Abstract: In a transistor including an oxide semiconductor, a change in electrical characteristics is suppressed and reliability is improved. The transistor includes an oxide semiconductor film over a first insulating film; a second insulating film over the oxide semiconductor film; a metal oxide film over the second insulating film; a gate electrode over the metal oxide film; and a third insulating film over the oxide semiconductor film and the gate electrode. The oxide semiconductor film includes a channel region overlapping with the gate electrode, a source region in contact with the third insulating film, and a drain region in contact with the third insulating film. The source region and the drain region contain one or more of hydrogen, boron, carbon, nitrogen, fluorine, phosphorus, sulfur, chlorine, titanium, and a rare gas.

Abstract: A novel metal oxide is provided. The metal oxide has a plurality of energy gaps, and includes a first region having a high energy level of a conduction band minimum and a second region having an energy level of a conduction band minimum lower than that of the first region. The second region comprises more carriers than the first region. A difference between the energy level of the conduction band minimum of the first region and the energy level of the conduction band minimum of the second region is 0.2 eV or more. The energy gap of the first region is greater than or equal to 3.3 eV and less than or equal to 4.0 eV and the energy gap of the second region is greater than or equal to 2.2 eV and less than or equal to 2.9 eV.

Abstract: The impurity concentration in the oxide semiconductor film is reduced, and a highly reliability can be obtained.

Abstract: There have been cases where transistors formed using oxide semiconductors are inferior in reliability to transistors formed using amorphous silicon. Thus, in the present invention, a semiconductor device including a highly reliable transistor formed using an oxide semiconductor is manufactured. An oxide semiconductor film is deposited by a sputtering method, using a sputtering target including an oxide semiconductor having crystallinity, and in which the direction of the c-axis of a crystal is parallel to a normal vector of the top surface of the oxide semiconductor. The target is formed by mixing raw materials so that its composition ratio can obtain a crystal structure.

Abstract: A novel metal oxide is provided. The metal oxide has a plurality of energy gaps, and includes a first region having a high energy level of a conduction band minimum and a second region having an energy level of a conduction band minimum lower than that of the first region. The second region comprises more carriers than the first region. A difference between the energy level of the conduction band minimum of the first region and the energy level of the conduction band minimum of the second region is 0.2 eV or more. The energy gap of the first region is greater than or equal to 3.3 eV and less than or equal to 4.0 eV and the energy gap of the second region is greater than or equal to 2.2 eV and less than or equal to 2.9 eV.

Abstract: A novel metal oxide is provided. The metal oxide has a plurality of energy gaps, and includes a first region having a high energy level of a conduction band minimum and a second region having an energy level of a conduction band minimum lower than that of the first region. The second region comprises more carriers than the first region. A difference between the energy level of the conduction band minimum of the first region and the energy level of the conduction band minimum of the second region is 0.2 eV or more. The energy gap of the first region is greater than or equal to 3.3 eV and less than or equal to 4.0 eV and the energy gap of the second region is greater than or equal to 2.2 eV and less than or equal to 2.9 eV.

Abstract: An object is to provide a material suitably used for a semiconductor included in a transistor, a diode, or the like. Another object is to provide a semiconductor device including a transistor in which the condition of an electron state at an interface between an oxide semiconductor film and a gate insulating film in contact with the oxide semiconductor film is favorable. Further, another object is to manufacture a highly reliable semiconductor device by giving stable electric characteristics to a transistor in which an oxide semiconductor film is used for a channel. A semiconductor device is formed using an oxide material which includes crystal with c-axis alignment, which has a triangular or hexagonal atomic arrangement when seen from the direction of a surface or an interface and rotates around the c-axis.

Abstract: A highly reliable semiconductor device and a method for manufacturing the semiconductor device are provided. The semiconductor device is manufactured with a high yield, so that high productivity is achieved. In a semiconductor device including a transistor in which a source electrode layer and a drain electrode layer are provided over and in contact with an oxide semiconductor film, entry of impurities and formation of oxygen vacancies in an end face portion of the oxide semiconductor film are suppressed. This can prevent fluctuation in the electric characteristics of the transistor which is caused by formation of a parasitic channel in the end face portion of the oxide semiconductor film.

Abstract: To provide a method for manufacturing a semiconductor device including an oxide semiconductor film having conductivity, or a method for manufacturing a semiconductor device including an oxide semiconductor film having a light-transmitting property and conductivity. The method for manufacturing a semiconductor device includes the steps of forming an oxide semiconductor film over a first insulating film, performing first heat treatment in an atmosphere where oxygen contained in the oxide semiconductor film is released, and performing second heat treatment in a hydrogen-containing atmosphere, so that an oxide semiconductor film having conductivity is formed.

Abstract: The stability of a step of processing a wiring formed using copper, aluminum, gold, silver, molybdenum, or the like is increased. Moreover, the concentration of impurities in a semiconductor film is reduced. Moreover, the electrical characteristics of a semiconductor device are improved. In a transistor including an oxide semiconductor film, an oxide film in contact with the oxide semiconductor film, and a pair of conductive films being in contact with the oxide film and including copper, aluminum, gold, silver, molybdenum, or the like, the oxide film has a plurality of crystal parts and has c-axis alignment in the crystal parts, and the c-axes are aligned in a direction parallel to a normal vector of a top surface of the oxide semiconductor film or the oxide film.

