Thin-film transistor, active element array substrate as well as liquid crystal display panel

Abstract

The invention discloses a thin film transistor, an active element array base plate and a liquid crystal display panel, wherein the thin film transistor comprises a base plate, a gate, a gate insulating layer, a channel layer, a source electrode and a drain electrode, the gate and the gate insulating layer are arranged on the base plate, and the gate insulating layer is covered on the gate. The channel layer is arranged on the gate insulating layer which is arranged on the upper of the gate, and the source electrode and the drain electrode are respectively arranged on a part of the channel layer, which are arranged on the two sides of the gate. At least one of the gate, the source electrode and the drain electrode is equipped with a conductive interlayer which is equipped with a bottom conductive layer and a top conductive layer and is located between the bottom conductive layer and the top conductive layer, the materials of the bottom conductive layer and the top conductive layer are different, and substantially, the thickness of the bottom conductive layer is smaller or equal to 150 angstrom. An electrode with the above structure is capable of avoiding that the gate, the source electrode and the drain electrode produce an undercut phenomenon during processing, thereby corresponding thin film transistors are capable of normally operating to maintain the element characteristics and the normal operation of a pixel and further maintain the display quality of the corresponding liquid crystal display panel.

Description

technical field [0001] The present invention relates to a structure of a semiconductor element, and in particular to a structure of a thin film transistor. Background technique [0002] In semiconductor manufacturing processes, thin film transistors (Thin Film Transistor, TFT) are often used as switching elements. Generally speaking, a thin film transistor includes a gate, a gate insulating layer, a channel layer, and a source and a drain. Wherein, the gate electrode, the source electrode and the drain electrode are respectively, for example, a single metal layer or a metal stack composed of aluminum, chromium, tungsten, tantalum, titanium and the like. Among the above-mentioned conductive materials, aluminum is widely used in thin film transistors due to its cheap price and many characteristics, such as low resistivity, good adhesion to the substrate, and good etching characteristics. In the electrode structure of the TFT, the electrode of the thin film transistor is, for...

AI Technical Summary

Problems solved by technology

However, since the etching rate of the etching solution to molybdenum is greater than that of the etching solution to aluminum, the etching solution tends to cause an undercut 110 (undercut) phenomenon as shown in FIG. 1 to the first molybdenum layer 102

In this way, when the electrode in the thin film transistor adopts the structure of molybdenum layer / aluminum layer / molybdenum layer, the above-mentioned undercut phenomenon will make the thin film transistor cannot operate normally; When wiring such as scan lines or data lines, the above-mentioned undercut phenomenon will increase the impedance of the wiring, and even cause disconnection of the scan lines or data lines, thereby affecting the device characteristics of the thin film transistors connected to it.

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