摘要 |
In a replacement gate approach, a top area of a gate opening has a superior cross-sectional shape which is accomplished on the basis of a plasma assisted etch process or an ion sputter process. During the process, a sacrificial fill material protects sensitive materials, such as a high-k dielectric material and a corresponding cap material. Consequently, the subsequent deposition of a work function adjusting material layer may not result in a surface topography which may result in a non-reliable filling-in of the electrode metal. In some illustrative embodiments, the sacrificial fill material may also be used as a deposition mask for avoiding the deposition of the work function adjusting metal in certain gate openings in which a different type of work function adjusting species is required.
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