| 摘要 |
Disclosed herein are embodiments of a method of forming a complementary metal oxide semiconductor (CMOS) device that has at least one high aspect ratio gate structure with a void-free and seam-free metal gate conductor layer positioned on top of a relatively thin high-k gate dielectric layer. These method embodiments incorporate a gate replacement strategy that uses an electroplating process to fill, from the bottom upward, a high-aspect ratio gate stack opening with a metal gate conductor layer. The source of electrons for the electroplating process is a current passed directly through the back side of the substrate. This eliminates the need for a seed layer and ensures that the metal gate conductor layer will be formed without voids or seams. Furthermore, depending upon the embodiment, the electroplating process is performed under illumination to enhance electron flow to a given area (i.e., to enhance plating) or in darkness to prevent electron flow to a given area (i.e., to prevent plating).
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