Abstract: In the transistor including an oxide semiconductor film, a gate insulating film of the transistor including an oxide semiconductor film has a stacked-layer structure of the hydrogen capture film and the hydrogen permeable film. At this time, the hydrogen permeable film is formed on a side which is in contact with the oxide semiconductor film, and the hydrogen capture film is formed on a side which is in contact with a gate electrode. After that, hydrogen released from the oxide semiconductor film is transferred to the hydrogen capture film through the hydrogen permeable film by the heat treatment.

Abstract: In a manufacturing process of a transistor including an oxide semiconductor film, oxygen doping treatment is performed on the oxide semiconductor film, and then heat treatment is performed on the oxide semiconductor film and an aluminum oxide film provided over the oxide semiconductor film. Consequently, an oxide semiconductor film which includes a region containing more oxygen than a stoichiometric composition is formed. The transistor formed using the oxide semiconductor film can have high reliability because the amount of change in the threshold voltage of the transistor by a bias-temperature stress test (BT test) is reduced.

Abstract: In a process of manufacturing a transistor including an oxide semiconductor layer, an amorphous oxide semiconductor layer which includes a region containing excess oxygen as compared to a stoichiometric composition ratio of an oxide semiconductor in a crystalline state is formed over a silicon oxide film, an aluminum oxide film is formed over the amorphous oxide semiconductor layer, and then heat treatment is performed so that at least part of the amorphous oxide semiconductor layer is crystallized and an oxide semiconductor layer which includes a crystal having a c-axis substantially perpendicular to a surface of the oxide semiconductor layer is formed.

Abstract: A highly reliable semiconductor device is manufactured by giving stable electric characteristics to a transistor in which an oxide semiconductor film is used for a channel. An oxide semiconductor film which can have a first crystal structure by heat treatment and an oxide semiconductor film which can have a second crystal structure by heat treatment are formed so as to be stacked, and then heat treatment is performed; accordingly, crystal growth occurs with the use of an oxide semiconductor film having the second crystal structure as a seed, so that an oxide semiconductor film having the first crystal structure is formed. An oxide semiconductor film formed in this manner is used for an active layer of the transistor.

Abstract: One of objects is to provide a semiconductor film having stable characteristics. Further, one of objects is to provide a semiconductor element having stable characteristics. Further, one of objects is to provide a semiconductor device having stable characteristics. Specifically, a structure which includes a seed crystal layer (seed layer) including crystals each having a first crystal structure, one of surfaces of which is in contact with an insulating surface, and an oxide semiconductor film including crystals growing anisotropically, which is on the other surface of the seed crystal layer (seed layer) may be provided. With such a heterostructure, electric characteristics of the semiconductor film can be stabilized.

Abstract: A normally-off transistor having an oxide semiconductor layer in a channel formation layer is provided. The transistor comprises: a first oxide semiconductor layer functioning as a channel formation region; a source electrode layer and a drain electrode layer which overlap with the first oxide semiconductor layer; a gate insulating layer which is provided over and in contact with the first oxide semiconductor layer, the source electrode layer, and the drain electrode layer; a second oxide semiconductor layer which is provided over and in contact with the gate insulating layer and overlaps with the first oxide semiconductor layer; and a gate electrode layer provided over the second oxide semiconductor layer. A manufacturing method thereof is also disclosed.

Abstract: According to one aspect of the present invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide is applied as an electrode on the side of injecting a hole (a hole injection electrode; an anode) instead of the conventional conductive transparent oxide layer such as ITO. In addition, according to another aspect of the invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide, each of which content is different, is applied as a hole injection electrode. Preferably, silicon or a silicon oxide, concentration of the conductive layer on the side where it is connected to a TFT ranges from 1 atomic % to 6 atomic % and a silicon or silicon oxide concentration on the side of a layer containing an organic compound ranges from 7 atomic % to 15 atomic %.

Abstract: It is an object of an embodiment of the present invention to reduce leakage current between a source and a drain in a transistor including an oxide semiconductor. As a first gate film in contact with a gate insulating film, a compound conductor which includes indium and nitrogen and whose band gap is less than 2.8 eV is used. Since this compound conductor has a work function of greater than or equal to 5 eV, preferably greater than or equal to 5.5 eV, the electron concentration in an oxide semiconductor film can be maintained extremely low. As a result, the leakage current between the source and the drain is reduced.

Abstract: According to one aspect of the present invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide is applied as an electrode on the side of injecting a hole (a hole injection electrode; an anode) instead of the conventional conductive transparent oxide layer such as ITO. In addition, according to another aspect of the invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide, each of which content is different, is applied as a hole injection electrode. Preferably, silicon or a silicon oxide concentration of the conductive layer on the side where it is connected to a TFT ranges from 1 atomic % to 6 atomic % and a silicon or silicon oxide concentration on the side of a layer containing an organic compound ranges from 7 atomic % to 15 atomic %.

Abstract: Many of the physical properties of a silicon semiconductor have already been understood, whereas many of the physical properties of an oxide semiconductor have been still unclear. In particular, an adverse effect of an impurity on an oxide semiconductor has been still unclear. In view of the above, a structure is disclosed in which an impurity that influences electrical characteristics of a semiconductor device including an oxide semiconductor layer is prevented or is eliminated. A semiconductor device which includes a gate electrode, an oxide semiconductor layer, and a gate insulating layer provided between the gate electrode and the oxide semiconductor layer and in which the nitrogen concentration in the oxide semiconductor layer is 1×1020 atoms/cm3 or less is provided.

