Method for producing polycrystalline thin film transistor

Abstract

Said polysilicon thin film transistor making method makes patterning to non-crystalline silicon layer after forming non-crystalline silicon layer on substrate to form silicon island graphic, advance defining out assembly active area. Then said method utilizes single shot long pulse laser bean to radiate silicon island graphic, to induce silicon island generating super transverse direction long glittering acting, converting non-crystalline silicon to polysilicon, finally according to sequence to proceed follow-up thin film transistor making process to complete polysilicon thin film transistor manufacture.

Description

technical field [0001] The present invention relates to a method for manufacturing polysilicon thin film transistors, and in particular to a method for manufacturing polysilicon thin films with regularly distributed super laterally grown crystal grains, so as to be applied to the manufacture of large-area thin film transistor displays. Background technique [0002] Polysilicon (poly-silicon) has been widely valued in the manufacture of thin-film transistors in recent years because of its electrical characteristics superior to amorphous silicon and its cost advantage lower than that of single-crystal silicon, especially in thin-film transistor-driven liquid crystal displays (TFT -LCD) applications. [0003] However, the grain size of polysilicon crystals directly has a great impact on electron mobility and component characteristics. Therefore, how to increase the crystal grain size of polysilicon to promote the improvement of the characteristics of thin film transistor compon...

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Problems solved by technology

However, the crystal grains of polysilicon formed by the above-mentioned solid phase crystallization method or direct vapor deposition method are quite small, with a particle size of only about 100nm. Therefore, the properties of polysilicon thin films formed by these methods are not good.

[0005] At present, the Excimer Laser Anneal (ELA) technology is most commonly used in the production of polysilicon thin films. Although the polysilicon grain size that can be obtained can reach about 600nm, for the development of higher performance Flat screens are still not enough

At the same time, the general existing excimer laser tempering technology must use high repetition rate irradiation to improve the shortcomings of uneven laser energy distribution and unstable energy output, so as to reduce the phenomenon of uneven grain size distribution.

[0006] Among them, the problem of uneven grain size distribution will directly damage the electrical uniformity of the components and the consistency of the threshold voltage or sub-threshold swing value between components, and affect the production quality of the display when it develops towards a large area.

In addition, the excimer laser tempering process irradiated at a high repetition rate will also lead to an increase in production costs and a decrease in productivity, which is even more unfavorable for mass production of large-area displays

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