Organic line width roughness with h2 plasma treatment

Abstract

An apparatus for reducing very low frequency line width roughness (LWR) is provided. A plasma processing chamber is provided, comprising a chamber wall, a substrate support, a pressure regulator, at least one antenna, a gas inlet, and a gas outlet. A gas source comprises an etchant gas source and a H 2 treatment gas source. A controller comprises at least one processor and computer readable media, comprising computer readable code for treating a patterned organic mask, comprising computer readable code for flowing a treatment gas comprising H 2 , wherein the treatment gas has a flow rate and H 2 has a flow rate that is at least 50% of the flow rate of the treatment gas, computer readable code for forming a plasma, and computer readable code for stopping the flow of the treatment gas, and computer readable code for etching the etch layer through the treated patterned organic mask.

What is claimed is: 
     
         1 . An apparatus for reducing very low frequency line width roughness (LWR) in forming etched features in an etch layer, disposed below a patterned organic mask with mask features, comprising:
 a plasma processing chamber, comprising:
 a chamber wall forming a plasma processing chamber enclosure; 
 a substrate support for supporting a wafer within the plasma processing chamber enclosure; 
 a pressure regulator for regulating the pressure in the plasma processing chamber enclosure; 
 at least one antenna for providing inductively coupled power to the plasma processing chamber enclosure for sustaining a plasma; 
 a gas inlet for providing gas into the plasma processing chamber enclosure; and 
 a gas outlet for exhausting gas from the plasma processing chamber enclosure; 
   a gas source in fluid connection with the gas inlet, comprising;
 an etchant gas source; and 
 a H 2  treatment gas source; 
   a controller controllably connected to the gas source and the at least one antenna, comprising:
 at least one processor; and 
 computer readable media, comprising:
 computer readable code for treating the patterned organic mask to reduce very low frequency line width roughness of the patterned organic mask, comprising:
 computer readable code for flowing a treatment gas comprising H 2 , wherein the treatment gas has a flow rate and H 2  has a flow rate that is at least 50% of the flow rate of the treatment gas; 
 computer readable code for forming a plasma from the treatment gas; and 
 computer readable code for stopping the flow of the treatment gas; and 
 
 computer readable code for etching the etch layer through the treated patterned organic mask with the reduced very low LWR. 
 
   
     
     
         2 . The apparatus, as recited in  claim 1 , wherein the computer readable code for forming a plasma comprises computer readable code for providing a low bias. 
     
     
         3 . The apparatus, as recited in  claim 2 , wherein the treatment gas is halogen free. 
     
     
         4 . The apparatus, as recited in  claim 2 , wherein the treatment gas consists essentially of Ar and H 2 . 
     
     
         5 . The apparatus, as recited in  claim 2 , wherein the treatment gas consists essentially of H 2 . 
     
     
         6 . The apparatus, as recited in  claim 5 , wherein the computer readable code for forming a plasma comprises computer readable code for using no more than 1500 watts of RF power. 
     
     
         7 . The apparatus, as recited in  claim 2 , wherein the low bias is between 0 to 100 volts. 
     
     
         8 . The apparatus, as recited in  claim 2 , wherein the low bias is between 0 to 50 volts. 
     
     
         9 . The apparatus, as recited in  claim 2 , wherein the low bias is 0 volts. 
     
     
         10 . The apparatus, as recited in  claim 1 , wherein the very low frequency LWR has a roughness repetition length of greater than 500 nm. 
     
     
         11 . The apparatus, as recited in  claim 10 , wherein the very low frequency LWR of the patterned organic mask after treatment is less than the very low frequency LWR before treatment. 
     
     
         12 . The apparatus, as recited in  claim 11 , further comprising:
 computer readable code for placing a wafer with the etch layer and patterned organic mask in a process chamber before the treating the patterned organic mask; and   computer readable code for removing the wafer from the process chamber after etching the etch layer.   
     
     
         13 . The apparatus, as recited in  claim 12 , wherein the plasma processing chamber is an inductively coupled TCP process chamber. 
     
     
         14 . The apparatus, as recited in  claim 13 , wherein the organic mask is a photoresist mask. 
     
