Abstract: According to one embodiment, a display device comprises a first area including a pixel and a second area different from the first area, wherein the pixel comprises a pixel electrode, an organic material layer including a light-emitting layer, a common electrode, a first insulating layer, a second insulating layer having a refractive index lower than that of the first insulating layer, and a third insulating layer, the second area is an area not overlapping the light-emitting layer in plan view, the second area is a transparent area, and the second area comprises the first insulating layer provided therein, the second area does not comprise the second insulating layer.

Abstract: An object is to provide a display device which operates stably with use of a transistor having stable electric characteristics. In manufacture of a display device using transistors in which an oxide semiconductor layer is used for a channel formation region, a gate electrode is further provided over at least a transistor which is applied to a driver circuit. In manufacture of a transistor in which an oxide semiconductor layer is used for a channel formation region, the oxide semiconductor layer is subjected to heat treatment so as to be dehydrated or dehydrogenated; thus, impurities such as moisture existing in an interface between the oxide semiconductor layer and the gate insulating layer provided below and in contact with the oxide semiconductor layer and an interface between the oxide semiconductor layer and a protective insulating layer provided on and in contact with the oxide semiconductor layer can be reduced.

Abstract: A diode having a simple structure and a simple manufacturing method of the diode are provided. A diode including: a semiconductor layer having a first region and a second region having a resistance lower than a resistance of the first region; a first insulating layer having a first aperture portion and a second aperture portion and covering the semiconductor layer other than the first aperture and the second aperture, the first aperture portion exposing the semiconductor layer in the first region, the second aperture portion exposing the semiconductor layer in the second region; a first conductive layer connected to the semiconductor layer in the first aperture portion and overlapping with the semiconductor layer in the first region via the first insulating layer in a planar view; and a second conductive layer connected to the semiconductor layer in the second aperture.

Abstract: A method for manufacturing semiconductor device according to an embodiment includes: forming an oxide semiconductor layer above a substrate; forming a gate insulating layer above the oxide semiconductor layer; forming a metal oxide layer containing aluminum as a main component above the gate insulating layer; performing a heat treatment in a state where the metal oxide layer is formed above the gate insulating layer; removing the metal oxide layer after the heat treatment; and forming a gate electrode above the gate insulating layer.

Abstract: A semiconductor device according to an embodiment includes: an oxide insulating layer; an oxide semiconductor layer; a gate electrode; a gate insulating layer; and a first insulating layer, wherein the semiconductor device is divided into a first to a third regions, a thickness of the gate insulating layer in the first region is 200 nm or more, the gate electrode contacts the first insulating layer in the first region, the oxide semiconductor layer contacts the first insulating layer in the second region, an amount of impurities contained in the oxide semiconductor layer in the second region is greater than an amount of impurities contained in the oxide semiconductor layer in the first region, and an amount of impurities contained in the oxide insulating layer in the third region is greater than an amount of impurities contained in the oxide insulating layer in the second region.

Abstract: It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided.

Abstract: A method for manufacturing a semiconductor device includes depositing a first metal oxide film with aluminum as a major component on a substrate, depositing an amorphous oxide semiconductor film on the first metal oxide film under an oxygen partial pressure of 3% to 5%, processing the oxide semiconductor film into a patterned oxide semiconductor layer, crystallizing the oxide semiconductor layer by performing a first heat treatment on the patterned oxide semiconductor layer, processing the first metal oxide film using the crystallized oxide semiconductor layer as a mask, depositing a gate insulating film on the oxide semiconductor layer, and forming a gate electrode on the gate insulating film, wherein a thickness of the oxide semiconductor film is more than 10 nm and 30 nm or less.

Abstract: A semiconductor device according to an embodiment of the present invention includes an oxide insulating layer, an oxide semiconductor layer, a gate insulating layer, a gate electrode, and a protective insulating layer. The gate insulating layer includes a first region overlapping the gate electrode and a second region not overlapping the gate electrode. The second region is in contact with the protective insulating layer. The oxide insulating layer includes a third region overlapping the gate electrode and a fourth region not overlapping the gate electrode and the oxide semiconductor layer. The fourth region is in contact with the gate insulating layer. The oxide semiconductor layer includes a channel region, a source region, and a drain region. Each of the source region, the drain region, and the second region contains an impurity. A hydrogen concentration of the second region is greater than a hydrogen concentration of the first region.

Abstract: A semiconductor device including: a first gate electrode; a first gate insulating layer on the first gate electrode; a first oxide semiconductor layer on the first insulating layer; source and drain electrodes connected to the first oxide semiconductor layer; a second gate insulating layer on the first oxide semiconductor layer; a second oxide semiconductor layer on the second gate insulating layer; a second gate electrode on the second oxide semiconductor layer, the second gate electrode being in contact with the second oxide semiconductor layer; a first insulating layer on the second gate electrode, the first insulating layer having a part of a first aperture overlapping with the second oxide semiconductor layer in a planar view; and a first connecting electrode electrically connecting the first gate electrode and the second gate electrode via the first aperture.

