A memory cell includes a transistor and a capacitor. The transistor includes a gate electrode, a gate dielectric disposed over the gate electrode, a channel feature disposed over the gate dielectric and overlapping the gate electrode, a source electrode disposed over the channel feature and electrically connected to the capacitor, and two drain electrodes disposed over the channel feature. The drain electrodes are disposed at opposite sides of the source electrode. The channel feature has a first channel portion extending between and interconnecting one drain electrode and the source electrode, and a second channel portion extending between and interconnecting the other drain electrode and the source electrode. The gate electrode overlaps both of the first channel portion and the second channel portion of the channel feature.

A memory cell includes a transistor and a capacitor. The transistor includes a gate electrode, a gate dielectric disposed over the gate electrode, a channel feature disposed over the gate dielectric and overlapping the gate electrode, a source electrode disposed over the channel feature and electrically connected to the capacitor, and two drain electrodes disposed over the channel feature. The drain electrodes are disposed at opposite sides of the source electrode. The channel feature has a first channel portion extending between and interconnecting one drain electrode and the source electrode, and a second channel portion extending between and interconnecting the other drain electrode and the source electrode. The gate electrode overlaps both of the first channel portion and the second channel portion of the channel feature.

A Field Effect Transistor (FET) may include a semiconductor substrate having a first conductivity type, a semiconductor layer of the first conductivity type formed over the substrate, and a pair of doped bodies of a second conductivity type opposite the first conductivity type formed in the semiconductor layer. A trench filled with a trench dielectric is formed within a region between the doped bodies. The FET may be a Vertical Metal-Oxide-Semiconductor FET (VMOSFET) including a gate dielectric disposed over the region between the doped bodies and the trench, and a gate electrode disposed over the gate dielectric, wherein the trench operates to prevent breakdown of the gate dielectric, or the FET may be a Junction FET. The FET may be designed to operate at radio frequencies or under heavy-ion bombardment. The semiconductor substrate and the semiconductor layer may comprise a wide band-gap semiconductor such as silicon carbide.

A semiconductor device includes a substrate, a 2-D material layer, source/drain contacts, and a gate electrode. The 2-D material layer is over the substrate, the 2-D material layer includes source/drain regions and a channel region between the source/drain regions, in which the 2-D material layer is made of a transition metal dichalcogenide (TMD). The source/drain contacts are in contact with source/drain regions of the 2-D material layer, in which a binding energy of transition metal atoms at the channel region of the 2-D material layer is different from a binding energy of the transition metal atoms at the source/drain regions of the 2-D material layer. The gate electrode is over the substrate.

A semiconductor device includes a substrate, a 2-D material layer, source/drain contacts, and a gate electrode. The 2-D material layer is over the substrate, the 2-D material layer includes source/drain regions and a channel region between the source/drain regions, in which the 2-D material layer is made of a transition metal dichalcogenide (TMD). The source/drain contacts are in contact with source/drain regions of the 2-D material layer, in which a binding energy of transition metal atoms at the channel region of the 2-D material layer is different from a binding energy of the transition metal atoms at the source/drain regions of the 2-D material layer. The gate electrode is over the substrate.

As a display device has a higher definition, the number of pixels, gate lines, and signal lines are increased. When the number of the gate lines and the signal lines are increased, a problem of high manufacturing cost, because it is difficult to mount an IC chip including a driver circuit for driving of the gate and signal lines by bonding or the like. A pixel portion and a driver circuit for driving the pixel portion are provided over the same substrate, and at least part of the driver circuit includes a thin film transistor using an oxide semiconductor interposed between gate electrodes provided above and below the oxide semiconductor. Therefore, when the pixel portion and the driver portion are provided over the same substrate, manufacturing cost can be reduced.

As a display device has a higher definition, the number of pixels, gate lines, and signal lines are increased. When the number of the gate lines and the signal lines are increased, a problem of high manufacturing cost, because it is difficult to mount an IC chip including a driver circuit for driving of the gate and signal lines by bonding or the like. A pixel portion and a driver circuit for driving the pixel portion are provided over the same substrate, and at least part of the driver circuit includes a thin film transistor using an oxide semiconductor interposed between gate electrodes provided above and below the oxide semiconductor. Therefore, when the pixel portion and the driver portion are provided over the same substrate, manufacturing cost can be reduced.

Techniques for forming a metastable phosphorous P-doped silicon Si source drain contacts are provided. In one aspect, a method for forming n-type source and drain contacts includes the steps of: forming a transistor on a substrate; depositing a dielectric over the transistor; forming contact trenches in the dielectric that extend down to source and drain regions of the transistor; forming an epitaxial material in the contact trenches on the source and drain regions; implanting P into the epitaxial material to form an amorphous P-doped layer; and annealing the amorphous P-doped layer under conditions sufficient to form a crystalline P-doped layer having a homogenous phosphorous concentration that is greater than about 1.5×10.sup.21 atoms per cubic centimeter (at./cm.sup.3). Transistor devices are also provided utilizing the present P-doped Si source and drain contacts.

Techniques for forming a metastable phosphorous P-doped silicon Si source drain contacts are provided. In one aspect, a method for forming n-type source and drain contacts includes the steps of: forming a transistor on a substrate; depositing a dielectric over the transistor; forming contact trenches in the dielectric that extend down to source and drain regions of the transistor; forming an epitaxial material in the contact trenches on the source and drain regions; implanting P into the epitaxial material to form an amorphous P-doped layer; and annealing the amorphous P-doped layer under conditions sufficient to form a crystalline P-doped layer having a homogenous phosphorous concentration that is greater than about 1.5×10.sup.21 atoms per cubic centimeter (at./cm.sup.3). Transistor devices are also provided utilizing the present P-doped Si source and drain contacts.

A multilayer structure of the present invention is a multilayer structure including a base substrate and a semiconductor film that is made of α-Ga.sub.2O.sub.3 or an α-Ga.sub.2O.sub.3-based solid solution and has a corundum crystal structure, the semiconductor film being disposed on the base substrate. The semiconductor film has an average film thickness of greater than or equal to 10 μm. The semiconductor film is convexly or concavely warped. An amount of warpage of the semiconductor film is 20 μm or greater and 64 μm or less.