Abstract: An object is to provide an oxide semiconductor having stable electric characteristics and a semiconductor device including the oxide semiconductor. A manufacturing method of a semiconductor film by a sputtering method includes the steps of holding a substrate in a treatment chamber which is kept in a reduced-pressure state; heating the substrate at lower than 400° C.; introducing a sputtering gas from which hydrogen and moisture are removed in the state where remaining moisture in the treatment chamber is removed; and forming an oxide semiconductor film over the substrate with use of a metal oxide which is provided in the treatment chamber as a target. When the oxide semiconductor film is formed, remaining moisture in a reaction atmosphere is removed; thus, the concentration of hydrogen and the concentration of hydride in the oxide semiconductor film can be reduced. Thus, the oxide semiconductor film can be stabilized.

Abstract: An object is to provide a thin film transistor and a method for manufacturing the thin film transistor including an oxide semiconductor with a controlled threshold voltage, high operation speed, a relatively easy manufacturing process, and sufficient reliability. An impurity having influence on carrier concentration in the oxide semiconductor layer, such as a hydrogen atom or a compound containing a hydrogen atom such as H2O, may be eliminated. An oxide insulating layer containing a large number of defects such as dangling bonds may be formed in contact with the oxide semiconductor layer, such that the impurity diffuses into the oxide insulating layer and the impurity concentration in the oxide semiconductor layer is reduced. The oxide semiconductor layer or the oxide insulating layer in contact with the oxide semiconductor layer may be formed in a deposition chamber which is evacuated with use of a cryopump whereby the impurity concentration is reduced.

Abstract: An object is to provide a transparent conductive film having favorable transparency and conductivity at low cost. Another object is to reduce the resistivity of a transparent conductive film formed using conductive oxynitride including zinc and aluminum. Another object is to provide a transparent conductive film that is formed using conductive oxynitride including zinc and aluminum. When aluminum and nitrogen are made to be included in a transparent conductive film formed using oxide including zinc to form a transparent conductive film that is formed using conductive oxynitride including zinc and aluminum, the transparent conductive film can have reduced resistivity. Heat treatment after the formation of the transparent conductive film that is formed using conductive oxynitride including zinc and aluminum enables reduction in resistivity of the transparent conductive film.

Abstract: The silicon nitride layer 910 formed by plasma CVD using a gas containing a hydrogen compound such as silane (SiH4) and ammonia (NH3) is provided on and in direct contact with the oxide semiconductor layer 905 used for the resistor 354, and the silicon nitride layer 910 is provided over the oxide semiconductor layer 906 used for the thin film transistor 355 with the silicon oxide layer 909 serving as a barrier layer interposed therebetween. Therefore, a higher concentration of hydrogen is introduced into the oxide semiconductor layer 905 than into the oxide semiconductor layer 906. As a result, the resistance of the oxide semiconductor layer 905 used for the resistor 354 is made lower than that of the oxide semiconductor layer 906 used for the thin film transistor 355.

Abstract: In a thin film transistor which uses an oxide semiconductor, buffer layers containing indium, gallium, zinc, oxygen, and nitrogen are provided between the oxide semiconductor layer and the source and drain electrode layers.

Abstract: An electrode formed using a transparent conductive oxide is likely to be crystallized by heat treatment performed in the manufacturing process of a semiconductor device. In the case of a thin film element using an electrode having a significantly uneven surface due to crystallization, a short circuit is likely to occur and thus reliability of the element is degraded. An object is to provide a light-transmitting conductive oxynitride which is not crystallized even if subjected to heat treatment and a manufacturing method thereof. It is found that an oxynitride containing indium, gallium, and zinc, to which hydrogen atoms are added as impurities, is a light-transmitting conductive film which is not crystallized even if heated at 350° C. and the object is achieved.

Abstract: According to one aspect of the present invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide is applied as an electrode on the side of injecting a hole (a hole injection electrode; an anode) instead of the conventional conductive transparent oxide layer such as ITO. In addition, according to another aspect of the invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide, each of which content is different, is applied as a hole injection electrode. Preferably, silicon or a silicon oxide concentration of the conductive layer on the side where it is connected to a TFT ranges from 1 atomic % to 6 atomic % and a silicon or silicon oxide concentration on the side of a layer containing an organic compound ranges from 7 atomic % to 15 atomic %.

Abstract: According to one aspect of the present invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide is applied as an electrode on the side of injecting a hole (a hole injection electrode; an anode) instead of the conventional conductive transparent oxide layer such as ITO. In addition, according to another aspect of the invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide, each of which content is different, is applied as a hole injection electrode. Preferably, silicon or a silicon oxide concentration of the conductive layer on the side where it is connected to a TFT ranges from 1 atomic % to 6 atomic % and a silicon or silicon oxide concentration on the side of a layer containing an organic compound ranges from 7 atomic % to 15 atomic %.

Abstract: It is an object to provide a sputtering system that enables forming a high-quality thin film including no impurity, and it is also an object of the present invention to provide a method for manufacturing a high-quality thin film with the sputtering system. The present invention provides a sputtering system including a target material and a part coated with a spray material including the same material as the target material. The present invention also provides a method for manufacturing a thin film including one of a target material, oxide of the target material, and nitride of the target material, which includes preparing a sputtering system including the target material and a part coated with a spray material including the same material as the target material, and applying high-frequency power in an atmosphere including rare gas.

Abstract: According to one aspect of the present invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide is applied as an electrode on the side of injecting a hole (a hole injection electrode; an anode) instead of the conventional conductive transparent oxide layer such as ITO. In addition, according to another aspect of the invention, a laminated structure of conductive transparent oxide layers containing silicon or silicon oxide, each of which content is different, is applied as a hole injection electrode. Preferably, silicon or a silicon oxide concentration of the conductive layer on the side where it is connected to a TFT ranges from 1 atomic % to 6 atomic % and a silicon or silicon oxide concentration on the side of a layer containing an organic compound ranges from 7 atomic % to 15 atomic %.