A wet etching device with plasma cleaning

Abstract

The present invention discloses a wet etching device with plasma cleaning, the wet etching device comprises a plasma cleaning chamber and an etching chamber; the wet etching device also comprises a vortex tube, a cooling air knife I, a cooling air knife II, a heating air knife I and a heating air knife II; the cold air pipe of the vortex tube is respectively connected with the cooling air knife I and the cooling air knife II, and the hot air pipe of the vortex tube is respectively connected with the heating air knife I and the heating air knife II. The present invention forms a special gas path device by introducing a vortex tube, and the device can separate the gas into cold gas and hot gas. The cold gas cools down the substrate and the plasma cleaning chamber, avoiding the damage of the high-pressure plasma to the film layers such as Al, Cu, and ITO, and can fully remove organic matter to avoid etching residues, and can also inhibit the corrosion of the film layer by the volatilized etching steam, and prevent the problem of small line width. At the same time, the hot gas separated by the device can ensure that the temperature distribution of the etching chamber is uniform, and improve the etching uniformity.

Description

Technical Field

[0001] The invention relates to the technical field of microelectronic processing, in particular to a wet etching device with plasma cleaning. Background Art

[0002] The gate, source, drain and pixel electrode of the thin film transistor (TFT) for liquid crystal display are made of Cu, Al and ITO thin films by wet etching.

[0003] like Figure 1 As shown, the existing wet etching equipment is generally composed of a plasma cleaning chamber 1, an etching chamber 2, a water washing chamber 3 and an air drying chamber 4. Each chamber is provided with a transmission roller 5 for transmitting the substrate. The substrate 6 is transmitted on the transmission roller 5 and passes through the above chambers in sequence to complete the wet etching.

[0004] A plasma generator 7 is provided in the plasma cleaning chamber 1. Nitrogen and dry gas are introduced into the plasma generator 7. The plasma generator 7 has upper and lower electrodes. Nitrogen is used as a carrier gas to drive the dry gas to flow. The dry gas generates plasma under the high voltage of the electrodes. The plasma bombards downward to remove the residual organic matter on the substrate 6, thereby avoiding etching residues. In order to ensure the removal effect of plasma on residual organic matter, the plasma generator needs to maintain a high voltage. However, the plasma intensity is high under high voltage, and excessive plasma bombardment will cause the Cu, Al, ITO and other film layers to heat up and melt, resulting in plasma damage. The damaged film layer will produce drilling in the subsequent wet etching stage, and the degree of lateral etching will be aggravated, which can easily cause uneven line width and broken lines. Such defects as Figure 2 and Figure 3 As shown in Figure 2, there is both a demand for increasing and a demand for decreasing the plasma voltage, and this contradiction is currently unresolved.

[0005] After the plasma cleaning chamber 1 is cleaned, the sealed door 8 at the entrance of the etching chamber 2 is opened, and the substrate 6 is transferred to the etching chamber 2. At the same time, the next substrate is transferred to the plasma cleaning chamber 1 and waits. At this time, the sealed door 8 at the entrance of the etching chamber 2 and the sealed door 9 at the exit are both in a closed state, and the spray pipe 10 sprays etching liquid onto the surface of the substrate 6 to perform the etching process. When the etching is completed, the sealed door 9 at the exit of the etching chamber 2 is opened, and the substrate 6 leaves the etching chamber 2. Then the sealed door 8 at the entrance of the etching chamber 2 is opened again, and the next glass substrate is transferred to the etching chamber 2. In this cycle, during the frequent opening of the sealed door, the etching steam will evaporate into the plasma cleaning chamber, and the etching steam will liquefy and deposit on the substrate. At this time, etching occurs prematurely, which is equivalent to extending the etching time, and ultimately causes the line width after etching to be thinner and there is a risk of line breakage. Such defects as Figure 4As shown. There is currently no effective solution to the risk of fine lines caused by etching liquid vapor. In addition, if the sealed doors at the inlet and outlet of the etching chamber are frequently opened, cold air will enter the etching chamber, causing the inlet and outlet temperatures of the etching chamber to be low, resulting in uneven etching. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a wet etching device with plasma cleaning, which can ensure that the plasma under high voltage removes organic residues, avoid damage to the metal film layer by the plasma under high voltage, and improve the etching uniformity at the same time.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A wet etching device with plasma cleaning, the wet etching device comprising a plasma cleaning chamber and an etching chamber; the plasma cleaning chamber is used to accommodate and plasma clean a substrate, and a plasma generator for bombarding plasma on the surface of the substrate is provided in the plasma cleaning chamber; the etching chamber is used to accommodate and etch the substrate, and a spray pipe for spraying etching liquid on the surface of the substrate is provided in the etching chamber; the plasma cleaning chamber is connected to the etching chamber through a sealed door; the wet etching device also comprises a vortex tube, a cooling air knife I, a cooling air knife II, a heating air knife I and a heating air knife II; the cold air pipes of the vortex tube are respectively The vortex tube is connected with the cooling air knife I and the cooling air knife II, and the hot air pipe of the vortex tube is respectively connected with the heating air knife I and the heating air knife II; the cooling air knife I and the cooling air knife II are arranged in the plasma cleaning chamber, the cooling air knife I is located in front of the plasma generator, and the cooling air knife II is located behind the plasma generator, and the cooling air knife I and the cooling air knife II blow cold gas to the surface of the substrate; the heating air knife I and the heating air knife II are arranged in the etching chamber, the heating air knife I is located at the entrance of the etching chamber, and the heating air knife II is located at the exit of the etching chamber, and the heating air knife I and the heating air knife II blow hot gas to the surface of the substrate.

