Etching solution compatible with multi-thickness aluminum / molybdenum lamination etching taper angles

Abstract

The invention provides an etching solution compatible with multi-thickness aluminum / molybdenum lamination etching taper angles, which is prepared from the following substances in percentage by mass: 55 to 75 percent of phosphoric acid, 1 to 8 percent of nitric acid, 10 to 20 percent of acetic acid, 0.1 to 5 percent of additive 1, 0.005 to 1 percent of additive 2 and the balance of water, the additive 1 is inorganic salt; and the additive 2 is S-2-benzylsuccinic acid or 4-nitrophenyl dimethyl carbamate. The invention further discloses a preparation method of the compound. The etching solution provided by the invention can be used for etching metal film layers with different thicknesses in a compatible manner, and etching shapes with similar angles are formed; meanwhile, the desired etching taper angle can be obtained by simply adjusting the ratio of the raw materials in the etching liquid, and the coverage range of the etching taper angle is wide.

Description

Technical Field

[0001] This invention belongs to the intersection of metal wet etching and semiconductor display technology, and specifically relates to an etching solution that is compatible with etching cone angles of aluminum / molybdenum stacks of multiple thicknesses. Background Technology

[0002] In TFT-LCD manufacturing, aluminum is widely used as the wiring material for both the gate and source / drain electrodes. Pure aluminum films are prone to hillock formation due to stress, deposition environment, and process factors, which can lead to insulation layer breakage and short circuits. To address this issue, a layer of molybdenum is typically deposited on the aluminum surface to suppress this defect. In the same etching solution, different metals exhibit different etching rates due to their varying chemical properties; furthermore, even with the same metal, different thicknesses can result in significantly different etching effects. In practical processes, different etching solutions are generally required to achieve different etch morphologies, which poses considerable challenges to process control and manufacturing efficiency.

[0003] Therefore, it is necessary to design an etching solution that is compatible with aluminum / molybdenum stacks of different thicknesses to etch the required etching cone angle. Summary of the Invention

[0004] To address the above problems, the present invention provides an etching solution compatible with etching cone angles of aluminum / molybdenum stacks of various thicknesses, comprising phosphoric acid, nitric acid, acetic acid, additive 1, additive 2, and water; The additive 1 is an inorganic salt; The additive 2 is one or both of S-2-benzylsuccinic acid or 4-nitrophenyl dimethylcarbamate.

[0005] Further, by mass fraction, it consists of the following substances: 55-75% phosphoric acid, 1-8% nitric acid, 10-20% acetic acid, 0.1%-5% additive 1, 0.005%-1% additive 2, and the balance being water.

[0006] Furthermore, the inorganic salt is at least one of phosphate or nitrate.

[0007] Furthermore, the inorganic salt is selected from one or more of sodium salts, potassium salts, or ammonium salts.

[0008] Further, by mass fraction, it consists of the following substances: 58-69% phosphoric acid, 1-3% nitric acid, 12-16% acetic acid, 1.2%-3.5% additive 1, 0.01%-0.3% additive 2, and the balance being water.

[0009] The present invention also provides a method for preparing an etching solution compatible with etching cones of multiple thickness aluminum / molybdenum stacks, comprising the following steps: mixing phosphoric acid, nitric acid, acetic acid, additive 1, additive 2 and water evenly to obtain an etching solution.

[0010] The above-mentioned etching solution, which is compatible with etching cone angles of aluminum / molybdenum stacks of various thicknesses, is used in etching aluminum / molybdenum stacks.

[0011] Furthermore, when the etching solution is used to etch aluminum / molybdenum stacks, the Al Taper is 35°-76° and the Mo Taper is 40-65°.

[0012] Furthermore, in the aluminum / molybdenum stack, the aluminum layer has a thickness of 2200-4500 Å and the molybdenum layer has a thickness of 150-1000 Å.

[0013] Furthermore, when the etching solution is used to etch aluminum / molybdenum stacks of different thicknesses, the range of Al Taper is ≤12° and the range of MoTaper is ≤15°.

