Electrolytic device for removing a sacrificial layer

Abstract

The present disclosure discloses an electrolytic device for removing a sacrificial layer, which comprises a liquid storage cavity, a first electrode, a second electrode and a power supply; the liquid storage cavity is connected with a workpiece to be processed, used for storing electrolyte and inputting the electrolyte into a liquid flow channel in communication with the sacrificial layer of the workpiece to be processed; the first electrode is connected with the sacrificial layer of the workpiece to be processed; the second electrode is arranged in the liquid storage cavity; the power supply is connected with the first electrode and the second electrode respectively, used for applying an alternating voltage to the first electrode and the second electrode, so that the sacrificial layer is electrolyzed and dissolved in the electrolyte. The present disclosure can remove the sacrificial layer in the workpiece to be processed.

Description

Technical Field

[0001] This application relates to the field of processing technology, and in particular to an electrolytic device for removing sacrificial layers. Background Technology

[0002] In existing chip or semiconductor manufacturing processes, three common methods for removing sacrificial layers are used: wet chemical etching, dry etching, and physical lift-off. In practical applications, the appropriate method is usually selected based on a comprehensive consideration of factors such as the sacrificial layer's material, structural complexity, and process compatibility. For example, in the manufacturing of MEMS devices, wet chemical etching or dry etching is typically preferred for removing the sacrificial layer to achieve suspended structures.

[0003] However, the chemical reagents used in existing wet chemical etching methods are toxic, and the processing time is long, making them unsuitable for fine machining. When the chip structure is complex, it is difficult to achieve the desired removal of the sacrificial layer, and it is also easy to erode the non-removed areas. In addition, although existing dry etching methods are more precise, the required equipment and processes are more complex.

[0004] In summary, existing methods for removing the sacrificial layer suffer from problems such as complex operation and long processing time. Utility Model Content

[0005] Embodiments of this disclosure provide an electrolytic apparatus for removing sacrificial layers.

[0006] In a first aspect, embodiments of this disclosure provide an electrolytic device for removing a sacrificial layer, the device comprising: a storage chamber, a first electrode, a second electrode, and a power source;

[0007] The liquid storage chamber is connected to the workpiece to be processed and is used to store electrolyte and input the electrolyte into a liquid flow channel that is connected to the sacrificial layer of the workpiece to be processed.

[0008] The first electrode is connected to the sacrificial layer of the workpiece to be processed;

[0009] The second electrode is disposed in the liquid storage chamber;

[0010] The power source is connected to the first electrode and the second electrode respectively, and is used to apply an AC voltage to the first electrode and the second electrode, so that the sacrificial layer is electrolyzed and dissolved in the electrolyte.

[0011] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0012] The accompanying drawings are provided to better understand this solution and do not constitute a limitation of this disclosure. Wherein:

[0013] Figure 1 This is a schematic diagram of the structure of an electrolytic device for removing the sacrificial layer in a specific embodiment of this disclosure.

[0014] Figure 2 This is a schematic diagram showing the sacrificial layer after it has been removed in a specific embodiment of this disclosure.

[0015] Figure 3 This is a schematic diagram of the structure of an electrolytic device for removing the sacrificial layer in another specific embodiment of this disclosure. Figure 1 .

[0016] Figure 4 This is a schematic diagram of the structure of an electrolytic device for removing the sacrificial layer in another specific embodiment of this disclosure. Figure 2 .

[0017] Figure 5 This is a schematic diagram of the structure of an electrolytic device for removing the sacrificial layer in another specific embodiment of this disclosure.

[0018] Figure 6 This is a schematic diagram of the structure of an electrolytic device for removing the sacrificial layer in another specific embodiment of this disclosure.

[0019] Figure 7 This is a schematic diagram of the structure of an electrolytic device for removing the sacrificial layer in another specific embodiment of this disclosure.

[0020] Figure 8 This is a schematic diagram of the sacrificial layer in another specific embodiment of this disclosure. Detailed Implementation

[0021] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of this disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] Where there is no conflict, the embodiments and features described herein can be combined with each other.

[0024] To make the technical solutions and advantages of this disclosure clearer, the following description, in conjunction with the accompanying drawings and specific embodiments, will provide a more detailed account of this disclosure.

