A dual-well metal oxide semiconductor (MOS) device includes: a semiconductor substrate, an active layer, a first conductive type well, a first conductive type body region, a second conductive type well, a gate, a second conductive type lightly doped diffusion (LDD) region, a second conductive type source, a second conductive type connection region, and a second conductive type drain. The second conductive type well is connected to the first conductive type well in a lateral direction, and a PN junction is formed therebetween right below the gate. The second conductive type connection region is formed right below a spacer of the gate, and is connected to the second conductive type source in a lateral direction to avoid OFF-channel. The second conductive type connection region is formed by a tilt-angle ion implantation process step through the spacer.

A metal-oxide-semiconductor transistor includes a substrate, a gate insulating layer disposed on the surface of the substrate layer, a metal gate disposed on the gate insulating layer and having at least one plug hole, at least one dielectric plug disposed in the plug hole, and two diffusion regions disposed at two sides of the metal gate in the substrate. The metal gate is configured to operate under an operation voltage greater than 5 v.

A transistor having a narrow bandgap semiconductor source/drain region is described. The transistor includes a gate electrode formed on a gate dielectric layer formed on a silicon layer. A pair of source/drain regions are formed on opposite sides of the gate electrode wherein said pair of source/drain regions comprise a narrow bandgap semiconductor film formed in the silicon layer on opposite sides of the gate electrode.

In an LCD driver, in a high voltage resistant MISFET, end portions of a gate electrode run onto electric field relaxing insulation regions. Wires to become source wires or drain wires are formed on an interlayer insulation film of the first layer over the high voltage resistant MISFET. At this moment, when a distance from an interface between a semiconductor substrate and a gate insulation film to an upper portion of the gate electrode is defined as a, and a distance from the upper portion of the gate electrode to an upper portion of the interlayer insulation film on which the wires are formed is defined as b, a relation of a>b is established. In such a high voltage resistant MISFET structured in this manner, the wires are arranged so as not to be overlapped planarly with the gate electrode of the high voltage resistant MISFET.

Various embodiments of the present disclosure provide a method for forming a recessed gate electrode that has high thickness uniformity. A gate dielectric layer is deposited lining a recess, and a multilayer film is deposited lining the recess over the gate dielectric layer. The multilayer film comprises a gate electrode layer, a first sacrificial layer over the gate dielectric layer, and a second sacrificial layer over the first sacrificial dielectric layer. A planarization is performed into the second sacrificial layer and stops on the first sacrificial layer. A first etch is performed into the first and second sacrificial layers to remove the first sacrificial layer at sides of the recess. A second etch is performed into the gate electrode layer using the first sacrificial layer as a mask to form the recessed gate electrode. A third etch is performed to remove the first sacrificial layer after the second etch.

A semiconductor device includes a substrate; a first well region disposed in the substrate and with a first electrical property; a second well region with the first electrical property disposed in the substrate and separated from the first well region; a first gate dielectric layer disposed on the first well region and having a first thickness; a second gate dielectric layer, disposed on the second well region, separated from the first gate dielectric layer and having a second thickness less than the first thickness; a first gate electrode disposed on the first gate dielectric layer; a second gate electrode disposed on the second gate dielectric layer and separated from the first gate electrode; a drain region disposed in the first well region; and a source region disposed in the second well region.

A high-voltage MOS transistor includes a semiconductor substrate, a plurality of active regions, a gate insulation layer, and a gate electrode. The active regions are defined by an isolation structure, wherein the active regions include a channel portion and two side portions, the channel portion has first opposite sides and second opposite sides, and the two side portions are at the first opposite sides of the channel portion. The gate insulation layer is disposed on a surface of the channel portion. The gate electrode is disposed on the gate insulation layer and extending on a portion of the isolation structure, wherein the gate electrode includes a pair of channel edge openings and a plurality of slits. The pair of channel edge openings are at the second opposite sides of the channel portion to expose a portion of the gate insulation layer, and the slits are disposed over the channel portion.

An integrated circuit and method includes a DEMOS transistor with improved CHC reliability that has a lower resistance surface channel under the DEMOS gate that transitions to a lower resistance subsurface channel under the drain edge of the DEMOS transistor gate.

A method for fabricating isolation device is disclosed. The method includes the steps of: providing a substrate; forming a shallow trench isolation (STI) in the substrate, the STI includes a first STI and a second STI, and the first STI surrounds a first device region and the second STI surrounds a second device region; forming a first doped region between and contact the first STI and the second STI; and forming a first gate structure on the first doped region, the first STI and the second STI.

An advanced transistor with punch through suppression includes a gate with length Lg, a well doped to have a first concentration of a dopant, and a screening region positioned under the gate and having a second concentration of dopant. The second concentration of dopant may be greater than 510.sup.18 dopant atoms per cm.sup.3. At least one punch through suppression region is disposed under the gate between the screening region and the well. The punch through suppression region has a third concentration of a dopant intermediate between the first concentration and the second concentration of dopant. A bias voltage may be applied to the well region to adjust a threshold voltage of the transistor.