MOSFETs having stacked metal gate electrodes and method
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsCheng-Tung Lin, Yung-Sheng Chiu, Hsiang-Yi Wang, Chia-Lin Yu, Chen-Hua Yu
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Abstract
MOSFETs having stacked metal gate electrodes and methods of making the same are provided. The MOSFET gate electrode includes a gate metal layer formed atop a high-k gate dielectric layer. The metal gate electrode is formed through a low oxygen content deposition process without charged-ion bombardment to the wafer substrate. Metal gate layer thus formed has low oxygen content and may prevent interfacial oxide layer regrowth. The process of forming the gate metal layer generally avoids plasma damage to the wafer substrate.
Claims15
A method for making a metal oxide semiconductor field effect transistor (MOSFET), the method comprising:
- forming a high-k dielectric layer on a semiconductor substrate;
- forming a first metal layer on the high-k dielectric layer, the first metal layer having low oxygen content;
- forming a second metal layer on the first metal layer;
- reducing an amount of oxygen within the second metal layer;
- and
- forming a polysilicon (poly) cap layer on the second metal layer.
A method for making a semiconductor device comprising:
- providing a semiconductor substrate;
- forming an interfacial oxide layer at a first region and a second region on the substrate;
- forming a high-k dielectric layer on the interfacial oxide layer at the first and the second regions;
- and
- forming a first metal layer on the high-k dielectric layer at the first and the second regions, the first metal layer having low oxygen content;
- forming a second metal layer on the first metal layer at the first and the second regions;
- degassing the second metal layer;
- and
- forming a poly cap layer on the second metal layer at the first and the second regions.
Dependencies are inferred from the claim text.