The present invention proposes a TFT, an array substrate, and a method of forming a TFT. The TFT includes a substrate, a buffer layer, a patterned poly-si layer, an isolation layer, a gate layer, and a source/drain pattern layer. The poly-si layer includes a heavily doped source and a heavily doped drain, and a channel. The gate layer includes a first gate area and a second gate area. The source/drain pattern layer includes a source pattern, a drain pattern and a bridge pattern, with the source pattern electrically connecting the heavily doped source, the drain pattern electrically connecting the heavily doped drain, and one end of the bridge pattern connecting the first gate area and the second gate area. The driving ability of the present inventive TFT is enhanced without affecting the leakage current.

An EL display device capable of performing clear multi-gradation color display and electronic equipment provided with the EL display device are provided, wherein gradation display is performed according to a time-division driving method in which the luminescence and non-luminescence of an EL element (109) disposed in a pixel (104) are controlled by time, and the influence by the characteristic variability of a current controlling TFT (108) is prevented. When this method is used, a data signal side driving circuit (102) and a gate signal side driving circuit (103) are formed with TFTs that use a silicon film having a peculiar crystal structure and exhibit an extremely high operation speed.

A display device includes an insulating substrate, a semiconductor layer formed of polycrystalline silicon, including a first impurity area, a second impurity area, and a channel area, an insulating film which covers the semiconductor layer, a gate electrode formed on the insulating film and opposed to the channel area, a source line electrically connected to the first impurity area, an electrode electrically connected to the second impurity area, and a light-shielding film located between the insulating substrate and the semiconductor layer, disposed at a position displaced from a position opposed to the source line, and opposed to an area including a boundary between the channel area and the second impurity area.

A metal element of a metal film is introduced into the oxide semiconductor film by performing heat treatment in the state where the oxide semiconductor film is in contact with the metal film, so that a low-resistance region having resistance lower than that of a channel formation region is formed. A region of the metal film, which is in contact with the oxide semiconductor film, becomes a metal oxide insulating film by the heat treatment. After that, an unnecessary metal film is removed. Thus, the metal oxide insulating film can be formed over the low-resistance region.

A preparation method of a poly-silicon thin film transistor (TFT) array substrate and an array substrate thereof are provided. The preparation method includes: forming a photoresist layer on a poly-silicon layer, and exposing and developing the photoresist layer with a gray tone mask to form patterns of a photoresist completely-reserved region, a photoresist partially-reserved regions and a photoresist completely-removed region; removing part of the poly-silicon layer located in the photoresist completely-removed region, to form patterns of active layers; ashing the photoresist so as to expose part of the active layer located in the photoresist partially-reserved regions and inject P+ ions of high concentration into the part of the active layer, to form doping regions of patterns of source-drain electrodes of a P-type TFT; and stripping off remaining photoresist.

A thin film transistor (TFT) includes a semiconductive layer, a first inter-layer drain (ILD) layer, a second ILD layer, and at least one contact hole passing through the first ILD layer and the second ILD layer. The semiconductive layer includes a channel region, a first lightly doped drain (LDD) region, a second LDD region, a first heavily doped drain (HDD) region, and a second HDD region. The at least one contact hole includes a first portion passing through the second ILD layer and a second portion passing through the first ILD layer. The second portion gradually narrows along a direction from a top to a bottom of the first ILD layer.

The present disclosure relates to the field of display technology, and provides a TFT, its manufacturing method and a display device. A first region of an active layer of the TFT corresponding to a gap between a source electrode and a drain electrode includes a metallic oxide semiconductor layer and a silicon semiconductor layer arranged on the metallic oxide semiconductor layer. The source electrode and the drain electrode are directly lapped onto the active layer.

A semiconductor device that can measure a minute current. The semiconductor device includes a first transistor, a second transistor, a node, and a capacitor. The first transistor includes an oxide semiconductor in a channel formation region. The node is electrically connected to a gate of the second transistor and a first terminal of the capacitor. The node is brought into an electrically floating state by turning off the first transistor after a potential V.sub.0 is supplied. Change in a potential V.sub.FN of the node over time is expressed by Formula (1). In Formula (1), t is elapsed time after the node is brought into the electrically floating state, is a constant with a unit of time, and is a constant greater than or equal to 0.4 and less than or equal to 0.6. $\begin{array}{cc}{V}_{\mathrm{FN}}\left(t\right)=V_0{}^{-{\left(\frac{t}{}\right)}^{}}& \left(1\right)\end{array}$

An active device of a pixel structure includes a semiconductor layer, an insulation layer covering the semiconductor layer, a gate electrode disposed on the insulation layer and electrically connected to a scan line, a protection layer covering the gate electrode, a source electrode and a drain electrode electrically connected to a source region and a drain region of the semiconductor layer. A channel region is disposed between the source region and the drain region. A source lightly doped region is disposed between the channel region and the source region. A drain lightly doped region is disposed between the channel region and the drain region. The light shielding pattern shields the source region, the drain region, the source lightly doped region and the drain lightly doped region. The light shielding pattern is overlapped with one side of the scan line and not overlapped with another side of the scan line.

The invention provides a manufacturing method of a low temperature polysilicon thin film transistor, including: providing a substrate; forming a buffer layer on the substrate; simultaneously forming a polysilicon layer and a photoresist layer on the buffer layer; implanting ions into a source region and a drain region; removing the photoresist layer; forming an insulating layer on the polysilicon layer; forming a gate electrode on the insulating layer; and forming a passivation layer on the insulating layer. The passivation layer covers the gate electrode. The invention can only use one time of mask process and one time of ion implantation process to complete the manufacturing processing of the polysilicon layer, the manufacturing process can be simplified and therefore the cost of process is reduced and the productivity is improved.