Processing method for improving threshold voltage of thin film transistor (TFT) device

Abstract

A processing method for improving a threshold voltage of a thin film transistor (TFT) device is applied before a gate insulation layer formed on a poly-silicon channel film layer and comprises the following steps of performing hydrofluoric acid cleaning operation on the poly-silicon channel film layer with hydrofluoric acid; performing protection atmosphere thermal processing operation on the poly-silicon channel film layer subjected to hydrofluoric acid cleaning operation; performing first-time ionization operation on hydrogen in a vacuum chamber to form first plasma, and performing first-time plasma cleaning operation with the first plasma; and performing second-time ionization operation on nitrogen monoxide in the vacuum chamber to form second plasma, and performing second-time plasma cleaning operation with the second plasma. By the processing method for improving the threshold voltage of the TFT device, an interface state between the poly-silicon channel film layer and the gate insulation layer can be improved, the threshold voltage of the TFT device can be reduced, so that the threshold voltage of the TFT device can be improved.

Description

technical field [0001] The invention relates to the technical field of display equipment manufacturing, in particular to a processing method for improving the threshold voltage of a TFT device. Background technique [0002] During the manufacturing process of LTPS (Low Temperature Poly-silicon, low-temperature polysilicon technology), the interface state between polycrystalline silicon (P-Si) and gate insulating layer (Gate Insulator, GI) affects the threshold voltage (Threshold) of TFT devices. voltage, V th ). The threshold voltage and its uniformity of the entire TFT device directly affect the electrical performance and service quality of the TFT device. Therefore, in the specific preparation process of TFT devices, TFT devices with lower threshold voltage should be prepared as far as possible to have excellent device performance. [0003] In the existing LTPS process system, a layer of amorphous silicon is usually deposited on the substrate by chemical vapor depositio...

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Problems solved by technology

At the same time, in the specific production process, it will also cause defects at the polysilicon film layer interface, such as the oxide layer caused by the ELA crystallization process, the silicon dangling bonds caused by ion etching, and the crystal structure damage caused by ion implantation, etc., thus As a result, there are many interface defects between the polysilicon channel film layer and the GI film layer, and the interface is uneven, which seriously affects the performance of TFT devices

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