Low-temp. polycrystalline silicon film transistor and its polycrystalline silicon layer making method

Abstract

The invention provides a low-temperature polycrystalline silicon film transistor and its polycrystalline silicon layer making method. First, form a noncrystalline silicon layer on a panel which including a display region and a peripheral circuit region. Then, form a metal layer on a part of the noncrystalline silicon layer in peripheral circuit region, then crystallize to make the other part form a polycrystalline silicon layer. Successively, make a quasi-molecular laser annealing processing to largen the crystal particles on the polycrystalline silicon layer and make the noncrystalline silicon layer in the display region into a polycrystalline silicon layer. Because the crystal particles of polycrystalline silicon in the peripheral circuit region are larger than those in the other parts, it can meet the demand of high-electron mobility. And because the crystal particles of polycrystalline silicon are smaller, it can meet the demand of low-leakage current.

Description

technical field [0001] The present invention relates to a method for manufacturing a low temperature polysilicon (LTPS) thin film transistor (thin film transistor, referred to as TFT), and in particular to a method for manufacturing a polysilicon layer in a low temperature polysilicon thin film transistor. Background technique [0002] With the development of high technology, video products, especially digital video or image devices have become common products in daily life. In these digital video or image devices, the display is an important component to display relevant information. Users can read information from the display, or further control the operation of the device. [0003] Thin-film transistors (TFT) can be applied to drive components of liquid crystal displays (LCDs for short), making this product the mainstream of straight flat-panel displays on desktops, and becoming a popular choice in markets such as personal computers, game consoles, and monitors. Future ...

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Problems solved by technology

However, the disadvantage of the metal-induced crystallization process is that there are too many defects in the grown polysilicon layer, and a high-temperature post-process, such as a rapid thermal process or laser annealing process, is required. laser annealing process

[0006] However, taking the known active-matrix liquid crystal display as an example, the low-temperature polysilicon thin-film transistors in its peripheral circuits must have high electron mobility and on-state current; the display area (pixel area) must have The requirement of low leakage current; and the current polysilicon formed by the excimer laser annealing process cannot meet these two requirements at the same time

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