Semiconductor device comprising replacement gate electrode structures and self-aligned contact elements formed by a late contact fill

摘要

When forming self-aligned contact elements in sophisticated semiconductor devices in which high-k metal gate electrode structures are to be provided on the basis of a replacement gate approach, the self-aligned contact openings are filled with an appropriate fill material, such as polysilicon, while the gate electrode structures are provided on the basis of a placeholder material that can be removed with high selectivity with respect to the sacrificial fill material. In this manner, the high-k metal gate electrode structures may be completed prior to actually filling the contact openings with an appropriate contact material after the removal of the sacrificial fill material. In one illustrative embodiment, the placeholder material of the gate electrode structures is provided in the form of a silicon/germanium material.

主权项

1. A method, comprising:
forming a gate electrode material layer stack on an active region of a semiconductor device, said gate electrode material layer stack comprising a layer of cap material formed above a layer of placeholder material; patterning said gate electrode material stack to form a gate electrode structure on said active region, said gate electrode structure comprising said cap material positioned above said placeholder material; forming a spacer structure adjacent to said gate electrode structure, said spacer structure covering sidewalls of said cap material and said placeholder material; after forming said sidewall spacer structure, forming an interlayer dielectric material above and adjacent to said active region; removing said interlayer dielectric material selectively from above at least a portion of said active region so as to expose a contact region of said active region that is positioned laterally adjacent to said gate electrode structure; forming a sacrificial fill material laterally adjacent to and above said gate electrode structure, said sacrificial fill material covering said spacer structure and said contact region; exposing a surface of said placeholder material by performing a planarization process to planarize said sacrificial fill material and remove said cap material from said gate electrode structure; replacing said placeholder material with at least an electrode metal in the presence of said sacrificial fill material; removing said sacrificial fill material so as to re-expose said contact region of said active region after replacing said placeholder material; and forming a conductive material on said exposed contact region so as to form a contact element.