A semiconductor substrate includes a base portion, an auxiliary layer and a surface layer. The auxiliary layer is formed on the base portion. The surface layer is formed on the auxiliary layer. The surface layer is in contact with a first main surface of the semiconductor substrate. The auxiliary layer has a different electrochemical dissolution efficiency than the base portion and the surface layer. At least a portion of the auxiliary layer and at least a portion of the surface layer are converted into a porous structure. Subsequently, an epitaxial layer is formed on the first main surface.

A method for fabricating semiconductor device is disclosed. The method includes the steps of: providing a source layer; removing part of the source layer to form a first opening; forming a first channel layer in the first opening; forming a gate layer around the first channel layer and on the source layer; forming a drain layer on the gate layer and the first channel layer; removing part of the drain layer to form a second opening; and forming a second channel layer in the second opening.

A method for fabricating semiconductor device is disclosed. The method includes the steps of: providing a source layer; removing part of the source layer to form a first opening; forming a first channel layer in the first opening; forming a gate layer around the first channel layer and on the source layer; forming a drain layer on the gate layer and the first channel layer; removing part of the drain layer to form a second opening; and forming a second channel layer in the second opening.

To provide a method by which a semiconductor device including a thin film transistor with excellent electric characteristics and high reliability is manufactured with a small number of steps. After a channel protective layer is formed over an oxide semiconductor film containing In, Ga, and Zn, a film having n-type conductivity and a conductive film are formed, and a resist mask is formed over the conductive film. The conductive film, the film having n-type conductivity, and the oxide semiconductor film containing In, Ga, and Zn are etched using the channel protective layer and gate insulating films as etching stoppers with the resist mask, so that source and drain electrode layers, a buffer layer, and a semiconductor layer are formed.

To provide a method by which a semiconductor device including a thin film transistor with excellent electric characteristics and high reliability is manufactured with a small number of steps. After a channel protective layer is formed over an oxide semiconductor film containing In, Ga, and Zn, a film having n-type conductivity and a conductive film are formed, and a resist mask is formed over the conductive film. The conductive film, the film having n-type conductivity, and the oxide semiconductor film containing In, Ga, and Zn are etched using the channel protective layer and gate insulating films as etching stoppers with the resist mask, so that source and drain electrode layers, a buffer layer, and a semiconductor layer are formed.

A display device may include a pixel circuit layer. A first electrode and a second electrode may be on the pixel circuit layer and spaced from each other. A first insulating layer may be on the pixel circuit layer, the first electrode, and the second electrode. A conductive pattern may be on the first insulating layer and electrically insulated from the first electrode and the second electrode. The bank may be on the conductive pattern. Light emitting elements may be located on the first insulating layer between the first electrode and the second electrode, and electrically coupled to the first electrode and the second electrode.

According to one embodiment, a thin-film transistor and a method of manufacturing the thin-film transistor provided herein achieve enhanced reliability by preventing a disconnection in a gate insulating film at a position corresponding to an end surface of an oxide semiconductor layer. The oxide semiconductor layer includes a channel region, a source region, and a drain region. The channel region is placed between the source region and the drain region. The gate insulating film covers the oxide semiconductor layer in a range from at least a part of an upper surface to an end surface continuous with the upper surface of the oxide semiconductor layer. The oxide semiconductor layer is formed so as to have an oxygen concentration that becomes lower from a top side to a bottom side and the end surface is inclined so as to diverge from the top side to the bottom side.

According to one embodiment, a thin-film transistor and a method of manufacturing the thin-film transistor provided herein achieve enhanced reliability by preventing a disconnection in a gate insulating film at a position corresponding to an end surface of an oxide semiconductor layer. The oxide semiconductor layer includes a channel region, a source region, and a drain region. The channel region is placed between the source region and the drain region. The gate insulating film covers the oxide semiconductor layer in a range from at least a part of an upper surface to an end surface continuous with the upper surface of the oxide semiconductor layer. The oxide semiconductor layer is formed so as to have an oxygen concentration that becomes lower from a top side to a bottom side and the end surface is inclined so as to diverge from the top side to the bottom side.

A chemical sensor is described having a substrate comprising a plurality of nanoribbons of an active layered nanomaterial, and a substance detection component for measuring a change in electrical or physical properties of at least a portion of the plurality of nanoribbons when in contact with a substance.

A chemical sensor is described having a substrate comprising a plurality of nanoribbons of an active layered nanomaterial, and a substance detection component for measuring a change in electrical or physical properties of at least a portion of the plurality of nanoribbons when in contact with a substance.