[0025] This disclosure presents an electrolytic apparatus for removing the sacrificial layer.

[0026] like Figures 1 to 7 As shown, in a specific embodiment of this disclosure, the electrolytic device for removing the sacrificial layer may include: a storage chamber 204, a first electrode 202, a second electrode 203, and a power supply (not shown in the figure);

[0027] The liquid storage chamber 204 is connected to the workpiece 100 to be processed, and is used to store electrolyte and input the electrolyte into a liquid flow channel that is connected to the sacrificial layer of the workpiece to be processed.

[0028] The first electrode 202 is connected to the sacrificial layer 101 of the workpiece 100 to be processed;

[0029] The second electrode 203 is disposed in the liquid storage chamber 204;

[0030] The power source is connected to the first electrode and the second electrode respectively, and is used to apply an AC voltage to the first electrode and the second electrode, so that the sacrificial layer is electrolyzed and dissolved in the electrolyte.

[0031] In the technical solution disclosed herein, when it is necessary to remove the sacrificial layer in the workpiece to be treated, the liquid storage chamber in the aforementioned electrolytic device for removing the sacrificial layer can be connected to the workpiece to be treated first, and the first electrode in the electrolytic device for removing the sacrificial layer can be connected to the sacrificial layer in the workpiece to be treated; then, the electrolyte can be injected into the liquid storage chamber first, and then the liquid storage chamber can be connected to one end of the liquid flow channel in the workpiece to be treated, so that the electrolyte in the liquid storage chamber is input into the liquid flow channel in the workpiece to be treated until the electrolyte contacts the sacrificial layer located at the other end of the liquid flow channel (for example, a liquid flow channel can be provided in the workpiece to be treated, so that the sacrificial layer in the workpiece to be treated is located at one end or a branch end of the liquid flow channel). Since the first electrode in the electrolytic device for removing the sacrificial layer is connected to the sacrificial layer of the workpiece to be treated, and the second electrode in the storage chamber is in contact with the electrolyte, by applying an AC voltage to the first and second electrodes by a power source, the sacrificial layer in contact with the electrolyte can be electrolyzed and dissolved in the electrolyte (electrolysis occurs at the contact point between the surface of the sacrificial layer and the electrolyte), thereby removing the sacrificial layer from the workpiece to be treated and obtaining a workpiece with the sacrificial layer removed.

[0032] Since the AC voltage applied by the aforementioned power source can accelerate ion movement, it can effectively improve the problem that the electrolyte is not easy to flow continuously or rapidly due to the size limitation of the liquid flow in the small-sized liquid channel (e.g., the shape, size, and / or material of the liquid channel). It can also effectively improve the inhibitory effect of the small-sized liquid channel on the diffusion of ions in the electrolyte after it enters.

[0033] The method for removing the sacrificial layer described in this disclosure has a short operation time and a simple and controllable operation process; in addition, the sacrificial layer metal ions can be eventually reduced on the surface of the second electrode, resulting in less environmental pollution.

[0034] Additionally, as an example, in a specific embodiment of this disclosure, the electrolytic device for removing the sacrificial layer may further include: a clamp 201;

[0035] The fixture 201 is connected to the workpiece 100 to be processed;

[0036] The liquid storage chamber 204 is disposed in the clamp 201.

[0037] In the specific embodiments of this disclosure, the liquid storage cavity 204 is disposed in the fixture 201, and the fixture 201 is connected to the workpiece 100 to be processed, so that the liquid storage cavity 204 can be better connected to the workpiece 100 to be processed.

[0038] Additionally, as an example, in one specific embodiment of this disclosure, the fixture 201 may be connected to the workpiece 100 to be processed via a fixing device.

[0039] For example, as an example, in one specific embodiment of this disclosure, the fixing device may include: a gasket and a bolt;

[0040] The gasket is fixedly connected to the bottom of the clamp 201; the gasket is provided with a through hole for the bolt to pass through;

[0041] The bolt is used to pass through the through hole in the washer to fix the washer to the workpiece 100 to be processed.

[0042] Of course, other forms of fixing devices can also be used in the technical solutions disclosed herein, which will not be listed here.

