Mueting, Raasch & Gebhardt, P.A.
Multiple step methods for forming conformal layers
 A two-step formation process provides conformal coverage at both the bottom surface and one or more side walls of an opening for various applications, e.g., high aspect ratio contact liners or storage cell capacitor electrode applications, and provides conformal coverage on any features requiring such coverage. A method for forming a conformal layer in the fabrication of integrated circuits includes providing a substrate assembly including at least a generally horizontal first surface and a second surface extending therefrom. A first portion of the layer is formed selectively on the horizontal first surface during a first period of time and a second portion of the layer is deposited selectively on the second surface during a second period of time. Further, one illustrative process for forming tungsten nitride in the fabrication of integrated circuits includes forming tungsten nitride on the horizontal first surface during a first period of time and depositing tungsten nitride on the second surface during a second period of time by plasma enhanced chemical vapor deposition. The tungsten nitride may be formed on the first surface by plasma enhanced chemical vapor deposition using a first reactant gas mixture including WF.sub.6, at least one of NF.sub.3 and N.sub.2, and H.sub.2 with the tungsten nitride being deposited on the second surface by plasma enhanced chemical vapor deposition using a second reactant gas mixture including WF.sub.6, at least one of NF.sub.3 and N.sub.2, H.sub.2, and He. 
Micron Technology, Inc.
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Gurtej S. Weimin
Sandhu Li