Abstract: To suppress deterioration in electrical characteristics in a transistor including an oxide semiconductor layer or a semiconductor device including the transistor. In a transistor in which a channel layer is formed using an oxide semiconductor, a silicon layer is provided in contact with a surface of the oxide semiconductor layer. Further, the silicon layer is provided in contact with at least a region of the oxide semiconductor layer, in which a channel is formed, and a source electrode layer and a drain electrode layer are provided in contact with regions of the oxide semiconductor layer, over which the silicon layer is not provided.

Abstract: An object is to provide a semiconductor device including an oxide semiconductor in which miniaturization is achieved while favorable characteristics are maintained. The semiconductor includes an oxide semiconductor layer, a source electrode and a drain electrode in contact with the oxide semiconductor layer, a gate electrode overlapping with the oxide semiconductor layer, a gate insulating layer provided between the oxide semiconductor layer and the gate electrode, and an insulating layer provided in contact with the oxide semiconductor layer. A side surface of the oxide semiconductor layer is in contact with the source electrode or the drain electrode. An upper surface of the oxide semiconductor layer overlaps with the source electrode or the drain electrode with the insulating layer interposed between the oxide semiconductor layer and the source electrode or the drain electrode.

Abstract: A thin film transistor is provided, which includes a gate insulating layer covering a gate electrode, a microcrystalline semiconductor layer provided over the gate insulating layer, an amorphous semiconductor layer overlapping the microcrystalline semiconductor layer and the gate insulating layer, and a pair of impurity semiconductor layers which are provided over the amorphous semiconductor layer and to which an impurity element imparting one conductivity type is added to form a source region and a drain region. The gate insulating layer has a step adjacent to a portion in contact with an end portion of the microcrystalline semiconductor layer. A second thickness of the gate insulating layer in a portion outside the microcrystalline semiconductor layer is smaller than a first thickness thereof in a portion in contact with the microcrystalline semiconductor layer.

Abstract: To improve problems with on-state current and off-state current of thin film transistors, a thin film transistor includes a pair of impurity semiconductor layers to which an impurity element imparting one conductivity type is added, provided with a space therebetween; a conductive layer which is overlapped, over the gate insulating layer, with the gate electrode and one of the pair of impurity semiconductor layers to which an impurity element imparting one conductivity type is added; and an amorphous semiconductor layer which is provided successively between the pair of impurity semiconductor layers to which an impurity element imparting one conductivity type is added in such a manner that the amorphous semiconductor layer extends over the gate insulating layer from the conductive layer and is in contact with both of the pair of impurity semiconductor layers to which an impurity element imparting one conductivity type is added.

Abstract: An object is to realize high performance and low power consumption in a semiconductor device having an SOI structure. In addition, another object is to provide a semiconductor device having a high performance semiconductor element which is more highly integrated. A semiconductor device is such that a plurality of n-channel field-effect transistors and p-channel field-effect transistors are stacked with an interlayer insulating layer interposed therebetween over a substrate having an insulating surface. By controlling a distortion caused to a semiconductor layer due to an insulating film having a stress, a plane orientation of the semiconductor layer, and a crystal axis in a channel length direction, difference in mobility between the n-channel field-effect transistor and the p-channel field-effect transistor can be reduced, whereby current driving capabilities and response speeds of the n-channel field-effect transistor and the p-channel field-effect can be comparable.

Abstract: It is an object of the present invention to obtain a transistor with a high ON current including a silicide layer without increasing the number of steps. A semiconductor device comprising the transistor includes a first region in which a thickness is increased from an edge on a channel formation region side and a second region in which a thickness is more uniform than that of the first region. The first and second region are separated by a line which is perpendicular to a horizontal line and passes through a point where a line, which passes through the edge of the silicide layer and forms an angle ? (0°<?<45°) with the horizontal line, intersects with an interface between the silicide layer and an impurity region, and the thickness of the second region to a thickness of a silicon film is 0.6 or more.

