Process chamber and multiple pattern etching method

Abstract

The application discloses a process chamber and a multiple pattern etching method, and belongs to the technical field of semiconductors. In the process chamber, a first electrode, a second electrode and an ionization coil are all installed in a process cavity; the second electrode is arranged on a bearing device for bearing a workpiece to be processed; the first electrode is opposite to the second electrode and is located above the second electrode; a gas inlet pipeline is in communication with the process cavity; the ionization coil is used for ionizing a process gas delivered to the process cavity through the gas inlet pipeline; in the case of needing to etch the workpiece to be processed, the second electrode is used for being connected with a radio frequency power supply, and the first electrode is used for being connected with a reference level; in the case of needing to deposit on the surface of the workpiece to be processed, the first electrode is used for being connected with the radio frequency power supply, and the second electrode is used for being connected with the reference level. When a process such as a self-aligned double imaging technology is performed by using the process chamber, the workpiece does not need to be frequently switched between the process chamber and a deposition chamber, the complexity of a process procedure can be reduced, a cycle can be shortened, and cost can be reduced.

Description

Technical Field

[0001] This application belongs to the field of semiconductor processing technology, specifically relating to a process chamber and a multi-pattern etching method. Background Technology

[0002] In the semiconductor field, as critical dimensions continue to shrink beyond the physical limits of current lithography technology, the application of self-aligned dual imaging technology is becoming increasingly widespread.

[0003] In the process of using self-aligned dual imaging technology, a sacrificial material layer is typically formed on the surface of the substrate facing away from its mask layer. Photolithography and plasma etching processes can transfer the photolithographic pattern onto the sacrificial material layer. Then, atomic layer deposition (ALD) is used to form a capping layer on the patterned sacrificial material layer and the substrate's mask layer. The capping layer is then removed by etching. However, during the etching process to remove the capping layer, due to the geometric effects of the sidewalls, a portion of the capping layer attached to the sidewalls of the patterned sacrificial material layer (commonly known as a "spacer") can remain. Afterward, by removing the patterned sacrificial material layer separately, only the spacer remains on the side of the substrate where the mask layer is located. Furthermore, in subsequent etching processes, the spacer can transfer to the substrate's mask layer and form a corresponding protective pattern, achieving a multiplication of spatial pattern density.

[0004] As mentioned above, the current self-aligned dual imaging technology requires two different processes: etching and deposition. Etching typically takes place in a process chamber, while deposition occurs in a deposition chamber. Therefore, current self-aligned dual imaging technology necessitates frequent switching between the process and deposition chambers, leading to relatively high process complexity, a longer overall process cycle, and higher costs. Summary of the Invention

[0005] The purpose of this application is to provide a process chamber and a multi-pattern etching method to solve the problem that when performing processes such as self-aligned dual imaging technology, the workpiece needs to be frequently switched between the process chamber and the deposition chamber, resulting in a relatively high complexity, long cycle and high cost of the process.

[0006] In a first aspect, embodiments of this application disclose a process chamber, which includes a process chamber body, a first electrode, a second electrode, an ionization coil, and an air inlet pipe, wherein,

[0007] The first electrode, the second electrode, and the ionization coil are all mounted in the process cavity;

[0008] The second electrode is disposed on a support device for carrying the workpiece to be processed;

[0009] The first electrode is opposite to the second electrode and is located above the second electrode;

[0010] The intake pipe is connected to the process chamber, and the ionization coil is used to ionize the process gas delivered to the process chamber through the intake pipe.

[0011] When it is necessary to etch the workpiece, the second electrode is used to connect to the radio frequency power supply, and the first electrode is used to connect to the reference level;

[0012] In cases where deposition is required on the surface of the workpiece, the first electrode is used to connect to the radio frequency power supply, and the second electrode is used to connect to a reference level.

[0013] Secondly, embodiments of this application disclose a multi-pattern etching method applied to the aforementioned process chamber, the multi-pattern etching method comprising:

[0014] The second electrode of the process chamber is controlled to be connected to the radio frequency power supply, the first electrode is controlled to be connected to the reference level, and the air inlet pipe is controlled to introduce etching gas into the process chamber to etch the workpiece to be processed on the support device, so as to transfer the mask pattern of the first mask layer in the workpiece to the sacrificial material layer.

[0015] The first electrode of the process chamber is controlled to be connected to the radio frequency power supply, the second electrode is controlled to be connected to the reference level, and the gas inlet pipe is controlled to introduce deposition gas into the process chamber to form a deposition layer on the surface of the workpiece to be processed. The deposition layer covers the second mask layer and the patterned sacrificial material layer of the workpiece to be processed.

[0016] The second electrode of the process chamber is controlled to be connected to the radio frequency power supply, the first electrode is controlled to be connected to the reference level, and the air inlet pipe is controlled to introduce etching gas into the process chamber to etch the workpiece to be processed supported on the support device, so as to etch the portion of the deposition layer covering the upper surface of the patterned sacrificial material layer.

