Interconnect structure with dielectric air gaps
AssigneeInternational Business Machines Corporation
InventorChih-Chao Yang
Life of this patent
Estimating the term…
Abstract
An interconnect structure with improved performance and capacitance by providing air gaps inside the dielectric layer by use of a multi-phase photoresist material. The interconnect features are embedded in a dielectric layer having a columnar air gap structure in a portion of the dielectric layer surrounding the interconnect features. The interconnect features may also be embedded in a dielectric layer having two or more phases with a different dielectric constant created. The interconnect structure is compatible with current back end of line processing.
Claims19
A method for forming an interconnect structure, comprising:
- forming interconnect features embedded in a first dielectric layer deposited on a substrate, said interconnect features having patterned exposed interconnect areas;
- forming a second layer material on the portion of said first dielectric layer surrounding said exposed interconnect areas;
- forming a cap layer on said exposed interconnect areas;
- depositing a multi-phase photoresist on said second layer material and said cap layer;
- and
- separating the portion of said multi-phase photoresist contiguous with said second layer material into a pattern of different phase materials, wherein said multi-phase photoresist is a two-phase photoresist having a first phase (A) photoresist and a second phase (B) photoresist, wherein second phase photoresist has a higher etching resistance that said firs phase (A) photoresist.
Dependencies are inferred from the claim text.