International Business Machines Corporation
Forming barrierless contact

Abstract:

Techniques for forming barrierless contacts filled with Co are provided. In one aspect, a method for forming barrierless contacts includes: forming bottom metal contacts in a first ILD; depositing a second ILD on the bottom metal contacts; forming contact vias in the second ILD landing on the bottom metal contacts; selectively forming a liner on a top surface of the second ILD and on the second ILD along sidewalls of the contact vias; filling the contact vias with a metal; and removing an excess of the metal to form the barrierless contacts whereby metal-to-metal contact is present between the barrierless contacts and the bottom metal contacts. A contact structure is also provided.