[0014] The beneficial effects of this invention are as follows: In actual manufacturing processes, films of different thicknesses need to be etched at the same angle in certain process stages. The etching solution provided by this invention can be compatible with etching metal films of different thicknesses and form etching morphologies with similar angles, thereby improving process efficiency. At the same time, the etching solution provided by this invention can also obtain the desired etching cone angle by simply adjusting the ratio of raw materials in the etching solution, and the etching cone angle coverage is wide. Detailed Implementation

[0015] The embodiments of the present invention will be described in detail below with reference to the examples. The following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention.

[0016] According to the proportions in Table 1, mix all the substances in the table and the remaining ultrapure water evenly to obtain the etching solution.

[0017] Table 1

[0018] The etching performance of the etching solutions prepared in the above examples and comparative examples was tested under the following conditions: temperature 40°C, etching time OE45.

[0019] The test results are shown in Table 2. In the table, Al / Mo (2200Å / 150Å) means that the thickness of Al is 2200Å and the thickness of Mo is 150Å.

[0020] Table 2

[0021] As can be seen from the above data, compared with the comparative example which can only meet the etching morphology requirements of a certain thickness at a certain angle, the embodiment can achieve an Al Taper range of ≤12° after etching of film layers of different thicknesses, and the Al Taper range from 35° to 76° can be covered, while always keeping the Mo Taper ≤65°. This solves the problem of incompatibility of etching solution with thickness, avoids frequent replacement of etching solution, and improves process production efficiency. By adjusting the etching solution concentration, the desired etching cone angle can also be controlled.

Claims

1. An etching solution compatible with etching cone angles of multi-thickness aluminum / molybdenum stacks, characterized in that, Includes phosphoric acid, nitric acid, acetic acid, additive 1, additive 2, and water; The additive 1 is an inorganic salt; The additive 2 is one or both of S-2-benzylsuccinic acid or 4-nitrophenyl dimethylcarbamate.

2. The etching solution according to claim 1, which is compatible with etching cone angles of multi-thickness aluminum / molybdenum stacks, is characterized in that, It consists of the following substances by mass fraction: 55-75% phosphoric acid, 1-8% nitric acid, 10-20% acetic acid, 0.1%-5% additive 1, 0.005%-1% additive 2 and balance water.

3. The etching solution according to claim 1, which is compatible with etching cone angles of multi-thickness aluminum / molybdenum stacks, is characterized in that... The inorganic salt is at least one of phosphate or nitrate.

4. The etching solution according to claim 1, which is compatible with etching cone angles of multi-thickness aluminum / molybdenum stacks, is characterized in that... The inorganic salt is selected from one or more of sodium salts, potassium salts, or ammonium salts.

5. The etching solution according to claim 1, which is compatible with etching cone angles of multi-thickness aluminum / molybdenum stacks, is characterized in that... It consists of the following substances by mass fraction: 58-69% phosphoric acid, 1-3% nitric acid, 12-16% acetic acid, 1.2%-3.5% additive 1, 0.01%-0.3% additive 2 and balance water.

6. A method for preparing an etching solution compatible with multi-thickness aluminum / molybdenum stack etching cone angles as described in any one of claims 1-5, characterized in that, The process includes the following steps: mixing phosphoric acid, nitric acid, acetic acid, additive 1, additive 2 and water evenly to obtain an etching solution.

7. The application of the etching solution with a cone angle compatible with multiple thickness aluminum / molybdenum stacks as described in any one of claims 1-5 in etching aluminum / molybdenum stacks.

8. The application according to claim 7, characterized in that, When the etching solution is used to etch aluminum / molybdenum stacks, the AlTaper is 35°-76° and the MoTaper is 40-65°.

9. The application according to claim 7, characterized in that, In the aluminum / molybdenum stack, the aluminum layer has a thickness of 2200-4500 Å and the molybdenum layer has a thickness of 150-1000 Å.

10. The application according to claim 7, characterized in that, When the etching solution is used to etch aluminum / molybdenum stacks of different thicknesses, the range of Al Taper is ≤12° and the range of Mo Taper is ≤15°.

Images