[0017] Remove the patterned sacrificial material layer;

[0018] The second electrode of the process chamber is controlled to be connected to the radio frequency power supply, the first electrode is controlled to be connected to the reference level, and the air inlet pipe is controlled to introduce etching gas into the process chamber to etch the workpiece to be processed on the carrier device, so as to transfer the mask pattern of the deposited layer to the substrate layer of the workpiece.

[0019] This application discloses a process chamber, which includes a process cavity body and a first electrode, a second electrode, and an ionization coil installed in the process cavity body. The process cavity body is provided with an air inlet pipe, which is connected to the process cavity body. Furthermore, the process chamber disclosed in this application embodiment can provide the relevant conditions for etching and deposition processes respectively. Specifically, when etching the workpiece is required, the second electrode is connected to a radio frequency power supply, the first electrode is connected to a reference level, and the air inlet pipe can be connected to an etching gas source. Under the action of the ionization coil, the etching gas can be ionized to generate corresponding plasma. Under the action of the second electrode located below the support device, the plasma can move towards the direction of the second electrode to interact with the upper surface of the workpiece supported on the support device, thereby achieving the purpose of etching the workpiece. When deposition is required on the surface of the workpiece, the first electrode can be connected to a radio frequency power supply, and the second electrode can be connected to a reference level. The air inlet pipe can be alternately connected to the first deposition gas source and the second deposition gas source. The gas sources are connected to each other, and under the action of the ionization coil, the first and second deposition gases can be ionized to form particles including silicon and particles including oxygen (and / or nitrogen). The two types of particles can react with each other to form silicon oxide (and / or silicon nitride). This material can be used as a deposition material to form a deposition layer on the surface of the workpiece. At the same time, under the action of the first electrode located above and opposite to the support device, the positively charged ions generated by the ionization of the first and second deposition gases can move away from the upper surface of the workpiece to prevent the plasma from etching the workpiece and hindering the normal progress of the deposition process. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of the process chamber disclosed in the embodiments of this application;

[0022] Figure 2 This is a flowchart of the control method disclosed in an embodiment of this application.

[0023] Figure label:

[0024] 100 - Process cavity, 101 - Workpiece to be processed

[0025] 210 - First electrode, 220 - Second electrode, 230 - Ionization coil

[0026] 310 - Intake line, 321 - First gas line, 322 - Second gas line, 323 - Third gas line

[0027] 401 - Ionization chamber, 402 - Nozzle. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0030] like Figure 1 As shown in the illustration, this application discloses a process chamber. By controlling the process parameters of the process chamber, etching and deposition processes can be performed using the process chamber. Specifically, the process chamber disclosed in this application includes a process chamber body 100, a first electrode 210, a second electrode 220, an ionization coil 230, and an air inlet pipe 310. Of course, the process chamber may also include a support device for carrying the workpiece 101, and an air extraction mechanism for removing byproducts, among other mechanisms. For the sake of brevity, these will not be described in detail here.

[0031] The process chamber 100 provides the process space and can be a circular or cylindrical structure, etc., which is not limited herein. The first electrode 210, the second electrode 220, and the ionization coil 230 can all be directly or indirectly installed in the process chamber 100. The first electrode 210 and the second electrode 220 can both be connected to an external radio frequency power supply, and their on / off states can be controlled according to process requirements to provide corresponding polarization radio frequency power energy to the plasma. More specifically, the radio frequency power supply is connected to an external AC power supply, and a matching device can be set to improve the operating stability of the first electrode 210 and the second electrode 220.

[0032] During installation, the second electrode 220 can be placed on the support device, with the first electrode facing the second electrode and the first electrode positioned above the second electrode. More specifically, the second electrode is positioned below the support device, and the first electrode is spaced apart above the support device. This allows the biased radio frequency power applied by the first electrode to the plasma to promote the plasma to move towards the first electrode, thereby moving the plasma away from the upper surface of the workpiece 101 supported on the support device. Correspondingly, the biased radio frequency power applied by the second electrode to the plasma can promote the plasma to move towards the second electrode, thereby moving the plasma towards the upper surface of the workpiece 101 supported on the support device.

[0033] The ionization coil 230 is used to ionize the process gas into plasma. Specifically, the process gas may include etching gas and deposition gas. The plasma generated from the ionization of the etching gas used for etching can etch the workpiece 101. Correspondingly, the plasma generated from the ionization of the deposition gas used for deposition can react again to generate a deposition film material, which is deposited on the surface of the workpiece 101 to form a deposition layer. Similarly, the ionization coil is also connected to a power source. Optionally, the frequency of the radio frequency power source connected to the ionization coil 230 can be 13.56 MHz, while the frequencies of the radio frequency power sources connected to the first electrode 210 and the second electrode 220 include 2 MHz and 13.56 MHz.

