Methods and apparatuses for roll-on coating

Abstract

Methods and apparatuses for a deposition system are provided to deposit a thin coating layer on flat substrates, such as semiconductors or panels. In an embodiment, liquid supplied rollers accepting liquid media provide liquid chemicals to the substrates for coating the substrates. The liquid delivery system can control the flow and the pressure of the liquid to achieve optimum process condition with minimum excess waste. In another embodiment, rollers with non-uniform distribution of liquid media provide a non-uniform thickness profile on the substrates, which can be used to compensate for the non-uniformity of subsequent processes.

What is claimed is: 
     
         1 . A roller comprising:
 an elongated rod, wherein the elongated rod is configured for accepting a fluid at an end of the elongated rod, wherein the elongated rod configured to transfer the fluid from the end of the rod to at least a first portion of an outer surface of the elongated rod; and   a layer covering at least a second portion of the outer surface of the elongated rod for receiving the fluid at the outer surface of the elongated rod,   wherein the elongated rod is operable to produce a coating layer on a substrate surface, wherein the coating layer is non-uniform in thickness in a direction along a length of the elongated rod.   
     
     
         2 . A roller as in  claim 1  wherein the elongated rod is configured to transfer a non-uniform amount of fluid along the elongated direction. 
     
     
         3 . A roller as in  claim 1  wherein the elongated rod comprises a hollow cylindrical shape with perforation holes at a portion of the cylindrical surface, wherein the perforation holes are distributed non uniformly in a direction along a length of the elongated rod. 
     
     
         4 . A roller as in  claim 1  wherein the perforation holes are larger at end portions of the elongated rod. 
     
     
         5 . A roller as in  claim 1  wherein the perforation holes are larger at a middle portion of the elongated rod. 
     
     
         6 . A roller as in  claim 1  further comprising:
 one or more tubes comprising perforation holes, wherein the one or more tubes are embedded in the elongated rod along the elongated direction of the rod, wherein the perforation holes are distributed non uniformly in a direction along a length of the elongated rod. 
 
     
     
         7 . A roller as in  claim 1  wherein the rod is concave along the elongated direction. 
     
     
         8 . A roller as in  claim 1  wherein the rod is convex along the elongated direction. 
     
     
         9 . A roller as in  claim 1  wherein the layer is thicker at a middle portion of the elongated rod. 
     
     
         10 . A roller as in  claim 1  wherein the layer is thinner at a middle portion of the elongated rod. 
     
     
         11 . A roller as in  claim 1  wherein the layer is porous, wherein the porous layer has a non-uniform pore size or pore density along the elongated direction of the rod. 
     
     
         12 . A roller comprising:
 an elongated rod, wherein the elongated rod is configured for accepting a fluid at an end of the elongated rod, wherein the elongated rod configured to transfer the fluid from the end of the rod to at least a first portion of an outer surface of the elongated rod; and   a layer covering at least a second portion of the outer surface of the elongated rod for receiving the fluid at the outer surface of the elongated rod,   wherein the elongated rod or the layer is convex or concave in a direction along a length of the elongated rod.   
     
     
         13 . A roller as in  claim 12  wherein the concave or convex elongated rod is configured to transfer a non-uniform amount of fluid along the elongated direction. 
     
     
         14 . A roller as in  claim 12  wherein the layer is thicker at a middle portion of the elongated rod. 
     
     
         15 . A roller as in  claim 12  wherein the layer is thinner at a middle portion of the elongated rod. 
     
     
         16 . A roller as in  claim 12  wherein the layer is porous, wherein the porous layer has a non-uniform thickness along the elongated direction of the rod. 
     
     
         17 . A roller comprising:
 an elongated rod, wherein the elongated rod is configured for accepting a fluid at an end of the elongated rod, wherein the elongated rod configured to transfer the fluid from the end of the rod to at least a first portion of an outer surface of the elongated rod; and   a layer covering at least a second portion of the outer surface of the elongated rod for receiving the fluid at the outer surface of the elongated rod,   wherein the elongated rod comprises a hollow cylindrical shape with perforation holes at a portion of the cylindrical surface, wherein the perforation holes are distributed non uniformly in a direction along a length of the elongated rod.   
     
     
         18 . A roller as in  claim 17  wherein the non uniformly distributed perforation holes elongated rod is configured to transfer a non-uniform amount of fluid along the elongated direction. 
     
     
         19 . A roller as in  claim 17  wherein the layer is non uniform along the elongated direction of the rod. 
     
     
         20 . A roller as in  claim 17  wherein the layer is porous, wherein the porous layer has a non-uniform thickness along the elongated direction of the rod.