A kind of etchant for silicon-based multilayer film

A multi-layer film and etching solution technology, applied in the direction of surface etching composition, chemical instruments and methods, etc., can solve the problem that it is difficult to meet the processing requirements of thin film transistors, and the etching speed of the silicon nitride layer and the silicon oxide layer cannot be basically the same etc. to achieve the effect of improving wettability and etching uniformity, fast etching speed and smooth etching surface

CN106854468BActive Publication Date: 2018-11-20ZHEJIANG KAISN FLUOROCHEM
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2018-11-20

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Abstract

The invention discloses an etching liquid for silicon system multilayer films. The etching liquid comprises a hydrofluoric acid solution, an ammonium fluoride solution, a surfactant and a compound represented by a general formula shown in the description; and in the formula, R1 is one of an amino group, hydrogen, oxygen and a hydroxyl group, and R2 is one of fluorine, chlorine, hydrogen, a hydroxyl group and a C1-C4 alkyl group. The etching liquid for silicon system multilayer films allows the etching speed of a silicon nitride layer to basically same to the etching speed of a silicon oxide layer, and has a good etching effect.
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Description

technical field

[0001] The invention relates to the technical field of etching an insulating layer of a polysilicon thin film transistor, and more specifically relates to an etchant for a silicon-based multilayer thin film. Background technique

[0002] At present, the low-temperature polysilicon thin-film transistor (LTPS TFT-LCD) of liquid crystal display has been developed and is increasingly mass-produced. The layer is a silicon oxide film. For the processing technology of this structure, using hydrofluoric acid or BOE (buffered oxide etchant, the main components are hydrofluoric acid, ammonium fluoride and water) wet etching is an important step in the preparation of high-performance thin film transistors.

[0003] The low-temperature polysilicon thin film transistor insulating layer etching process is divided into two steps. The first step is to remove the ILD layer and part of the GI silicon oxide layer by dry etching, and the remaining GI silicon oxide layer is remo...

Examples

Embodiment 1

[0029] The components and mass percentages of the etchant for silicon-based multilayer films are:

[0030]

[0031] Pyrimidine and its derivatives are cytosine, and the resistivity of the ultrapure water at 25°C is not less than 18 megohms.

Embodiment 2

[0033] The components and mass percentages of the etchant for silicon-based multilayer films are:

[0034]

[0035] Pyrimidine and its derivatives are uracil, and the resistivity of the ultrapure water at 25°C is not less than 18 megohms.

Embodiment 3

[0037] The components and mass percentages of the etchant for silicon-based multilayer films are:

[0038]

[0039]

[0040] The pyrimidine and its derivatives are 5-fluorocytosine, and the resistivity of the ultrapure water at 25° C. is not lower than 18 megohms.