[0043] In the technical solution disclosed herein, the first electrode 202 can be separated from the liquid storage chamber 204 and / or the clamp 201, or from the structure of the workpiece to be processed itself, so that the first electrode 202 and the liquid storage chamber 204 and the electrolyte connected to the liquid storage chamber 204 will not form a circuit between the first electrode 202 and the second electrode 203 through the electrolyte.

[0044] For example, such as Figure 3 and Figure 4 As shown, in a specific embodiment of this disclosure, the workpiece 100 to be processed is combined with the fixture 201 to form two liquid storage chambers 204 and 205 for storing electrolyte. These two liquid storage chambers are not interconnected. The second electrode 203 is disposed in the liquid storage chamber 204. Since the location of the first electrode 202 is separated from the liquid storage chamber 204 and the liquid flow channel containing the electrolyte, the first electrode 202 and the second electrode 203 do not form a circuit through the electrolyte.

[0045] Additionally, as an example, in one specific embodiment of this disclosure, the liquid storage chamber is provided with an injection port and an output port;

[0046] The injection port is used to inject electrolyte into the storage chamber.

[0047] The output port is used to input the stored electrolyte into a liquid flow channel that is connected to the sacrificial layer of the workpiece to be processed.

[0048] Additionally, as an example, in one specific embodiment of this disclosure, the power source may be a voltage signal generator (not shown in the figure). Therefore, in this specific embodiment, the fixture 201 can be connected to the workpiece 100 to be processed first, and the working electrode of the voltage signal generator can be connected to the first electrode 202 (so that the working electrode can be connected to the sacrificial layer 101), and the counter electrode and / or reference electrode of the voltage signal generator can be connected to the second electrode 203. Then, the electrolyte can be injected into the storage chambers 204 and 205. Since the working electrode of the voltage signal generator of the sacrificial layer removal electrolysis device is connected to the sacrificial layer 101 of the workpiece 100 to be processed through the first electrode 202, and the second electrode 203 provided in the storage chamber 204 is in contact with the electrolyte, by applying an AC voltage to the first electrode and the second electrode through the power source, the sacrificial layer in contact with the electrolyte can be electrolyzed and dissolved in the electrolyte (electrolysis occurs at the contact point between the surface of the sacrificial layer and the electrolyte), thereby removing the sacrificial layer from the workpiece to be processed and obtaining a workpiece with the sacrificial layer removed.

[0049] Additionally, as an example, in a specific embodiment of this disclosure, the workpiece to be processed can be a chip such as a biochip including a sequencing chip such as a nanopore sequencing chip, or other semiconductor devices with a sacrificial layer.

[0050] In addition, in the technical solution disclosed herein, the shape and size of the liquid flow channel can be preset according to the needs of the actual application scenario. The liquid flow channel may exist before the sacrificial layer is electrolyzed, or it may be gradually formed during the process of the sacrificial layer being electrolyzed.

[0051] For example, as an example, in one specific embodiment of this disclosure, the liquid channel (which gradually forms during the electrolysis of the sacrificial layer) located at at least a portion of the surface of the sacrificial layer in contact with the electrolyte can be elongated. When the elongated liquid channel has a relatively long length and a small cross-sectional area, it can be used in conjunction with the structure to provide sufficiently high resistance. Of course, the shape of the liquid channel can be other suitable shapes.

[0052] For example, as an example, in a specific embodiment of this disclosure, the cross-sectional area of ​​the liquid flow channel at at least a portion of the surface of the sacrificial layer in contact with the electrolyte can be 0.005 to 1 square micrometer (e.g., 0.005, 0.006, 0.01, 0.05, 0.06, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 square micrometer), and the length can be 2.5 to 500 micrometers.

[0053] Additionally, as an example, in one specific embodiment of this disclosure, the first electrode is an anode (or positive electrode) and the second electrode is a cathode (or negative electrode).

[0054] Additionally, as an example, in one specific embodiment of this disclosure, the first electrode is the working electrode and the second electrode is the counter electrode.

[0055] Additionally, as an example, in a specific embodiment of this disclosure, the second electrode may be disposed on the inner wall of the liquid storage cavity (e.g., Figure 5 and Figure 7 As shown), or disposed in the liquid storage cavity (e.g. Figure 1 , 2 4 and Figure 6 (As shown), it can also be achieved by inserting an external electrode into the inlet and outlet of the storage chamber 204. For example, the second electrode can be directly set on the inner wall of the storage chamber, or the second electrode can be placed in the electrolyte in the storage chamber.

