Patent ID: 8241992
Filing Date: 2012-08-14
Classification: H01L

Abstract:
1. A method of forming an air gap-containing interconnect structure comprising: providing a patterned mask on a surface of an initial structure, said initial structure including a substrate, a material stack located on an upper surface of the substrate, a first low k material located on an uppermost surface of the material stack, and a second low k material located on an upper surface of said first low k material, wherein said patterned mask has at least one first opening that exposes a portion of said second low k material; etching the exposed portion of the second low k material utilizing the patterned mask as an etch mask to form a patterned second low k material, said patterned second low k material includes an extended portion of said at least one first opening; forming a patterned photoresist on an upper surface of said patterned second low k material, wherein a portion of said patterned photoresist fills the extended portion of the at least one first opening within the patterned second low k material, said patterned photoresist having at least one second opening that exposes a portion of said patterned second low k material; etching the exposed portion of the patterned second low k material as well as underlying portions of the first low k material utilizing the patterned photoresist as an etch mask to form a twice patterned second low k material having said extended portion of the at least one first opening and an upper portion of said at least one second opening therein and a patterned first low k material having a lower portion of said at least one second opening therein; forming a patterned and cured photo-patternable low k material having a plurality of electrically conductive filled regions and gaps located therein atop the twice patterned second low k material, wherein at least one of the plurality of electrically conductive filled regions is located within the at least one second opening and wherein one of the gaps is located above and connected with the extended portion of the at least one first opening located within the twice patterned second low k material; performing a lateral etching process that forms an expanded width gap within the patterned first low k material which is located beneath and connected with the extended portion of the at least one first opening formed in the twice patterned second low k dielectric material; and forming a dielectric cap atop the patterned and cured photo-patternable low k material forming air gaps at least within the patterned and cured photo-patternable low k material.