A cleaning system, a substrate etching device, and a cleaning method

Abstract

The present invention provides a cleaning system, a substrate etching apparatus, and a cleaning method. The cleaning system includes a base body (410) and a cleaning member (420) mounted on the base body (410) and adapted to expand under the influence of ambient air pressure and temperature changes to enter and fill a space to be cleaned, thereby adhering to contaminants in the space to be cleaned. The cleaning system, substrate etching apparatus, and cleaning method of the present invention are novel in design and strong in practicability.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor device manufacturing, and particularly to a cleaning system, a substrate etching device, and a cleaning method. Background Art

[0002] In the manufacturing process of semiconductor devices, various by-products are likely to accumulate at multiple positions in the reaction chambers of multiple devices (such as the inner wall of the chamber, corners, or narrow gaps between components). In particular, in a plasma etching device, when etching a device through plasma to form a patterned structure, the generated by-products (such as metal-containing by-products) are likely to float in the chamber; after the reaction ends, there will be a small amount of residual by-products accumulated in the chamber (such as the peripheral wall of the device reaction chamber, the peripheral wall of the loading unit, the corners of the edge ring (such as the focusing ring in the etching device), etc.), which are difficult to remove.

[0003] At the current stage, the existing solution of dry-cleaning metal by-products using a chlorine-containing plasma has obvious defects. Specifically, as Figure 1 shown, when a loaded substrate connected to a bias voltage is placed on the loading stage, the metal by-products in the chamber can be removed by ion bombardment. However, since the edge of the loaded substrate protrudes beyond the outer periphery of the loading stage, the by-products on the outer peripheral sidewall of the loading stage are blocked by the loaded substrate and cannot be completely removed. When there is no loaded substrate on the loading stage, the ion bombardment is likely to cause damage to the surface of the loading stage. In addition, the edge ring is arranged to surround the loading stage, and the material is generally an insulating material, such as a silicide. A stepped structure is formed on the inner side of the edge ring, and by-products are also likely to accumulate at the steps, and these by-products cannot be completely removed due to the characteristics of the stepped structure. Summary of the Invention

[0004] The present invention aims at the above technical problems and provides a cleaning system, a substrate etching device, and a cleaning method.

[0005] The technical solutions proposed by the present invention are as follows:

[0006] The present invention provides a cleaning system, including a base body and a cleaning member installed on the base body, which expands into and fills a space to be cleaned under the influence of environmental air pressure and temperature changes, so as to adhere to the pollutants in the space to be cleaned.

[0007] In the above cleaning system of the present invention, the thermal conductivity coefficient of the material of the base body is 200 W / (m·K) or more; and / or, the material of the base body is at least one of aluminum and copper.

[0008] In the above cleaning system of the present invention, the cleaning member includes a fluid part, an extension part installed on the base body and used to completely or partially surround and limit the extension of the fluid part, and an attachment part attached to the extension part.

[0009] In the above-mentioned cleaning system of the present invention, when the fluid part is affected by changes in ambient air pressure and temperature, it expands due to gas-liquid phase transition.

[0010] In the above-mentioned cleaning system of the present invention, when the working pressure is 10 -3 MT to 200 MT, the boiling point of the fluid part is 10 °C to 120 °C.

[0011] In the above-mentioned cleaning system of the present invention, the elastic modulus of the extension part > 8 Mpa; and / or, the elongation at break of the extension part > 500%, and the elongation at break of the extension part refers to the elongation of the material of the extension part at the breaking point.

[0012] In the above-mentioned cleaning system of the present invention, the fluid part adopts at least one of H2O, n-heptane, 2-butanol, 2-butyl mercaptan, methoxyacetyl chloride, and 2-methyl butyraldehyde;

[0013] and / or, the extension part adopts at least one of polyisoprene, styrene-butadiene rubber, cis-butadiene rubber, and TPE;

[0014] and / or, the attachment part adopts at least one of natural rubber, silicone rubber, and acrylic polymers.

[0015] The present invention also provides a substrate etching device, including a stage, an edge ring surrounding the outside of the stage, and a cleaning system directly or indirectly installed on the stage;

[0016] There is a gap between the edge ring and the stage; the cleaning system includes a base directly or indirectly installed on the stage; the cleaning system further includes a cleaning member installed on the base and facing the gap, which expands and fills the gap under the influence of changes in ambient air pressure and temperature, so as to adhere to the residues in the gap.

