Method for preparing polycrystalline silicon thin film by laser crystallization and product and thin film transistor obtained

Abstract

The invention relates to the technical field of TFT thin film transistors, in particular to a method for preparing a polycrystalline silicon thin film by laser crystallization and a product and a thinfilm transistor obtained. The preparation steps are as follows: S1, forming a thermistor layer on a glass substrate; S2, forming an amorphous silicon layer on the thermistor layer; and S3, irradiating the amorphous silicon film layer in S2 with laser pulse, and heating the thermistor layer by electric heating or electromagnetic heating to convert the amorphous silicon layer into a polycrystallinesilicon layer. There is a process of forming an isolation layer on the glass substrate before S1, and the isolation layer is made of silicon oxide and / or silicon nitride. The polycrystalline siliconthin film obtained has the characteristics of high grain uniformity, high consistency of grain density, high grain migration rate and high stability. The thin film transistor obtained has the characteristics of no spot, uniform brightness and good electrical performance.

Description

technical field [0001] The invention relates to the technical field of TFT thin film transistors, in particular to a method for preparing polysilicon thin films by laser crystallization, the obtained products and thin film transistors. Background technique [0002] Polysilicon has been widely valued in the manufacture of thin film transistors in recent years, especially in the application of thin film transistors to drive displays, due to its superior electrical properties to amorphous silicon and the advantages of lower cost than single crystal silicon. [0003] At present, the excimer laser tempering technology and metal-induced amorphous silicon crystallization are commonly used in the production of polysilicon thin films, namely ELA technology and MIA technology, but the existing ELA technology has the following defects: laser Energy fluctuations between different pulses, uneven energy density at different parts of the laser beam cross-section, uneven thickness of amorph...

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Problems solved by technology

[0003] At present, the excimer laser tempering technology and metal-induced amorphous silicon crystallization are commonly used in the production of polysilicon thin films, namely ELA technology and MIA technology, but the existing ELA technology has the following defects: laser Energy fluctuations between different pulses, uneven energy density at different parts of the laser beam cross-section, uneven thickness of amorphous silicon film, etc., these defects will lead to temperature fluctuations and unevenness of amorphous silicon after being heated by laser, thus affecting the uniformity of crystallization Insufficient brightness of transistors, uneven color ELA mura and other problems

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