Metal gate with composite film stack
AssigneeNanya Technology Corporation
InventorsShian-Jyh Lin, Chung-Yuan Lee, Yu-Chang Lin
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Abstract
A novel metal gate structure includes a gate oxide layer formed on a surface of a silicon substrate, a doped silicon layer stacked on the gate oxide layer, a CVD ultra-thin titanium nitride film deposited on the doped silicon layer, a tungsten nitride layer stacked on the CVD ultra-thin titanium nitride film, a tungsten layer stacked on the tungsten nitride layer, and a nitride cap layer stacked on the tungsten layer. A liquid phase deposition (LPD) oxide spacer is formed on each sidewall of the metal gate stack. A silicon nitride spacer is formed on the LPD oxide spacer. The thickness of the CVD ultra-thin titanium nitride film is between 10 and 100 angstroms.
Claims14
A metal gate structure, comprising:
- a gate oxide layer formed on a silicon substrate;
- a doped silicon layer stacked on said gate oxide layer;
- an ultra-thin titanium nitride barrier layer deposited on said doped silicon layer;
- a tungsten nitride layer stacked on said ultra-thin titanium nitride barrier layer;
- a tungsten layer stacked on said tungsten nitride layer;
- and
- a silicon nitride cap layer stacked on said tungsten layer.
A metal gate structure, comprising:
- a gate oxide layer formed on a silicon substrate;
- a doped silicon layer stacked on said gate oxide layer;
- an metal barrier stack deposited on said doped silicon layer;
- a tungsten nitride layer stacked on said metal barrier stack;
- a tungsten layer stacked on said tungsten nitride layer;
- and
- a silicon nitride cap layer stacked on said tungsten layer.
Dependencies are inferred from the claim text.