Plasma processing apparatus for etching including consumable metal member

Abstract

A plasma processing procedure for etching involving a consumable metal component is disclosed. [Solution] The plasma processing apparatus for etching includes a vacuum chamber, a substrate support member disposed inside the chamber, a gas supply member that injects gas into the chamber, a consumable part disposed inside the chamber that generates metal by-products including ions or radicals of a first metal when plasma is generated inside the chamber, a first electrode to which power is applied to generate plasma inside the chamber, a second electrode opposite the first electrode, and a power supply that supplies power to the first and second electrodes.

Description

[Technical field]

[0001] The present invention relates to a plasma processing apparatus for etching that includes a consumable metal member that contains a refractory metal, which is a component contained in a special gas. [Background technology]

[0002] In the conventional high aspect ratio contact process, which is one of the semiconductor etching processes, uneven polymer passivation of the sidewall and charging effect that prevents vertical ion incidence remain as problems to be solved. In order to improve the problems of uneven polymer passivation and charging effect, a process of injecting a special purpose gas during etching has been researched, and the most representative is WF6 (tungsten hexafluoride) special gas. Tungsten in the injected WF6 special gas combines with the polymer of the sidewall during the etching process, which can form a thinner and more uniform metal-doped polymer protective layer compared to conventional carbon-based polymers. The metal-doped polymer protective layer shows superior performance in protecting the sidewall compared to conventional carbon-based polymer single component layers due to the hard properties of the refractory metal, and improves the charging effect caused by cations, thereby enabling vertical etching results to be obtained. In addition, the bonding between the metal contained in the special gas injected in the etching process and the ACL can further improve the etching selectivity of the ACL mask layer.

[0003] However, such a special gas addition process requires the installation of an additional gas line for the addition of the special gas, and also requires an additional step of supplying a limited variety of refractory metal bonding materials in the form of gas to the chamber. Also, there are very few types of materials that can be used as the special gas, and even in the case of WF6 gas, which is widely known as a conventional technology, there are disadvantages in that the conventional process needs to be modified or only a very small amount of the special gas needs to be added in order to show a favorable metal addition effect. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-501538 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to solve the above problems, one object of the present invention is to provide an etching plasma processing apparatus including a consumable metal member containing a refractory metal, which can replace special gases introduced to improve etching quality. [Means for solving the problem]

[0006] In one aspect, the present invention provides a plasma processing apparatus for etching, including a vacuum chamber, a substrate support member disposed inside the chamber, a gas supply member that injects gas into the chamber, a consumable unit disposed inside the chamber that generates a metal by-product including ions or radicals of a first metal when plasma is generated inside the chamber, a first electrode to which power is applied to generate plasma inside the chamber, a second electrode opposite the first electrode, and a power supply that supplies power to the first and second electrodes. In one embodiment, the expendable unit is provided in a shower head located in an upper portion of the chamber and having one or more gas ejection holes.

[0007] In one embodiment, the consumable part is provided on an edge ring disposed at a lower portion of the chamber to surround an edge of the substrate disposed on the substrate support member. In one embodiment, the consumable part is provided on an inner wall of the chamber. In one embodiment, the consumable part includes a silicon (Si) compound or mixture containing the first metal.

[0008] In one embodiment, the first metal includes one or more of niobium (Nb), molybdenum (Mo), tantalum (Ta), tungsten (W), rhenium (Re), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), zinc (Zr), technetium (Tc), rubidium (Rb), rhodium (Rh), hafnium (Hf), osmium (Os), and iridium (Ir). In one embodiment, the device further includes a power source connected to the consumable unit for applying power to the consumable unit to promote generation of ions or radicals of the first metal.

[0009] In one embodiment, the device is one of a dual frequency capacitively coupled plasma (CCP) device, an inductively coupled plasma (ICP) device, a microwave plasma device, a helicon plasma device, an electron cyclotron resonance (ECR) plasma device, and a remote plasma device. Effect of the Invention

[0010] According to the present invention, by using a consumable metal part containing a refractory metal component in an etching plasma processing device instead of a special gas containing a refractory metal for preferred sidewall passivation, an improvement effect of an etching process in which a special gas containing a refractory metal component is injected can be obtained. Therefore, it is possible to perform a more economical etching process in that it is not necessary to install an additional gas line for injecting the special gas and the by-product of the consumable metal part can be utilized. In addition, since deposition by sputtering can be performed immediately without directly injecting the special gas, it is effective for sidewall passivation and sidewall protection, which overcomes the limitations of fine pattern etching in the HARC etching process. [Brief description of the drawings]