[0017] The present invention also provides a cleaning method, including the following steps:

[0018] Step S1, moving the above-mentioned cleaning system to the vicinity of the space to be cleaned;

[0019] Step S2, raising the temperature of the cleaning member to a preset first working temperature, so that the cleaning member expands and fills the space to be cleaned, so as to adsorb the pollutants in the space to be cleaned;

[0020] Step S3, lowering the temperature of the cleaning member to a preset second working temperature, so that the cleaning member shrinks and withdraws from the space to be cleaned, so as to take out the adsorbed pollutants from the space to be cleaned.

[0021] In the above-mentioned cleaning method of the present invention, step S1 includes:

[0022] Sub-step S11: Move the cleaning system above a substrate carrier, and press and adhere to the substrate carrier through the thermal conductive adhesive layer.

[0023] Sub-step S12: Move the cleaning system and the substrate carrier together above the device to be cleaned, so that the cleaning member faces the space to be cleaned.

[0024] The cleaning system, substrate etching device and cleaning method of the present invention use a deformable and adherable cleaning member to remove contaminants in the space to be cleaned. Further, by controlling the temperature of the cleaning system, the physical state in the fluid part is changed, thereby changing the volume of the extension part and the attachment part, so that the extension part and the attachment part fill the gap space; and then relying on the viscous property of the attachment part to strongly remove the residues. The cleaning system, substrate etching device and cleaning method of the present invention have novel designs and strong practicability. Description of the Drawings

[0025] Figure 1 Shows a schematic diagram of the position state of the stage and the edge ring of an existing reaction chamber in the semiconductor device manufacturing process;

[0026] Figure 2 Shows a schematic structural diagram of the cleaning system according to a preferred embodiment of the present invention;

[0027] Figure 3 Shows Figure 2 A reference diagram of the usage state of the cleaning system shown;

[0028] Figure 4 Shows a schematic structural diagram of the substrate etching device according to a preferred embodiment of the present invention;

[0029] Figure 5 Shows a schematic diagram of the installation state of the cleaning member according to a preferred embodiment of the present invention;

[0030] Figure 6 Shows a first reference diagram of the usage state of the substrate etching device according to a preferred embodiment of the present invention;

[0031] Figure 7 Shows a second reference diagram of the usage state of the substrate etching device according to a preferred embodiment of the present invention;

[0032] Figure 8 Shows a third reference diagram of the usage state of the substrate etching device according to a preferred embodiment of the present invention. Detailed Embodiments

[0033] For the convenience of those skilled in the art to understand and implement the present invention, the technical objectives, technical solutions and technical effects of the present invention will be further elaborated in detail below in conjunction with the drawings and specific embodiments.

[0034] As Figure 2 - Figure 3As shown Figure 2 shows a schematic structural view of a cleaning system according to a preferred embodiment of the present invention; Figure 3 shows Figure 2 a reference view of the usage state of the cleaning system shown. The present invention provides a cleaning system, including a base body 410 and a cleaning member 420 installed on the base body 410 and adapted to expand under the influence of environmental air pressure and temperature changes to fill a space to be cleaned, thereby adhering to contaminants in the space to be cleaned. Specifically, a groove 411 is formed on the base body 410, and the cleaning member 420 is installed in the groove 411.

[0035] The most important innovation of the present invention is to remove contaminants in the space to be cleaned through a deformable and adherable cleaning member. The space to be cleaned is not specifically limited to the gap in an etching device, and can also be gaps, holes, and grooves in other scenarios. The deformation of the cleaning member comes from the deformation in its internal fluid part. The optimal solution is to utilize the gas-liquid phase transition characteristic of the fluid part, but other change solutions are not excluded.