Abstract: A change in electrical characteristics of a semiconductor device including an interlayer insulating film over a transistor including an oxide semiconductor as a semiconductor film is suppressed. The structure includes a first insulating film which includes a void portion in a step region formed by a source electrode and a drain electrode over the semiconductor film and contains silicon oxide as a component, and a second insulating film containing silicon nitride, which is provided in contact with the first insulating film to cover the void portion in the first insulating film. The structure can prevent the void portion generated in the first insulating film from expanding outward.

Abstract: A display device including a pixel having a memory. The pixel includes at least a display element, a capacitor, an inverter, and a switch. The switch is controlled with a signal held in the capacitor and a signal output from the inverter so that voltage is supplied to the display element. The inverter and the switch can be constituted by transistors with the same polarity. A semiconductor layer included in the pixel may be formed using a light-transmitting material. Moreover, a gate electrode, a drain electrode, and a capacitor electrode may be formed using a light-transmitting conductive layer. The pixel is formed using a light-transmitting material in such a manner, whereby the display device can be a transmissive display device while including a pixel having a memory.

Abstract: A semiconductor device according to an embodiment includes: a substrate; a metal oxide layer arranged above the substrate and having aluminum as the main component of the metal oxide layer; an oxide semiconductor layer arranged above the metal oxide layer; a gate electrode facing the oxide semiconductor layer; and a gate insulating layer between the oxide semiconductor layer and the gate electrode, wherein a thickness of the metal oxide layer is 1 nm or more and 4 nm or less.

Abstract: To reduce defects in an oxide semiconductor film in a semiconductor device. To improve the electrical characteristics and the reliability of a semiconductor device including an oxide semiconductor film. In a semiconductor device including a transistor including a gate electrode formed over a substrate, a gate insulating film covering the gate electrode, a multilayer film overlapping with the gate electrode with the gate insulating film provided therebetween, and a pair of electrodes in contact with the multilayer film, a first oxide insulating film covering the transistor, and a second oxide insulating film formed over the first oxide insulating film, the multilayer film includes an oxide semiconductor film and an oxide film containing In or Ga, the first oxide insulating film is an oxide insulating film through which oxygen is permeated, and the second oxide insulating film is an oxide insulating film containing more oxygen than that in the stoichiometric composition.

Abstract: A display device includes a display panel including a display portion having a plurality of pixels; and a sensor element disposed on a rear side of the display portion. The display portion has a first region overlapping the sensor element and a second region other than the first region in a plan view. Each of the plurality of pixels has a semiconductor device including a channel portion and a conductive portion made of an oxide semiconductor having a polycrystalline structure. Each of the plurality of pixels in the first region is connected by a first signal line comprising the same layer as the conductive portion, and each of the plurality of pixels in the second region is connected by a second signal line comprising a metal layer connected to the conductive portion.

Abstract: A diode having a simple structure and a simple manufacturing method of the diode are provided. A diode including: a semiconductor layer having a first region and a second region having a resistance lower than a resistance of the first region; a first insulating layer having a first aperture portion and a second aperture portion and covering the semiconductor layer other than the first aperture and the second aperture, the first aperture portion exposing the semiconductor layer in the first region, the second aperture portion exposing the semiconductor layer in the second region; a first conductive layer connected to the semiconductor layer in the first aperture portion and overlapping with the semiconductor layer in the first region via the first insulating layer in a planar view; and a second conductive layer connected to the semiconductor layer in the second aperture.

Abstract: A semiconductor device includes a oxide semiconductor layer provided on an insulating surface and having a channel area, a source area and a drain area sandwiching the channel area, a gate electrode opposite the channel area, and a gate insulating layer provided between the oxide semiconductor layer and the gate electrode, wherein the gate electrode is an oxide conductive layer having the same composition as the oxide semiconductor layer, and the oxide conductive layer includes the same impurity element as the source area and the drain area.

Abstract: A semiconductor device includes an oxide semiconductor layer having a polycrystalline structure on an insulating surface, a gate electrode over the oxide semiconductor layer, and a gate insulating layer between the oxide semiconductor layer and the gate electrode. The oxide semiconductor layer includes a first region having a first crystal structure overlapping the gate electrode and a second region having a second crystal structure not overlapping the gate electrode. An electrical conductivity of the second region is larger than an electrical conductivity of the first region. The second crystal structure is identical to the first crystal structure.

Abstract: It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided.

Abstract: A highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics, and a manufacturing method thereof. In the manufacturing method of the semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region is an oxide semiconductor layer, heat treatment which reduces impurities such as moisture to improve the purity of the oxide semiconductor layer and oxidize the oxide semiconductor layer (heat treatment for dehydration or dehydrogenation) is performed. Not only impurities such as moisture in the oxide semiconductor layer but also those existing in a gate insulating layer are reduced, and impurities such as moisture existing in interfaces between the oxide semiconductor layer and films provided over and under and in contact with the oxide semiconductor layer are reduced.

Abstract: It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer having a channel formation region, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer and reduce impurities such as moisture. Moreover, the oxide semiconductor layer subjected to the heat treatment is slowly cooled under an oxygen atmosphere.