A kind of tft copper molybdenum laminated film etchant composition and etching method

Abstract

The invention discloses a TFT copper-molybdenum laminated film etching solution composition. The components and weight percentages of the composition are: 5-30% hydrogen peroxide, 0.1-5% H2SO4, persulfide, chloride, 0.005-0.3% hydrogen peroxide stabilizer, 0.005-0.3% metal complexing agent, 0.005-0.2% surfactant, 0.001-1% azole additives and the balance of water, the sum of the weight percentages of persulfide and chloride 0.01-0.5%. The TFT copper-molybdenum laminated film etchant composition etches the copper-molybdenum laminated film uniformly, has moderate etching rate and long service life.

Description

technical field [0001] The invention relates to the technical field of thin film transistor copper-molybdenum laminated film etching, in particular to a TFT copper-molybdenum laminated film etchant composition. Background technique [0002] Thin film transistor (TFT) liquid crystal display is an active matrix display formed by introducing a thin film transistor switch into a twisted nematic liquid crystal display. In a thin film transistor, amorphous silicon is generally used for the TFT layer, and molybdenum, aluminum, or aluminum alloy is used for the wiring material. Studies have found that molybdenum, aluminum, and aluminum alloys have high resistance, and with the increase in size and resolution of displays, signal delays will occur due to field effect mobility, resulting in uneven display of the screen. The improved technical solution uses copper with low resistivity as the wiring material, but the bonding between copper and glass substrate or silicon substrate is not...

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Problems solved by technology

[0004] However, the above-mentioned hydrogen peroxide-based etching solution has technical defects when used in TFT metal chips: first, the etching solution will continuously decompose during use, and the oxygen bubbles that will be generated by the decomposition of hydrogen peroxide will inevitably adhere to the copper surface or etch The formed side bevel will affect further etching, resulting in uneven etching, poor graphics profile and flatness of copper and molybdenum, and unsatisfactory control of etching angle; second, hydrogen peroxide system The etching of the copper metal film by the etching solution will produce copper ions free in the etching solution. The copper ions have a catalytic effect on the decomposition of hydrogen peroxide and will further accelerate the decomposition of hydrogen peroxide. Therefore, the etching process of the copper-molybdenum laminated film is unstable. At the same time, the life of the etching solution is shortened; third, the time rate selection ratio of the copper / molybdenum laminated film is different; fourth, the activity of fluorine ions is strong, and the use of fluorine-containing etching solutions will cause certain pollution to the operating environment, which is not conducive to operators health, and if the invalid etching solution is not handled correctly, it will also cause serious pollution to the environment