A method of fabricating a device on a substrate includes doping a channel region of the device with dopants. The method further includes growing an undoped epitaxial layer over the channel region, wherein growing the undoped epitaxial layer comprises deactivating dopants in the channel region to form a deactivated region. The method further includes forming a gate structure over the deactivated region.

A method for fabricating a field-effect transistor includes: providing a structure including a first layer of semiconductor material, a doped second layer of semiconductor material arranged on top of the first layer of semiconductor material, the composition of which is different from that of the first layer, two spacers made of dielectric material arranged on top of the second layer of semiconductor material and separated by a groove, the second layer of semiconductor material being accessible at the bottom of the groove; etching the second layer of semiconductor material at the bottom of the groove until reaching the first layer of semiconductor material in such a way as to retain the second layer of semiconductor material beneath the spacers on either side of the groove; and then forming a gate stack in the groove.

A semiconductor device includes a channel region comprising dopants, a gate structure over the channel region and a deactivated region underneath the gate structure and partially within the channel region. Dopants within the deactivated region are deactivated. The deactivated region includes carbon. The deactivated region is physically separated from a top surface of a substrate by a portion of the substrate that is free of carbon.

A method for fabricating semiconductor device includes the steps of first providing a substrate, forming a gate structure on the substrate, forming a hard mask on the substrate and the gate structure, patterning the hard mask to form trenches exposing part of the substrate, and forming raised epitaxial layers in the trenches. Preferably, the gate structure is extended along a first direction on the substrate and the raised epitaxial layers are elongated along a second direction adjacent to two sides of the gate structure.

A device may include a semiconductor-on-insulator (SOI) structure that may include a substrate, an insulator layer over the substrate, and a semiconductor layer over the insulator layer. The semiconductor layer may include a first conductivity region and a second conductivity region at least partially arranged within the semiconductor layer. The device may further include a gate structure arranged over the semiconductor layer and between the first conductivity region and the second conductivity region; a first conductor element arranged through the semiconductor layer and the insulator layer of the SOI structure to electrically contact the substrate; a second conductor element arranged to electrically contact the gate structure; and a conducting member connecting the first conductor element and the second conductor element to electrically couple the first conductor element and the second conductor element.

A semiconductor device includes a substrate and a semiconductor layer. The substrate includes a planar portion and a plurality of pillars on a periphery of the planar portion. The pillars are shaped as rectangular columns, and corners of two of the pillars at the same side of the planar portion are aligned in a horizontal direction or a direction perpendicular to the horizontal direction. The semiconductor layer is disposed over the planar portion and between the pillars.

A semiconductor device includes a first layer of a first semiconductor material disposed on a semiconductor substrate and a second layer of a second semiconductor material disposed on the first layer. The second semiconductor material is formed of an alloy that includes a first element and a second element. The first semiconductor material and the second semiconductor material are different. A gate structure is disposed on a first portion of the second layer. A surface region of a second portion of the second layer not covered by the gate structure has a higher concentration of the second element than an internal region of the second portion of the second layer, and the surface region surrounds the internal region.

An integrated circuit device includes a gate stack structure on a base layer, the gate stack structure having a gate insulating layer with a first dielectric layer on the base layer and having first relative permittivity, and a gate structure on the gate insulating layer, and a gate spacer structure on opposite side walls of the gate stack structure and on the base layer, the gate spacer structure including a buried dielectric layer buried in a recess hole of the gate insulating layer at a lower portion of the gate spacer structure on the base layer, and the buried dielectric layer including a same material as the first dielectric layer.

A device may include a semiconductor-on-insulator (SOI) structure that may include a substrate, an insulator layer over the substrate, and a semiconductor layer over the insulator layer. The semiconductor layer may include a first conductivity region and a second conductivity region at least partially arranged within the semiconductor layer. The device may further include a gate structure arranged over the semiconductor layer and between the first conductivity region and the second conductivity region; a first conductor element arranged through the semiconductor layer and the insulator layer of the SOI structure to electrically contact the substrate; a second conductor element arranged to electrically contact the gate structure; and a conducting member connecting the first conductor element and the second conductor element to electrically couple the first conductor element and the second conductor element.

The present disclosure relates to a method of forming a transistor device. In this method, first and second well regions are formed within a semiconductor substrate. The first and second well regions have first and second etch rates, respectively, which are different from one another. Dopants are selectively implanted into the first well region to alter the first etch rate to make the first etch rate substantially equal to the second etch rate. The first, selectively implanted well region and the second well region are etched to form channel recesses having equal recess depths. An epitaxial growth process is performed to form one or more epitaxial layers within the channel recesses.