Abstract: A thin film transistor in which an effect of photo current is small and an On/Off ratio is high is provided. In a bottom-gate bottom-contact (coplanar) thin film transistor, a channel formation region overlaps with a gate electrode, a first impurity semiconductor layer is provided between the channel formation region and a second impurity semiconductor layer which is in contact with a wiring layer. A semiconductor layer which serves as the channel formation region and the first impurity semiconductor layer preferably overlap with each other in a region where they overlap with the gate electrode. The first impurity semiconductor layer and the second impurity semiconductor layer preferably overlap with each other in a region where they do not overlap with the gate electrode.

Abstract: An object is to provide a semiconductor device including an oxide semiconductor in which miniaturization is achieved while favorable characteristics are maintained. The semiconductor includes an oxide semiconductor layer, a source electrode and a drain electrode in contact with the oxide semiconductor layer, a gate electrode overlapping with the oxide semiconductor layer, a gate insulating layer provided between the oxide semiconductor layer and the gate electrode, and an insulating layer provided in contact with the oxide semiconductor layer. A side surface of the oxide semiconductor layer is in contact with the source electrode or the drain electrode. An upper surface of the oxide semiconductor layer overlaps with the source electrode or the drain electrode with the insulating layer interposed between the oxide semiconductor layer and the source electrode or the drain electrode.

Abstract: An object is to provide a semiconductor device which solves a problem that can occur when a substrate having an insulating surface is used. The semiconductor device includes a base substrate having an insulating surface; a conductive layer over the insulating surface; an insulating layer over the conductive layer; a semiconductor layer having a channel formation region, a first impurity region, a second impurity region, and a third impurity region provided between the channel formation region and the second impurity region over the insulating layer; a gate insulating layer configured to cover the semiconductor layer; a gate electrode over the gate insulating layer; a first electrode electrically connected to the first impurity region; and a second electrode electrically connected to the second impurity region. The conductive layer is held at a given potential.

Abstract: An object is to provide a semiconductor device including an oxide semiconductor, which maintains favorable characteristics and achieves miniaturization. The semiconductor device includes an oxide semiconductor layer, a source electrode and a drain electrode in contact with the oxide semiconductor layer, a gate electrode overlapping with the oxide semiconductor layer, and a gate insulating layer provided between the oxide semiconductor layer and the gate electrode, in which the source electrode and the drain electrode each include a first conductive layer, and a second conductive layer having a region which extends in a channel length direction from an end portion of the first conductive layer.

Abstract: An object is to provide an n-channel transistor and a p-channel transistor having a preferred structure using an oxide semiconductor. A first source or drain electrode which is electrically connected to a first oxide semiconductor layer and is formed using a stacked-layer structure including a first conductive layer containing a first material and a second conductive layer containing a second material, and a second source or drain electrode which is electrically connected to a second oxide semiconductor layer and is formed using a stacked-layer structure including a third conductive layer containing the first material and a fourth conductive layer containing the second material are included. The first oxide semiconductor layer is in contact with the first conductive layer of the first source or drain electrode, and the second oxide semiconductor layer is in contact with the third and the fourth conductive layers of the second source or drain electrode.

Abstract: One object is to provide a semiconductor device that includes an oxide semiconductor and is reduced in size with favorable characteristics maintained. The semiconductor device includes an oxide semiconductor layer, a source electrode and a drain electrode in contact with the oxide semiconductor layer, a gate electrode overlapping with the oxide semiconductor layer; and a gate insulating layer between the oxide semiconductor layer and the gate electrode. The source electrode or the drain electrode includes a first conductive layer and a second conductive layer having a region extended in a channel length direction from an end face of the first conductive layer. The sidewall insulating layer has a length of a bottom surface in the channel length direction smaller than a length in the channel length direction of the extended region of the second conductive layer and is provided over the extended region.

Abstract: There are provided a semiconductor device having a structure which can realize not only suppression of a punch-through current but also reuse of a silicon wafer used for bonding, in manufacturing a semiconductor device using an SOI technique, and a manufacturing method thereof. A semiconductor film into which an impurity imparting a conductivity type opposite to that of a source region and a drain region is implanted is formed over a substrate, and a single crystal semiconductor film is bonded to the semiconductor film by an SOI technique to form a stacked semiconductor film. A channel formation region is formed using the stacked semiconductor film, thereby suppressing a punch-through current in a semiconductor device.

