Abstract: A method for forming a semiconductor device includes providing a semiconductor substrate; forming a gate dielectric over the semiconductor substrate; forming a gate electrode over the gate dielectric; forming an insulating layer over a sidewall of the gate electrode; defining source and drain regions in the semiconductor substrate adjacent to the insulating layer; implanting a dopant in the source and drain regions of the semiconductor substrate to form doped source and drain regions; forming a sidewall spacer adjacent to the insulating layer; forming a recess in the semiconductor substrate in the source and drain regions, wherein the recess extends directly underneath the spacer a predetermined distance from a channel regions; and forming a stressor material in the recess. The method allows the stressor material to be formed closer to a channel region, thus improving carrier mobility in the channel while not degrading short channel effects.

Abstract: A method for forming a semiconductor device includes forming a recess in a source region and a recess in a drain region of the semiconductor device. The method further includes forming a first semiconductor material layer in the recess in the source region and a second semiconductor material layer in the recess in the drain region, wherein each of the first semiconductor material layer and the second semiconductor material layer are formed using a stressor material having a first ratio of an atomic concentration of a first element and an atomic concentration of a second element, wherein the first element is silicon and a first level of concentration of a doping material. The method further includes forming additional semiconductor material layers overlying the first semiconductor material layer and the second semiconductor material layer that have a different ratio of the atomic concentration of the first element and the second element.

Abstract: A method for forming a semiconductor device includes providing a semiconductor substrate; forming a gate dielectric over the semiconductor substrate; forming a gate electrode over the gate dielectric; forming an insulating layer over a sidewall of the gate electrode; defining source and drain regions in the semiconductor substrate adjacent to the insulating layer; implanting a dopant in the source and drain regions of the semiconductor substrate to form doped source and drain regions; forming a sidewall spacer adjacent to the insulating layer; forming a recess in the semiconductor substrate in the source and drain regions, wherein the recess extends directly underneath the spacer a predetermined distance from a channel regions; and forming a stressor material in the recess. The method allows the stressor material to be formed closer to a channel region, thus improving carrier mobility in the channel while not degrading short channel effects.

Abstract: A method for forming a semiconductor device includes forming a recess in a source region and a recess in a drain region of the semiconductor device. The method further includes forming a first semiconductor material layer in the recess in the source region and a second semiconductor material layer in the recess in the drain region, wherein each of the first semiconductor material layer and the second semiconductor material layer are formed using a stressor material having a first ratio of an atomic concentration of a first element and an atomic concentration of a second element, wherein the first element is silicon and a first level of concentration of a doping material. The method further includes forming additional semiconductor material layers overlying the first semiconductor material layer and the second semiconductor material layer that have a different ratio of the atomic concentration of the first element and the second element.