[0009] As a preferred technical solution, the air outlets of the cooling air knife I, the heating air knife I and the heating air knife II are slit-shaped.

[0010] As a preferred technical solution, the cooling air knife II includes a circular tubular knife body and a circular air outlet opened on the knife body.

[0011] As a preferred technical solution, the plasma cleaning chamber and the etching chamber are respectively provided with transfer rollers for transferring the substrate.

[0012] As a preferred technical solution, the gas temperature of the cold air pipe of the vortex tube is 5-20°C, and the gas temperature of the hot air pipe of the vortex tube is 30-60°C.

[0013] The beneficial effects of the present invention are:

[0014] The present invention forms a special gas path device by introducing a vortex tube, which can separate the gas into cold gas and hot gas. The cold gas cools the substrate and the plasma cleaning chamber to avoid damage to the Al, Cu, ITO and other film layers by high-pressure plasma, and can fully remove organic matter to avoid etching residues, and can also inhibit the corrosion of the film layer by the volatilized etching steam to prevent the problem of small line width. At the same time, the hot gas separated by the device can ensure uniform temperature distribution in the etching chamber and improve etching uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0016] Figure 1 It is a structural schematic diagram of an existing wet etching device;

[0017] Figure 2 This is a photo of the defects of ITO damaged by plasma;

[0018] Figure 3 This is a defect photo of the Al film layer damaged by plasma;

[0019] Figure 4 This is a defect photo of thin line width after etching caused by etching vapor overflow;

[0020] Figure 5 It is a structural schematic diagram of the wet etching device of the present invention;

[0021] Figure 6 It is a schematic diagram of the structures of cooling air knife I, heating air knife I and heating air knife II;

[0022] Figure 7 It is the structural schematic diagram of cooling air knife II. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0024] The front in the present invention refers to the upstream direction of the substrate moving direction, and the rear refers to the downstream direction of the substrate moving direction.

[0025] like Figure 5A wet etching device with plasma cleaning is shown, the wet etching device comprises a plasma cleaning chamber 1 and an etching chamber 2; the plasma cleaning chamber 1 and the etching chamber 2 are respectively provided with a transfer roller 5 for transferring a substrate 6; the plasma cleaning chamber 1 is used to accommodate and plasma clean the substrate 6, and the plasma cleaning chamber 1 is provided with a plasma generator 7 for bombarding plasma on the surface of the substrate 6; the etching chamber 2 is used to accommodate and etch the substrate 6, and the etching chamber 2 is provided with a spray pipe 10 for spraying etching liquid on the surface of the substrate 6; the plasma cleaning chamber 1 is connected with the etching chamber 2 through a sealing door 8.

[0026] The wet etching device also includes a vortex tube 11, a cooling air knife I 12, a cooling air knife II 13, a heating air knife I 14 and a heating air knife II 15; the cold air pipe of the vortex tube 11 is connected to the cooling air knife I 12 and the cooling air knife II 13 respectively, and the hot air pipe of the vortex tube 11 is connected to the heating air knife I 14 and the heating air knife II 15 respectively. The vortex tube 11 separates the gas introduced into hot gas and cold gas, the cold gas is divided into two branches, which are respectively led to the cooling air knife I 12 and the cooling air knife II 13, and the hot gas is also divided into two branches, which are respectively led to the heating air knife I 14 and the heating air knife II 15. The gas temperature of the cold air pipe of the vortex tube 11 is 5-20°C, and the gas temperature of the hot air pipe of the vortex tube 11 is 30-60°C.

