Low-temperature polysilicon thin film transistor, preparation method and array substrate

Abstract

The invention discloses a low-temperature polysilicon thin film transistor, preparation method and array substrate. The method includes providing a substrate; sequentially forming a buff layer, a low-temperature polycrystalline silicon layer, a source contact region, a drain contact region, a gate insulating layer, a gate layer and a dielectric layer on a substrate; forming a first contact hole and a second contact hole through the dielectric layer and the gate insulating layer, respectively, by dry etching to expose the source contact region and the drain contact region, respectively; Depositing a titaniumaluminumtitanium three-layer structure film layer on the dielectric layer; C2HF5 gas is use for plasma cleaning the surface of the source electrode and the drain electrode. The implementation of the invention can improve the effect of preparing the source electrode and the drain electrode post-treatment process and reduce the cost.

Description

Technical field [0001] The invention relates to the technical field of low-temperature polysilicon thin film transistors (LTPS-TFF), in particular to a low-temperature polysilicon thin film transistor, a preparation method and an array substrate. Background technique [0002] At present, in the traditional low-temperature polysilicon thin-film transistor (LTPS-TFT) manufacturing process, the titanium / aluminum / titanium (Ti / AL / Ti) film layer is dry etched to form a source / drain (Source) / Drain) driving circuit; and Ti / AL / Ti film layer generally adopts chlorine gas (CL 2 ) For etching, in CL 2 After the etching is completed, CL and AL are replaced with AlCL 3 The form attached to the surface of the AL film, the specific chemical reactions involved are as follows: [0003] Cl 2 Cl - +Cl + +Cl*+Cl 2 * [0004] Ti+Cl*+Cl - TiCl x ↑(where TiCl x Take TiCl 4 Mainly, there are transitional compounds at the same time) [0005] Al+ Cl*+Cl - ALCl x ↑(where AlCl x AlCl 3 Mainly, there are tran...

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Problems solved by technology

[0011] However, for CF 4 In this compound, C-F is a covalent bond, and the binding force of C and F is particularly strong. If you want to break the C-F covalent bond, you need to provide a high amount of extra energy. Therefore, for dry etching equipment, a higher power supply is required. For the factory, it will use higher power, that is, more power consumption; at the same time, in order to ensure sufficient F*, CF 4 CF with higher flow must be fed 4 , which will increase the factory investment cost; therefore, there are some deficiencies in the processing effect of the existing method, such as figure 1 shown, showing that the CF used in the prior art 4 The schematic diagram of the local structure of the structure formed by etching the Ti-AL-Ti film layer above; it can be seen that the CF 4 The result of the product film layer obtained after post-processing, the side wall of the film layer is sunken, and there will be concave and convex corrosion on the surface of the film layer

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