International Business Machines Corporation

Arun Vijayakumar

Keith Kwong Hon Wong

Brett H Engel

Domingo A Ferrer

Patrick William Dehaven

A method of forming a titanium nitride (TiN) diffusion barrier includes exposing a deposition surface to a first pulse of a titanium-containing precursor and to a first pulse of a nitrogen-rich plasma to form a first TiN layer with a first nitrogen concentration making a lower portion of the TiN diffusion barrier, the first nitrogen concentration of the first TiN layer is increased by the first pulse of the nitrogen-rich plasma reducing a reactivity of the lower portion of the TiN diffusion barrier to prevent fluorine diffusion. The first TiN layer is exposed to second pulses of the titanium-containing precursor and the nitrogen-rich plasma to form a second TiN layer with a second nitrogen concentration above the first TiN layer making an upper portion of the TiN diffusion barrier, the first pulse of the nitrogen-rich plasma has a substantially longer duration than the second pulse of the nitrogen-rich plasma.

Diffusion barrier layer formation

A method includes forming a first metal liner conformally along a sidewall and a bottom of a contact opening. A second metal liner is formed above and in direct contact with the first metal liner, a grain size of the first metal liner is larger than a grain size of the second metal liner. A barrier layer is formed above and in direct contact with the second metal liner and the contact opening is filled with a conductive material to form a middle-of-the-line contact.

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Austin, TX, United States of America

Arun Vijayakumar