[0056] Additionally, as an example, in one specific embodiment of this disclosure, the first electrode may be disposed on the side, top, or bottom of the sacrificial layer, such that the first electrode is in electrical contact with the sacrificial layer.

[0057] For example, as an illustration, in one specific embodiment of this disclosure, the first electrode may be disposed on the side or bottom of the sacrificial layer at the end away from the liquid flow channel. In this specific embodiment, the electrolyte will first contact the sacrificial layer and begin electrolysis from the surface of the sacrificial layer at the end away from the first electrode (electrolysis occurs at the contact point between the surface of the sacrificial layer and the electrolyte), and finally contact and electrolyze the sacrificial layer at the connection point with the first electrode, thereby ensuring that the sacrificial layer is electrolyzed as completely as possible.

[0058] For example, such as Figure 1 and Figure 4 As shown, in one specific embodiment of this disclosure, the first electrode may be disposed on the side of the sacrificial layer.

[0059] For example, such as Figure 5 , Figure 6 and Figure 7 As shown, in one specific embodiment of this disclosure, the first electrode may be disposed at the bottom of the sacrificial layer.

[0060] In addition, in one specific embodiment of this disclosure, Figure 7 The diagram shown is a cross-sectional view, in which the sacrificial layer 101 is actually continuous. For example, as... Figure 8 As shown.

[0061] Additionally, as an example, in a specific embodiment of this disclosure, the first electrode 202 is located at a preset electrolysis end of the sacrificial layer.

[0062] For example, in a specific embodiment of this disclosure, the second electrode 203 is located in the liquid storage chamber 204 and has no direct physical contact with the sacrificial layer 101. An electrolyte exists between the second electrode 203 and the sacrificial layer 101. The contact point between the sacrificial layer 101 and the electrolyte output from the liquid storage chamber 204 is the starting point of the sacrificial layer electrolysis process. The first electrode 202 is in contact with the other end of the sacrificial layer 101 and is located at the end point of the sacrificial layer electrolysis process. Therefore, the electrolysis process of the sacrificial layer 101 will begin from the chamber where the second electrode 203 is located and gradually electrolyze the sacrificial layer, connecting the chamber where the second electrode 203 is located with the chamber where the first electrode 202 is located. For example, Figure 1 The sacrificial layer 101 will be electrolyzed gradually from right to left until it is electrolyzed and dissolved in the electrolyte, forming a layer as shown in the figure. Figure 2 The liquid resistance flow channel shown in the figure.

[0063] By setting the electrolysis start end and electrolysis end end as described above, the start and end positions or directions of the electrolysis process can be defined, thereby enabling the sacrificial layer to be completely electrolyzed or to be electrolyzed as expected.

[0064] Additionally, as an example, in a specific embodiment of this disclosure, an opening can be provided directly above the sacrificial layer at the first electrode, or an optically transparent structure can be provided above the sacrificial layer to facilitate observation of whether the sacrificial layer is completely electrolyzed. For example, the complete electrolysis of the sacrificial layer can be observed using an observation device such as a microscope.

[0065] Additionally, as an example, in one specific embodiment of this disclosure, the liquid channel is formed by engaging the workpiece to be processed (such as a chip) with a fixture.

[0066] For example, as an example, in a specific embodiment of this disclosure, the liquid channel is disposed in the workpiece 100 to be processed, the first end of the liquid channel is connected to the liquid storage chamber 204, and the second end is connected to the sacrificial layer.

[0067] Additionally, as an example, in one specific embodiment of this disclosure, the sacrificial layer may be a metal layer.

[0068] For example, as an example, in one specific embodiment of this disclosure, the sacrificial layer may be made of at least one material selected from chromium (Cr), gold (Au), or aluminum.

[0069] Additionally, as an example, in one specific embodiment of this disclosure, the first electrode may be made of any one of platinum, graphite, silver, or silver chloride.

[0070] Furthermore, in the technical solution disclosed herein, the second electrode can be selected according to the choice of the first electrode and the electrolyte. For example, considering the case of ions, it is preferable to use inert electrodes for both the second electrode and the first electrode.