[0036] As Figure 4 shown Figure 4 shows a schematic structural view of a substrate etching device according to a preferred embodiment of the present invention; In this embodiment, the present invention further provides a substrate etching device, including a stage 100, an edge ring 300 surrounding the outside of the stage 100, and a cleaning system 400 directly or indirectly installed on the stage 100;

[0037] A gap is provided between the edge ring 300 and the stage 100; the cleaning system 400 includes a base body 410 directly or indirectly installed on the stage 100; a groove 411 is formed at the bottom of the base body 410 facing the gap; the cleaning system 400 further includes a cleaning member 420 installed in the groove 411 and adapted to expand under the influence of environmental air pressure and temperature changes to fill the gap, thereby adhering to residues 500 located in the gap.

[0038] Here, the substrate etching device further includes a substrate 200 installed on the top surface of the stage 100; the cleaning system 400 is installed on the top surface of the substrate 200.

[0039] Based on the above technical solution, through the feature that the shape of the cleaning member 420 can be changed during expansion, the purpose of filling the gap is achieved, and at the same time, the technical effect of removing residues 500 is realized by utilizing the self-adhesion characteristic of the cleaning member 420.

[0040] Furthermore, in the above technical solution, the stage 100 can be configured as an electrostatic chuck (ESC) for carrying a substrate.

[0041] In this embodiment, the outer side of the placement substrate 200 protrudes beyond the outer side of the stage 100; the inner part of the edge ring 300 is stepped and configured to surround the outer sides of the stage 100 and the placement substrate 200 and correspond to their outer sides. There is a gap of 0.1 mm - 2 mm between the inner part of the edge ring 300 and the outer side of the stage 100, which greatly increases the difficulty of removing residues in the gap by conventional cleaning methods. The edge ring 300 is mainly used to limit the diffusion area of plasma during the substrate etching process and improve the etching uniformity of the substrate edge area. The material of the edge ring 300 is generally an insulating material, such as silicon oxide, silicon carbide.

[0042] Further, for the cleaning system 400, the base body 410 is the main body of the cleaning system 400; the groove 411 is annular and is arranged around the outer peripheral area at the bottom of the base body 410, and the cleaning member 420 is arranged along the extending direction of the groove 411. The cleaning member 420 is partially or entirely embedded in the groove 411.

[0043] Here, the material used for the base body 410 needs to meet the following two requirements: 1) high thermal conductivity, such as a thermal conductivity coefficient of 200 W / (m·K) or more; 2) not introducing pollutants of other non-etching equipment materials. Specifically, the base body 410 can be made of aluminum (about 238 W / (m·K)), copper (about 397 W / (m·K)), or at least one of copper alloy and aluminum alloy.

[0044] Further, a thermal conductive adhesive layer (not shown in the figure) for connecting the base body 410 and the placement substrate 200 is arranged below the base body 410. Through the thermal conductive adhesive layer, the base body 410 is bonded to the placement substrate 200 to realize the transfer of the placement substrate 200. Secondly, based on the placement substrate 200, the height of the cleaning system is adjusted to facilitate controlling the distance between the cleaning system and the pre-cleaning area (gap). Moreover, the base body 410 and the stage 100 are isolated by the placement substrate 200 to avoid their direct contact and reduce the risk of introducing pollutants into the machine.

[0045] Further, in this embodiment, the cleaning member 420 includes a fluid part 421, an extension part 422 installed on the base body 410 for restricting part or all of the fluid part 421 in the groove 411, and an attachment part 423 attached to the extension part 422.

[0046] It can be understood that in this embodiment, the fluid part 421 is located at the top of the cleaning member 420. Preferably, the material of the fluid part 421 has the following characteristics:

[0047] 1) The boiling point under the working pressure is 10°C to 120°C. Among them, the boiling point is preferably 10°C to 80°C, more preferably 40°C to 60°C; the working pressure is the pressure in the chamber during the cleaning process.

[0048] The reason for setting the above boiling point range is that if the boiling point is too high, the thermal expansion and contraction of various materials in the equipment will be increased. Especially when the gap between the stage 100 and the edge ring 300 is too small, there may be a risk that the edge ring 300 cracks due to the volume expansion of the stage 100.

[0049] The above working pressure can refer to the pressure during the etching process of the substrate etching device, such as 10 -3 MT to 200 MT (mTorr), or it can also be set according to the requirements of the cleaning process to adjust the boiling point of the fluid part 421, such as 1 atmosphere or 10 -3 mTorr.

[0050] The pressure control method can directly control the opening size of the turbopump and valve parts of the machine originally configured in the substrate etching device.

