Fin-shaped field-effect transistor with a germanium epitaxial cap and a method for fabricating the same
AssigneeUnited Microelectronics Corp.
InventorYu-Cheng Tung
Life of this patent
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Abstract
A FinFET includes a fin-shaped structure, a gate structure, an epitaxial layer, an interlayer dielectric layer, an opening, a germanium cap and a contact plug. The fin-shaped structure is disposed on the substrate. The gate structure covers a portion of the fin-shaped structure. The epitaxial layer is disposed on the fin-shaped structure adjacent to the gate structure. The interlayer dielectric layer covers the gate structure and the epitaxial layer. The opening is in the interlayer dielectric layer. The germanium cap fills the bottom of the opening and has a germanium concentration in excess of 50 atomic %. The contact plug is disposed on the germanium cap in the opening.
Claims20
A fin-shaped field-effect transistor (FinFET), comprising:
- a fin-shaped structure disposed on a substrate;
- a gate structure covering a portion of the fin-shaped structure;
- an epitaxial layer disposed on the fin-shaped structure adjacent to the gate structure;
- an interlayer dielectric layer covering the gate structure and the epitaxial layer;
- an opening in the interlayer dielectric layer;
- a germanium cap at the bottom of the opening, wherein the germanium cap has a germanium concentration in excess of 50 atomic %;
- a silicon cap disposed in the opening and between the germanium cap and the fin-shaped structure;
- and
- a contact plug disposed on the germanium cap in the opening.
(canceled)
A method for fabricating a fin-shaped field-effect transistor (FinFET), comprising:
- providing a substrate;
- forming a fin-shaped structure on the substrate;
- forming a gate structure on the fin-shaped structure;
- forming an epitaxial layer in the fin-shaped structure adjacent to the gate structure;
- forming an interlayer dielectric layer on the gate structure and the epitaxial layer;
- forming an opening in the interlayer dielectric layer;
- forming a germanium cap at the bottom of the opening, wherein the germanium cap has a germanium concentration in excess of 50 atomic %;
- forming a silicon cap layer on the epitaxial layer between the steps of forming the opening and forming the germanium cap;
- and
- forming a contact plug on the germanium cap in the opening.
(canceled)
(canceled)
Dependencies are inferred from the claim text.