[0071] For example, as an example, in one specific embodiment of this disclosure, the second electrode may be made of any one of platinum, graphite, silver or silver chloride.

[0072] Additionally, as an example, in one specific embodiment of this disclosure, the solvent of the electrolyte is water.

[0073] Additionally, as an example, in one specific embodiment of this disclosure, the pH value of the electrolyte can be 5.5–7.5, 6.0–7.5, 6.5–7.2, or 6.8–7.1.

[0074] Preferably, the pH value of the electrolyte can be 6.0 to 7.5.

[0075] Additionally, as an example, in one specific embodiment of this disclosure, the concentration of the solute in the electrolyte can be 0.1 to 1 mol / L.

[0076] Additionally, as an example, in one specific embodiment of this disclosure, the electrolyte does not electrolyze or modify the materials in the workpiece to be treated, except for the sacrificial layer.

[0077] Additionally, as an example, in one specific embodiment of this disclosure, the anions in the solute of the electrolyte include Cl-. - [Fe(CN)6] 3- At least one anion in it.

[0078] Additionally, as an example, in one specific embodiment of this disclosure, the cations in the solute of the electrolyte include K. + Na + At least one cation in it.

[0079] For example, as an example, in a specific embodiment of this disclosure, the electrolyte may be a KCl and / or NaCl solution.

[0080] In the technical solution disclosed herein, chloride ions, due to their small radius and strong penetrating power, preferentially adsorb onto the passivation film of metals, displacing oxygen atoms. They then combine with cations in the passivation film to form soluble chlorides, thus creating small pits at specific points on the metal, leading to corrosion. The effects of chloride ions on metal corrosion are mainly manifested in two aspects: firstly, they reduce the formation of the passivation film on the material surface or accelerate its destruction, thereby promoting localized corrosion; secondly, they reduce the solubility of sulfur dioxide and carbon dioxide in aqueous solutions, thereby alleviating material corrosion. Therefore, chloride ions, when present in aqueous solutions for extended periods, can accelerate corrosion reactions, easily penetrating the protective film on the metal surface, causing crevice corrosion and pitting corrosion.

[0081] Therefore, when the anion in the electrolyte is chloride ion (Cl... - When chloride ions are present, their presence can greatly accelerate the electrolysis process of metals such as chromium and gold.

[0082] For example, the effect of chloride ions on chromium is as follows:

[0083] 1) Formation of complexes:

[0084] Chloride ions can form stable complexes with chromium ions, such as [CrCl6]3-. During electrolysis, this complexation alters the form in which chromium ions exist in solution and the chemical environment of the electrode surface, reducing the effective concentration of chromium ions. According to the Nernst equation, this changes the electrode potential of chromium, making it easier for chromium to gain electrons at the cathode and be reduced and deposited.

[0085] 2) Promotes anodic dissolution:

[0086] At the anode, chloride ions can promote the dissolution of metallic chromium. Chloride ions adsorb on the chromium surface and react chemically with chromium to form soluble chromium chloride compounds, which can accelerate the process of chromium entering the solution from the anode and facilitate the electrolysis process.

[0087] For example, the effect of chloride ions on gold is as follows:

[0088] 1) Increase the concentration of gold ions:

[0089] Gold is chemically stable under normal conditions, but in the presence of chloride ions, it can form complexes with gold, such as [AuCl4]-. This complexation reaction makes gold more soluble in solution, increasing the concentration of gold ions in the solution. The increased concentration of gold ions facilitates the reduction of gold ions to elemental gold at the cathode during electrolysis, thereby improving the electrolysis efficiency of gold.

[0090] 2) Enhanced conductivity:

[0091] Electrolytes containing chloride ions typically exhibit good conductivity, which enhances the current efficiency in the electrolytic cell and facilitates a smoother electrolysis process. This good conductivity ensures efficient electron transport between the electrodes and the solution, aiding in the reduction and deposition of gold ions at the cathode.

[0092] Additionally, as an example, in one specific embodiment of this disclosure, the AC voltage can be 0.9 to 1.5V.

[0093] Additionally, as an example, in one specific embodiment of this disclosure, the duration of applying the alternating voltage (i.e., electrolysis) can be 1 to 10 minutes.

