AVS 49th International Symposium
    Plasma Science Wednesday Sessions
       Session PS+TF-WeP

Paper PS+TF-WeP3
RF Inductively Coupled Plasma Assisted Re-sputtering Techniques for Step Coverage Control in sub 0.13µm Structures

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Plasma Etching & Deposition
Presenter: J. Forster, Applied Materials Inc.
Authors: P. Gopalraja, Applied Materials Inc.
S. Rengarajan, Applied Materials Inc.
J. Forster, Applied Materials Inc.
X. Tang, Applied Materials Inc.
R. Jauhari, Applied Materials Inc.
U. Kelkar, Applied Materials Inc.
A. Chan, Applied Materials Inc.
M. Schweitzer, Applied Materials Inc.
K. Miller, Applied Materials Inc.
A. Bhatnagar, Applied Materials Inc.
N. Maity, Applied Materials Inc.
J. Van Gogh, Applied Materials Inc.
S. Parikh, Applied Materials Inc.
Z. Xu, Applied Materials Inc.
Correspondent: Click to Email
A sputter deposition source has been developed that allows the bottom coverage in small structures to be made arbitrarily small, while retaining significant sidewall coverage. This ability is becoming increasingly desirable as copper based back-end metallization schemes in integrated circuits shrink to 0.13µm and below. The reduction in bottom coverage is made possible by utilizing a process, which combines deposition onto and re-sputtering of material from the wafer. The deposition occurs via a partially ionized PVD process, and the re-puttering occurs via a RF inductively coupled plasma assisted re-sputtering process. The hardware components for both deposition and re-sputtering have been integrated into a single chamber. The data presented in this paper will include simulations of plasma characteristics for the re-sputtering process for varying power and pressure conditions, and the correlation of these simulation results with the properties of the thin films deposited. Transmission electron micrographs show bottom coverage arbitrarily close to zero can be achieved in both via and dual damascene structures. Electrical testing on dual damascene structures shows that minimal bottom coverage improves via resistance, and that substantial sidewall coverage improves stress migration and electro-migration properties.