IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Thin Films Tuesday Sessions
       Session TF-TuA

Paper TF-TuA7
The Impact of Residual By-Products from Tungsten Film Deposition on Process Integration due to Non-Uniformity of the Tungsten Film

Tuesday, October 30, 2001, 4:00 pm, Room 123

Session: Growth and Properties of Thin Films
Presenter: A. Sidhwa, STMicroelectronics, Inc. and University of Arkansas
Authors: A. Sidhwa, STMicroelectronics, Inc. and University of Arkansas
C. Spinner, STMicroelectronics, Inc.
T. Gandy, STMicroelectronics, Inc.
S. Melosky, STMicroelectronics, Inc.
W. Brown, University of Arkansas
S. Ang, University of Arkansas
H. Naseem, University of Arkansas
R. Ulrich, University of Arkansas
Correspondent: Click to Email
The effects of residual by-products from a tungsten film deposition process and their impact on process integration due to the non-uniformity of the tungsten film were investigated in this work. The tungsten film deposition process involves three steps: nucleation, stabilization, and tungsten bulk fill. Six experiments were conducted in search for a solution to the problem. The resulting data suggest that excess nitrogen left in the chamber following the tungsten nucleation step, along with residual by-products, causes a shift in the tungsten film uniformity during the tungsten bulk fill process. Data reveal that, due to the residual by-products, an abnormal grain growth occurs causing a variation in the tungsten thickness across the wafer during the bulk fill step. Although several possible solutions were revealed by the experiments, potential integration problems limited the acceptable solutions to one. The solution chosen was the introduction of a 10 second pumpdown immediately following the nucleation step. This choice did not create any integration problems as confirmed by subsequent studies.