Thin film transistor and manufacturing method thereof

Abstract

The embodiment of the invention relates to the technical field of display panels, in particular to a thin film transistor and a manufacturing method thereof, for the thin film transistor, a first active layer can be protected by a second active layer, and structural defects cannot be caused to the first active layer when a drain-source layer is etched. Therefore, when a positive voltage is applied to the first gate electrode, carriers deviate towards the surface, close to the first gate dielectric layer, of the first active layer and are not captured, a stable carrier transport channel (a first conductive channel) can be formed, the turn-on current can be improved, and the sub-threshold swing can be reduced. Besides, based on the fact that the Fermi level of the second active layer is higher than that of the first active layer, when the thin film transistor is communicated for electric conduction, electrons drift from the second active layer with the high Fermi level to the first active layer with the low Fermi level, more electrons participate in electric conduction in the first conducting channel, and the conductivity of the thin film transistor is improved. And the turn-on current of the thin film transistor can be further effectively improved.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of display panels, and in particular, to a thin film transistor and a method for manufacturing the same. Background technique [0002] Thin film transistors (TFTs) are an important part of display panels. TFTs can be formed on glass substrates or plastic substrates and used as switching and driving components in flat display devices such as LCD and OLED. The thin film transistor includes a single-gate thin-film transistor (Single-Gate TFT) and a double-gate thin-film transistor (Double-Gate TFT). Wherein, the single-gate thin film transistor includes a top-gate thin-film transistor and a bottom-gate thin-film transistor, wherein the gate and insulating layer of the bottom-gate thin-film transistor can simultaneously serve as an optical protective layer, thereby avoiding the generation of photo-generated carriers and having Good electrical stability, can be widely used. In addition, th...

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Problems solved by technology

Wherein, after the active layer is completed, when the drain / source electrode 15 is etched, the etchant will cause damage to the active layer 14, such as figure 2 As shown, the surface of the active layer 14 produces more defects

First, when figure 1 When the bottom-gate thin film transistor shown is turned on, the defects will trap carriers, resulting in reduced turn-on current and weakened gate control capability

Second, the defect will lead to higher subthreshold swing and lower stability when the bottom gate TFT is turned on

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