[0034] The intake pipe 310 provides a transport path for the process gas, allowing process gas outside the process chamber 100 to be transported into the process chamber 100 via the intake pipe 310. The process gas transported via the intake pipe 310 can also be ionized by the ionization coil 230, generating corresponding particles, i.e., plasma. This plasma is then used for etching processes, or, by causing the corresponding plasmas to react with each other, a deposition material is formed and deposited on the surface of the workpiece 101 to complete the deposition process. Specifically, the intake pipe 310 is connected to the process chamber 100, allowing the process gas to be transported into the process chamber 100 via the intake pipe 310 to participate in the corresponding processes.

[0035] In an optional embodiment of this application, the first end of the inlet pipe 310 can extend between the first electrode 210 and the second electrode 220. This allows the process gas delivered to the process chamber 100 via the inlet pipe 310 to be delivered more directly and quickly to the workpiece 101 located between the first electrode 210 and the second electrode 220, thereby enabling the plasma formed by the ionization of the process gas to quickly perform the corresponding process, improving process efficiency. Optionally, by having the first end of the inlet pipe 310 bypass the first electrode 210 and the second electrode 220 and extend from the outside of them into the space between the first electrode 210 and the second electrode 220, it can be ensured that the process gas can be delivered more quickly to the space between the first electrode 210 and the second electrode 220.

[0036] In another embodiment of this application, a perforation can be provided at the top of the process cavity 100, so that one end of the air intake pipe 310 can extend into the process cavity 100 through the aforementioned perforation. Correspondingly, by also providing a corresponding perforation at the top of the first electrode 210, the first end of the air intake pipe 310 can pass through the perforations at the top of the process cavity 100 and the first electrode 210, which can also ensure that the air intake pipe 310 can extend into the area between the first electrode 210 and the second electrode 220, so that the process gas can be delivered to the area between the first electrode 210 and the second electrode 220 more quickly. In this case, the path of the air intake pipe 310 is relatively short.

[0037] To further enhance the completeness of process gas ionization, in another embodiment of this application, such as... Figure 1 As shown, the process chamber may further include an ionization chamber 401, which is located above the process chamber. The inlet pipe is connected to the process chamber through the ionization chamber 401. Meanwhile, an ionization coil is arranged around the outer periphery of the ionization chamber 401, so that the ionization chamber 401 can provide a temporary containment space for the process gas. Under the action of the ionization coil, the process gas contained in the ionization chamber 401 is ionized, improving the ionization efficiency and thoroughness of the process gas. This reduces the proportion of process gas introduced into the process chamber, improves the utilization efficiency of the process gas, and can also improve the etching efficiency and deposition efficiency to a certain extent.

[0038] Specifically, the ionization chamber 401 can be made of the same material as the process chamber. For example, both the process chamber and the ionization chamber 401 can be formed of ceramic material, and an anti-corrosion coating can be formed on the inner surface of both. The anti-corrosion coating material can include one of alumina, yttrium oxide, and zirconium oxide. A nozzle 402 can be provided at the end of the ionization chamber 401 away from the inlet pipe. The nozzle 402 can be disposed in the process chamber to deliver plasma into the process chamber.

[0039] Furthermore, the size of the ionization chamber 401 can be smaller than the size of the process chamber. For example, the diameter of the ionization chamber 401 can be one-fifth of the diameter of the process chamber, and the axes of all process chambers in the ionization chamber 401 can be aligned on the same straight line, so that the plasma in the ionization chamber 401 can diffuse more uniformly into the process chamber. In a specific embodiment of this application, the ionization chamber 401 can be a circular cylindrical structure with an inner diameter of 10 cm and a height of 18 cm.

[0040] Based on the above embodiments, perforations can be further provided on the top of the process cavity and on the first electrode, and the ionization cavity 401 can be connected to the perforations, so that the plasma in the ionization cavity 401 can move through the perforations to the space between the first electrode and the second electrode to interact with the workpiece 101.

[0041] As described above, the process chamber disclosed in this application can perform etching and deposition processes separately under different process parameters. Therefore, during the assembly of the air inlet pipe 310 in the process chamber disclosed in this application, it is necessary to ensure that the second end of the air inlet pipe 310 outside the process chamber 100 can selectively communicate with both the etching gas source and the deposition gas source. Of course, considering that the deposition process performed during self-aligned dual imaging technology is typically atomic layer deposition, in this application embodiment, the deposition gas source can include two parts: one part for providing silicon, and the other part for providing at least one of oxygen and nitrogen, thereby enabling the two deposition gas sources to form at least one of silicon oxide and silicon nitride within the process chamber 100. That is, in this application embodiment, the deposition gas source includes a first deposition gas source and a second deposition gas source, wherein the first deposition gas source includes silicon, and the second deposition gas source includes at least one of oxygen and nitrogen. As for the etching gas source, it can usually include fluorine to react with silicon and oxygen in the workpiece 101 to achieve the purpose of etching the workpiece 101.

