Cu-MTD etching solution composition for oxide semiconductor protection

Abstract

The present invention relates to a Cu-MTD etching solution composition for oxide semiconductor protection. By weight percentage, the components include: 13-25% hydrogen peroxide, 2-6% chelating agent, 0.1-4% etching agent, 0.02-5% inhibitor, 0.01-3% hydrogen peroxide stabilizer, and water makes up the surplus; the inhibitor includes a first inhibitor, a second inhibitor and a third inhibitor, the first inhibitor includes a heterocyclic aromatic compound and / or a heterocyclic aliphatic compound, the second inhibitor includes an ammonium hydroxide, and the third inhibitor includes an organic acid zinc. Adding heterocyclic aromatic compounds and / or heterocyclic aliphatic compounds, ammonium hydroxide and organic acid zinc at the same time can effectively suppress the change of IGZO surface characteristics during the etching process, thereby ensuring that the finally formed electronic components have the excellent characteristics of high mobility.

Description

Technical Field

[0001] The invention relates to the technical field of etching solutions, and in particular to a Cu-MTD etching solution composition for protecting oxide semiconductors. Background Art

[0002] In the complex manufacturing process of oxide TFT (oxide thin film transistor) panels, the precise formation of source / drain metal wiring is one of the key steps to ensure device performance. In this process, In-Ga-Zn-O (IGZO, indium gallium zinc oxide), as a high-performance oxide semiconductor material, is widely used in TFT structures due to its excellent electron mobility and high transparency. However, as the metal wiring is gradually formed, the IGZO layer will inevitably be exposed. The exposure of the IGZO layer is a sensitive stage, and any slight damage may have a significant impact on the final device performance. It directly affects the display quality and reliability of the oxide TFT panel. Although the existing etching solution has excellent etching effect, it often causes serious damage to the IGZO layer, limiting its wide application in actual production. Therefore, the development of new etching technology and materials that can effectively etch metal wiring and protect the IGZO layer from damage to the maximum extent is still a key challenge to be solved in the current oxide TFT panel manufacturing field.

[0003] Chinese invention patent CN111902569B provides an etching solution for inhibiting damage to IGZO. It contains: hydroxyethane diphosphonic acid (A), phosphonic acid (B), hydrogen peroxide (C), nitric acid (D), fluorine compound (E), azole (F) and base (G), the aforementioned phosphonic acid (B) contains one or more selected from the group consisting of diethylenetriamine pentamethylenephosphonic acid, N,N,N',N'-ethylenediamine tetramethylenephosphonic acid and aminotrimethylenephosphonic acid, the proportion of the aforementioned hydroxyethane diphosphonic acid (A) is in the range of 0.01 to 0.1 mass%, and the proportion of the aforementioned phosphonic acid (B) is in the range of 0.003 to 0.04 mass%. The invention can reduce the degree of damage to a certain extent, but since the damage on the IGZO surface often shows unevenness, this uneven damage will lead to inconsistent surface characteristics, thereby affecting the overall performance of the device. Summary of the invention

[0004] The invention provides a Cu-MTD etching solution composition for oxide semiconductor protection. The components include, by weight percentage, 13-25% of hydrogen peroxide, 2-6% of a chelating agent, 0.1-4% of an etching agent, 0.02-5% of an inhibitor, 0.01-3% of a hydrogen peroxide stabilizer, and the balance is made up of water; the inhibitor includes a first inhibitor, a second inhibitor and a third inhibitor, the first inhibitor includes a heterocyclic aromatic compound and / or a heterocyclic aliphatic compound, the second inhibitor includes ammonium hydroxide, and the third inhibitor includes organic acid zinc.

[0005] The present application has found that by adding a first inhibitor, a second inhibitor and a third inhibitor at the same time, and the first inhibitor includes a heterocyclic aromatic compound and / or a heterocyclic aliphatic compound, the second inhibitor includes an ammonium hydroxide, and the third inhibitor includes an organic acid zinc, the changes in the surface properties of IGZO can be effectively suppressed during the etching process, thereby ensuring that the electronic components finally formed have excellent characteristics of high mobility. It may be that the IGZO surface is mainly composed of dense In oxides. When Zn ions are adsorbed onto its surface, it can effectively suppress the damage to the IGZO surface structure by etching agents such as hydrogen peroxide or organic acids. At the same time, a large amount of N-group (nitrogen group) raw materials are used as chelating agents, which synergize with Zn ions to jointly protect the IGZO surface.

