Low-temperature polycrystalline silicon thin film transistor and preparation method thereof

Abstract

The invention relates to a low-temperature polycrystalline silicon thin film transistor. The low-temperature polycrystalline silicon thin film transistor comprises a substrate, a buffer layer formed on the substrate, a semiconductor layer formed on the buffer layer, a gate insulation layer formed on the buffer layer and the semiconductor layer, gate electrodes formed on the gate insulation layer, a dielectric layer formed on the gate insulation layer and the gate electrodes, and a passivation layer formed on the dielectric layer; first contact holes and second contact holes are formed in the passivation layer, the dielectric layer and the gate insulation layer, a source electrode and a drain electrode are respectively formed on the first contact holes, and a source electrode and a drain electrode are respectively formed on the second contact holes; and the semiconductor layer is a low-temperature polycrystalline silicon layer, and a reflection layer and / or a heat insulation layer are further disposed between the buffer layer and the semiconductor layer. The invention further relates to a preparation method of the thin film transistor, and the thin film transistor is prepared mainly through utilization of deposition, photoetching, etching, laser irradiation and the other process methods. According to the low-temperature polycrystalline silicon thin film transistor, the large dimensions of polycrystalline silicon grains can be obtained, and obtaining of the large electron mobility is facilitated.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a low-temperature polysilicon thin film transistor and a preparation method thereof. Background technique [0002] Thin film transistors (TFT, ThinFilmTransistor) are used as switching elements in liquid crystal display devices, which have the characteristics of low power consumption, small volume and low driving voltage, and are very suitable for display devices of computers, notebooks and other devices . In the current liquid crystal display device, the active layer of the thin film transistor mainly uses amorphous silicon (amorphous silicon, a-Si), but the mobility of the thin film transistor using amorphous silicon as the active layer is very low, and it is difficult to meet the driving requirements of the peripheral circuit. The technology of using low temperature polysilicon (LowTemperaturePoly-silicon, LTPS) instead of amorphous silicon came into being. [0003] The mob...

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Problems solved by technology

It can be seen that the polysilicon grain size manufactured by the above two methods is small, which limits the practical application of polysilicon

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