| 摘要 |
An apparatus and method of tungsten via fill using a low pressure, 2-step nucleation tungsten deposition process. The tungsten via fill includes a silane soak, a nucleation film growth, and a bulk tungsten film deposition. The nucleation film growth is a low pressure, 2-step process including a controlled first nucleation film growth and a second nucleation film growth. A wafer fabricating system that includes a film depositing system and a control system is used. The film depositing system includes a reaction chamber with at least one silane-containing gas source, a tungsten-containing gas source, and a substrate heating source. The control system instructs the silane-containing gas source and the tungsten-containing gas source to flow with a significantly higher ratio of silane-containing gas (SiH4) to form a first silane-rich nucleation layer. The control system then instructs the gas sources to flow with a higher ratio of tungsten-containing gas, such as WF6, to form a second tungsten nucleation layer. The low pressure, 2-step process results with improved nucleation film step coverage.
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