The disclosure provides an N-type thin film transistor, including a poly-silicon layer, a gate layer, a source and a drain. The poly-silicon layer includes a channel region, a source region and a drain region at two side of the channel region. The gate layer is on the channel region, a projection of the gate layer on the poly-silicon layer partially overlaps the source region and the drain region, and a thickness of the gate layer on the source region and the drain region are smaller than a thickness of the gate layer on the channel region. The source region and the drain region both include a heavily-doping region and a lightly-doping region connected to the heavily-doping region, the source and the drain are respectively on the heavily-doping region of the source region and the drain, and respectively electrically connects to the heavily-doping region of the source region and the drain.

A method of sidewall engineering with negative capacitance materials is disclosed. For example, the negative capacitance material is a ferroelectric material. The method includes providing a dielectric liner on the sidewall of the gate and providing a negative capacitance liner or spacer over the dielectric liner. In one embodiment, the dielectric liner is an oxide liner and the negative capacitance liner or spacer is a ferroelectric liner or spacer. The engineered negative capacitance liner or spacer enhances the gate-to-S/D region and gate-to-contact coupling and hence the device I.sub.ON-I.sub.OFF performance is improved.

A semiconductor device includes a substrate, a gate structure, a first doped region and a second doped region. The substrate has a plurality of recesses therein. A gate structure covers the plurality of recesses and a surface of the substrate between the plurality of recesses. The gate structure includes a gate dielectric layer and a gate conductive layer. The gate dielectric layer covers bottom surfaces and sidewalls of the plurality of recesses and the surface of the substrate between the plurality of recesses. The gate conductive layer is formed on the gate dielectric layer, fills in the plurality of recesses and covers the surface of the substrate between the plurality of recesses. The first doped region and the second doped region are located at two sides of the gate structure.

Disclosed examples include LDMOS transistors and integrated circuits with a gate, a body region implanted in the substrate to provide a channel region under a portion of the gate, a source adjacent the channel region, a drain laterally spaced from a first side of the gate, a drift region including a first highly doped drift region portion, a low doped gap drift region above the first highly doped drift region portion, and a second highly doped region portion above the gap drift region, and an isolation structure extending through the second highly doped region portion into the gap drift region portion, with a first end proximate the drain region and a second end under the gate dielectric layer, where the body region includes a tapered side laterally spaced from the second end of the isolation structure to define a trapezoidal JFET region.

A MOS transistor is produced on and in an active zone and included a source region and a drain region. The active zone has a width measured transversely to a source-drain direction. A conductive gate region of the MOS transistor includes a central zone and, at a foot of the central zone, at least one stair that extends beyond the central zone along at least an entirety of the width of the active zone.

A method of fabricating a transistor with reduced hot carrier injection effects includes providing a substrate covered by a gate material layer. Later, the gate material layer is patterned into a gate electrode. Then, a mask layer is formed to cover part of the gate electrode and expose two ends of the gate electrode. Finally, a first implantation process is performed to implant dopants through the exposed two ends of the gate electrode into the substrate directly under the gate electrode to form two LDD regions by taking the mask layer as a mask.

Semiconductor devices and methods of manufacturing the same are provided. In one embodiment, the method may include: forming a first shielding layer on a substrate; forming one of source and drain regions with the first shielding layer as a mask; forming a second shielding layer on the substrate, and removing the first shielding layer; forming a shielding spacer on a sidewall of the second shielding layer; forming the other of the source and drain regions with the second shielding layer and the shielding spacer as a mask; removing at least a portion of the shielding spacer; and forming a gate dielectric layer, and forming a gate conductor as a spacer on a sidewall of the second shielding layer or a possible remaining portion of the shielding spacer.

A method of making a semiconductor device is provided. The method includes forming a deep well (DWELL) and a well (WELL) in a first region of a substrate, the WELL adjacent a surface of the substrate so that an interface between the WELL and DWELL is exposed on the surface of the substrate. A channel for a DEMOS transistor is formed in the first region over the interface and includes a first channel formed in the WELL and a second channel formed in the DWELL. A gate layer is deposited and patterned to concurrently form in the first region a first gate for the DEMOS transistor and in a second region a second gate for an ESD device. Dopants are implanted in the first and second regions to concurrently form a drain extension of the DEMOS transistor, and an ESD diffusion region of the ESD device.

A complementary metal oxide semiconductor field-effect transistor (MOSFET) includes a substrate, a first MOSFET and a second MOSFET. The first MOSFET is disposed on the substrate within a first transistor region and the second MOSFET is disposed on the substrate within a second transistor region. The first MOSFET includes a first fin structure, two first lightly-doped regions, two first doped regions and a first gate structure. The first fin structure includes a first body portion and two first epitaxial portions, wherein each of the first epitaxial portions is disposed on each side of the first body portion. A first vertical interface is between the first body portion and each of the first epitaxial portions so that the first-lightly doped region is able to be uniformly distributed on an entire surface of each first vertical interface.

To enhance reliability and performance of a semiconductor device that has a fully-depleted SOI transistor, while a width of an offset spacer formed on side walls of a gate electrode is configured to be larger than or equal to a thickness of a semiconductor layer and smaller than or equal to a thickness of a sum total of a thickness of the semiconductor layer and a thickness of an insulation film, an impurity is ion-implanted into the semiconductor layer that is not covered by the gate electrode and the offset spacer. Thus, an extension layer formed by ion implantation of an impurity is kept from entering into a channel from a position lower than the end part of the gate electrode.