Low-temperature poly-crystal thin film transistor and preparation method thereof

Abstract

A preparation method of a low-temperature poly-silicon thin film transistor comprises the following steps of forming a first amorphous-silicon layer on a substrate; forming doping layers on regions, corresponding to a source doping layer and a drain doping layer to be formed, on the first amorphous-silicon layer; carrying out laser irradiation on the substrate formed with the first amorphous-silicon layer and the doping layers so as to convert the first amorphous-silicon layer to a first poly-silicon layer; forming a second amorphous-silicon layer on the first amorphous-silicon layer and the doping layers; and carrying out laser irradiation on the substrate formed with the second amorphous-silicon layer to form a second poly-silicon layer, the source doping layer and the drain doping layer. According to the preparation method of the low-temperature poly-silicon thin film transistor, the first poly-silicon layer also can be taken as a second amorphous-silicon thin film to be converted into a grain structure induction layer of the poly-silicon layers, the requirements of excimer laser pulse energy stability and light beam energy density uniformity during preparation of the low-temperature poly-silicon thin film can be effectively reduced, and the problem of non-uniform display caused by laser annealing processing can be effectively solved.

Description

technical field [0001] The invention relates to the technical field of transistor manufacturing, in particular to a low-temperature polysilicon thin film transistor and a preparation method thereof. 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] At present, the most widely used polysilicon film crystallization method i...

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Problems solved by technology

It needs to go through a process of photoresist coating, mask exposure, development and etching, which increases the complexity of the process, high manufacturing cost and low production efficiency

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