摘要:
Disclosed is a thin film transistor which includes, over a substrate having an insulating surface, a gate insulating layer covering a gate electrode; a semiconductor layer which functions as a channel formation region; and a semiconductor layer including an impurity element imparting one conductivity type. The semiconductor layer exists in a state that a plurality of crystalline particles is dispersed in an amorphous silicon and that the crystalline particles have an inverted conical or inverted pyramidal shape. The crystalline particles grow approximately radially in a direction in which the semiconductor layer is deposited. Vertexes of the inverted conical or inverted pyramidal crystal particles are located apart from an interface between the gate insulating layer and the semiconductor layer.
摘要:
A thin film transistor includes, over a substrate having an insulating surface, a gate insulating layer covering a gate electrode; a semiconductor layer which includes a plurality of crystalline regions in an amorphous structure and which forms a channel formation region, in contact with the gate insulating layer; a semiconductor layer including an impurity element imparting one conductivity type, which forms source and drain regions; and a buffer layer including an amorphous semiconductor between the semiconductor layer and the semiconductor layer including an impurity element imparting one conductivity type. The crystalline regions have an inverted conical or inverted pyramidal crystal particle which grows approximately radially in a direction in which the semiconductor layer is deposited, from a position away from an interface between the gate insulating layer and the semiconductor layer.
摘要:
A thin film transistor includes, as a buffer layer, a semiconductor layer which contains nitrogen and includes crystal regions in an amorphous structure between a gate insulating layer and source and drain regions, at least on the source and drain regions side. As compared to a thin film transistor in which an amorphous semiconductor is included in a channel formation region, on-current of a thin film transistor can be increased. In addition, as compared to a thin film transistor in which a microcrystalline semiconductor is included in a channel formation region, off-current of a thin film transistor can be reduced.
摘要:
A thin film transistor includes, as a buffer layer, an amorphous semiconductor layer having nitrogen or an NH group between a gate insulating layer and source and drain regions and at least on the source and drain regions side. As compared to a thin film transistor in which an amorphous semiconductor is included in a channel formation region, on-current of a thin film transistor can be increased. In addition, as compared to a thin film transistor in which a microcrystalline semiconductor is included in a channel formation region, off-current of a thin film transistor can be reduced.
摘要:
An object is to reduce off-state leakage current between a source electrode and a drain electrode. One embodiment of the present invention is a semiconductor device including a gate electrode, gate insulating films and formed to cover the gate electrode, an active layer formed over the gate insulating films and located above the gate electrode, silicon layers and formed over side surfaces of the active layer and the gate insulating films, and a source electrode and a drain electrode formed over the silicon layers. The active layer is not in contact with each of the source electrode and the drain electrode.
摘要:
One embodiment of the present invention is a semiconductor device which includes a gate electrode; a gate insulating film formed to cover the gate electrode; a semiconductor layer formed over the gate insulating film and placed above the gate electrode; a second insulating film formed over the semiconductor layer; a first insulating film formed over a top surface and a side surface of the second insulating film, a side surface of the semiconductor layer, and the gate insulating film; silicon layers and which are formed over the first insulating film and electrically connected to the semiconductor layer; and a source electrode and a drain electrode which are formed over the silicon layers. The source electrode and the drain electrode are electrically separated from each other over the first insulating film. The semiconductor layer is not in contact with each of the source electrode and the drain electrode.
摘要:
A method for forming a microcrystalline semiconductor film over a base formed of a different material, which has high crystallinity in the entire film and at an interface with the base, is proposed. Further, a method for manufacturing a thin film transistor including a microcrystalline semiconductor film with high crystallinity is proposed. Furthermore, a method for manufacturing a photoelectric conversion device including a microcrystalline semiconductor film with high crystallinity is proposed. By forming crystal nuclei with high density and high crystallinity over a base film and then growing crystals in a semiconductor from the crystal nuclei, a microcrystalline semiconductor film which has high crystallinity at an interface with the base film, which has high crystallinity in crystal grains, and which has high adhesion between the adjacent crystal grains is formed.
摘要:
A method for manufacturing a semiconductor device having favorable electric characteristics with high productivity is provided. A first microcrystalline semiconductor film is formed over an oxide insulating film under a first condition that mixed phase grains with high crystallinity are formed at a low particle density. After that, a second microcrystalline semiconductor film is stacked over the first microcrystalline semiconductor film under a second condition that a space between the mixed phase grains are filled by the crystal growth of the mixed phase grains of the first microcrystalline semiconductor film.
摘要:
To provide a manufacturing method of a microcrystalline silicon film having both high crystallinity and high film density. In the manufacturing method of a microcrystalline silicon film according to the present invention, a first microcrystalline silicon film that includes mixed phase grains is formed over an insulating film under a first condition, and a second microcrystalline silicon film is formed thereover under a second condition. The first condition and the second condition are a condition in which a deposition gas containing silicon and a gas containing hydrogen are used as a first source gas and a second source gas. The first source gas is supplied under the first condition in such a manner that supply of a first gas and supply of a second gas are alternately performed.
摘要:
A method for manufacturing a semiconductor device comprises the steps of forming a seed over the insulating film by introducing hydrogen and a deposition gas into a first treatment chamber under a first condition and forming a microcrystalline semiconductor film over the seed by introducing hydrogen and the deposition gas into a second treatment chamber under a second condition: a second flow rate of the deposition gas is periodically changed between a first value and a second value; and a second pressure in the second treatment chamber is higher than or equal to 1.0×102 Torr and lower than or equal to 1.0×103 Torr.