[0006] In the process of etching copper metal, when the upper metal is MTD (Mo, Ti, Ni) or molybdenum alloy, and the lower metal is molybdenum alloy, the adhesion between these metals and photoresist is relatively small, which may cause the etching liquid composition to corrode the upper metal, thereby causing poor etching. Especially when the upper metal is MTD, this problem is particularly prominent. The applicant further found that by limiting the weight ratio of the first inhibitor, the second inhibitor and the third inhibitor to (0.1-0.8): (0.3-1): (0.01-0.2), poor etching can be further avoided. It may be that the raw materials of the inhibitors in a specific ratio at the interface of the photoresist and the MTD form huge ligand cations, which can effectively inhibit the chemical liquid from penetrating into the fine seam through capillary action, thereby significantly reducing the corrosion phenomenon of the upper metal, helping to improve the etching quality and ensure the reliability and stability of electronic components.

[0007] Preferably, the components include: 18-25% hydrogen peroxide, 2.5-4.5% chelating agent, 1-3% etching agent, 0.5-4.8% inhibitor, 0.2-1% hydrogen peroxide stabilizer, and water makes up the balance.

[0008] The etchant includes an organic acid not containing a nitrogen atom and / or a salt of an organic acid not containing a nitrogen atom.

[0009] Preferably, the non-nitrogen-containing organic acid includes at least one of acetic acid, formic acid, butyric acid, citric acid, glycolic acid, oxalic acid, malonic acid, malic acid, valeric acid, propionic acid, tartaric acid, gluconic acid, and succinic acid.

[0010] The weight ratio of the first inhibitor, the second inhibitor and the third inhibitor is (0.1-0.8): (0.3-1): (0.01-0.2).

[0011] Preferably, the weight ratio of the first inhibitor, the second inhibitor and the third inhibitor is 1:(1-5):(0.1-1).

[0012] Further preferably, the weight ratio of the first inhibitor, the second inhibitor and the third inhibitor is 1:(2-4):(0.1-0.6).

[0013] The heterocyclic aromatic compound includes at least one of furan, thiophene, pyrrole, oxazole, imidazole, pyrazole, triazole, tetrazole, 5-aminotetrazole, and methyltetrazole.

[0014] The heterocyclic aliphatic compound includes at least one of piperazine, methyl piperazine, hydroxyethyl piperazine, pyrrolidine and alloxan.

[0015] The ammonium hydroxide includes at least one of ammonium hydroxide, tetraalkylammonium hydroxide, and trihydroxyalkylammonium hydroxide.

[0016] The tetraalkylammonium hydroxide includes at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide and tetrabutylammonium hydroxide.

[0017] The organic acid zinc includes at least one of zinc acetate, zinc borate, zinc gluconate, zinc glycinate, zinc citrate, zinc malate and zinc succinate.

[0018] The chelating agent includes at least one of diethylenetriaminepentaacetic acid, iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethyltrinitrovaleric acid, aminotrimethylenephosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepenta(methylenephosphonic acid), alanine, glutamic acid, aminobutyric acid, and glycine.

[0019] The hydrogen peroxide stabilizer includes alkylamine compounds.

[0020] Preferably, the hydrogen peroxide stabilizer includes at least one of butylamine, pentylamine, octylamine, 2-ethyl-1-butylamine, 2-hexylamine, 2-ethyl-hexylamine, 2-ethyl-hexylamine, heptylamine, hexylamine, and cyclohexylamine.

[0021] Beneficial Effects

[0022] 1. Adding a first inhibitor, a second inhibitor and a third inhibitor at the same time, wherein the first inhibitor comprises a heterocyclic aromatic compound and / or a heterocyclic aliphatic compound, the second inhibitor comprises an ammonium hydroxide, and the third inhibitor comprises an organic acid zinc, can effectively inhibit the change of the surface properties of IGZO during the etching process, thereby ensuring that the finally formed electronic components have the excellent property of high mobility.

[0023] 2. By limiting the weight ratio of the first inhibitor, the second inhibitor and the third inhibitor to (0.1-0.8):

[0024] (0.3-1):(0.01-0.2), which can further avoid poor etching.

[0025] 3. By limiting the weight ratio of the first inhibitor, the second inhibitor and the third inhibitor to 1:(1-5):

[0026] (0.1-1), can further improve the etching effect, ensure CD-loss (single-side loss) is 0.5~0.6μm,

[0027] Taper angle: 40~50°, Tip: less than 0.02μm.

