摘要 |
Semiconductor devices with replacement gate electrodes and integrated self aligned contacts are formed with enhanced gate dielectric layers and improved electrical isolation properties between the gate line and a contact. Embodiments include forming a removable gate electrode on a substrate, forming a self aligned contact stop layer over the removable gate electrode and the substrate, removing a portion of the self aligned contact stop layer over the removable gate electrode and the electrode itself leaving an opening, forming a replacement gate electrode of metal, in the opening, transforming an upper portion of the metal into a dielectric layer, and forming a self aligned contact. Embodiments include forming the contact stop layer of a dielectric material, e.g., a hafnium oxide, an aluminum oxide, or a silicon carbide and transforming the upper portion of the metal into a dielectric layer by oxidation, fluorination, or nitridation. Embodiments also include forming a hardmask layer over the removable gate electrode to protect the electrode during silicidation in source/drain regions of the semiconductor device.
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