Semiconductor device having a low-resistance gate electrode
AssigneeElpida Memory, Inc.
InventorTetsuya Taguwa
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Abstract
A gate electrode structure in a semiconductor device has a doped polysilicon (DOPOS) film, a tungsten silicide film, a tungsten silicide nitride film, a tungsten nitride film and a tungsten film consecutively as viewed from the substrate. The tungsten silicide nitride film is formed between the tungsten silicide film and the tungsten nitride film by a plurality of heat treatments. The tungsten silicide nitride film has a small thickness of 2 to 5 nm and has a lower interface resistance for achieving a low-resistance gate electrode, suited for a higher-speed operation of the semiconductor device.
Claims9
A semiconductor device comprising a substrate, and a gate electrode structure overlying said substrate, said gate electrode structure including a doped polysilicon (DOPOS) film having a three-layer structure and a crystal structure with multiple crystal orientations formed on a surface region of said substrate, a silicide film including a first refractory metal formed on said DOPOS film, a nitride film including said first refractory metal formed on said silicide film, and a metallic film including a second refractory metal different from said first refractory metal formed on said nitride film.
A semiconductor device comprising a substrate, and a gate electrode structure overlying said substrate, said gate electrode structure including a doped polysilicon (DOPOS) film having a three-layer structure and a crystal structure with multiple crystal orientations formed on a surface region of said substrate, a suicide film including a first refractory metal formed on said DOPOS film, a nitride silicide film including said first refractory metal formed on said silicide film, and a metallic film including a second refractory metal different from said first refractory metal formed on said nitride silicide film,
- wherein said gate electrode structure further includes a nitride film including said first refractory metal formed between said nitride silicide film and said metallic film.
A semiconductor device comprising a substrate, and a gate electrode structure overlying said substrate, said gate electrode structure including a doped polysilicon (DOPOS) film having a three-layer structure and a crystal structure with multiple crystal orientations formed on a surface region of said substrate, a silicide film including a first refractory metal formed on said DOPOS film, a nitride film including said first refractory metal formed on said silicide film, and a metallic film including a second refractory metal formed on said nitride film, wherein each of said first and second refractory metals is independently selected from the group consisting of tungsten, molybdenum, titanium and tantalum.
A semiconductor device comprising a substrate, and a gate electrode structure overlying said substrate, said gate electrode structure including a doped polysilicon (DOPOS) film having a crystal structure with multiple crystal orientations formed on a surface region of said substrate, a suicide film including a first refractory metal formed on said DOPOS film, a nitride suicide film including said first refractory metal formed on said suicide film, and a metallic film including a second refractory metal formed on said nitride silicide film, wherein said DOPOS film has a three-layer structure wherein the crystal structure has three different orientations.
Dependencies are inferred from the claim text.