Influence of SiH2Cl2 on the kinetics of the chemical vapor deposition of tungsten by SiH4 reduction of WF6

The influence of adding dichlorosilane (SiH2Cl2) to the silane (SiH4)-based reduction reaction of tungsten hexafluoride (WF6) has been investigated to enhance the properties of this chemical vapor deposition process, especial ly the control of the growth rate. The growth rate of tungsten by the reduc tion reaction based on SiH4 and SiH2Cl2 has been measured. It is shown that the kinetics of the silane-dichlorosilane process can be characterized by a surface reaction limitation. The sole effect of the SiH2Cl2 in the proces s is blocking of surface sites by preferential absorption, thereby reducing the growth rate of the tungsten film. (C) 1999 The Electrochemical Society . S0013-4651(97)11-088-6. All rights reserved.