Abstract: One object is to provide a p-channel transistor including an oxide semiconductor. Another object is to provide a complementary metal oxide semiconductor (CMOS) structure of an n-channel transistor including an oxide semiconductor and a p-channel transistor including an oxide semiconductor. A p-channel transistor including an oxide semiconductor includes a gate electrode layer, a gate insulating layer, an oxide semiconductor layer, and a source and drain electrode layers in contact with the oxide semiconductor layer. When the electron affinity and the band gap of an oxide semiconductor used for the oxide semiconductor layer in the semiconductor device, respectively, are ? (eV) and Eg (eV), the work function (?m) of the conductor used for the source electrode layer and the drain electrode layer satisfies ?m>?+Eg/2 and the barrier for holes (?Bp) represented by (?+Eg??m) is less than 0.25 eV.

Abstract: A novel display device with higher reliability having a structure of blocking moisture and oxygen, which deteriorate the characteristics of the display device, from penetrating through a sealing region and a method of manufacturing thereof is provided.

Abstract: An intrinsic or substantially intrinsic semiconductor, which has been subjected to a step of dehydration or dehydrogenation and a step of adding oxygen so that the carrier concentration is less than 1×1012/cm3 is used for an oxide semiconductor layer of an insulated gate transistor, in which a channel region is formed. The length of the channel formed in the oxide semiconductor layer is set to 0.2 ?m to 3.0 ?m an inclusive and the thicknesses of the oxide semiconductor layer and the gate insulating layer are set to 15 nm to 30 nm inclusive and 20 nm to 50 nm inclusive, respectively, or 15 nm to 100 nm inclusive and 10 nm to 20 nm inclusive, respectively. Consequently, a short-channel effect can be suppressed, and the amount of change in threshold voltage can be less than 0.5 V in the range of the above channel lengths.

Abstract: A transistor includes an island-like semiconductor film over a substrate, and a conductive film forming a gate electrode over the island-like semiconductor film with a gate insulating film interposed therebetween. The semiconductor film includes a channel forming region, a first impurity region forming a source or drain region, and a second impurity region. The channel forming region is overlapped with the gate electrode crossing the island-like semiconductor film. The first impurity region is adjacent to the channel forming region. The second impurity region is adjacent to the channel forming region and the first impurity region. The first impurity region and the second impurity region have different conductivity. The second impurity region and the channel forming region have different conductivity or have different concentration of an impurity element contained in the second impurity region and the channel forming region in a case of having the same conductivity.

Abstract: An object is to provide a transistor including an oxide layer which includes Zn and does not include a rare metal such as In or Ga. Another object is to reduce an off current and stabilize electric characteristics in the transistor including an oxide layer which includes Zn. A transistor including an oxide layer including Zn is formed by stacking an oxide semiconductor layer including insulating oxide over an oxide layer so that the oxide layer is in contact with a source electrode layer or a drain electrode layer with the oxide semiconductor layer including insulating oxide interposed therebetween, whereby variation in the threshold voltage of the transistor can be reduced and electric characteristics can be stabilized.

Abstract: The object is to suppress deterioration in electrical characteristics in a semiconductor device comprising a transistor including an oxide semiconductor layer. In a transistor in which a channel layer is formed using an oxide semiconductor, a p-type silicon layer is provided in contact with a surface of the oxide semiconductor layer. Further, the p-type silicon layer is provided in contact with at least a region of the oxide semiconductor layer, in which a channel is formed, and a source electrode layer and a drain electrode layer are provided in contact with regions of the oxide semiconductor layer, over which the p-type silicon layer is not provided.

Abstract: A thin film transistor includes: a gate electrode layer; a first semiconductor layer; a second semiconductor layer having lower carrier mobility than the first semiconductor layer, which is provided over and in contact with the first semiconductor layer; a gate insulating layer which is provided between and in contact with the gate electrode layer and the first semiconductor layer; first impurity semiconductor layers which are provided so as to be in contact with the second semiconductor layer; second impurity semiconductor layers which are provided so as to be partially in contact with the first impurity semiconductor layers and the first and second semiconductor layers; and source and drain electrode layers which are provided so as to be in contact with entire surfaces of the second impurity semiconductor layers, in which an entire surface of the first semiconductor layer on the gate electrode layer side overlaps with the gate electrode layer.