[0042] Alternatively, by detachably connecting the intake pipe 310 to different gas sources, it can be ensured that when an etching process is required, the etching gas can be delivered to the process chamber 100 via the intake pipe 310, and when a deposition process is required, the first deposition gas and the second deposition gas can be delivered to the process chamber 100.

[0043] In another embodiment of this application, corresponding gas pipelines may also be provided, for example, a first gas pipeline 321, a second gas pipeline 322, and a third gas pipeline 323, with the second ends of each of the three pipelines being closably connected to the second end of the inlet pipeline 310 located outside the process chamber 100 via valves or other devices. Simultaneously, the first end of the first gas pipeline 321 is connected to an etching gas source, the first end of the second gas pipeline 322 is connected to a first deposition gas source, and the first end of the third gas pipeline 323 is connected to a second deposition gas source.

[0044] In addition, considering that etching gas is not required in the deposition process, in a specific embodiment of this application, one of the first deposition gas source and the second deposition gas source can share a gas pipeline with the etching gas source. For example, the first gas pipeline 321 can be used to connect the etching gas source and the second deposition gas source, and by setting valves or other devices, the etching gas or the second deposition gas can be selectively introduced. Correspondingly, the second gas pipeline 322 is used to connect the first deposition gas source to introduce the first deposition gas.

[0045] Based on the above-described process chamber structure, the connectivity between devices within the process chamber 100, as well as the on / off states between the first electrode 210 and the second electrode 220 and the RF power supply, can be controlled according to actual process requirements. Specifically, when etching the workpiece 101 is required, the second electrode 220 can be connected to the RF power supply, and the first electrode 210 can be connected to a reference level. Optionally, the reference level can be ground, meaning the first electrode 210 is grounded. This allows electrons generated by the ionized process gas to be discharged outside the process chamber via the first electrode 210, ensuring the electrical balance of the process chamber. Simultaneously, when etching the workpiece 101 is required, the inlet pipe 310 is connected to the etching gas source, allowing the etching gas to be introduced into the process chamber as a process gas. Under the action of the ionization coil 230, the etching gas can be ionized into plasma, thereby utilizing the plasma generated by the etching gas to achieve the purpose of etching the workpiece 101. Furthermore, under the action of the second electrode 220, the positively charged plasma generated by the ionization of the etching gas can be affected by the radio frequency power energy, and tend to move in the direction of the second electrode 220, thereby causing the plasma to move in the direction of the upper surface of the workpiece 101 supported on the carrier device, so as to achieve the purpose of etching the workpiece 101.

[0046] When a deposition process is required in the process chamber, that is, when a deposition layer needs to be formed on the surface of the workpiece 101, the first electrode 210 can be connected to the radio frequency power supply, and the second electrode 220 can be connected to the reference level, that is, the second electrode 220 can be grounded, so that the electrons generated by the ionized process gas can be led out of the process chamber using the second electrode 220. At the same time, when performing the deposition process, the gas inlet pipe 310 needs to be alternately connected to the first deposition gas source and the second deposition gas source, so that the first deposition gas and the second deposition gas can be alternately introduced into the process chamber. Under the action of the ionization coil 230, the first deposition gas and the second deposition gas are ionized to generate particles with silicon element and particles with oxygen element (and / or nitrogen element), respectively. The two types of particles can undergo an oxidation reaction to form silicon oxide (and / or silicon nitride). This material can be deposited on the surface of the workpiece 101 as a deposition film material to complete the deposition process. Furthermore, under the action of the first electrode 210, the positively charged plasma generated by ionization in the deposition gas can be affected by the radio frequency power energy, and tend to move in the direction of the first electrode 210. This causes the plasma that has not yet reacted with each other to form a film compound to move away from the upper surface of the workpiece 101 supported on the carrier device, so as to prevent the positively charged plasma from causing an etching effect on the workpiece 101 and disrupting the normal progress of the deposition process.

[0047] It should be noted that in the above embodiments, the devices used to control which air source the air intake pipe 310 is connected to, and to control the on / off state of the first electrode 210 and the second electrode 220, can be separate controllers. For example, the process chamber may also include a controller, or the control device of a device such as a wafer transfer robot may be used to achieve the control purpose of the process chamber disclosed in the embodiments of this application. This is not limited in this document.

