Low-k spacer for rmg finfet formation

Abstract

A method for semiconductor fabrication includes providing mask layers on opposite sides of a substrate, the substrate having one or more mandrels. Dummy spacers are formed along a periphery of the mask layers. A dummy gate structure is formed between the dummy spacers. The dummy spacers are removed to provide a recess. Low-k spacers are formed in the recess.

What is claimed is: 
     
         1 . A semiconductor device, comprising:
 a substrate having one or more mandrels formed thereon;   a replacement gate structure formed over the one or more mandrels;   low-k spacers formed about a periphery of the replacement gate structure, the low-k spacers extending through the one or more mandrels to an underlying oxide layer; and   raised source/drain regions.   
     
     
         2 . The device as recited in  claim 1 , wherein source/drain regions for neighboring mandrels are epitaxially merged. 
     
     
         3 . The device as recited in  claim 1 , wherein the low-k spacers are non-conformal. 
     
     
         4 . The device as recited in  claim 1 , further comprising an oxide formed over the raised source/drain regions. 
     
     
         5 . The device as recited in  claim 1 , wherein the replacement gate structure includes a replacement metal gate structure. 
     
     
         6 . The device as recited in  claim 1 , wherein the one or more mandrels include one or more fins. 
     
     
         7 . The device as recited in  claim 1 , wherein the low-k spacer is comprised of a material selected from the group consisting of hydrogen silsesquioxane polymer (HSQ), methyl silsesquioxane polymer (MSQ), polyphenylene oligomer, methyl doped silica, SiO x (CH 3 ) y , SiC x O y H y , SiOCH, organosilicate glass (SiCOH), porous SiCOH, silicon oxide, boron nitride, silicon oxynitride and combinations thereof. 
     
     
         8 . A semiconductor device, comprising:
 a substrate having one or more mandrels formed thereon;   a replacement gate structure formed over the one or more mandrels;   low-k spacers formed about a periphery of the replacement gate structure, the low-k spacers extending through the one or more mandrels to an underlying oxide layer; and   epitaxially merged raised source/drain regions.   
     
     
         9 . The device as recited in  claim 8 , wherein the low-k spacers are non-conformal. 
     
     
         10 . The device as recited in  claim 8 , further comprising an oxide formed over the raised source/drain regions. 
     
     
         11 . The device as recited in  claim 8 , wherein the replacement gate structure includes a replacement metal gate structure. 
     
     
         12 . The device as recited in  claim 8 , wherein the one or more mandrels include one or more fins. 
     
     
         13 . The device as recited in  claim 8 , wherein the low-k spacer is comprised of a material selected from the group consisting of hydrogen silsesquioxane polymer (HSQ), methyl silsesquioxane polymer (MSQ), polyphenylene oligomer, methyl doped silica, SiO x (CH 3 ) y , SiC x O y H y , SiOCH, organosilicate glass (SiCOH), porous SiCOH, silicon oxide, boron nitride, silicon oxynitride and combinations thereof. 
     
     
         14 . A semiconductor device, comprising:
 a substrate having one or more mandrels formed thereon;   a replacement gate structure formed over the one or more mandrels;   low-k spacers formed about a periphery of the replacement gate structure, the low-k spacers extending through the one or more mandrels to an underlying oxide layer, wherein the low-k spacers are non-conformal; and   raised source/drain regions.   
     
     
         15 . The device as recited in  claim 14 , wherein source/drain regions for neighboring mandrels are epitaxially merged. 
     
     
         16 . The device as recited in  claim 14 , further comprising an oxide formed over the raised source/drain regions. 
     
     
         17 . The device as recited in  claim 14 , wherein the replacement gate structure includes a replacement metal gate structure. 
     
     
         18 . The device as recited in  claim 14 , wherein the one or more mandrels include one or more fins. 
     
     
         19 . The device as recited in  claim 14 , wherein have a dielectric constant less than 5.0 
     
     
         20 . The device as recited in  claim 14 , wherein the low-k spacer is comprised of a material selected from the group consisting of hydrogen silsesquioxane polymer (HSQ), methyl silsesquioxane polymer (MSQ), polyphenylene oligomer, methyl doped silica, SiO x (CH 3 ) y , SiC x O y H y , SiOCH, organosilicate glass (SiCOH), porous SiCOH, silicon oxide, boron nitride, silicon oxynitride and combinations thereof.