Semiconductor device and method of manufacturing a gate stack
AssigneeRenesas Technology Corp.
InventorsJiro Yugami, Masao Inoue, Kenichi Mori, Shinsuke Sakashita
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Abstract
The semiconductor device includes a semiconductor substrate, a gate insulating film formed in contact with an upper side of the semiconductor substrate, and a gate electrode formed on the upper side of the gate insulating film and made of metal nitride or metal nitride silicide. A buffer layer for preventing diffusion of nitrogen and silicon is interposed between the gate insulating film and the gate electrode. Preferably, the buffer layer has a thickness of 5 nm or less. In the case where gate electrode contains Ti elements, and the gate insulating film contains Hf elements, the buffer layer preferably contains a titanium film.
Claims7
A method of manufacturing a semiconductor device, comprising the steps of:
- forming a gate structure on a surface of a semiconductor substrate, the gate structure including
- a gate insulation film having hafnium elements and oxygen elements,
- a gate electrode having a titanium nitride film, and
- a layer being provided between the gate insulation film and the gate electrode, and having a titanium film not including nitrogen elements, oxygen elements and silicon elements;
- forming a source region and a drain region in the surface of the semiconductor substrate, the gate structure located above a region between the source and drain;
- and
- performing a heat treatment on the semiconductor substrate after forming the gate structure.
Dependencies are inferred from the claim text.