Abstract: A method of forming an epitaxial layer includes the following steps. At first, a first epitaxial growth process is performed to form a first epitaxial layer on a substrate, and a gas source of silicon, a gas source of carbon, a gas source of phosphorous and a gas source of germanium are introduced during the first epitaxial growth process to form the first epitaxial layer including silicon, carbon, phosphorous and germanium. Subsequently, a second epitaxial growth process is performed to form a second epitaxial layer, and a number of elements in the second epitaxial layer is smaller than a number of elements in the first epitaxial layer.

Abstract: A semiconductor device having epitaxial structures includes a gate structure positioned on a substrate, epitaxial structures formed in the substrate at two sides of the gate structure, and an undoped cap layer formed on the epitaxial structures. The epitaxial structures include a dopant, a first semiconductor material having a first lattice constant, and a second semiconductor material having a second lattice constant, and the second lattice constant is larger than the first lattice constant. The undoped cap layer also includes the first semiconductor material and the second semiconductor material. The second semiconductor material in the epitaxial structures includes a first concentration, the second semiconductor material in the undoped cap layer includes at least a first concentration, and the second concentration is lower than the first concentration.

Abstract: A multigate field effect transistor includes two fin-shaped structures and a dielectric layer. The fin-shaped structures are located on a substrate. The dielectric layer covers the substrate and the fin-shaped structures. At least two voids are located in the dielectric layer between the two fin-shaped structures. Moreover, the present invention also provides a multigate field effect transistor process for forming said multigate field effect transistor including the following steps. Two fin-shaped structures are formed on a substrate. A dielectric layer covers the substrate and the two fin-shaped structures, wherein at least two voids are formed in the dielectric layer between the two fin-shaped structures.

Abstract: A method for fabricating a compound semiconductor epitaxial structure includes the following steps. Firstly, a first compound epitaxial layer is formed on a substrate. Then, a continuous epitaxial deposition process is performed to form a second compound epitaxial layer on the first compound epitaxial layer, so that the second compound epitaxial layer has a linearly-decreased concentration gradient of metal. Afterwards, a semiconductor material layer is formed on the second compound epitaxial layer.

Abstract: A semiconductor device includes: a substrate having a first region and a second region; a first gate structure disposed on the first region, wherein the first gate structure comprises a first high-k dielectric layer, a first work function metal layer, and a first metal layer disposed between the first high-k dielectric layer and the first work function metal layer; and a second gate structure disposed on the second region, wherein the second gate structure comprises a second high-k dielectric layer, a second work function metal layer, and a second metal layer disposed between the second high-k dielectric layer and the second work function metal layer, wherein the thickness of the second metal layer is lower than the thickness of the first metal layer.

Abstract: A method for fabricating a compound semiconductor epitaxial structure includes the following steps. Firstly, a first compound epitaxial layer is formed on a substrate. Then, a continuous epitaxial deposition process is performed to form a second compound epitaxial layer on the first compound epitaxial layer, so that the second compound epitaxial layer has a linearly-decreased concentration gradient of metal. Afterwards, a semiconductor material layer is formed on the second compound epitaxial layer.

Abstract: A method of fabricating a semiconductor device includes the following steps. First, a semiconductor substrate is provided, which includes at least a fin structure and at least a gate semiconductor layer disposed thereon. The gate semiconductor layer covers a portion of the fin structure. Then a sacrificial layer is deposited to cover the fin structure entirely. Subsequently, a top surface of the fin structure is exposed from the sacrificial layer through an etching process. A material layer is then deposited, which covers the gate semiconductor layer, the fin structure and the sacrificial layer conformally. Finally, the material layer is etched until the top surface of the fin structure is exposed and a first spacer is concurrently formed on side surfaces of the gate semiconductor layer.

Abstract: A semiconductor structure includes a gate structure, an epitaxial layer and a carbon-containing silicon germanium cap layer. The gate structure is located on a substrate. The epitaxial layer is located in the substrate beside the gate structure. The carbon-containing silicon germanium cap layer is located on the epitaxial layer. Otherwise, semiconductor processes for forming said semiconductor structure are also provided.

Abstract: A fin field-effect transistor structure includes a substrate, a fin channel and a high-k metal gate. The high-k metal gate is formed on the substrate and the fin channel. A process of manufacturing the fin field-effect transistor structure includes the following steps. Firstly, a polysilicon pseudo gate structure is formed on the substrate and a surface of the fin channel. By using the polysilicon pseudo gate structure as a mask, a source/drain region is formed in the fin channel. After the polysilicon pseudo gate structure is removed, a high-k dielectric layer and a metal gate layer are successively formed. Afterwards, a planarization process is performed on the substrate having the metal gate layer until the first dielectric layer is exposed, so that a high-k metal gate is produced.

