Structures for a field-effect transistor and methods of forming a structure for a field-effect transistor. A gate structure is formed over a channel region of a substrate. A first source/drain region is positioned in the substrate adjacent to a first sidewall of the gate structure, a second source/drain region is positioned in the substrate adjacent to a second sidewall of the gate structure, and an extension region is positioned in the substrate. The extension region includes first and second sections that each overlap with the first source/drain region. The first and second sections of the extension region are spaced apart along a longitudinal axis of the gate structure. A portion of the channel region is positioned along the longitudinal axis of the gate structure between the first and second sections of the extension region.

In one embodiment, method of making a high voltage PMOS (HVPMOS) transistor, can include: (i) providing a P-type substrate; (ii) implanting N-type dopants in the P-type substrate; (iii) dispersing the implanted N-type dopants in the P-type substrate to form a deep N-type well; (iv) implanting P-type dopants of different doping concentrations in the deep N-type well along a horizontal direction of the deep N-type well; and (v) dispersing the implanted P-type dopants to form a composite drift region having an increasing doping concentration and an increasing junction depth along the horizontal direction of the deep N-type well.

In the semiconductor device, a high-concentration diffusion layer and a low-concentration diffusion layer are disposed around a drain diffusion layer of an ESD protection element. The high-concentration diffusion layer is separated from a gate electrode, and a medium concentration LDD diffusion layer is disposed in a separation gap. Variations in characteristics are suppressed by reducing thermal treatment on the high-concentration diffusion layer and a medium concentration diffusion layer.

The present disclosure provides a method of manufacturing a semiconductor device includes forming a first gate insulating film on a substrate for a first device, forming a first gate electrode on the first gate insulating film; forming a mask pattern on the first gate electrode to expose opposing end portions of the first gate electrode, wherein a length of the mask pattern is smaller than a length of the first gate electrode; performing ion implantation through the exposed opposing end portions of the first gate electrode using the mask pattern to simultaneously form first and second drift regions in the substrate; forming spacers on sidewalls of the first gate electrode, respectively; and forming a first source region and a first drain region in the first and second drift regions, respectively.

The semiconductor device includes a well region disposed in a surface layer of a semiconductor substrate, a source region and a drain region arranged separated from each other in a surface layer of the well region, a channel region disposed between the source region and the drain region, and a gate electrode disposed on the channel region via a gate insulating film containing fluorine, in which concentration of fluorine existing in a first interface, the first interface being an interface of the gate insulating film with the gate electrode, and concentration of fluorine existing in a second interface, the second interface being an interface of the gate insulating film with the channel region, are higher than concentration of fluorine existing in a middle region in the depth direction of the gate insulating film, and fluorine concentration in the first interface is higher than fluorine concentration in the second interface.

A device includes a first transistor, a second transistor, and a contact. The first transistor includes a first source/drain, a second source/drain, and a first gate between the first and second source/drains. The second transistor includes a third source/drain, a fourth source/drain, and a second gate between the third and fourth source/drains. The contact covers the first source/drain of the first transistor and the third source/drain of the third transistor. The first contact is electrically connected to the first source/drain of the first transistor and electrically isolated from the third source/drain of the third transistor.

A semiconductor transistor includes a first lightly doped-drain region disposed in a drain region of a semiconductor substrate; a first heavily doped region disposed in the first lightly doped-drain region; and a gate located on the channel region; a gate oxide layer between the gate and the channel region; and a first insulating feature disposed in the first lightly doped-drain region between the channel region and the first heavily doped region. The gate overlaps with the first insulating feature. The thickness of the first insulating feature is greater than that of the gate oxide layer.

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 display driver semiconductor device includes a high voltage well region formed on a substrate, a first semiconductor device, a second semiconductor device, and a third semiconductor device. The first semiconductor device is formed on the high voltage well region and includes a first gate insulating layer formed using a deposition process. The second semiconductor device is formed adjacent to the first semiconductor device and includes a second gate insulating layer formed using a thermal process. The third semiconductor device is formed adjacent to the second semiconductor device and includes a third gate insulating layer.

A semiconductor structure includes a source region, a drain region, a channel region located between the source region and the drain region, a gate stack structure including a gate dielectric and a gate electrode that overlies the gate dielectric, such that a first gap region is present between an area of the source region and an area of the gate electrode in a plan view and a second gap region is present between an area of the drain region and the area of the gate electrode in the plan view, a contact-level dielectric layer overlying the source region and the drain region and laterally surrounding the gate stack structure, and at least one assist-field metallic plate located vertically above a top surface of the gate electrode and having an areal overlap with at least one of the first gap region and the second gap region in the plan view.