[0011] [Figure 1] 1 is a circuit diagram and a schematic diagram of a consumable section of an apparatus according to one embodiment of the present invention; [Diagram 2] FIG. 1 is a circuit diagram of a device having a single power source connected to a consumable unit and a schematic diagram of the consumable unit. [Diagram 3] FIG. 1 is a circuit diagram of a device having two power sources connected to a consumable unit and a schematic diagram of the consumable unit. [Figure 4] 1 is a structural diagram of a dual frequency Capacitively Coupled Plasma (CCP) device of the present invention. [Diagram 5] 1 is a structural diagram of a dual frequency Capacitively Coupled Plasma (CCP) device of the present invention. [Figure 6] 1 is a structural diagram of an inductively coupled plasma (ICP) device of the present invention. [Figure 7] 1 is a structural diagram of an electromagnetic (microwave) plasma device of the present invention. [Figure 8] FIG. 2 is a structural diagram of a remote plasma device of the present invention. [Figure 9] FIG. 1 is a structural diagram of an embodiment of the present invention using self DC bias. [Figure 10] FIG. 11 is a structural diagram of another embodiment of the present invention using self DC bias. BEST MODE FOR CARRYING OUT THEINVENTION

[0012] A most preferred embodiment of the present invention includes a vacuum chamber, a substrate support member disposed within the chamber, a gas supply member for injecting gas into the chamber, a consumable unit disposed within the chamber for generating metal by-products including ions or radicals of a first metal when plasma is generated within the chamber, a first electrode to which power is applied to generate plasma within the chamber, a second electrode opposite the first electrode, and a power source for supplying power to the first and second electrodes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiments of the present invention will be described in detail. Since the present invention can be modified in various ways and can have various forms, specific embodiments will be illustrated in the drawings and described in detail in the present text. However, this is not intended to limit the present invention to the specific disclosed form, and it should be understood that the present invention includes all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0014] Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another.

[0015] Throughout the specification, when a part "comprises" or "contains" a certain component, this means that it may further include other components, unless otherwise specified. In addition, as used in this specification, the singular expression includes the plural expression unless the context clearly indicates otherwise.

[0016] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and are not to be construed as ideal or overly formal unless expressly defined in this application. The plasma etching treatment method disclosed in the present invention will now be described in more detail with reference to the accompanying drawings.

[0017] The present invention provides a plasma processing apparatus for etching, comprising: a vacuum chamber; a substrate support member disposed inside the chamber; a gas supply member for injecting gas into the chamber; a consumable part disposed inside the chamber for generating metal by-products including ions or radicals of a first metal when plasma is generated inside the chamber; a first electrode to which power is applied to generate plasma inside the chamber; a second electrode opposed to the first electrode; and a power supply for supplying power to the first and second electrodes.

[0018] The plasma processing apparatus for etching can be used in a semiconductor etching process, preferably a semiconductor high aspect ratio contact etching process. The plasma processing apparatus for etching can be a dual frequency capacitively coupled plasma (CCP) apparatus, an inductively coupled plasma (ICP) apparatus, a microwave plasma apparatus, a helicon plasma apparatus, an electron cyclotron resonance (ECR) plasma apparatus, or a remote plasma apparatus. The plasma processing apparatus for etching can include a vacuum chamber capable of maintaining an internal vacuum, and can inject gas into the chamber and generate plasma in the chamber by applying power. In this case, the power source can be an RF power source. In addition, in the present invention, the passivation efficiency and vertical etching efficiency of the etching process can be improved by using a consumable metal part that sputters or reacts as an indirect injection method rather than a direct injection method in which an etching gas is directly injected. The plasma etching treatment method disclosed in the present invention will now be described in more detail with reference to the accompanying drawings.

[0019] The present invention may include a vacuum chamber, a substrate support member disposed inside the chamber, a gas supply member that injects gas into the chamber, a consumable part disposed inside the chamber that generates a metal by-product including ions or radicals of a first metal when plasma is generated inside the chamber, a first electrode to which power is applied to generate plasma inside the chamber, a second electrode opposite the first electrode, and a power supply that supplies power to the first and second electrodes.

