said deposition chamber has heated walls. 
   
   
       9 . The apparatus of  claim 1 , wherein said deposition chamber is provided with one or more radiant heat sources. 
   
   
       10 . The apparatus of  claim 1 , further comprising a heater substantially surrounding said deposition chamber. 
   
   
       11 . The apparatus of  claim 10 , wherein said heater is a multi-zone heater/cooler temperature controller that heats and cools. 
   
   
       12 . The apparatus of  claim 1 , wherein the substrate holder is cooled. 
   
   
       13 . The apparatus of  claim 12 , wherein the substrate holder comprises a temperature-control block. 
   
   
       14 . The apparatus of  claim 1 , wherein said organic small molecule material source is an open container holding said organic small molecule material. 
   
   
       15 . The apparatus of  claim 14 , wherein said open container is heated. 
   
   
       16 . The apparatus of  claim 1 , wherein said apparatus comprises two or more flow paths. 
   
   
       17 . An apparatus for physical vapor deposition of a film comprising an organic small molecule material on a substrate, said apparatus comprising:
 a deposition chamber;   means for heating said deposition chamber;   means for introducing vapors of non-polymeric organic small molecule materials including a source containing the organic small molecule materials, wherein the organic small molecule materials form a non-polymeric organic thin film that remains non-polymeric after deposition, into said deposition chamber;   means for cooling a substrate within said deposition chamber; and   means for maintaining the pressure in said reaction chamber at a pressure ranging from 0.001 torr to 100 torr;   means for heating the deposition chamber walls to a temperature sufficiently high to avoid re-condensation of vapors of the organic small molecule materials, without decomposing the organic small molecule materials.   
   
   
       18 . The apparatus of  claim 17 , further comprising means for moving the substrate through the deposition chamber. 
   
   
       19 . 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.