摘要:
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.
摘要:
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.
摘要:
An impurity element imparting one conductivity type is included in a layer close to a gate insulating film of layers with high crystallinity, so that a channel formation region is formed not in a layer with low crystallinity which is formed at the beginning of film formation but in a layer with high crystallinity which is formed later in a microcrystalline semiconductor film. Further, the layer including an impurity element is used as a channel formation region. Furthermore, a layer which does not include an impurity element imparting one conductivity type or a layer which has an impurity element imparting one conductivity type at an extremely lower concentration than other layers, is provided between a pair of semiconductor films including an impurity element functioning as a source region and a drain region and the layer including an impurity element functioning as a channel formation region.
摘要:
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.
摘要:
A thin-film transistor in which problems with ON-state current and OFF-state current are solved, and a thin-film transistor capable of high-speed operation. The thin-film transistor includes a pair of impurity semiconductor layers in which an impurity element imparting one conductivity type is added to form a source and drain regions, provided with a space therebetween so as to be overlapped with a gate electrode with a gate insulating layer interposed between the gate electrode and the impurity semiconductor layers; a pair of semiconductor layers in which an impurity element which serves as an acceptor is added, overlapped over the gate insulating layers with the gate electrode and the impurity semiconductor layers, and disposed with a space therebetween in a channel length direction; and an amorphous semiconductor layer being in contact with the gate insulating layer and the pair of semiconductor layers and extended between the pair of semiconductor layers.
摘要:
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.
摘要:
Off current of a bottom gate thin film transistor in which a semiconductor layer is shielded from light by a gate electrode is reduced. A thin film transistor includes a gate electrode layer; a first semiconductor layer; a second semiconductor layer, provided on and in contact with the first semiconductor layer; a gate insulating layer between and in contact with the gate electrode layer and the first semiconductor layer; impurity semiconductor layers in contact with the second semiconductor layer; and source and drain electrode layers partially in contact with the impurity semiconductor layers and the first and second semiconductor layers. The entire surface of the first semiconductor layer on the gate electrode layer side is covered by the gate electrode layer; and a potential barrier at a portion where the first semiconductor layer is in contact with the source or drain electrode layer is 0.5 eV or more.
摘要:
An impurity element imparting one conductivity type is included in a layer close to a gate insulating film of layers with high crystallinity, so that a channel formation region is formed not in a layer with low crystallinity which is formed at the beginning of film formation but in a layer with high crystallinity which is formed later in a microcrystalline semiconductor film. Further, the layer including an impurity element is used as a channel formation region. Furthermore, a layer which does not include an impurity element imparting one conductivity type or a layer which has an impurity element imparting one conductivity type at an extremely lower concentration than other layers, is provided between a pair of semiconductor films including an impurity element functioning as a source region and a drain region and the layer including an impurity element functioning as a channel formation region.
摘要:
A thin-film transistor includes a pair of impurity semiconductor layers in which an impurity element imparting one conductivity type is added to form a source and drain regions so as to be overlapped at least partly with a gate electrode with a gate insulating layer interposed between the gate electrode and the impurity semiconductor layers; a pair of conductive layers which is overlapped over the gate insulating layers at least partly with the gate electrode and the impurity semiconductor layers, and is disposed with a space therebetween in a channel length direction; and an amorphous semiconductor layer which is in contact with the gate insulating layer and the pair of conductive layers and is extended between the pair of conductive layers.
摘要:
An object is to provide a method for manufacturing a thin film transistor and a display device with reduced number of masks, in which adverse effects of optical current are suppressed. A manufacturing method comprises forming a stack including, from bottom to top, a light-blocking film, a base film, a first conductive film, a first insulating film, a semiconductor film, an impurity semiconductor film, and a second conductive film; performing first etching on the whole thickness of the stack using a first resist mask formed over it; forming a gate electrode layer by side etching the first conductive film in a second etching; forming a second resist mask over the stack; and performing third etching down to the semiconductor film, and partially etching it, using the second resist mask to form a source and drain electrode layer, a source and drain region, and a semiconductor layer.