Apparatus and method for deposition for organic thin films

Abstract

The invention provides apparatus and methods for organic continuum vapor deposition of organic materials on large area substrates.

What is claimed is: 
     
         1 . A method of depositing an organic thin film onto a substrate, comprising:
 heating an organic material, forming an organic vapor;   transporting the organic vapor in a carrier gas from a heated source cell into a chamber, wherein a back plate of the chamber is heated, the source cell being positioned at the back plate;   heating the chamber sufficiently to form a substantially uniform organic flux of the carrier gas and organic vapor by diffusive mixing of the gas and vapor within the heated chamber;   directing the uniform organic flux to a cooled substrate; and   depositing the organic material onto a surface of the cooled substrate, thereby forming an organic film on the substrate.   
     
     
         2 . The method of  claim 1 , wherein the chamber is heated by supplying heat from all walls of the chamber. 
     
     
         3 . The method according to  claim 1 , wherein the chamber has a length to width ratio of at least about 0.75. 
     
     
         4 . The method according to  claim 1 , wherein the uniform organic flux is a steady state flux. 
     
     
         5 . The method according to  claim 1 , wherein the uniform organic flux is directed to the cooled substrate by a pressure differential. 
     
     
         6 . The method according to  claim 1 , further comprising positioning the source cell, so that the output is aligned with the center of the cooled substrate. 
     
     
         7 . The method according to  claim 1 , further comprising depositing a plurality of organic materials from a plurality of source cells. 
     
     
         8 . The method according to  claim 7 , further comprising depositing the plurality of organic materials successively. 
     
     
         9 . The method according to  claim 7 , further comprising depositing the plurality of organic materials simultaneously. 
     
     
         10 . The method according to  claim 9 , further comprising forming the organic vapors of the organic materials in a series of successive source cells, wherein organic vapor produced in one cell passes through at least one additional source cell. 
     
     
         11 . The method according to  claim 1 , further comprising controlling vapor flow from the source cell with a valve within a source cell. 
     
     
         12 . The method according to  claim 1 , further comprising controlling vapor flow from a source cell by moving a stopper relative to an opening in the source cell, wherein the stopper has a shape that corresponds to that of the opening, and stops the vapor flow when the stopper is moved fully into the opening. 
     
     
         13 . The method according to  claim 12 , further comprising opening a bypass line when the opening of the source cell is closed by the stopper. 
     
     
         14 . The method according to  claim 1 , further comprising maintaining the cooled substrate at a temperature sufficiently low to reduce the organic material concentration in a region directly above the surface of the cooled substrate to a concentration substantially less than the organic material concentration in the rest of the heated chamber. 
     
     
         15 . The method according to  claim 1 , further comprising maintaining a flow rate of the organic vapor and carrier gas sufficient to maintain the organic vapor in the heated chamber at a substantially uniform concentration other than in the region directly above the surface of the cooled substrate.