Method of preventing damage to porous low-K materials during resist stripping

Abstract

A method of forming a feature in a porous low-K dielectric layer is provided. A porous low-K dielectric layer is placed over a substrate. A patterned photoresist mask is placed over the porous low-K dielectric layer. A feature is etched into the porous low-K dielectric layer. A protective layer is deposited over the feature after the etching the feature. The patterned photoresist mask is stripped, so that part of the protective layer is removed, where protective walls formed from the protective layer remain in the feature.

1 - 15 . (canceled)  
   
   
       16 . An apparatus for etching a feature in a porous low-K dielectric layer through a mask over a substrate, comprising: 
 a plasma processing chamber, comprising: 
 a chamber wall forming a plasma processing chamber enclosure;  
 a substrate support for supporting a substrate within the plasma processing chamber enclosure;  
 a pressure regulator for regulating the pressure in the plasma processing chamber enclosure;  
 at least one electrode for providing 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;  
 a protective layer gas source; and  
 a stripping gas source;  
   a controller controllably connected to at least one of the gas source the at least one electrode, the pressure regulator, the gas inlet, and the gas outlet, comprising: 
 at least one processor; and  
 computer readable media, comprising: 
 computer readable code for providing an etch plasma for etching a feature into a porous low-K dielectric layer;  
 computer readable code for for forming a protective layer over the feature in the porous low-K dielectric layer after the feature has been etched by providing a protective layer gas from the protective layer gas source; and  
 computer readable code for stripping a photoresist mask from over the porous low-K dielectric layer, where the stripping removes part of the protective layer and leaves protective walls formed from the protective layer.  
 
   
   
   
       17 . (canceled)  
   
   
       18 . (canceled)  
   
   
       19 . The apparatus, as recited in  claim 16 , wherein the computer readable media further comprises computer readable code for depositing a deposition layer over the protective walls.  
   
   
       20 . The apparatus, as recited in  claim 16 , wherein the protective layer gas source contains a fluorine free protective layer gas.  
   
   
       21 . The apparatus, as recited in  claim 20 , wherein the protective layer gas source contains a polymer forming gas.  
   
   
       22 . The apparatus, as recited in  claim 21 , wherein the computer readable code for forming the protective layer comprises computer readable code for making the protective layer with a thickness between 100 Å and 1500 Å.  
   
   
       23 . The apparatus, as recited in  claim 22 , wherein the protective layer gas source further comprises C 2 H 4  and O 2 .  
   
   
       24 . The apparatus, as recited in  claim 16 , wherein the computer readable code for stripping the photoresist mask, comprises computer readable code for providing ion bombardment.  
   
   
       25 . The apparatus, as recited in  claim 24 , wherein the ion bombardment removes top layers of the protective layer, but leaves protective sidewalls formed by the protective layer.  
   
   
       26 . The apparatus, as recited in  claim 16 , wherein the protective layer gas source contains a polymer forming gas.  
   
   
       27 . The apparatus, as recited in  claim 26 , wherein the computer readable code for forming the protective layer comprises computer readable code for making the protective layer with a thickness between 100 Å and 1500 Å.  
   
   
       28 . The apparatus, as recited in  claim 27 , wherein the protective layer gas source comprises C 2 H 4  and O 2 .  
   
   
       29 . The apparatus, as recited in  claim 16 , wherein the protective layer gas source comprises a C 2 H 4  source and an O 2  source.  
   
   
       30 . A semiconductor device formed by the method of forming a feature in a porous low-K dielectric layer, comprising: 
 placing a porous low-K dielectric layer over a substrate;    placing a patterned photoresist mask over the porous low-K dielectric layer;    etching a feature into the porous low-K dielectric layer;    depositing a protective layer over the feature after the etching the feature; and    stripping the patterned photoresist mask, so that part of the protective layer is removed, where protective walls formed from the protective layer remain in the feature.    
   
   
       31 . The semiconductor device, as recited in  claim 30 , further comprising placing a cap layer over the porous low-K dielectric layer before placing the photoresist mask, wherein the photoresist mask is placed over the cap layer.  
   
   
       32 . The semiconductor device, as recited in  claim 31 , further comprising depositing a deposition layer over the protective walls.  
   
   
       33 . The semiconductor device, as recited in  claim 32 , further comprising forming an antireflective coating over the cap layer before placing the photoresist mask, wherein the photoresist mask is placed over the antireflective coating.  
   
   
       34 . The semiconductor device, as recited in  claim 30 , wherein the depositing the protective layer comprises depositing a fluorine free layer.  
   
   
       35 . The semiconductor device, as recited in  claim 30 , wherein the depositing the protective layer further comprises depositing a polymer layer.  
   
   
       36 . The semiconductor device, as recited in  claim 35 , wherein the protective layer is between 100 Å to 1500 Å thick.