Abstract: A method of forming a semiconductor device includes the following steps. A semiconductor substrate having a first strained silicon layer is provided. Then, an insulating region such as a shallow trench isolation (STI) is formed, where a depth of the insulating region is substantially larger than a depth of the first strained silicon layer. Subsequently, the first strained silicon layer is removed, and a second strained silicon layer is formed to substitute the first strained silicon layer.

Abstract: A method for fabricating a metal oxide semiconductor (MOS) device is described, including following steps. Two recesses are formed in a substrate. A first epitaxy growth process is performed, so as to form a first semiconductor compound layer in each of the recesses. A second epitaxy growth process is performed with an epitaxial temperature lower than 700° C., so as to form a cap layer on each of the first semiconductor compound layers. Each of the cap layers includes a second semiconductor compound layer protruding from a surface of the substrate. The first and the second semiconductor compound layers are composed of a first Group IV element and a second Group IV element, wherein the second Group IV element is a nonsilicon element. The content of the second Group IV element in the second semiconductor compound layers is less than that in the first semiconductor compound layers.

Abstract: A MOS transistor including a silicon substrate, a first gate structure and a second gate structure disposed on the silicon substrate is provided. The first gate structure and the second gate structure each includes a high-k dielectric layer disposed on the silicon substrate, a barrier layer disposed on the high-k dielectric layer, and a work function layer disposed on and contacted with the barrier layer. The MOS transistor further includes a dielectric material spacer. The dielectric material spacer is disposed on the barrier layer of each of the first gate structure and the second gate structure and surrounding the work function layer of each of the first gate structure and the second gate structure.

Abstract: A method of fabricating a through silicon via (TSV) structure, in which, a patterned mask is formed on a substrate, the patterned mask has an opening, a spacer-shaped structure is formed on a sidewall of the opening, and a via hole having a relatively enlarged opening is formed by etching the spacer-shaped structure and the substrate through the opening after the spacer-shaped structure is formed. A TSV structure, in which, a via hole has an opening portion and a body portion, the opening portion is a relatively enlarged opening and has a tapered shape having an opening size of an upper portion greater than an opening size of a lower portion.

Abstract: A MOS transistor process includes the following steps. A gate structure is formed on a substrate. A source/drain is formed in the substrate beside the gate structure. After the source/drain is formed, (1) at least a recess is formed in the substrate beside the gate structure. An epitaxial structure is formed in the recess. (2) A cleaning process may be performed to clean the surface of the substrate beside the gate structure. An epitaxial structure is formed in the substrate beside the gate structure.

Abstract: A method for manufacturing a MOS transistor is provided. A substrate has a high-k dielectric layer and a barrier in each of a first opening and a second opening formed by removing a dummy gate and located in a first transistor region and a second transistor region. A dielectric barrier layer is formed on the substrate and filled into the first opening and the second opening to cover the barrier layers. A portion of the dielectric barrier in the first transistor region is removed. A first work function metal layer is formed. The first work function metal layer and a portion of the dielectric barrier layer in the second transistor region are removed. A second work function metal layer is formed. The method can avoid a loss of the high-k dielectric layer to maintain the reliability of a gate structure, thereby improving the performance of the MOS transistor.

Abstract: A strained silicon substrate structure includes a first transistor and a second transistor disposed on a substrate. The first transistor includes a first gate structure and two first source/drain regions disposed at two sides of the first gate structure. A first source/drain to gate distance is between each first source/drain region and the first gate structure. The second transistor includes a second gate structure and two source/drain doped regions disposed at two side of the second gate structure. A second source/drain to gate distance is between each second source/drain region and the second gate structure. The first source/drain to gate distance is smaller than the second source/drain to gate distance.

Abstract: A semiconductor structure including a substrate and a gate structure disposed on the substrate is disclosed. The gate structure includes a gate dielectric layer disposed on the substrate, a gate material layer disposed on the gate dielectric layer and an outer spacer with a rectangular cross section. The top surface of the outer spacer is lower than the top surface of the gate material layer.

Abstract: The present invention provides a non-planar FET which includes a substrate, a fin structure, a gate and a gate dielectric layer. The fin structure is disposed on the substrate. The fin structure includes a first portion adjacent to the substrate wherein the first portion shrinks towards a side of the substrate. The gate is disposed on the fin structure. The gate dielectric layer is disposed between the fin structure and the gate. The present invention further provides a method of manufacturing the non-planar FET.

Abstract: A semiconductor structure includes agate structure, an epitaxial layer and a carbon-containing silicon germanium cap layer. The gate structure is located on a substrate. The epitaxial layer is located in the substrate beside the gate structure. The carbon-containing silicon germanium cap layer is located on the epitaxial layer. Otherwise, semiconductor processes for forming said semiconductor structure are also provided.

Abstract: A semiconductor device is provided. The semiconductor device includes a substrate, a recess and a stress-providing structure. A channel structure is formed in the substrate. The recess is formed in the substrate and arranged beside the channel structure. The recess has a round inner surface. The stress-providing structure is formed within the recess. Corresponding to the profile of the round inner surface of the recess, the stress-providing structure has a round outer surface.