BACKGROUND OF INVENTION

Field of Invention

This disclosure relates to the field of display technology, particularly, relates to TFT device and manufacturing method of same, TFT array substrate, and display device.

Description of Prior Art

Thin film transistors (TFTs) are important components of a tablet display device. They can be formed on a glass substrate or a plastic substrate. Generally, they are used in liquid crystal display (LCD) devices and organic light emitting (OLED) devices as a switching device and a driving device.

As a metal oxide semiconductor is quite sensitive to illumination, when the metal oxide semiconductor is illuminated by light, obviously, a threshold voltage of a metal oxide semiconductor TFT shifts negatively. Presently, an improved method configures a metal light-shielding layer under an active layer consisted of the metal oxide semiconductor material to eliminate the negative shift of the threshold voltage of the TFT induced by illumination. But the metal light-shielding layer can be easily affected by voltages of other charged structural layers so as to carry various uncertain voltages, which can easily lead to a floating gate effect. The threshold voltage of the TFT will be changing continuously during working, which leads to an unstable operation of the TFT. Presently, an improved method is to form holes in the light-shielding layer and a buffer layer and connecting a source electrode, the active layer and the light-shielding layer with conductive lines to shield the voltage of the light-shielding layer.

Above all, the TFT device in prior art can easily induce a floating gate effect so as to affect operational stability of the TFT. It is needed to form holes in the light-shielding layer and the buffer layer and connect the source electrode, the active layer and the light-shielding layer with conductive lines, which adds one more mask, and corresponding exposure and etching process. Problem of manufacturing cost-up of the TFT needs to be solved.

SUMMARY OF INVENTION

This disclosure provides a TFT device and manufacturing method of the same, TFT array substrate, and display device to solve following problems: a floating gate effect can easily happen in the TFT device in prior art so as to affect the operational stability of the TFT. It is needed to form holes in the light-shielding layer and the buffer layer and connect the source electrode, the active layer and the light-shielding layer with conductive lines, which adds one more mask, and corresponding exposure and etching process, thus increase manufacturing cost of the TFT.

To solve the above problems, a TFT thin film transistor(TFT) device is provided, comprising:

a base substrate;

a light-shielding layer disposed on the base substrate;

a buffer layer disposed on the light-shielding layer and covering the light-shielding layer;

an active layer disposed on the buffer layer and corresponding to the light-shielding layer, wherein the active layer comprises a channel, and a source doping member and a drain doping member which are disposed on two sides of the channel;

wherein one of the source doping member and the drain doping member is attached to the buffer layer and the light-shielding layer.

In one exemplary embodiment, a cross-sectional shape of the active layer comprises a bending shape and comprises a horizontal part and an inclined part, and the horizontal part is connected to the light-shielding layer through the inclined part.

In one exemplary embodiment, the horizontal part and the inclined part are integrally formed, and the inclined part is attached to the buffer layer and the light-shielding layer, and the inclined part extends to a surface of the base substrate.

In one exemplary embodiment, the materials of the active layer is metal oxide, and the source doping member and the drain doping member are defined as conductive layers after a conductive treatment.

In one exemplary embodiment, a source electrode of the TFT device is electrically connected to the light-shielding layer by the source doping member, and a drain electrode of the TFT device is insulated from the light-shielding layer.

In one exemplary embodiment, a drain electrode of the TFT device is electrically connected to the light-shielding layer by the drain doping member, and a source electrode of the TFT device is insulated from the light-shielding layer.

To solve the above problems, a manufacturing method of a TFT device is also provided, comprising following steps:

a step of S10of providing a base substrate, forming a light-shielding layer on the base substrate, forming a buffer layer which covers the light-shielding layer on the light-shielding layer, and forming an active layer on the buffer layer corresponding to the light-shielding layer, wherein the active layer comprises a channel, and a source doping member and a drain doping member which are disposed on two sides of the channel; and

a step of S20of attaching one of the source doping member and the drain doping member to the buffer layer and the light-shielding layer.

In one exemplary embodiment, the step of S20of attaching one of the source doping member and the drain doping member to the buffer layer and the light-shielding layer further comprises the steps:

selecting metal oxide semiconductor material as materials of the source doping member and the drain doping member, and processing conductive treatment on the metal oxide semiconductor to decrease the oxygen content, so that a resistivity of the metal oxide semiconductor material decreases and the metal oxide semiconductor material turns into conductor.

According to the above TFT device, a TFT array substrate is provided, comprising the above-mentioned TFT device.

According to the purpose of this disclosure, a display device is provided, comprising the above-mentioned TFT array substrate.

Beneficial effects of disclosure would be as below: by configuring the light-shielding layer under the active layer, the active layer can be protected from illumination, the negative shift of the threshold voltage of the TFT can be prevented. One end of the active layer is attached to the buffer layer and the light-shielding layer and extends to the surface of the base substrate. A conductive treatment is conducted on the active layer with a gate electrode and a gate insulator as stopper layers, one of the source doping member and the drain doping member is attached to the buffer layer and the light-shielding layer to generate a stable voltage on the light-shielding layer to prevent the floating gate effect from happening and increase the operational stability of the TFT. At the same time, forming holes in the light-shielding layer and the buffer layer is avoided and connecting the source electrode, the active layer and the light-shielding layer with conductive lines is no more needed, which decreases one mask, and corresponding exposure and etching process, thus decreases manufacturing cost of the TFT.

