A flexible fully transparent amorphous oxide thin film transistor and its preparation method

Abstract

The invention relates to the field of a thin film transistor, and provides a flexible full-transparent amorphous oxide thin film transistor and a preparation method thereof. The flexible full-transparent amorphous oxide thin film transistor comprises a substrate, a channel layer, a dielectric layer, a gate (G) electrode layer and a source / drain electrode layer, wherein the source / drain electrode layer is a silver-based transparent conductive multi-layer film composed of two layers of transparent conductive oxide (TCO) films and a silver (Ag) film sandwiched between the two layers of transparent conductive oxide (TCO) films, a TCO is a high-valence doping tin oxide based oxide SnO2 containing Sn element and M element, in the oxide SnO2, the atomic weight of the M element in M is that M / (M+Sn) is equal to 0-0.01, and the M element is at least one of Cr, Mo and W. The amorphous oxide thin film transistor provided by the invention has the advantages of compatibility of a preparation process temperature with a flexible transparent substrate, high visible light transmittance and favorable electrical property.

Description

technical field [0001] The invention relates to the field of thin film transistors, in particular to a flexible fully transparent amorphous oxide thin film transistor. Background technique [0002] With the in-depth development of the flat panel display industry, flexible and transparent active matrix organic light-emitting diode display (AMOLED) technology has become a new type of "dream display" technology that has attracted much attention. [0003] Therefore, many scholars have begun to turn their attention to thin-film organic light-emitting display devices. For example, Patent No. 200710075139.2 discloses a transparent conductive film substrate, a metal electrode layer, and an organic thin film layer sandwiched between the transparent conductive film substrate and the metal electrode layer. organic electroluminescent display devices. [0004] This behavior makes the core component "thin film transistor (TFT) device" in the active drive of flat panel display face new ch...

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Problems solved by technology

[0005] However, finding suitable source / drain electrode materials for flexible fully transparent amorphous oxide TFTs has become a difficult problem that needs to be broken through in this field.

Although traditional transparent conductive oxides (TCO), such as: In 2 o 3 : Sn(ITO), ZnO:Al(AZO), ZnO:Ga(GZO), etc. are recognized transparent electrode materials, but studies have shown that when traditional TCO films are used as source / drain electrodes, the performance of amorphous oxide TFT devices is comparable to that of When an opaque metal electrode is used as the source / drain electrode, it shows obvious deterioration, mainly reflected in: the on-state current decreases sharply, and even the device shows poor stability and the output characteristics lose the typical linear saturation characteristics

[0006] In fact, since the source (S) / drain (D) electrodes in an amorphous oxide TFT are in direct contact with the amorphous oxide channel layer, it can be used as a traditional TCO material for the gate electrode of an amorphous oxide TFT, which It is not ideal as the source (S) / drain (D) electrode of the device. The reasons are as follows: First, the resistivity of traditional TCO prepared at low temperature is too high, generally higher than 1×10 -4 Ω cm; secondly, it is not easy to balance the ohmic contact between the TCO electrode and the amorphous oxide channel layer and the TCO electrode with low resistivity; thirdly, the traditional TCO composition contains indium or zinc element At least one, and, in the indium-containing oxide electrode, there is a problem that indium is easy to diffuse into the amorphous oxide channel layer, or there is an oxygen adsorption problem in the zinc-containing oxide electrode, and the diffusion problem and / or the oxygen adsorption problem are both Will degrade the electrical stability of amorphous oxide TFT

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