Patterning of electrodes in oled devices

Abstract

An OLED device includes pillars, wherein the pillars serve to pattern a conductive layer during deposition. The profile of the pillars covers the edges of at least one functional layer to protect it from exposure to potentially deleterious substances.

1 . A method for forming an OLED device comprising: 
 forming a first conductive layer on a substrate;    forming pillars on the substrate;    depositing at least one organic layer on the substrate; and    depositing a second conductive layer on the substrate, wherein the pillars serve to pattern the second conductive layer and cover the edges of the second conductive layer.    
   
   
       2 . The method of  claim 1  wherein the pillars cover the edges of the organic layers.  
   
   
       3 . The method of  claim 1  wherein a pillar comprises a cap formed on a base.  
   
   
       4 . The method of  claim 3  wherein the base comprises an upper portion and a lower portion, a width of the upper portion is smaller than a width of the lower portion.  
   
   
       5 . The method according to  claim 4  wherein forming the pillars on the substrate comprises forming at least two device layers on the substrate and patterning the device layers.  
   
   
       6 . The method according to  claim 5  wherein patterning the device layers comprises patterning device layers with different characteristics.  
   
   
       7 . The method according to  claim 6  wherein the device layers comprise photosensitive layers.  
   
   
       8 . The method according to  claim 7  wherein patterning the device layers comprises patterning an upper photosensitive layer and a lower photosensitive layer.  
   
   
       9 . The method according to  claim 8  wherein the device layers comprise photosensitive layers that are sensitive to different exposure wavelengths, wherein the upper layer is transparent to the lower layer's exposure wavelength.  
   
   
       10 . The method according to  claim 8  wherein the upper photosensitive layer comprises a photoresist selected from the group consisting of negative acting photoresist and positive acting photoresist.  
   
   
       11 . The method according to  claim 8  wherein the lower photosensitive layer comprises a photoresist selected from the group consisting of negative acting photoresist and positive acting photoresist.  
   
   
       12 . The method according to  claim 8  wherein the upper photosensitive layer and the lower photosensitive layer comprise negative acting photoresist.  
   
   
       13 . The method according to  claim 8  wherein the upper photosensitive layer and the lower photosensitive layer comprise positive acting photoresist.  
   
   
       14 . The method according to  claim 8  wherein patterning the photosensitive layers comprises selectively exposing and developing the upper photosensitive layer and the lower photosensitive layer successively.  
   
   
       15 . The method according to  claim 14  wherein selectively exposing the lower photosensitive layer comprises successively exposing the lower photosensitive layer with electrons or charged particles having different energies which have different penetration depths to form pillar bases during developing.  
   
   
       16 . The method according to  claim 8  wherein the photosensitive layers comprise pre-dyed resist layers.  
   
   
       17 . The method according to  claim 8  comprises curing the pillars to render the pillars inert against organic solvents.  
   
   
       18 . The method according to  claim 8  wherein the lower photosensitive layer comprises a positive acting photoresist and the upper photosensitive layer comprises a negative action.