[0094] Preferably, the duration of applying the AC voltage can be 5 minutes.

[0095] In the technical solutions disclosed herein, the above specific embodiments can be combined in accordance with the needs of actual application scenarios to obtain various different specific implementation methods, which will not be listed one by one here.

[0096] In addition, in one specific embodiment of this disclosure, the sacrificial layer can be removed by the following steps:

[0097] Step 501: Electrolyte is introduced into the workpiece to be treated, so that the sacrificial layer in the workpiece to be treated comes into contact with the electrolyte.

[0098] In the technical solution disclosed herein, when it is necessary to remove the sacrificial layer in the workpiece to be treated, an electrolyte for removing the sacrificial layer can be introduced into the workpiece to be treated, so that the sacrificial layer to be removed in the workpiece to be treated comes into contact with the electrolyte.

[0099] For example, as an illustration, in a specific embodiment of this disclosure, a liquid flow channel can be provided in the workpiece to be processed, such that the sacrificial layer in the workpiece is located at one end or a branch end of the liquid flow channel. Therefore, electrolyte can flow into the liquid flow channel in the workpiece to be processed until the electrolyte contacts the sacrificial layer located at the other end of the liquid flow channel;

[0100] For example, as an example, in a specific embodiment of this disclosure, a fixture with a liquid reservoir can be used to connect the liquid reservoir in the fixture to the liquid flow channel in the workpiece to be processed, so that the electrolyte in the liquid reservoir can flow into the liquid flow channel in the workpiece to be processed until the electrolyte contacts the sacrificial layer located at the other end of the liquid flow channel.

[0101] Step 502: Connect the sacrificial layer to the first electrode and make the second electrode contact the electrolyte.

[0102] In the technical solution disclosed herein, the first electrode can be connected to the sacrificial layer of the workpiece to be processed, and the second electrode can be made to contact the electrolyte.

[0103] Step 502 can be executed simultaneously with step 501, or it can be executed sequentially with step 501. This will not be elaborated further here.

[0104] Step 503: Apply an AC voltage to the first electrode and the second electrode so that the sacrificial layer is electrolyzed and dissolved in the electrolyte.

[0105] Since the first electrode is connected to the sacrificial layer of the workpiece to be treated, and the second electrode is in contact with the electrolyte, by applying an AC voltage to the first and second electrodes by a power source, the sacrificial layer in contact with the electrolyte can be electrolyzed and dissolved in the electrolyte, thereby removing the sacrificial layer from the workpiece to be treated and obtaining a workpiece with the sacrificial layer removed.

[0106] Therefore, the sacrificial layer in the workpiece to be processed can be removed through the above steps 501 to 503.

[0107] In the technical solution disclosed herein, since the electrolyte can contact one end of the sacrificial layer through the liquid flow channel in the workpiece to be treated, the first electrode is connected to the sacrificial layer, and the second electrode is placed in the electrolyte, by applying an AC voltage to the first electrode and the second electrode by a power source, the sacrificial layer in contact with the electrolyte can be electrolyzed and dissolved in the electrolyte, thereby removing the sacrificial layer from the workpiece to be treated and obtaining a workpiece with the sacrificial layer removed.

[0108] Therefore, the technical solution disclosed herein has the following advantages:

[0109] 1. Liquid flow at small scales is limited by size; for example, electrolyte or sacrificial layer etchant cannot easily penetrate continuously or rapidly, resulting in a longer time to remove the sacrificial layer. The present disclosure utilizes alternating current voltage, effectively improving upon these limitations.

[0110] 2. When the liquid flow channel is elongated, ion diffusion efficiency is limited, resulting in low electrolysis efficiency. Since the technical solution of this disclosure uses alternating voltage, ion movement can be accelerated, thereby effectively improving the above situation.

[0111] 3. Existing chemical etching methods may affect the surface properties of MEMS due to the presence of an acidic environment. In contrast, the electrochemical method in this disclosure reacts only on the electrodes, without affecting other locations. Furthermore, the electrolyte in this disclosure can be neutral, weakly acidic, or weakly alkaline (e.g., with a pH of 5.5–7.5), thus having little or no impact on the surface properties of the workpiece.