[0051] 2) Having good volatility

[0052] The reason for requiring the fluid part 421 to have volatility: Once the fluid part 421 leaks into the chamber of the substrate etching device, it is easy to cause damage to the etching equipment. Using the volatile property can conveniently and quickly remove the leaked fluid part 421.

[0053] 3) The materials of the fluid part 421 and the extension part 422 will not undergo chemical reactions, such as corrosion.

[0054] Therefore, the fluid part 421 can be at least one of H2O, n-heptane, 2-butanol, 2-butanethiol, methoxyacetyl chloride, 2-methylbutyraldehyde. The fluid part 421 is most preferably n-heptane.

[0055] Furthermore, the extension part 422 should be made of high-elastic materials, such as rubber (such as polyisoprene, styrene-butadiene rubber, cis-1,4-polybutadiene rubber, etc.), thermoplastic materials (TPE, Thermoplastic Elastomer).

[0056] The extension part 422 has the following characteristics:

[0057] 1) The volume expansion rate of the extension part 422 can reach more than eight times;

[0058] The volume expansion rate refers to the ratio of the volume V1 in the maximum expansion state to the initial volume V0 of the extension part 422 under the working environment during the cleaning process. Among them, the working environment during the cleaning process can be 10-3 Under the conditions of MT~200MT and 10°C~120°C, with the initial state being normal temperature and pressure and the fluid part being in a liquid state.

[0059] The reason for restricting the volume expansion rate is that when the volume expansion rate of the extension part 422 reaches eight times or more, it can fill the gap between the stage and the edge ring and closely abut against the side wall of the space to be cleaned.

[0060] 2) The extension part 422 has the property of extension or elasticity

[0061] When the extension part 422 is at 10°C~120°C, it should satisfy: the elastic modulus of the extension part 422 > 8 Mpa, the elongation at break of the extension part 422 > 500%, and the elongation at break refers to the elongation rate (△L / L) of the material of the extension part 422 at the break point.

[0062] The reason for requiring the extension part 422 to have the property of extension or elasticity is to ensure the elastic performance and extension ability of the extension part 422 to avoid the overflow of the ruptured fluid part.

[0063] 3) The boiling point temperature of the extension part 422 in the working environment is higher than 120°C.

[0064] Furthermore, in this embodiment, the attachment part 423 adopts an adhesive material, such as a pressure-sensitive adhesive (PSA).

[0065] The attachment part 423 has the following characteristics:

[0066] 1) The boiling point temperature of the attachment part 423 under the working pressure (such as 100MT~200MT) is higher than 120°C. The material combination performance of the attachment part 423 with the extension part 422 is strong, and the adhesion performance with metal is average.

[0067] 2) The attachment part 423 can quickly adhere to pollutants and does not cause pollution to the cleaning surface.

[0068] The attachment portion 423 may specifically be made of natural rubber, silicone rubber, or acrylic polymers. Among them, the monomers of the acrylic polymers may be, for example, acrylic acid, methacrylates, acrylonitrile, ethyl acrylate, 2-chloroethyl vinyl ether, 2-ethylhexyl acrylate, hydroxyethyl methacrylate, butyl acrylate, butylmethacrylate, TMPTA, and so on.

[0069] Furthermore, the attachment portion 423 and the extension portion 422 may be the same component, that is, made of the same material (such as synthetic thermoplastic elastomer), which is a material with both elasticity and viscosity. Of course, it is a more preferable solution that the attachment portion 423 and the extension portion 422 are independent of each other. With this design, the attachment portion 423 can be more conveniently replaced.

[0070] Furthermore, the present invention proposes an installation method for the cleaning member 420. First, invert the base body 410 so that the groove 411 opens upward. Then, after injecting the material of the fluid portion 421, place the extension portion 422, and inject sealant around the outer periphery of the extension portion 422 to fix and seal the extension portion 422. Then, set the attachment portion 423 above the extension portion 422.

