Novellus Systems Incorporated

Karen Chu

Michal Danek

Anil Justin Vijayendran

Methods and structures are provided for conformal lining of dual damascene structures in semiconductor devices that contain porous or low k dielectrics. Features, such as trenches and contact vias are formed in the dielectrics. The features are subjected to low-power plasma predeposition treatment to irregularities on the porous surfaces and/or reactively form an permeation barrier before a diffusion barrier material is deposited on the feature. The diffusion barrier may, for example, be deposited by CVD using metalorganic vapor reagents. The feature is then filled with copper metal and further processed to complete a dual damascene interconnect. The plasma predeposition treatment advantageously reduces the amount of permeation of the metalorganic reagent into the interlayer dielectric.

Method for preventing metalorganic precursor penetration into porous dielectrics

The present invention provides a method to improve adhesion of barrier, metal, dielectric interfaces. In the process flow, a first barrier material is formed on a dielectric layer and bombarded with a plasma to effectively push the barrier material into the dielectric interface while leaving a portion of the barrier material over the dielectric. A second barrier material, which may or may not be the same as the first barrier material, is then formed on the remaining first barrier material. Advantageously, the method of the present invention allows the barrier material to be pushed into the dielectric to insure excellent adhesion, which prevents chemical mechanical polishing delamination. Furthermore, the presence of the first barrier material on the sidewalls of via apertures through the dielectric can prevent Cu poisoning from sputtered Cu or C O .

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Pleasanton, CA, United States of America

Karen Chu