Low temperature polysilicon thin film and its preparation method, and thin film transistor

Abstract

Provided is a LTPS film preparation method, comprising the steps of: forming a buffer layer on a substrate; performing composition processing on the buffer layer, and forming a groove on the buffer layer corresponding with a non-channel region; forming a graphene layer in the groove; depositing an amorphous silicon layer on the buffer layer; and performing laser annealing processing on the amorphous silicon layer to allow the amorphous silicon to form a p-Si layer. The LTPS film is provided with the graphene layer in the corresponding area of the no-channel region, and utilizes the thermal conductivity of grapheme to form a temperature gradient in the film, thereby ensuring that LTPS p-Si grains are larger and are uniformly distributed.

Description

technical field [0001] The invention relates to the technical field, in particular to a method for preparing a low-temperature polysilicon thin film, a thin film transistor, and a thin film transistor. Background technique [0002] Polycrystalline silicon (p-Si) thin film has a high carrier mobility much higher than that of amorphous silicon (a-Si) and comparable to that of single crystal silicon, and is often used instead of amorphous silicon in the active layer, and thus have very important applications in integrated peripheral-driven active liquid crystal displays (AMLCDs) and active organic light-emitting diodes (AMOLEDs). The substrate of the polysilicon thin film of the flat panel display is glass which is difficult to withstand the high temperature process. Under the constraints of this condition, the low temperature polysilicon (LTPS) technology is an inevitable choice for the industry. [0003] As far as the current technology is concerned, the low-temperature poly...

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Problems solved by technology

In the prior art, the amorphous silicon layer is directly formed on the buffer layer. During the process of excimer laser annealing, the heating conditions of each region of the amorphous silicon layer tend to be consistent. The starting point of recrystallization and the growth direction of the crystal grains are Messy, resulting in small grain size of low-temperature polysilicon after recrystallization, and more grain boundaries between grains, which affects the electron mobility of polysilicon, and then affects the reaction speed of flat panel display

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