[0048] This application discloses a process chamber, which includes a process chamber 100 and a first electrode 210, a second electrode 220, and an ionization coil 230 installed in the process chamber 100. The process chamber 100 is provided with an air inlet pipe 310, which is connected to the process chamber 100. Furthermore, the process chamber disclosed in this application can provide the necessary conditions for performing etching and deposition processes, respectively. In the case where etching of the workpiece 101 is required, the second electrode 220 is connected to the radio frequency power supply, the first electrode 210 is connected to the reference level, and the air intake pipe 310 can be connected to the etching gas source. Under the action of the ionization coil 230, the etching gas can be ionized to generate corresponding plasma. Under the action of the second electrode 220 located below the support device, the plasma can move in the direction of the second electrode 220 to interact with the upper surface of the workpiece 101 supported on the support device, thereby achieving the purpose of etching the workpiece 101. In the case where deposition is required on the surface of the workpiece 101, the first electrode 210 can be connected to the radio frequency power supply, and the second electrode 220 can be connected to the reference level. The air intake pipe 310 can be alternately connected to the reference level. The first and second deposition gas sources are connected to the ground, respectively. Under the action of the ionization coil 230, the first and second deposition gases are ionized to form particles including silicon and particles including oxygen (and / or nitrogen). The two types of particles can react with each other to form silicon oxide (and / or silicon nitride). This material can be used as a deposition material to form a deposition layer on the surface of the workpiece 101. At the same time, under the action of the first electrode 210, which is located above the support device and opposite to the support device, the positively charged ions generated by the ionization of the first and second deposition gases can move away from the upper surface of the workpiece 101 to prevent the plasma from etching the workpiece 101 and hindering the normal progress of the deposition process.

[0049] Obviously, the process chamber disclosed in the above embodiments of this application can perform etching and deposition processes under different process conditions. Therefore, if the process chamber disclosed in the embodiments of this application is used for self-aligned dual imaging technology, it is not necessary to frequently switch the workpiece 101 between different process equipment. In this way, the complexity of the process can be greatly reduced, the process cycle can be shortened, and the process cost can be reduced.

[0050] To provide a more detailed description of the process chamber disclosed in the embodiments of this application, this document describes in detail the process of performing self-aligned dual imaging technology using the aforementioned process chamber. First, a second mask layer can be formed on the substrate. The specific material of the second mask layer can be silicon nitride. A sacrificial material layer can be formed on the side of the second mask layer facing away from the substrate. The specific material of the sacrificial material layer can be polysilicon. A photoresist layer can be disposed on the side of the sacrificial material layer facing away from the mask layer. The photoresist layer can serve as the first mask layer.

[0051] Based on the above structure, during the process, the photoresist layer can be patterned by means of exposure and development to serve as the first mask layer for etching the sacrificial material layer. Afterwards, the workpiece 101 can be transferred to the process chamber disclosed in this embodiment. Then, the second electrode 220 is controlled to be connected to the radio frequency power supply, and the first electrode 210 is controlled to be connected to the reference level. Etching gas is introduced into the process chamber by connecting the air intake pipe 310 to the etching gas source. Specifically, the etching gas can be carbon tetrafluoride, but it can also include oxygen, etc. Under the action of the ionization coil 230, the etching gas ionizes to generate plasma. Under the action of the second electrode 220, the plasma can move in the direction of the second electrode 220 to etch the upper surface of the workpiece 101 and transfer the pattern on the photoresist layer to the sacrificial material layer. Then, the second electrode 220 is controlled to be connected to the reference level, and the first electrode 210 is controlled to be connected to the radio frequency power supply. Simultaneously, the air intake pipe 310 is alternately connected to the first deposition gas source and the second deposition gas source. The first deposition gas can include silicon chloride, and the second deposition gas can be... The deposition gas can include at least one of oxygen and nitrogen. Under the action of the ionization coil 230, silicon chloride is dissociated. Correspondingly, oxygen and nitrogen can also dissociate and react with silicon-containing particles generated by silicon chloride to form silicon oxide and silicon nitride. Both can be used as deposition film materials and deposited on the upper surface of the workpiece 101, thereby covering the patterned sacrificial material layer and the exposed second mask layer. During this process, the first electrode 210 can provide electro-adsorption for positively charged particles, thereby preventing positively charged particles from moving in the direction of the workpiece 101 (i.e., the direction of the second electrode 220) to etch the workpiece 101 and hinder the normal progress of the deposition process. Afterward, the first electrode 210 of the process chamber is reconnected to the reference level, and the second electrode 220 is connected to the radio frequency power supply. The air inlet pipe 310 is connected to the etching gas source to etch the workpiece 101 again. It should be noted that during this etching process, due to the geometric effect of the sidewalls, the deposited material adhering to the sidewalls of the patterned sacrificial material layer within a certain range cannot be etched away. Subsequently, based on the specific materials of the sacrificial material layer and the deposited material, an etchant is selected accordingly to remove the patterned sacrificial material layer separately, while retaining the deposited material originally adhering to the sidewalls of the sacrificial material layer. Broadly speaking, the pattern formed by the deposited material remaining on the mask layer is the mask pattern of the first mask layer after the spatial frequency is doubled. Then, by further etching the deposited material, the pattern of the deposited material can be transferred to the second mask layer and finally to the substrate, thereby forming an etching pattern with a relatively smaller critical size.