[0112] 4. Since the electrolysis process requires ions to undergo redox reactions on the surface of the metal sacrificial layer, simply applying a DC voltage will cause the aggregation of similar ions, and the ions undergoing redox reactions on the sacrificial layer surface cannot be effectively replenished. Therefore, when using DC voltage for electrolysis, the electrolysis rate will gradually decrease. However, the AC voltage used in the technical solution of this disclosure changes direction periodically, allowing the electrolyzed metal ions (e.g., chromium ions) to leave the surface of the sacrificial layer, while introducing new ions to the surface of the sacrificial layer. Therefore, the electrolysis rate in the technical solution of this disclosure can remain basically constant, thereby reducing the overall electrolysis time.

[0113] For example, specific experimental results show that, under the same conditions, assuming the sacrificial layer is made of chromium, the existing technology requires 4 to 8 hours, or even longer, to etch the sacrificial layer using chromium etchant. However, if the technical solution disclosed herein is used, and high-frequency AC voltage is employed for electrolysis, the electrolysis time can be shortened to less than 5 minutes.

[0114] In summary, the technical solution disclosed herein has advantages such as short processing time, convenient operation, no pollution, and suitability for precision processing.

[0115] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An electrolytic apparatus for removing a sacrificial layer, characterized in that, The device includes: a liquid storage chamber, a first electrode, a second electrode, and a power supply; The liquid storage chamber is connected to the workpiece to be processed and is used to store electrolyte and input the electrolyte into a liquid flow channel that is connected to the sacrificial layer of the workpiece to be processed. The first electrode is connected to the sacrificial layer of the workpiece to be processed; The second electrode is disposed in the liquid storage chamber; The power source is connected to the first electrode and the second electrode respectively, and is used to apply an AC voltage to the first electrode and the second electrode, so that the sacrificial layer is electrolyzed and dissolved in the electrolyte.

2. The apparatus according to claim 1, characterized in that, The electrolytic device for removing the sacrificial layer further includes: a clamp; The fixture is connected to the workpiece to be processed; The liquid storage chamber is located in the clamp.

3. The apparatus according to claim 2, characterized in that: The first electrode is separated from the liquid storage chamber and the electrolyte connected to the liquid storage chamber. The separation is achieved through the structure of the fixture or the workpiece itself.

4. The apparatus according to claim 1, characterized in that: The first electrode is the anode, and the second electrode is the cathode; The first electrode is disposed on the side, top, or bottom of the sacrificial layer. The first electrode is located at the preset electrolysis end of the sacrificial layer.

5. The apparatus according to claim 1, characterized in that: The first electrode is made of any one of platinum, graphite, silver or silver chloride.

6. The apparatus according to claim 1, characterized in that: The second electrode is disposed on the inner wall of the liquid storage cavity, or disposed in the liquid storage cavity.

7. The apparatus according to claim 1, characterized in that: An opening is provided directly above the sacrificial layer at the first electrode; or... An optically transparent structure is provided above the sacrificial layer.

8. The apparatus according to claim 1, characterized in that: The sacrificial layer is a metal layer.

9. The apparatus according to claim 1, characterized in that: The sacrificial layer is made of at least one of chromium, gold, or aluminum.

10. The apparatus according to claim 1, characterized in that: The electrolyte has a pH value of 5.5–7.5, 6.0–7.5, 6.5–7.2, or 6.8–7.

1.

11. The apparatus according to claim 1, characterized in that: The concentration of the solute in the electrolyte is 0.1 to 1 mol / L.

12. The apparatus according to claim 1, characterized in that: The anions in the solute of the electrolyte include Cl. - Or [Fe(CN)6] 3- ; The cations in the solute of the electrolyte include K. + Or Na + .

13. The apparatus according to claim 1, characterized in that: The AC voltage is 0.9 to 1.5V; the duration of applying the AC voltage is 1 to 10 minutes.

14. The apparatus according to claim 1, characterized in that: The cross-sectional area of ​​the liquid flow channel at at least a portion of the surface of the sacrificial layer in contact with the electrolyte is 0.005 to 1 square micrometer, and the length is 2.5 to 500 micrometers.

15. The apparatus according to claim 1, characterized in that: The workpiece to be processed is a chip, a biochip, a sequencing chip, or a nanopore sequencing chip.

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