[0071] As Figure 5 shown, Figure 5 illustrates a schematic diagram of the installation state of the cleaning member in the preferred embodiment of the present invention. The present invention also proposes an installation method for the cleaning member 420. Similarly, first invert the base body 410 so that the groove 411 opens upward. An inner step is provided inside the groove 411. Place the extension portion 422 in the groove 411 and make the extension portion 422 supported on the inner step. Then, use sealant to fix the extension portion 422 and set the attachment portion 423 on the extension portion 422. Thereafter, right the base body 410, and then inject the fluid portion 421 through the through hole communicating with the groove 411 on the base body 410.

[0072] Furthermore, in this embodiment, the cleaning system is configured to be connected to a temperature control unit (not shown in the figure) for regulating the temperature of the fluid portion 421. Through the temperature control unit, heat is introduced into the base body made of a material with high thermal conductivity to be transferred to the cleaning member 420.

[0073] Furthermore, in this embodiment, the temperature control unit configured on the stage in the substrate etching device can be directly utilized without additionally adding a heat source. Specifically, the stage is an electrostatic chuck with a temperature control unit configured inside, including a fixing plate for supporting the substrate, an electrostatic plate provided below the fixing plate and configured to generate an electrostatic force to fix the substrate, and a heating element provided below the electrostatic plate and configured to generate heat to control the temperatures of the electrostatic plate and the substrate. Thus, through the temperature control unit, the heat generated by the heat source is sequentially transferred to the stage, the placed substrate 200, the thermal conductive adhesive layer, the base body 410, and the fluid part in the cleaning member. Further, the size of the base body 410 is correspondingly set in match with the placed substrate 200, and the placed substrate is of a general wafer size, such as 6 inches, 8 inches, 12 inches, 20 inches, and so on.

[0074] Wherein, the distance between the area of the base body 410 corresponding to the embedded cleaning member and the center of the base body is less than 1 cm smaller than the radius size of the matched placed substrate 200, so that when the cleaning member 420 expands in volume, it can exactly fill the gap between components, such as the gap between the stage and the edge ring.

[0075] Wherein, the overall thickness of the cleaning system is less than twice the thickness of the wafer, and the thickness of the cleaning system is below 2 mm to enable the cleaning system to be transferred into the chamber of the substrate etching device. Because there is only a narrow entrance for transferring the substrate in a conventional substrate etching device (i.e., a plasma etching device) to place it on the stage.

[0076] Furthermore, the present invention also proposes a cleaning method, including the following steps:

[0077] Step S1, move the cleaning system 400 above the space to be cleaned;

[0078] Step S2, raise the temperature of the cleaning member 420 to a preset first working temperature so that the cleaning member 420 expands to fill the space to be cleaned and adsorb pollutants in the space to be cleaned;

[0079] Step S3, lower the temperature of the cleaning member 420 to a preset second working temperature so that the cleaning member 420 shrinks out of the space to be cleaned and take out the adsorbed pollutants from the space to be cleaned.

[0080] Specifically, step S1 includes:

[0081] Sub-step S11, move the cleaning system 400 above a placed substrate 200 and press and adhere to the placed substrate 200 through the thermal conductive adhesive layer;

[0082] Sub-step S12, move the cleaning system 400 and the placed substrate 200 together above the device to be cleaned so that the cleaning member 420 faces the space to be cleaned.

[0083] Furthermore, the present invention also provides a cleaning method for a substrate etching device, comprising the following steps:

[0084] Step S1: Support and place the cleaning system 400 on the top surface of the substrate carrier 200 through its base body 410; specifically, adhere it to the substrate carrier 200 through the heat-conducting adhesive layer at the bottom of the base body 410.

[0085] In the initial state, the temperature of the cleaning member 420 is lower than the boiling point under its working pressure, so the cleaning member 420 is in a natural extended state.

[0086] Step S2: As Figure 6 shown, place the substrate carrier 200 supporting the cleaning system 400 on the top surface of the stage 100.

[0087] Step S3: As Figure 7 shown, adjust the air pressure in the environment where the cleaning system 400 is located so that the air pressure reaches 100 MT to 200 MT; then, through the temperature control unit provided in the stage 100, raise the temperature of the fluid part in the cleaning member to above 60 °C, so that the cleaning member 420 expands to fill the gap between the edge ring 300 and the stage 100, and then adhere to the residue 500 in the gap.

