Abstract: An object is to establish a processing technique in manufacture of a semiconductor device in which an oxide semiconductor is used. A gate electrode is formed over a substrate, a gate insulating layer is formed over the gate electrode, an oxide semiconductor layer is formed over the gate insulating layer, the oxide semiconductor layer is processed by wet etching to form an island-shaped oxide semiconductor layer, a conductive layer is formed to cover the island-shaped oxide semiconductor layer, the conductive layer is processed by dry etching to form a source electrode, and a drain electrode and part of the island-shaped oxide semiconductor layer is removed by dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.

Abstract: In a method for manufacturing a semiconductor device including a channel-etched inverted-staggered thin film transistor, an oxide semiconductor film and a conductive film are etched using a mask layer formed with the use of a multi-tone mask which is a light-exposure mask through which light is transmitted so as to have a plurality of intensities. The etching step is performed by dry etching in which an etching gas is used.

Abstract: An object is to manufacture a semiconductor device including an oxide semiconductor at low cost with high productivity in such a manner that a photolithography process is simplified by reducing the number of light-exposure masks. In a method for manufacturing a semiconductor device including a channel-etched inverted-staggered thin film transistor, an oxide semiconductor film and a conductive film are etched using a mask layer formed with the use of a multi-tone mask which is a light-exposure mask through which light is transmitted so as to have a plurality of intensities. In etching steps, a first etching step is performed by wet etching in which an etchant is used, and a second etching step is performed by dry etching in which an etching gas is used.

Abstract: An object is to manufacture a semiconductor device including an oxide semiconductor at low cost with high productivity in such a manner that a photolithography process is simplified by reducing the number of light-exposure masks. In a method for manufacturing a semiconductor device including a channel-etched inverted-staggered thin film transistor, an oxide semiconductor film and a conductive film are etched using a mask layer formed with the use of a multi-tone mask which is a light-exposure mask through which light is transmitted so as to have a plurality of intensities. In etching steps, a first etching step is performed by dry etching in which an etching gas is used, and a second etching step is performed by wet etching in which an etchant is used.

Abstract: An object is to establish a processing technique in manufacture of a semiconductor device in which an oxide semiconductor is used. A gate electrode is formed over a substrate, a gate insulating layer is formed over the gate electrode, an oxide semiconductor layer is formed over the gate insulating layer, the oxide semiconductor layer is processed by wet etching to form an island-shaped oxide semiconductor layer, a conductive layer is formed to cover the island-shaped oxide semiconductor layer, the conductive layer is processed by dry etching to form a source electrode, and a drain electrode and part of the island-shaped oxide semiconductor layer is removed by dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.

Abstract: A step of forming an insulating film over a semiconductor substrate and forming an embrittled region in the semiconductor substrate by irradiating the semiconductor substrate with accelerated ions through the insulating film; a step of disposing a surface of the semiconductor substrate and a surface of a base substrate opposite to each other and bonding the surface of the insulating film to the surface of the base substrate; a step of forming a semiconductor layer over the base substrate with the insulating film interposed therebetween by causing separation along the embrittled region by performing heat treatment after the surface of the insulating film and the surface of the base substrate are bonded to each other; a step of performing etching treatment on the semiconductor layer; a step of irradiating the semiconductor layer subjected to the etching treatment with a laser beam; and a step of irradiating the semiconductor layer irradiated with the laser beam with plasma.

Abstract: It is an object of the preset invention to increase adhesiveness of a semiconductor layer and a base substrate and to reduce defective bonding. An oxide film is formed on a semiconductor substrate and the semiconductor substrate is irradiated with accelerated ions through the oxide film, whereby an embrittled region is formed at a predetermined depth from a surface of the semiconductor substrate. Plasma treatment is performed on the oxide film on the semiconductor substrate and the base substrate by applying a bias voltage, the surface of the semiconductor substrate and a surface of the base substrate are disposed opposite to each other, a surface of the oxide film is bonded to the surface of the base substrate, heat treatment is performed after the surface of the oxide film is bonded to the surface of the base substrate, and separation is caused along the embrittled region, whereby a semiconductor layer is formed over the base substrate with the oxide film interposed therebetween.

Abstract: Forming an insulating film on a surface of the single crystal semiconductor substrate, forming a fragile region in the single crystal semiconductor substrate by irradiating the single crystal semiconductor substrate with an ion beam through the insulating film, forming a bonding layer over the insulating film, bonding a supporting substrate to the single crystal semiconductor substrate by interposing the bonding layer between the supporting substrate and the single crystal semiconductor substrate, dividing the single crystal semiconductor substrate at the fragile region to separate the single crystal semiconductor substrate into a single crystal semiconductor layer attached to the supporting substrate, performing first dry etching treatment on a part of the fragile region remaining on the single crystal semiconductor layer, performing second dry etching treatment on a surface of the single crystal semiconductor layer subjected to the first etching treatment, and irradiating the single crystal semiconductor la