Taiwan Semiconductor Manufacturing Comp. Ltd.

Kuo-Pi Tseng

Chun-An Lin

Tzu-Chieh Su

Chao-Cheng Chen

De-Fang Chen

Source and drain formation techniques disclosed herein provide FinFETs with reduced channel resistance and reduced drain-induced barrier lowering. An exemplary three-step etch method for forming a source/drain recess in a source/drain region of a fin includes a first anisotropic etch, an isotropic etch, and a second anisotropic etch. The first anisotropic etch and the isotropic etch are tuned to define a location of a source/drain tip. A depth of the source/drain recess after the first anisotropic etch and the isotropic etch is less than a target depth. The second anisotropic etch is tuned to extend the depth of the source/drain recess to the target depth. The source/drain tip is near a top of the fin to reduce channel resistance while a bottom portion of the source/drain recess is spaced a distance from a gate footing that can minimize DIBL. The source/drain recess is filled with an epitaxial semiconductor material.

Optimized proximity profile for strained source/drain feature and method of fabricating thereof

A device includes a substrate, a channel layer, a gate structure, a first source/drain epitaxial structure, a second source/drain epitaxial structure, and a bottom dielectric structure. The channel layer is over the substrate. The gate structure is across the channel layer. The first source/drain epitaxial structure and the second source/drain epitaxial structure are on opposite sides of the channel layer and are connected to the channel layer. The bottom dielectric structure is between the first source/drain epitaxial structure and the substrate. A maximum width of the first source/drain epitaxial structure is greater than or equal to a maximum width of the bottom dielectric structure in a cross-sectional view.

Semiconductor device and manufacturing method thereof

A device includes a substrate, a channel layer, a gate structure, a source/drain epitaxial structure, and a bottom dielectric structure. The channel layer is over the substrate. The gate structure is over the substrate and surrounds the channel layer. The source/drain epitaxial structure is over the substrate and is connected to the channel layer. The bottom dielectric structure is between the source/drain epitaxial structure and the substrate.

Source and drain formation techniques are disclosed herein. An exemplary three-step etch method for forming a source/drain recess in a source/drain region of a fin includes a first anisotropic etch, an isotropic etch, and a second anisotropic etch. The first anisotropic etch and the isotropic etch are tuned to define a location of a source/drain tip. A depth of the source/drain recess after the first anisotropic etch and the isotropic etch is less than a target depth. The second anisotropic etch is tuned to extend the depth of the source/drain recess to the target depth. The source/drain tip is near a top of the fin while a bottom portion of the source/drain recess is spaced a distance from a gate footing. The source/drain recess is filled with an epitaxial semiconductor material.

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Hsinchu, Taiwan

Kuo-Pi Tseng