The present disclosure provides a semiconductor device. The semiconductor device includes a semiconductor substrate. The semiconductor device includes a gate that is disposed over the substrate. The substrate has a recess. The semiconductor device includes a trench liner that is coated along the recess. The trench liner contains a semiconductor crystal material. The trench liner directly abuts the source/drain stressor device. The semiconductor device also includes a dielectric trench component that is disposed on the trench liner and filling the recess. The semiconductor device includes a source/drain stressor device that is disposed in the substrate. The source/drain stressor device is disposed between the gate and the trench liner.

There is set forth herein a field effect transistor (FET) configured as an ESD protection device. In one embodiment, the FET can be configured to operate in a snapback operating mode. The FET can include a semiconductor substrate, a gate formed on the substrate and a dummy gate formed on the substrate spaced apart from the gate.

Some embodiments include integrated circuits having first and second transistors. The first transistor is wider than the second transistor. The first and second transistors have first and second active regions, respectively. Dielectric features are associated with the first active region and break up the first active region. The second active region is not broken up to the same extent as the first active region. Some embodiments include methods of forming transistors. Active areas of first and second transistors are formed. The active area of the first transistor is wider than the active area of the second transistor. Dielectric features are formed in the active area of the first transistor. The active area of the first transistor is broken up to a different extent than the active area of the second transistor. The active areas of the first and second transistors are simultaneously doped.

A three-dimensional transistor includes a channel with a center portion (forked channel) or side portions (narrow channel) removed, or fins without shaping, after removal of the dummy gate and before a replacement metal gate is formed.

An integrated circuit and method has an isolated well with an improved isolated well contact. The well contact diffusion is isolated from a device diffusion of opposite conductivity type within the isolated well by an isolation transistor gate.

A transistor device includes a substrate, a source region provided on the substrate, a drain region spaced apart from the source region in a direction parallel to a top surface of the substrate, a pair of constant current generating patterns provided in the substrate to be adjacent to the source region and the drain region, respectively, a gate electrode provided on the substrate and between the source region and the drain region, and a gate insulating film interposed between the gate electrode and the substrate, wherein, the pair of constant current generating patterns generate a constant current between the drain region and the substrate, and the constant current is independent from a gate voltage applied to the gate electrode.

A method for fabricating a semiconductor device includes first providing a substrate having a high-voltage (HV) region, a medium-voltage (MV) region, and a low-voltage (LV) region, forming a HV device on the HV region, and forming a LV device on the LV region. Preferably, the HV device includes a first base on the substrate, a first gate dielectric layer on the first base, and a first gate electrode on the first gate dielectric layer. The LV device includes a fin-shaped structure on the substrate, and a second gate electrode on the fin-shaped structure, in which a top surface of the first gate dielectric layer is even with a top surface of the fin-shaped structure.

A method for fabricating a semiconductor device includes the steps of forming a gate structure on a substrate, forming an interlayer dielectric (ILD) layer on the gate structure, forming a contact hole in the ILD layer adjacent to the gate structure, performing a plasma doping process to form a doped layer in the ILD layer and a source/drain region adjacent to the gate structure, forming a conductive layer in the contact hole, planarizing the conductive layer to form a contact plug, removing the doped layer to form an air gap adjacent to the contact plug, and then forming a stop layer on the ILD layer and the contact plug.

A method for fabricating a semiconductor device includes the steps of forming a gate structure on a substrate, forming an interlayer dielectric (ILD) layer on the gate structure, forming a contact hole in the ILD layer adjacent to the gate structure, performing a plasma doping process to form a doped layer in the ILD layer and a source/drain region adjacent to the gate structure, forming a conductive layer in the contact hole, planarizing the conductive layer to form a contact plug, removing the doped layer to form an air gap adjacent to the contact plug, and then forming a stop layer on the ILD layer and the contact plug.

A semiconductor device includes a gate structure on a substrate, a source/drain region adjacent to the gate structure, an interlayer dielectric (ILD) layer around the gate structure, a contact plug in the ILD layer and adjacent to the gate structure, an air gap around the contact plug, a barrier layer on and sealing the air gap, a metal layer on the barrier layer, a stop layer adjacent to the barrier layer and on the ILD layer, and an inter-metal dielectric (IMD) layer on the ILD layer. Preferably, bottom surfaces of the barrier layer and the stop layer are coplanar and top surfaces of the IMD layer and the barrier layer are coplanar.