[0052] To further improve the process performance, a purging process can be added between different process steps during the operation of the process chamber disclosed in this application embodiment. Specifically, after transferring the photoresist layer pattern onto the sacrificial material layer, a purging process can be used to remove byproducts and other contaminants from the process chamber 100, ensuring a relatively clean process environment within the chamber. Following this, the deposition process can then proceed with better uniformity and other parameters of the deposited layers on the sacrificial material layer and mask layer. Correspondingly, a purging process can also be performed after the deposition process is completed and before the next etching process to ensure better results in the subsequent etching process.

[0053] Furthermore, a corresponding cleaning gas can be introduced to clean the inner wall of the process chamber 100 and the surface of the device, so as to prevent by-products from adversely affecting subsequent processes due to their adhesion to the inner wall of the process chamber 100 and the surface of the device. Specifically, in the process chamber disclosed in this application embodiment, the air inlet pipe 310 can be selectively connected to etching gas and deposition gas, and can also be selectively connected to a cleaning gas source, so that cleaning gas can also be delivered into the process chamber 100 through the air inlet pipe 310, and clean by-products and other impurities adhering to the inner wall of the process chamber 100 and the surface of the device.

[0054] Specifically, the cleaning gas may include nitrogen trifluoride. In this case, when the process chamber 100 needs to be cleaned, the second electrode 220 can be kept in the state of being connected to the radio frequency power supply. Under the action of the ionization coil 230, the cleaning gas can generate corresponding plasma. Under the action of the second electrode 220, the plasma tends to move towards the workpiece 101 and interacts with the by-products adhering to the inner wall of the process chamber 100 and the surface of the workpiece 101, thereby achieving the purpose of cleaning the inner wall of the process chamber 100 and the surface of the workpiece 101. This further prevents the by-products generated in the previous process from having an adverse effect on the process effect of the subsequent process.

[0055] As described above, the process chamber disclosed in this application includes a first electrode 210 and a second electrode 220. Additionally, the process chamber includes a support device for supporting the workpiece 101. The support device is typically positioned on the side of the second electrode 220 facing the first electrode 210. Therefore, the support device and the workpiece 101 can provide some protection to the second electrode 220, preventing direct interaction between the plasma and the second electrode 220. The first electrode 210 is entirely exposed within the process chamber. Therefore, to extend the service life of the first electrode 210, it can be made of aluminum or copper. Furthermore, after a period of use, replacing the first electrode 210 ensures its continued and normal function.

[0056] As described above, the process chamber disclosed in the embodiments of this application can be used to provide etching and deposition functions. Therefore, this process chamber can be used as a device for performing self-aligned dual imaging technology. In detail, the embodiments of this application also disclose a multi-pattern etching method, which can be applied to the process chamber disclosed in the above embodiments. Figure 2 As shown, the multi-pattern etching method may include:

[0057] S1. The second electrode of the control process chamber is connected to the RF power supply, the first electrode is connected to the reference level, and the inlet pipe is controlled to introduce etching gas into the process chamber to etch the workpiece carried on the carrier device, thereby transferring the mask pattern of the first mask layer in the workpiece to the sacrificial material layer. It should be noted that the workpiece includes a substrate, a second mask layer, a sacrificial material layer, and a first mask layer stacked sequentially. The first mask layer can specifically be a patterned photoresist layer. Accordingly, after etching is completed, the mask pattern of the first mask layer in the workpiece can be transferred to the sacrificial material layer, so that the workpiece after this etching step can include a substrate, a second mask layer, and a patterned sacrificial material layer.

[0058] In detail, as described above, the process chamber includes a process cavity, within which a support device is provided. The workpiece to be processed can be placed within the process cavity and supported on the support device. The process chamber also includes a first electrode and a second electrode, with the second electrode positioned below the support device and the first electrode positioned above it, opposite and spaced apart. The energization state of both the first and second electrodes can be flexibly controlled according to process requirements, and the gas inlet pipe can be connected to the corresponding gas source according to the specific process to be performed. Therefore, in this step, to perform the etching process, radio frequency power needs to be applied to the second electrode, and the gas inlet pipe needs to be connected to the etching gas source to deliver the etching gas into the process chamber. Under the action of the ionization coil, plasma is generated, and under the electro-adsorption effect of the second electrode, the purpose of etching the workpiece using plasma is achieved. Simply put, in this etching process, the purpose is to transfer the pattern on the photoresist layer to the sacrificial material layer.

