Abstract: A Multi-Gate Field-Effect Transistor includes a fin-shaped structure, a gate structure, at least an epitaxial structure and a gradient cap layer. The fin-shaped structure is located on a substrate. The gate structure is disposed across a part of the fin-shaped structure and the substrate. The epitaxial structure is located on the fin-shaped structure beside the gate structure. The gradient cap layer is located on each of the epitaxial structures. The gradient cap layer is a compound semiconductor, and the concentration of one of the ingredients of the compound semiconductor has a gradient distribution decreasing from inner to outer. Moreover, the present invention also provides a Multi-Gate Field-Effect Transistor process forming said Multi-Gate Field-Effect Transistor.

Abstract: A method for removing silicon nitride material includes following steps. A substrate having at least a gate structure formed thereon is provided, and at least a silicon nitride hard mask is formed on top of the gate structure. A first removal is performed to remove a portion of the silicon nitride hard mask with a first phosphoric acid (H3PO4) solution. A second removal is subsequently performed to remove remnant silicon nitride hard mask with a second phosphoric acid solution. The first removal and the second removal are performed in-situ. A temperature of the second phosphoric acid solution is lower than a temperature of the first phosphoric acid solution.

Abstract: A Multi-Gate Field-Effect Transistor includes a fin-shaped structure, a gate structure, at least an epitaxial structure and a gradient cap layer. The fin-shaped structure is located on a substrate. The gate structure is disposed across a part of the fin-shaped structure and the substrate. The epitaxial structure is located on the fin-shaped structure beside the gate structure. The gradient cap layer is located on each of the epitaxial structures. The gradient cap layer is a compound semiconductor, and the concentration of one of the ingredients of the compound semiconductor has a gradient distribution decreasing from inner to outer. Moreover, the present invention also provides a Multi-Gate Field-Effect Transistor process forming said Multi-Gate Field-Effect Transistor.

Abstract: A method for removing silicon nitride material includes following steps. A substrate having at least a gate structure formed thereon is provided, and at least a silicon nitride hard mask is formed on top of the gate structure. A first removal is performed to remove a portion of the silicon nitride hard mask with a first phosphoric acid (H3PO4) solution. A second removal is subsequently performed to remove remnant silicon nitride hard mask with a second phosphoric acid solution. The first removal and the second removal are performed in-situ. A temperature of the second phosphoric acid solution is lower than a temperature of the first phosphoric acid solution.

Abstract: A Multi-Gate Field-Effect Transistor includes a fin-shaped structure, a gate structure, at least an epitaxial structure and a gradient cap layer. The fin-shaped structure is located on a substrate. The gate structure is disposed across a part of the fin-shaped structure and the substrate. The epitaxial structure is located on the fin-shaped structure beside the gate structure. The gradient cap layer is located on each of the epitaxial structures. The gradient cap layer is a compound semiconductor, and the concentration of one of the ingredients of the compound semiconductor has a gradient distribution decreasing from bottom to top. Moreover, the present invention also provides a Multi-Gate Field-Effect Transistor process forming said Multi-Gate Field-Effect Transistor.

Abstract: A semiconductor process includes the following steps. A semiconductor substrate is provided. The semiconductor substrate has a patterned isolation layer and the patterned isolation layer has an opening exposing a silicon area of the semiconductor substrate. A silicon rich layer is formed on the sidewalls of the opening. An epitaxial process is performed to form an epitaxial structure on the silicon area in the opening.

Abstract: A semiconductor process includes the following steps. A substrate is provided. At least a fin-shaped structure is formed on the substrate. An oxide layer is formed on the substrate without the fin-shaped structure being formed thereon. A gate is formed to cover a part of the oxide layer and a part of the fin-shaped structure. An etching process is performed to etch a part of the fin-shaped structure beside the gate, therefore at least a recess is formed in the fin-shaped structure. An epitaxial process is performed to form an epitaxial layer in the recess, wherein the epitaxial layer has a hexagon-shaped profile structure.

Abstract: A Multi-Gate Field-Effect Transistor includes a fin-shaped structure, a gate structure, at least an epitaxial structure and a gradient cap layer. The fin-shaped structure is located on a substrate. The gate structure is disposed across a part of the fin-shaped structure and the substrate. The epitaxial structure is located on the fin-shaped structure beside the gate structure. The gradient cap layer is located on each of the epitaxial structures. The gradient cap layer is a compound semiconductor, and the concentration of one of the ingredients of the compound semiconductor has a gradient distribution decreasing from bottom to top. Moreover, the present invention also provides a Multi-Gate Field-Effect Transistor process forming said Multi-Gate Field-Effect Transistor.

Abstract: A semiconductor process includes the following steps. A semiconductor substrate is provided. The semiconductor substrate has a patterned isolation layer and the patterned isolation layer has an opening exposing a silicon area of the semiconductor substrate. A silicon rich layer is formed on the sidewalls of the opening. An epitaxial process is performed to form an epitaxial structure on the silicon area in the opening.

Abstract: A method for manufacturing multi-gate transistor device includes providing a semiconductor substrate having a patterned semiconductor layer and a patterned hard mask sequentially formed thereon, removing the patterned hard mask, performing a thermal treatment to rounding the patterned semiconductor layer with a process temperature lower than 800° C., and sequentially forming a gate dielectric layer and a gate layer covering a portion of the patterned semiconductor layer on the semiconductor substrate.

Abstract: A method for manufacturing multi-gate transistor device includes providing a semiconductor substrate having a patterned semiconductor layer and a patterned hard mask sequentially formed thereon, removing the patterned hard mask, performing a thermal treatment to rounding the patterned semiconductor layer with a process temperature lower than 800° C., and sequentially forming a gate dielectric layer and a gate layer covering a portion of the patterned semiconductor layer on the semiconductor substrate.

Abstract: A semiconductor process includes the following steps. A substrate is provided. At least a fin-shaped structure is formed on the substrate. An oxide layer is formed on the substrate without the fin-shaped structure being formed thereon. A gate is formed to cover a part of the oxide layer and a part of the fin-shaped structure. An etching process is performed to etch a part of the fin-shaped structure beside the gate, therefore at least a recess is formed in the fin-shaped structure. An epitaxial process is performed to form an epitaxial layer in the recess, wherein the epitaxial layer has a hexagon-shaped profile structure.