[0088] In this step, when the temperature of the stage 100 increases, the temperature of the cleaning member 420 will also increase accordingly due to heat transfer. At the same time, the temperature of the fluid part 421 will eventually be higher than its boiling point, so it will change from a liquid to a gas, resulting in the expansion of the cleaning member 420.

[0089] Step S4: Through the temperature control unit provided in the stage 100, adjust the temperature of the fluid part to below 30 °C, so that the cleaning member 420 shrinks and withdraws from the gap between the edge ring 300 and the stage 100.

[0090] Step S5: Remove the substrate carrier 200 supporting the cleaning system 400 from the stage 100.

[0091] In the above usage method, by controlling the temperature of the cleaning system and changing the physical form in the fluid part, the volume sizes of the extension part and the attachment part are changed, so that the extension part and the attachment part fill the gap space; then, relying on the viscous characteristics of the attachment part, the residue is strongly removed.

[0092] Utilize the boiling point characteristics of the fluid part under working pressure. It converts into a gas when the temperature is higher than the boiling point and reverts to a liquid when the temperature is lower than the boiling point. By changing the volume of the extension part through the state change, it can extend at high temperatures and recover at low temperatures. Specifically, when the device is in a normal room temperature environment, the fluid part is in a liquid state; as the temperature gradually rises, the fluid part transforms into a gas state, causing the extension part to increase in volume under the action of gas pressure to fill the gap between components; and then the residue is adhered through the attachment part.

[0093] The cleaning system of the present invention can be applied to clean pollutants in the gap. Specifically, it can remove pollutants in the gap between the stage and the edge ring in the etching equipment, such as metal by-products. The cleaning system of the present invention does not require the provision of plasma gas and does not introduce impurities during the cleaning process, and does not involve ion bombardment and does not cause additional losses to the equipment, efficiently and quickly removing pollutants.

[0094] Secondly, the cleaning system of the present invention can meet the requirements that the diameter size of the plane is similar to that of the wafer and the thickness is close to the thickness of the wafer, and can fully meet the inlet requirements of the plasma etching equipment.

[0095] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims, and all of these fall within the protection scope of the present invention.

Claims

1. A substrate etching device, characterized in that, The invention comprises a stage (100), an edge ring (300) surrounding the stage (100), and a cleaning system (400) directly or indirectly mounted on the stage (100); There is a gap between the edge ring (300) and the carrier (100); the cleaning system (400) includes a base (410) directly or indirectly mounted on the carrier (100); the cleaning system (400) further includes a cleaning member (420); the cleaning member (420) is mounted on the base (410) and faces the gap; the cleaning member (420) is used to expand and fill the gap under the influence of ambient air pressure and temperature changes, thereby adhering to residues (500) located in the gap.

2. The substrate etching apparatus according to claim 1, wherein, The thermal conductivity coefficient of the material of the substrate (410) is greater than 200 W / (m·K); and / or the material of the substrate (410) is at least one of aluminum and copper.

3. The substrate etching apparatus according to claim 1, characterized in that, The cleaning member (420) includes a fluid portion (421), an extension portion (422) mounted on a base (410) and used to completely or partially surround and restrict the fluid portion (421), and an attachment portion (423) attached to the extension portion (422).

4. The substrate etching device according to claim 3, wherein: The fluid portion (421) expands due to a gas-liquid phase transition under the influence of changes in ambient air pressure and temperature.

5. The substrate etching device according to claim 3, wherein At working pressure of 10 -3 When MT to 200MT, the boiling point of the fluid portion (421) is 10°C to 120°C.

6. The substrate etching device according to claim 3, wherein: The elastic modulus of the extension portion (422) is greater than 8 MPa; and / or the elongation at break of the extension portion (422) is greater than 500%, where the elongation at break of the extension portion (422) refers to the elongation of the material of the extension portion (422) at the breaking point.

7. The substrate etching device according to any one of claims 2 to 6, wherein: The fluid portion (421) uses at least one of H2O, n-heptane, 2-butanol, 2-butanethiol, methoxyacetyl chloride and 2-methylbutanal; and / or, the extension portion (422) is made of at least one of polyisoprene, styrene-butadiene rubber, butadiene rubber and TPE; And / or, the attachment portion (423) is made of at least one of natural rubber, silicone rubber and acrylic polymer.

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