[0059] After step S1, the first mask layer in the workpiece can be removed, and the mask pattern of the first mask layer can be transferred to the sacrificial material layer. Then, the multi-pattern etching method disclosed in this application further includes:

[0060] S2. The first electrode of the control process chamber is connected to the radio frequency power supply, the second electrode is connected to the reference level, and the gas inlet pipe is controlled to introduce deposition gas into the process chamber to form a deposition layer on the surface of the workpiece. The deposition layer covers the second mask layer and the patterned sacrificial material layer of the workpiece. Specifically, the deposition gas may include a first deposition gas and a second deposition gas. The first deposition gas includes silicon, and the second deposition gas includes at least one of oxygen and nitrogen. Under the action of the ionization coil, the first and second deposition gases can be ionized to generate particles including silicon and particles including oxygen (and / or nitrogen), respectively. Accordingly, silicon can form silicon oxide with oxygen and silicon nitride with nitrogen. Both materials can be used as deposition layer forming materials. As this step continues, a deposition layer can be formed on the surface of the workpiece, covering the patterned sacrificial material layer in the workpiece and the area of ​​the second mask layer exposed to the sacrificial material layer. In addition, in this step, the first electrode can provide electro-adsorption, thereby preventing positively charged particles from moving towards the workpiece and thus causing an etching effect on the workpiece, which would hinder the normal progress of the deposition process.

[0061] Subsequently, the multi-pattern etching method disclosed in the embodiments of this application further includes:

[0062] S3. The second electrode of the control process chamber is connected to the RF power supply, the first electrode is connected to the reference level, and the intake pipe is controlled to introduce etching gas into the process chamber to etch the workpiece supported on the carrier device, thereby etching the deposited layer. During this process, the appropriate type of etching gas can be selected according to the material of the deposited layer. Furthermore, in this step, due to the geometric effect of the sidewalls, a certain range of deposited material adhering to the sidewalls of the patterned sacrificial material layer cannot be etched away. After etching until the top surface of the patterned sacrificial material layer is exposed again, this etching step is complete. During this process, etching can essentially remove the portion of the deposited layer covering the upper surface of the sacrificial material layer, while still retaining some of the portion of the deposited layer adhering to the sidewalls of the patterned structure of the sacrificial material layer.

[0063] Subsequently, multiple pattern etching methods also include:

[0064] S4. Remove the patterned sacrificial material layer. Specifically, based on the actual materials of the sacrificial material layer, deposition layer, second mask layer, and substrate, appropriate types of etchants can be selected to remove the sacrificial material layer individually without damaging the deposition layer, second mask layer, and substrate. After removing the patterned sacrificial material layer, the deposition layer that originally adhered to the patterned structure of the sacrificial material layer remains on the upper surface of the second mask layer on both sides opposite to it. This allows the aforementioned deposition layer to serve as a mask structure for etching the second mask layer, and compared to the mask pattern of the first mask layer, it can achieve a doubling of the spatial frequency of the mask pattern.

[0065] Subsequently, the multi-pattern etching method disclosed in the embodiments of this application further includes:

[0066] S5. The second electrode of the control process chamber is connected to the RF power supply, the first electrode is connected to the reference level, and the gas inlet is controlled to introduce etching gas into the process chamber to etch the workpiece supported on the carrier device, thereby transferring the mask pattern of the deposited layer to the substrate layer of the workpiece. In this process, the deposited layer is used as a mask structure to achieve the purpose of etching the second mask layer. By designing the materials of the deposited layer, the second mask layer, and the substrate, while ensuring that the mask pattern of the deposited layer can be transferred to the substrate and forming an etching pattern with smaller critical dimensions, the etching depth of the etching structure on the substrate can also be increased by using the second mask layer.

[0067] In the process of controlling the first electrode or the second electrode to be connected to the radio frequency power supply, the radio frequency power of the second electrode can be between 20 and 5000W, while the radio frequency power of the first electrode can be between 10 and 500W. This ensures that both can provide the required electro-adsorption effect.

[0068] As described above, in the process chamber, the air inlet pipe can be selectively connected to a clean air source. Therefore, the multi-pattern etching method disclosed in the embodiments of this application may further include:

[0069] The second electrode of the control process chamber is connected to the radio frequency power supply, the first electrode is connected to the reference level, and the inlet pipe is controlled to introduce cleaning gas into the process chamber to clean it. In this configuration, the ionization coil can generate plasma from the cleaning gas delivered to the process chamber via the inlet pipe. During this process, the electro-adsorption effect provided by the second electrode allows the plasma generated by the cleaning gas to clean the inner wall of the process chamber and the surface of the workpiece, thereby removing byproducts and other impurities that adhere to the inner wall of the process chamber and the surface of the workpiece during the aforementioned process. This ensures a relatively high cleanliness level of the process chamber in subsequent processes, thus improving the process efficiency of subsequent processes. Specifically, the cleaning gas may include nitrogen trifluoride.