[0027] The cooling air knife I12 and the cooling air knife II13 are arranged in the plasma cleaning chamber 1, the cooling air knife I12 is located in front of the plasma generator 7, and the cooling air knife II13 is located behind the plasma generator 7. The cooling air knife I12 and the cooling air knife II13 blow cold gas to the surface of the substrate 6. The cold gas sprayed by the cooling air knife I12 cools the substrate 6, and the temperature of the metal film layer on the substrate 6 decreases. The metal film layer after cooling can withstand the plasma bombardment without melting damage, which can ensure that the plasma removes organic residues under high voltage and avoids the damage of the metal film layer under high voltage, avoiding the risk of drilling and breaking. The cold gas sprayed by the cooling air knife II13 cools the environment and the substrate 6. Even if the etching steam in the etching chamber evaporates to the plasma cleaning chamber 1, the corrosion will be suppressed by the low temperature, avoiding the risk of thin line width. The flow of cold gas is controlled by adjusting the valves 16, 17 and the flowmeters 18, 19, and then the degree of cooling is adjusted.

[0028] like Figure 6 As shown, the air outlet 12a of the cooling air knife I 12 is slit-shaped, forming a waterfall-shaped cold air flow, thereby enhancing the cooling effect on the substrate.

[0029] like Figure 7As shown, the cooling air knife II 13 includes a circular tubular knife body 13a and a circular air outlet 13b opened on the knife body 13a, which increases the diffusion area of ​​the cold gas and enhances the corrosion inhibition effect on the etching steam.

[0030] The heating air knife I14 and the heating air knife II15 are arranged in the etching chamber 2, the heating air knife I14 is located at the entrance of the etching chamber 2, and the heating air knife II15 is located at the exit of the etching chamber 2. The heating air knife I14 and the heating air knife II15 blow hot gas to the surface of the substrate 6. The hot gas ejected by the heating air knife I14 and the heating air knife II15 can ensure that the temperature at the entrance and exit of the etching chamber 2 remains stable, thereby improving the etching uniformity. The hot gas flow is controlled by adjusting the valves 20, 21 and the flowmeters 22, 23, thereby adjusting the degree of temperature rise.

[0031] Similar to the cooling air knife I, the air outlets of the heating air knife I 14 and the heating air knife II 15 are slit-shaped, forming a waterfall-like hot air flow, thereby enhancing the heating effect on the substrate.

[0032] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A wet etching device with plasma cleaning, the wet etching device comprising a plasma cleaning chamber and an etching chamber; the plasma cleaning chamber is used to accommodate and plasma clean a substrate, and a plasma generator is provided in the plasma cleaning chamber to bombard the surface of the substrate with plasma; the etching chamber is used to accommodate and etch the substrate, and a spray pipe is provided in the etching chamber to spray etching liquid on the surface of the substrate; the plasma cleaning chamber is connected to the etching chamber through a sealed door; Features: The wet etching device also includes a vortex tube, a cooling air knife I, a cooling air knife II, a heating air knife I and a heating air knife II; The cold air pipe of the vortex tube is connected to the cooling air knife I and the cooling air knife II respectively, and the hot air pipe of the vortex tube is connected to the heating air knife I and the heating air knife II respectively; The cooling air knife I and the cooling air knife II are arranged in the plasma cleaning chamber, the cooling air knife I is located in front of the plasma generator, and the cooling air knife II is located behind the plasma generator, and the cooling air knife I and the cooling air knife II blow cold gas to the surface of the substrate; The heating air knife I and the heating air knife II are arranged in the etching chamber, the heating air knife I is located at the entrance of the etching chamber, and the heating air knife II is located at the exit of the etching chamber. The heating air knife I and the heating air knife II blow hot gas to the surface of the substrate.

2. The wet etching device with plasma cleaning according to claim 1, characterized in that: The air outlets of the cooling air knife I, the heating air knife I and the heating air knife II are slit-shaped.

3. The wet etching device with plasma cleaning according to claim 1, characterized in that: The cooling air knife II comprises a circular tubular knife body and a circular air outlet opened on the knife body.

4. The wet etching device with plasma cleaning according to claim 1, characterized in that: The plasma cleaning chamber and the etching chamber are respectively provided with transmission rollers for transmitting the substrate.

5. The wet etching device with plasma cleaning according to any one of claims 1 to 4, characterized in that: The gas temperature of the cold gas pipe of the vortex tube is 5-20°C, and the gas temperature of the hot gas pipe of the vortex tube is 30-60°C.

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