A memory cell includes a transistor over a semiconductor substrate. The transistor includes a ferroelectric layer arranged along a sidewall of a word line. The ferroelectric layer includes a species with valence of 5, valence of 7, or a combination thereof. An oxide semiconductor layer is electrically coupled to a source line and a bit line. The ferroelectric layer is disposed between the oxide semiconductor layer and the word line.

A memory cell includes a transistor over a semiconductor substrate. The transistor includes a ferroelectric layer arranged along a sidewall of a word line. The ferroelectric layer includes a species with valence of 5, valence of 7, or a combination thereof. An oxide semiconductor layer is electrically coupled to a source line and a bit line. The ferroelectric layer is disposed between the oxide semiconductor layer and the word line.

A method of forming an optical thin film, comprises providing an assembly comprising a layer of semiconductor material deposited on a substrate, the semiconductor material comprising a compound of at least one metal and a group VI element; depositing a masking layer onto the layer of semiconductor material, the masking layer being patterned to expose one or more regions of the layer of semiconductor material; applying to the assembly a plasma of the group VI element in order to cause indiffusion of the group VI element into the semiconductor material in the exposed regions while the masking layer blocks indiffusion in unexposed regions, the indiffusion causing a reduction in carrier density in the semiconductor material; and removing the masking layer; thereby forming, from the layer of semiconductor material, an optical thin film having a variation in carrier density and corresponding variation in optical properties matching the patterning of the masking layer in a plane parallel to the substrate.

A semiconductor device includes a substrate, a semiconductor structure, a gate dielectric layer, a first gate, a source and a drain. The semiconductor structure is disposed above the substrate. The semiconductor structure includes a first thick portion, a second thick portion, and a thin portion between the first thick portion and the second thick portion. The gate dielectric layer is disposed on the semiconductor structure. The first gate is disposed on the gate dielectric layer. The first gate overlaps a portion of the first thick portion and a portion of the thin portion. The first gate does not overlap another portion of the thin portion and the second thick portion. The source is electrically connected to the first thick portion. The drain is electrically connected to the second thick portion.

A semiconductor device includes a substrate, a semiconductor structure, a gate dielectric layer, a first gate, a source and a drain. The semiconductor structure is disposed above the substrate. The semiconductor structure includes a first thick portion, a second thick portion, and a thin portion between the first thick portion and the second thick portion. The gate dielectric layer is disposed on the semiconductor structure. The first gate is disposed on the gate dielectric layer. The first gate overlaps a portion of the first thick portion and a portion of the thin portion. The first gate does not overlap another portion of the thin portion and the second thick portion. The source is electrically connected to the first thick portion. The drain is electrically connected to the second thick portion.

One object of one embodiment of the present invention is to provide a highly reliable semiconductor device including an oxide semiconductor, which has stable electrical characteristics. In a method for manufacturing a semiconductor device, a first insulating film is formed; source and drain electrodes and an oxide semiconductor film electrically connected to the source and drain electrodes are formed over the first insulating film; heat treatment is performed on the oxide semiconductor film so that a hydrogen atom in the oxide semiconductor film is removed; oxygen doping treatment is performed on the oxide semiconductor film, so that an oxygen atom is supplied into the oxide semiconductor film; a second insulating film is formed over the oxide semiconductor film; and a gate electrode is formed over the second insulating film so as to overlap with the oxide semiconductor film.

One object of one embodiment of the present invention is to provide a highly reliable semiconductor device including an oxide semiconductor, which has stable electrical characteristics. In a method for manufacturing a semiconductor device, a first insulating film is formed; source and drain electrodes and an oxide semiconductor film electrically connected to the source and drain electrodes are formed over the first insulating film; heat treatment is performed on the oxide semiconductor film so that a hydrogen atom in the oxide semiconductor film is removed; oxygen doping treatment is performed on the oxide semiconductor film, so that an oxygen atom is supplied into the oxide semiconductor film; a second insulating film is formed over the oxide semiconductor film; and a gate electrode is formed over the second insulating film so as to overlap with the oxide semiconductor film.

A semiconductor device and a manufacturing method thereof are provided. The semiconductor device includes a gate layer, a low-doping semiconductor layer, a crystalline ferroelectric layer and source and drain terminals. The crystalline ferroelectric layer is disposed between the gate layer and the low-doping semiconductor layer. The source terminal and the drain terminal are disposed on the low-doping semiconductor layer.

A semiconductor device and a manufacturing method thereof are provided. The semiconductor device includes a gate layer, a low-doping semiconductor layer, a crystalline ferroelectric layer and source and drain terminals. The crystalline ferroelectric layer is disposed between the gate layer and the low-doping semiconductor layer. The source terminal and the drain terminal are disposed on the low-doping semiconductor layer.

A memory cell includes a transistor over a semiconductor substrate. The transistor includes a ferroelectric layer arranged along a sidewall of a word line. The ferroelectric layer includes a species with valence of 5, valence of 7, or a combination thereof. An oxide semiconductor layer is electrically coupled to a source line and a bit line. The ferroelectric layer is disposed between the oxide semiconductor layer and the word line.