Forming semiconductor structures

Abstract

A semiconductor structure may be covered with a thermally decomposing film. That film may then be covered by a sealing cover. Subsequently, the thermally decomposing material may be decomposed, forming a cavity.

What is claimed is:  
     
         1 . A method comprising: 
 covering a semiconductor structure with a thermally decomposing layer selected from the group consisting of polypropylene oxide, polymethylstyrene, polycaprolactone, polycarbonate, polyamideimide, polyamide-6,6, polyphthalamide, polyetherketone, polyethretherketone, polybutyllene terephthalate, polyethyllene terephthalate, polystyrene, syndiotactic-polystyrene, polyphenylene sulfide, and polyether sulfone;    forming a cover over said thermally decomposing layer; and    thermally decomposing the thermally decomposing layer underneath said cover.    
     
     
         2 . The method of  claim 1  wherein thermally decomposing includes causing the thermally decomposing layer to pass through said cover.  
     
     
         3 . The method of  claim 1  including allowing the thermally decomposing material to escape through said cover and thereafter sealing said cover.  
     
     
         4 . The method of  claim 1  including providing a thermally decomposing layer that does not decompose at temperatures below 260° C.  
     
     
         5 . A semiconductor structure comprising: 
 a semiconductor support;    a thermally decomposing layer formed over said support, said layer consisting of a polymer selected from the group composed of polypropylene oxide, polymethyl-styrene, polycaprolactone, polycarbonate, polyamideimide, polyamide-6,6, polyphthalamide, polyetherketone, polyethretherketone, polybutyllene terephthalate, polyethyllene terephthalate, polystyrene, syndiotactic-polystyrene, polyphenylene sulfide, and polyether sulfone; and    a cover over said thermally decomposing layer.    
     
     
         6 . The structure of  claim 5  wherein said structure is a semiconductor wafer.  
     
     
         7 . The structure of  claim 5  wherein said thermally decomposing layer is formed of a material that decomposes at a temperature above 260° C.  
     
     
         8 . The structure of  claim 5  wherein said cover includes Silsesquioxane.  
     
     
         9 . A method comprising: 
 treating a semiconductor substrate to match the surface energy of a sacrificial material; and    forming said sacrificial material over said substrate.    
     
     
         10 . The method of  claim 9  including treating the substrate to make the substrate more hydrophobic.  
     
     
         11 . The method of  claim 10  including treating the substrate to match the surface energy of a polymer, thermally decomposing film.  
     
     
         12 . The method of  claim 9  including treating the substrate with hexamethyldisilazane saturated nitrogen.  
     
     
         13 . A semiconductor structure comprising: 
 a substrate;    a coating on a substrate; and    a decomposing layer formed on said substrate, said layer to match the surface energies of said substrate and said decomposing layer.    
     
     
         14 . The structure of  claim 13  wherein said decomposing layer includes a polymer.  
     
     
         15 . The structure of  claim 13  wherein said layer includes hexamethyldisilazane.  
     
     
         16 . The structure of  claim 13  wherein said decomposing layer is a decomposing layer that only decomposes at a temperature above 260° C.  
     
     
         17 . A method comprising: 
 covering a semiconductor structure with a thermally decomposing layer;    forming a cover over said thermally decomposing layer including spin-on glass; and    thermally decomposing the thermally decomposing layer underneath said cover.    
     
     
         18 . The method of  claim 17  including using a silsesquioxane to form said cover.  
     
     
         19 . The method of  claim 18  including using hydrogen silsesquioxane.  
     
     
         20 . The method of  claim 18  including using methylsilsesquioxane.  
     
     
         21 . The method of  claim 17  including covering said spin-on glass with a layer of oxide.  
     
     
         22 . A semiconductor structure comprising: 
 a semiconductor layer;    a thermally decomposing layer formed over said layer; and    a cover over said thermally decomposing layer, said cover including a silsesquioxane.    
     
     
         23 . The structure of  claim 22  wherein said cover includes hydrogen silsesquioxane.  
     
     
         24 . The structure of  claim 22  wherein said cover includes methylsilsesquioxane.  
     
     
         25 . The structure of  claim 22  including an oxide layer formed over said silsesquioxane.