Abstract: In a semiconductor device using a transistor including an oxide semiconductor, a change in electrical characteristics is suppressed and reliability is improved. The semiconductor device includes a gate electrode over an insulating surface; an oxide semiconductor film overlapping with the gate electrode; a gate insulating film that is between the gate electrode and the oxide semiconductor film and in contact with the oxide semiconductor film; a protective film in contact with a surface of the oxide semiconductor film that is an opposite side of a surface in contact with the gate insulating film; and a pair of electrodes in contact with the oxide semiconductor film. The spin density of the gate insulating film or the protective film measured by electron spin resonance spectroscopy is lower than 1×1018 spins/cm3, preferably higher than or equal to 1×1017 spins/cm3 and lower than 1×1018 spins/cm3.

Abstract: A highly reliable semiconductor device and a method for manufacturing the semiconductor device are provided. The semiconductor device is manufactured with a high yield, so that high productivity is achieved. In a semiconductor device including a transistor in which a source electrode layer and a drain electrode layer are provided over and in contact with an oxide semiconductor film, entry of impurities and formation of oxygen vacancies in an end face portion of the oxide semiconductor film are suppressed. This can prevent fluctuation in the electric characteristics of the transistor which is caused by formation of a parasitic channel in the end face portion of the oxide semiconductor film.

Abstract: There have been cases where transistors formed using oxide semiconductors are inferior in reliability to transistors formed using amorphous silicon. Thus, in the present invention, a semiconductor device including a highly reliable transistor formed using an oxide semiconductor is manufactured. An oxide semiconductor film is deposited by a sputtering method, using a sputtering target including an oxide semiconductor having crystallinity, and in which the direction of the c-axis of a crystal is parallel to a normal vector of the top surface of the oxide semiconductor. The target is formed by mixing raw materials so that its composition ratio can obtain a crystal structure.

Abstract: The stability of a step of processing a wiring formed using copper, aluminum, gold, silver, molybdenum, or the like is increased. Moreover, the concentration of impurities in a semiconductor film is reduced. Moreover, the electrical characteristics of a semiconductor device are improved. In a transistor including an oxide semiconductor film, an oxide film in contact with the oxide semiconductor film, and a pair of conductive films being in contact with the oxide film and including copper, aluminum, gold, silver, molybdenum, or the like, the oxide film has a plurality of crystal parts and has c-axis alignment in the crystal parts, and the c-axes are aligned in a direction parallel to a normal vector of a top surface of the oxide semiconductor film or the oxide film.

Abstract: A highly reliable semiconductor device and a method for manufacturing the semiconductor device are provided. The semiconductor device is manufactured with a high yield, so that high productivity is achieved. In a semiconductor device including a transistor in which a source electrode layer and a drain electrode layer are provided over and in contact with an oxide semiconductor film, entry of impurities and formation of oxygen vacancies in an end face portion of the oxide semiconductor film are suppressed. This can prevent fluctuation in the electric characteristics of the transistor which is caused by formation of a parasitic channel in the end face portion of the oxide semiconductor film.

Abstract: An object is to provide a material suitably used for a semiconductor included in a transistor, a diode, or the like. Another object is to provide a semiconductor device including a transistor in which the condition of an electron state at an interface between an oxide semiconductor film and a gate insulating film in contact with the oxide semiconductor film is favorable. Further, another object is to manufacture a highly reliable semiconductor device by giving stable electric characteristics to a transistor in which an oxide semiconductor film is used for a channel. A semiconductor device is formed using an oxide material which includes crystal with c-axis alignment, which has a triangular or hexagonal atomic arrangement when seen from the direction of a surface or an interface and rotates around the c-axis.

Abstract: An object is to provide a material suitably used for a semiconductor included in a transistor, a diode, or the like. Another object is to provide a semiconductor device including a transistor in which the condition of an electron state at an interface between an oxide semiconductor film and a gate insulating film in contact with the oxide semiconductor film is favorable. Further, another object is to manufacture a highly reliable semiconductor device by giving stable electric characteristics to a transistor in which an oxide semiconductor film is used for a channel. A semiconductor device is formed using an oxide material which includes crystal with c-axis alignment, which has a triangular or hexagonal atomic arrangement when seen from the direction of a surface or an interface and rotates around the c-axis.

Abstract: A highly reliable semiconductor device and a method for manufacturing the semiconductor device are provided. The semiconductor device is manufactured with a high yield, so that high productivity is achieved. In a semiconductor device including a transistor in which a source electrode layer and a drain electrode layer are provided over and in contact with an oxide semiconductor film, entry of impurities and formation of oxygen vacancies in an end face portion of the oxide semiconductor film are suppressed. This can prevent fluctuation in the electric characteristics of the transistor which is caused by formation of a parasitic channel in the end face portion of the oxide semiconductor film.

Abstract: In a semiconductor device using a transistor including an oxide semiconductor, a change in electrical characteristics is suppressed and reliability is improved. The semiconductor device includes a gate electrode over an insulating surface; an oxide semiconductor film overlapping with the gate electrode; a gate insulating film that is between the gate electrode and the oxide semiconductor film and in contact with the oxide semiconductor film; a protective film in contact with a surface of the oxide semiconductor film that is an opposite side of a surface in contact with the gate insulating film; and a pair of electrodes in contact with the oxide semiconductor film. The spin density of the gate insulating film or the protective film measured by electron spin resonance spectroscopy is lower than 1×1018 spins/cm3, preferably higher than or equal to 1×1017 spins/cm3 and lower than 1×1018 spins/cm3.

Abstract: A highly reliable semiconductor device and a method for manufacturing the semiconductor device are provided. The semiconductor device is manufactured with a high yield, so that high productivity is achieved. In a semiconductor device including a transistor in which a source electrode layer and a drain electrode layer are provided over and in contact with an oxide semiconductor film, entry of impurities and formation of oxygen vacancies in an end face portion of the oxide semiconductor film are suppressed. This can prevent fluctuation in the electric characteristics of the transistor which is caused by formation of a parasitic channel in the end face portion of the oxide semiconductor film.