     
         15 . The apparatus, as recited in  claim 1 , wherein the treatment gas is halogen free. 
     
     
         16 . The apparatus, as recited in  claim 1 , wherein the treatment gas consists essentially of Ar and H 2 . 
     
     
         17 . The apparatus for reducing very low frequency line width roughness (LWR) with a roughness repetition length of greater than 500 nm in forming etched features in an etch layer disposed below a patterned organic mask, wherein a hard mask layer is below the etch layer and a conductive layer is below the hard mask layer, comprising:
 a plasma processing chamber, comprising:
 a chamber wall forming a plasma processing chamber enclosure; 
 a substrate support for supporting a wafer within the plasma processing chamber enclosure; 
 a pressure regulator for regulating the pressure in the plasma processing chamber enclosure; 
 at least one antenna for providing inductively coupled power to the plasma processing chamber enclosure for sustaining a plasma; 
 a gas inlet for providing gas into the plasma processing chamber enclosure; and 
 a gas outlet for exhausting gas from the plasma processing chamber enclosure; 
 a gas source in fluid connection with the gas inlet, comprising; 
 an etchant gas source; and 
 a H 2  treatment gas source; 
   a controller controllably connected to the gas source and the at least one antenna, comprising:
 at least one processor; and 
 computer readable media, comprising:
 computer readable code for treating the patterned organic mask to reduce very low frequency line width roughness with a roughness repetition length of greater than 500 nm of the patterned organic mask, comprising:
 computer readable code for flowing a treatment gas comprising H 2 , wherein the treatment gas has a flow rate and H 2  has a flow rate that is at least 50% of the flow rate of the treatment gas; 
 computer readable code for forming a plasma from the treatment gas; 
 computer readable code for stopping the flow of the treatment gas; and 
 computer readable code for etching the etch layer through the treated patterned organic mask with the reduced very low LWR; 
 
 computer readable code for etching the hard mask layer, and 
 computer readable code for etching the conductive layer, before removing the wafer from the process chamber, so that the treating the patterned organic mask, etching the etch layer, etching the hard mask layer, and etching the conductive layer are all done in situ in the same process chamber. 
 
   
     
     
         18 . An apparatus for reducing very low frequency line width roughness (LWR) in forming etched features in a conductive layer disposed below a hard mask layer disposed below an ARC layer disposed below a patterned photoresist mask forming a stack on a wafer, comprising:
 a plasma processing chamber, comprising:
 a chamber wall forming a plasma processing chamber enclosure; 
 a substrate support for supporting a wafer within the plasma processing chamber enclosure; 
 a pressure regulator for regulating the pressure in the plasma processing chamber enclosure; 
 at least one antenna for providing inductively coupled power to the plasma processing chamber enclosure for sustaining a plasma; 
 a gas inlet for providing gas into the plasma processing chamber enclosure; and 
 a gas outlet for exhausting gas from the plasma processing chamber enclosure; 
   a gas source in fluid connection with the gas inlet, comprising;
 an etchant gas source; and 
 a H 2  treatment gas source; 
   a controller controllably connected to the gas source and the at least one antenna, comprising:
 at least one processor; and 
 computer readable media, comprising:
 computer readable code for placing the wafer in a process chamber; 
 computer readable code for treating the patterned photoresist mask to reduce very low frequency line width roughness of the patterned photoresist mask, comprising:
 computer readable code for flowing a treatment gas comprising H 2 , wherein the treatment gas has a flow rate and H 2  has a flow rate that is at least 50% of the flow rate of the treatment gas into the process chamber; 
 computer readable code for forming a plasma from the treatment gas; and 
 computer readable code for stopping the flow of the treatment gas; 
 
 computer readable code for etching the ARC layer through the treated patterned photoresist mask; 
 computer readable code for etching the hard mask layer through the ARC layer; 
 computer readable code for etching the conductive layer through the hard mask layer; and 
 computer readable code for removing the wafer from the process chamber, so that the treating the patterned organic mask, etching the ARC layer, etching the hard mask layer, and etching the conductive layer are all done in situ in the same process chamber.