[0028] 4. The etching solution prepared in the present application has no residue, no cracks, and no undercut during the etching process.

[0029] 5. The etching solution prepared in this application can meet the application in the manufacturing process of oxide TFT panels. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is an etching electron microscope image of the etching solution composition prepared in Example 1.

[0031] Figure 2 This is an etching electron microscope image of the etching solution composition prepared in Comparative Example 1.

[0032] Figure 3 This is an etching electron microscope image of the etching solution composition prepared in Comparative Example 2.

[0033] Figure 4 This is an etching electron microscope image of the etching solution composition prepared in Comparative Example 3. DETAILED DESCRIPTION

[0034] Examples 1-4, Comparative Examples 1-3

[0035] A Cu-MTD etching solution composition for oxide semiconductor protection, the components of which are shown in Table 1 by weight percentage:

[0036] Table 1

[0037]

[0038] Preparation of the etching solution composition: all components are mixed evenly to obtain the etching solution.

[0039] Performance testing methods and data

[0040] The etching performance of the etching solutions prepared in the examples and comparative examples was tested, and the test data are listed in Table 2.

[0041] Etching performance evaluation: After etching is completed, the etching performance is confirmed using SEM analysis equipment.

[0042] Among them, IGZO damage: An IGZO (indium oxide, gallium oxide and zinc oxide weight ratio of 1:1:1) glass substrate was placed in the above composition for 30 minutes to confirm whether the thickness and surface state changed.

[0043] The etching solutions prepared in Example 1 and Comparative Examples 1-3 were used for etching, and the substrates after etching were tested by electron microscope.

[0044] Table 2

[0045]

[0046] like Figure 1-4 As shown, Figure 1 Shows excellent etching effect; Figure 2 Obvious IGZO damage appears in the Figure 3-4 All of them showed poor etching, among which Figure 3 The cone angle is too large. Figure 4 The cone angle is too small.

Claims

1. A Cu-MTD etching solution composition for oxide semiconductor protection, characterized in that: The components include, by weight percentage, 13-25% hydrogen peroxide, 2-6% chelating agent, 0.1-4% etching agent, 0.02-5% inhibitor, 0.01-3% hydrogen peroxide stabilizer, and the balance is made up of water; the inhibitor includes a first inhibitor, a second inhibitor and a third inhibitor, the first inhibitor includes a heterocyclic aromatic compound and / or a heterocyclic aliphatic compound, the second inhibitor includes ammonium hydroxide, and the third inhibitor includes organic acid zinc.

2. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 1, characterized in that: The components include: 18-25% hydrogen peroxide, 2.5-4.5% chelating agent, 1-3% etching agent, 0.5-4.8% inhibitor, 0.2-1% hydrogen peroxide stabilizer, and the balance is made up of water.

3. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 1 or 2, characterized in that: The weight ratio of the first inhibitor, the second inhibitor and the third inhibitor is (0.1-0.8): (0.3-1)：(0.01-0.2)。 4. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 3, characterized in that: The weight ratio of the first inhibitor, the second inhibitor and the third inhibitor is 1:(1-5): (0.1-1)。 5. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 1, characterized in that: The heterocyclic aromatic compound includes at least one of furan, thiophene, pyrrole, oxazole, imidazole, pyrazole, triazole, tetrazole, 5-aminotetrazole, and methyltetrazole.

6. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 5, characterized in that: The heterocyclic aliphatic compound includes at least one of piperazine, methyl piperazine, hydroxyethyl piperazine, pyrrolidine and alloxan.

7. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 6, characterized in that: The ammonium hydroxide includes at least one of ammonium hydroxide, tetraalkylammonium hydroxide, and trihydroxyalkylammonium hydroxide.

8. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 7, characterized in that: The tetraalkylammonium hydroxide includes at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide and tetrabutylammonium hydroxide.

9. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 8, characterized in that: The organic acid zinc includes at least one of zinc acetate, zinc borate, zinc gluconate, zinc glycinate, zinc citrate, zinc malate and zinc succinate.

10. The Cu-MTD etching solution composition for oxide semiconductor protection according to claim 1, characterized in that: The chelating agent includes at least one of diethylenetriaminepentaacetic acid, iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethyltrinitrovaleric acid, aminotrimethylenephosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepenta(methylenephosphonic acid), alanine, glutamic acid, aminobutyric acid, and glycine.

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