The present invention provides a method for manufacturing the N-type TFT, which includes subjecting a light shielding layer to a grating like patternization treatment for controlling different zones of a poly-silicon layer to induce difference of crystallization so as to have different zones of the poly-silicon layer forming crystalline grains having different sizes, whereby through just one operation of ion doping, different zones of the poly-silicon layer have differences in electrical resistivity due to difference of grain size generated under the condition of identical doping concentration to provide an effect equivalent to an LDD structure for providing the TFT with a relatively low leakage current and improved reliability. Further, since only one operation of ion injection is involved, the manufacturing time and manufacturing cost can be saved, damages of the poly-silicon layer can be reduced, the activation time can be shortened, thereby facilitating the manufacture of flexible display devices.

Solved is a problem of attenuation of output amplitude due to a threshold value of a TFT when manufacturing a circuit with TFTs of a single polarity. In a capacitor (105), a charge equivalent to a threshold value of a TFT (104) is stored. When a signal is inputted thereto, the threshold value stored in the capacitor (105) is added to a potential of the input signal. The thus obtained potential is applied to a gate electrode of a TFT (101). Therefore, it is possible to obtain the output having a normal amplitude from an output terminal (Out) without causing the amplitude attenuation in the TFT (101).

A method is provided for fabricating thin-film transistors (TFTs) for an LCD having an array of pixels. The method includes depositing a first photoresist layer over a portion of a TFT stack. The TFT stack includes a conductive gate layer, and a semiconductor layer. The method also includes doping the exposed semiconductor layer with a first doping dose. The method further includes etching a portion of the conductive gate layer to expose a portion of the semiconductor layer, and doping the exposed portion of the semiconductor layer with a second doping dose. The method also includes removing the first photoresist layer, and depositing a second photoresist layer over a first portion of the doped semiconductor layer in an active area of the pixels to expose a second portion of the doped semiconductor layer in an area surrounding the active area. The method further includes doping the second portion of the doped semiconductor layer with a third doping dose, the first dose being higher than the second dose and the third dose.

A semiconductor device includes a first oxide semiconductor film, a second oxide semiconductor film over the first oxide semiconductor film, a source electrode in contact with the second oxide semiconductor film, a drain electrode in contact with the second oxide semiconductor film, a metal oxide film over the second oxide semiconductor film, the source electrode, and the drain electrode, a gate insulating film over the metal oxide film, and a gate electrode over the gate insulating film. The metal oxide film contains M (M represents Ti, Ga, Y, Zr, La, Ce, Nd, or Hf) and Zn. The metal oxide film includes a portion where x/(x+y) is greater than 0.67 and less than or equal to 0.99 when a target has an atomic ratio of M:Zn=x:y.

As a display device has a higher definition, the number of pixels, gate lines, and signal lines are increased. When the number of the gate lines and the signal lines are increased, a problem of higher manufacturing cost, because it is difficult to mount an IC chip including a driver circuit for driving of the gate and signal lines by bonding or the like. A pixel portion and a driver circuit for driving the pixel portion are provided over the same substrate, and at least part of the driver circuit includes a thin film transistor using an oxide semiconductor interposed between gate electrodes provided above and below the oxide semiconductor. Therefore, when the pixel portion and the driver portion are provided over the same substrate, manufacturing cost can be reduced.

The present invention provides a manufacture method of a TFT substrate structure and a TFT substrate structure. In the manufacture method of the TFT substrate structure according to the present invention, by adjusting the parameter of etching as manufacturing the gate, the angular surfaces are formed at the two sides of the gate, and the gate is used to be a mask to implement ion implantation to the polysilicon layer to form the n-type heavy doping area and the n-type light doping area are formed at the polysilicon layer at the same time. In the TFT structure according to the present invention, the polysilicon layer comprises n-type heavy doping areas at two sides and n-type light doping areas between the channel area of the polysilicon layer and the n-type heavy doping areas.

The present invention provides a LTPS array substrate and a manufacturing method thereof. The method comprises: forming a source electrode and a drain electrode on a substrate, forming polysilicon layers of a first region and a second region on the substrate including the source electrode and the drain electrode, and the thickness of the polysilicon layer of the first region is greater than the one of the second region, the polysilicon layer of the first region partially covers the source electrode and the drain electrode; passivating the surface of the polysilicon layer in order to turn the part of the adjacent surface of the polysilicon layer of the second region and the first region into an insulating layer; forming a gate electrode on the insulating layer between the source electrode and the drain electrode. The present invention can simplify the LTPS technical process and reduce the producing costs.

The embodiments of present disclosure provide a thin film transistor, a method for manufacturing the same, and an array substrate. The thin film transistor comprises an active layer provided on a substrate, the active layer including a middle channel region, a first high resistance region and a second high resistance region provided respectively on external sides of the middle channel region, a source region provided on an external side of the first high resistance region and a drain region provided on an external side of the second high resistance region, wherein a base material of the active layer is diamond single crystal. According to the thin film transistor, the method for manufacturing the same, and the array substrate provided in the embodiments of present disclosure, by providing high resistance regions on external sides of the middle channel region of the active layer, the carrier mobility is reduced and the leakage current of the thin film transistor made of single crystalline diamond is effectively suppressed.

A semiconductor device that operates at high speed. A semiconductor device with favorable switching characteristics. A highly integrated semiconductor device. A miniaturized semiconductor device. The semiconductor device is formed by: fainting a semiconductor film including an opening, on an insulating surface; forming a conductive film over the semiconductor film and in the opening, and removing the conductive film over the semiconductor film to form a conductive pillar in the opening; forming an island-shaped mask over the conductive pillar and the semiconductor film; etching the conductive pillar and the semiconductor film using the mask to form a first electrode and a first semiconductor; forming a gate insulating film on a top surface and a side surface of the first semiconductor; and forming a gate electrode that is in contact with a top surface of the gate insulating film and faces the top surface and the side surface of the first semiconductor.

A novel semiconductor device including an oxide semiconductor is provided. In particular, a planar semiconductor device including an oxide semiconductor is provided. A semiconductor device including an oxide semiconductor and having large on-state current is provided. The semiconductor device includes an oxide insulating film, an oxide semiconductor film over the oxide insulating film, a source electrode and a drain electrode in contact with the oxide semiconductor film, a gate insulating film between the source electrode and the drain electrode, and a gate electrode overlapping the oxide semiconductor film with the gate insulating film. The oxide semiconductor film includes a first region overlapped with the gate electrode and a second region not overlapped with the gate electrode, the source electrode, and the drain electrode. The first region and the second region have different impurity element concentrations. The gate electrode, the source electrode, and the drain electrode contain the same metal element.