Porous dielectric material with improved pore surface properties for

Abstract

This invention provides an improved porous structure for semiconductor devices and a process for making the same. This process may be applied to an existing porous structure 28, which may be deposited, for example, between patterned conductors 24. The method may comprise providing a substrate comprising a microelectronic circuit and a porous silica layer, the porous silica layer having an average pore diameter between 2 and 80 nm; and heating the substrate to one or more temperatures between 100 and 490 degrees C. in a substantially halogen-free atmosphere, whereby one or more dielectric properties of the porous dielectric are improved. In some embodiments, the atmosphere comprises a phenyl-containing atmosphere, such as hexaphenyldisilazane. In some embodiments, the method further comprises cooling the substrate and exposing the substrate to a substantially halogen-free atmosphere comprising either a phenyl-containing compound, such as hexaphenyldisilazane; or a methyl-containing compound, such as hexamethyldisilazane. It has been found that a porous structure treated in such a manner generally exhibits improved dielectric properties relative to an untreated sample.