Transistor and preparation method thereof, display substrate and display device

Abstract

The invention provides a transistor, a preparation method thereof, a display substrate and a display device. The transistor comprises a substrate structure, a gate electrode, a source electrode, a drain electrode and an active layer, wherein the gate electrode, the source electrode, the drain electrode and the active layer are arranged on the substrate structure. The gate electrode, the source electrode and the drain electrode are all located at one side, deviating from the substrate structure, of the active layer. The active layer comprises a first region corresponding to an orthographic projection region of the gate electrode on the substrate structure and a second region located outside the orthographic projection region, wherein the second region is made of a conductive semiconductor material, and the surface, in contact with the first region, of the substrate structure and the surface, in contact with the second region, of the substrate structure are not in the same plane. The surface, in contact with the first region, of the substrate structure and the surface, in contact with the second region, of the substrate structure are not in the same plane, so the transistor enables the height difference to be formed between the first region and the second region of the active layer, and the diffusion path of an active layer material from the second region to the first region in the conductor formation is lengthened, and the diffusion of the active layer material needs greater energy, thereby improving the poor threshold voltage uniformity of the transistor caused by the short-channel effect.

Description

technical field [0001] The present invention relates to the field of display technology, in particular to a transistor and its preparation method, a display substrate and a display device. Background technique [0002] At present, AMOLED products are developing towards high definition, large size and high refresh rate. This puts higher requirements on the thin film transistor (TFT) of the AMOLED driving circuit. Since the top gate (Top Gate) oxide semiconductor transistor can effectively reduce the parasitic capacitance, the refresh frequency is better; and its channel is shorter, the size is smaller, and it can better meet the needs of AMOLED development, so the top gate oxide semiconductor transistor It is a key direction of future research and development. [0003] However, the short-channel effect of the top-gate oxide semiconductor transistor will affect the uniformity of the threshold voltage of the transistor to a certain extent. Especially in the conductorization ...

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Problems solved by technology

[0003] However, the short-channel effect of the top-gate oxide semiconductor transistor will affect the uniformity of the threshold voltage of the transistor to a certain extent.

Especially in the conductorization process of the active layer of the transistor, the oxide semiconductor material in the active layer will diffuse into the channel, so that the effective channel length of the transistor is further shortened, which further aggravates the short channel effect of the transistor on its threshold value. Effect of Voltage Uniformity

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