[0070] Furthermore, to further improve the cleanliness of the process chamber before the next process, a purging step can be added between adjacent steps in the aforementioned multi-pattern etching method. This purging gas removes gaseous impurities, such as byproducts, from the process chamber. The purging gas can be nitrogen, or it can be an inert gas such as neon.

[0071] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0072] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A process chamber, characterized in that, It includes a process chamber, a first electrode, a second electrode, an ionization coil, and an intake pipe, among which, The first electrode, the second electrode, and the ionization coil are all mounted in the process cavity; The second electrode is disposed on a support device for carrying the workpiece to be processed; The first electrode is opposite to the second electrode and is located above the second electrode; The intake pipe is connected to the process chamber, and the ionization coil is used to ionize the process gas delivered to the process chamber through the intake pipe. When it is necessary to etch the workpiece, the second electrode is used to connect to the radio frequency power supply, and the first electrode is used to connect to the reference level; In cases where deposition is required on the surface of the workpiece, the first electrode is used to connect to the radio frequency power supply, and the second electrode is used to connect to a reference level.

2. The process chamber according to claim 1, characterized in that, The intake pipe can be selectively connected to an etched gas source, a deposited gas source, and a clean gas source.

3. The process chamber according to claim 2, characterized in that, The etching gas source includes carbon tetrafluoride; The deposition gas source includes a first deposition gas source and a second deposition gas source. When deposition is required on the surface of the workpiece, the air inlet pipe is controlled to alternately connect to the first deposition gas source and the second deposition gas source respectively. The first deposition gas source includes silicon chloride, and the second deposition gas source includes at least one of oxygen and nitrogen.

4. The process chamber according to claim 1, characterized in that, The projection of the first electrode in a plane perpendicular to the axial direction of the process cavity covers the workpiece, and / or the projection of the second electrode in a plane perpendicular to the axial direction of the process cavity covers the workpiece.

5. The process chamber according to claim 1, characterized in that, The process chamber includes a first gas pipeline, a second gas pipeline, and a third gas pipeline. The first end of the first gas pipeline is connected to an etching gas source, the first end of the second gas pipeline is connected to a first deposition gas source, and the third gas pipeline is connected to a second deposition gas source. The second ends of the first gas pipeline, the second gas pipeline, and the third gas pipeline are all connected to a valve, and the valve is also connected to the second end of the inlet pipeline.

6. The process chamber according to claim 1, characterized in that, The process chamber further includes an ionization chamber, which is located above the process chamber. The air intake pipe is connected to the process chamber through the ionization chamber, and the ionization coil is arranged around the outer periphery of the ionization chamber.

7. The process chamber according to claim 6, characterized in that, Both the top of the process chamber and the first electrode are provided with perforations, and the ionization chamber is connected to the perforations.

8. A multi-pattern etching method, applied to the process chamber of claim 1, characterized in that, The multi-pattern etching method includes: The second electrode of the process chamber is controlled to be connected to the radio frequency power supply, the first electrode is controlled to be connected to the reference level, and the air inlet pipe is controlled to introduce etching gas into the process chamber to etch the workpiece to be processed on the support device, so as to transfer the mask pattern of the first mask layer in the workpiece to the sacrificial material layer. The first electrode of the process chamber is controlled to be connected to the radio frequency power supply, the second electrode is controlled to be connected to the reference level, and the gas inlet pipe is controlled to introduce deposition gas into the process chamber to form a deposition layer on the surface of the workpiece to be processed. The deposition layer covers the second mask layer and the patterned sacrificial material layer of the workpiece to be processed. The second electrode of the process chamber is controlled to be connected to the radio frequency power supply, the first electrode is controlled to be connected to the reference level, and the air inlet pipe is controlled to introduce etching gas into the process chamber to etch the workpiece to be processed supported on the support device, so as to etch the deposition layer. Remove the patterned sacrificial material layer; The second electrode of the process chamber is controlled to be connected to the radio frequency power supply, the first electrode is controlled to be connected to the reference level, and the air inlet pipe is controlled to introduce etching gas into the process chamber to etch the workpiece to be processed on the carrier device, so as to transfer the mask pattern of the deposited layer to the substrate layer of the workpiece.

9. The multi-pattern etching method according to claim 8, characterized in that, The multi-pattern etching method further includes: The second electrode of the process chamber is controlled to be connected to the radio frequency power supply, the first electrode is controlled to be connected to the reference level, and the air inlet pipe is controlled to introduce cleaning gas into the process chamber to clean the process chamber.

10. The multi-pattern etching method according to claim 8, characterized in that, The radio frequency power of the second electrode is between 20 and 5000W, and / or the radio frequency power of the first electrode is between 10 and 500W.

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