A thin-film transistor (TFT) switch includes a gate, a drain, a source, a semiconductor layer, and a fourth electrode. The drain is connected to a first signal. The gate is connected to a control signal to control the switch on or off. The source outputs the first signal when the switch turns on. The fourth electrode and the gate are respectively located at two sides of the semiconductor layer. The fourth electrode is conductive and is selectively coupled to different voltage levels, thereby reducing leakage current in a channel to improve switch characteristic when the switch turns off.

An object is to reduce to reduce variation in threshold voltage to stabilize electric characteristics of thin film transistors each using an oxide semiconductor layer. An object is to reduce an off current. The thin film transistor using an oxide semiconductor layer is formed by stacking an oxide semiconductor layer containing insulating oxide over the oxide semiconductor layer so that the oxide semiconductor layer and source and drain electrode layers are in contact with each other with the oxide semiconductor layer containing insulating oxide interposed therebetween; whereby, variation in threshold voltage of the thin film transistors can be reduced and thus the electric characteristics can be stabilized. Further, an off current can be reduced.

A semiconductor device includes a fin extending from a substrate. The fin has a source/drain region and a channel region. The channel region includes a first semiconductor layer and a second semiconductor layer disposed over the first semiconductor layer and vertically separated from the first semiconductor layer by a spacing area. A high-k dielectric layer at least partially wraps around the first semiconductor layer and the second semiconductor layer. A metal layer is formed along opposing sidewalls of the high-k dielectric layer. The metal layer includes a first material. The spacing area is free of the first material.

A semiconductor device may include a substrate, a first nanowire, a gate electrode, a first gate spacer, a second gate spacer, a source/drain and a spacer connector. The first nanowire may be extended in a first direction and spaced apart from the substrate. The gate electrode may surround a periphery of the first nanowire, and extend in a second direction intersecting the first direction, and include first and second sidewalls opposite to each other. The first gate spacer may be formed on the first sidewall of the gate electrode. The first nanowire may pass through the first gate spacer. The second gate spacer may be formed on the second sidewall of the gate electrode. The first nanowire may pass through the second gate spacer. The source/drain may be disposed on at least one side of the gate electrode and connected with the first nanowire. The spacer connector may be disposed between the first nanowire and the substrate. The spacer connector may connect the first gate spacer and the second gate spacer to each other.

This semiconductor device includes a substrate and a thin film transistor supported on the substrate. The thin film transistor includes a gate electrode, a semiconductor layer, a gate-insulating layer provided between the gate electrode and the semiconductor layer, and a source electrode and a drain electrode respectively making contact with the semiconductor layer. The source electrode and the drain electrode respectively include a main layer containing aluminum or copper, a lower layer having a first layer containing refractory metal and positioned at a substrate side of the main layer, and an upper layer having a second layer containing refractory metal. The upper layer is provided so as to cover an upper surface of the main layer and at least the section of the side face of the main layer that overlaps the semiconductor layer.

There are provided a method of manufacturing a thin film transistor and a display including a thin film transistor. The method of manufacturing a thin film transistor includes forming a barrier layer cm a substrate, forming a semiconductor layer on the barrier layer, forming a gate insulating layer on the semiconductor layer, forming a gate electrode on the gate insulating layer, forming an offset region on an external surface of the gate electrode through a plasma heat treatment process or an annealing process, etching, an offset region of the gate electrode, etching a gate insulating layer except for a portion of the gate insulating layer, positioned below the gate electrode, forming an interlayer insulating layer on the gate electrode, and etching, the interlayer insulating layer to form a source electrode and a drain electrode.

A thin film transistor is provided as follows. A first gate electrode and a second gate electrode are stacked on each other. A semiconductor layer is interposed between the first and second gate electrodes. A source electrode and a drain electrode are interposed between the semiconductor layer and the second gate electrode. A connection electrode connects electrically the first gate electrode and the second gate electrode. A first insulating film is interposed between the first gate electrode and the semiconductor layer. A second insulating film includes a first part interposed between the semiconductor layer and the second gate electrode and a second part interposed between the second gate electrode and the drain electrode. A third insulating film includes a first part interposed between the connection electrode and the second gate electrode.

A method for forming active regions of a semiconductor device comprising forming a nanosheet stack on a substrate, forming the nanosheet stack comprising forming a sacrificial nanosheet layer on the substrate, and forming a nanosheet layer on the sacrificial nanosheet layer, forming an etch stop layer on the nanosheet stack, forming a mandrel layer on the etch stop layer, removing portions of the mandrel layer to form a mandrel on the etch stop layer, forming sidewalls adjacent to sidewalls of the mandrel, depositing a fill layer on exposed portions of the etch stop layer, removing the sidewalls and removing exposed portions of the etch stop layer and the nanosheet stack to expose portions of the substrate.

An SOI wafer contains a compressively stressed buried insulator structure. In one example, the stressed buried insulator (BOX) may be formed on a host wafer by forming silicon oxide, silicon nitride and silicon oxide layers so that the silicon nitride layer is compressively stressed. Wafer bonding provides the surface silicon layer over the stressed insulator layer. Preferred implementations of the invention form MOS transistors by etching isolation trenches into a preferred SOI substrate having a stressed BOX structure to define transistor active areas on the surface of the SOI substrate. Most preferably the trenches are formed deep enough to penetrate through the stressed BOX structure and some distance into the underlying silicon portion of the substrate. The overlying silicon active regions will have tensile stress induced due to elastic edge relaxation.

Provided is a method of forming a nanowire-based device. The method includes forming a first mask layer over a substrate; forming a first opening in the first mask layer; growing a first nanowire that protrudes through the first opening in the first mask layer, wherein the first nanowire has a first diameter; removing the first mask layer; oxidizing a sidewall of the first nanowire; etching the oxidized sidewall of the first nanowire; forming a second mask layer overlaying the substrate; removing the first nanowire thereby forming a second opening in the second mask layer; and growing a second nanowire that protrudes through the second opening in the second mask layer, wherein the second nanowire has a second diameter and the second diameter is different than the first diameter.