[0020] The high aspect ratio contact etching process is a process for high aspect ratio etching including vertical etching of NAND type flash having a high aspect ratio due to the high number of layers of stacked dielectric films. In the high aspect ratio contact etching process, since many dielectric layers are stacked, problems such as bowing, twisting, loading effect, charging effect, and non-uniform passivation of sidewalls may occur on the etched pattern. Therefore, in order to solve this, it is necessary to inject a special gas containing a metal in addition to the etching gas. However, this requires the installation of additional special gas injection equipment.

[0021] In the present invention, instead of injecting a special gas containing a metal, a refractory metal, preferably a silicon (Si) compound or mixture containing a metal, more preferably a silicide containing a metal, can be included in the consumable metal parts in the conventional plasma processing apparatus for etching. In this case, the consumable metal parts may be called consumable parts, and the consumable parts may be located in a chamber of the plasma processing apparatus for etching, and preferably may be provided in a removable and replaceable part located in the chamber, and the consumable parts may have a surface exposed in the chamber, and the surface may be exposed to plasma during the etching process.

[0022] The surface of the consumable part is exposed in the chamber, where plasma etching occurs, and the effect of additives obtained by injecting special gases containing metals (TaF6, WF6, WF5Cl, Wbr6, W(CO)6, WCl6, BiF5, etc.) used in the conventional technology can be replaced by using metal halide compounds such as molybdenum (Mo), nickel (Ni), tantalum (Ta), and tungsten (W), which are reaction by-products of etching the consumable part. At this time, the metal ions or radicals are combined with the polymer material to be plasma-deposited on the substrate and deposited on the substrate.

[0023] In this case, the consumable unit may be provided in a shower head located in an upper portion of the chamber and having one or more gas ejection holes, or the consumable unit may be provided in an edge ring located in a lower portion of the chamber so as to surround an edge portion of a substrate placed on the substrate support member, or the consumable unit may be provided on an inner wall of the chamber. In this case, when the consumable unit is provided on the inner wall of the chamber, the consumable unit may partially replace the inner wall of the chamber or may be provided on the inner wall of the chamber. The consumable unit may be provided in various forms and structures, not limited to those described above, as long as it is located inside the chamber and the surface of the consumable unit is exposed to plasma so that etching can occur.

[0024] The consumable part may comprise a silicon (Si) compound or mixture containing the first metal, the first metal preferably comprising one or more of niobium (Nb), molybdenum (Mo), tantalum (Ta), tungsten (W), rhenium (Re), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), zinc (Zr), technetium (Tc), rubidium (Rb), rhodium (Rh), hafnium (Hf), osmium (Os), and iridium (Ir) in the form of a refractory metal, preferably one or more of niobium (Nb), molybdenum (Mo), tantalum (Ta), tungsten (W), and rhenium (Re), and most preferably the first metal comprises tungsten (W) in the form of a metal-containing silicon (Si) compound or mixture.

[0025] The plasma processing apparatus for etching of the present invention may further include a power source connected to the consumable unit, which applies power to the consumable unit to promote generation of ions or radicals of the first metal.

[0026] When plasma is generated inside a chamber of the plasma processing apparatus for etching, the surface of the consumable part exposed to the plasma may be consumed by radicals or sputtering, generating by-products. In this case, in order to control the generation of the by-products, a power source may be further connected to the consumable part to apply power, and the power source connected to the consumable part may be a DC power source, an AC power source, or an RF power source (including a pulse power source).

[0027] Furthermore, the device is any one of a dual frequency Capacitively Coupled Plasma (CCP) device, an Inductively Coupled Plasma (ICP) device, a microwave plasma device, a Helicon plasma device, an Electron Cyclotron Resonance (ECR) plasma device, and a remote plasma device. An embodiment of the present invention using the device will be described below with reference to the drawings.

[0028] Various examples and embodiments of the present invention will be described in detail below. However, the following examples are merely some of the examples of the present invention, and the present invention should not be construed as being limited to the following examples. Working Example FIG. 1 is a circuit diagram and a schematic diagram of the consumables section of an apparatus according to one embodiment of the present invention.

[0029] Referring to FIG. 1, a plasma processing apparatus for etching is shown including an A region located in the upper part of a chamber and including a consumable part, and an B region located in the lower part of the chamber and including a substrate support member, preferably an electrostatic chuck (ESC). In this case, the inclusion of the consumable part in the A region means that the consumable part is provided on a gas supply device, preferably a gas injection plate (DGDP, Distribution Gas Distributed Plate), or on an upper electrode of the A region. The apparatus further includes a lower electrode that supplies energy to generate plasma, and an upper electrode that faces the lower electrode from above and below and is grounded. In this embodiment, the upper electrode may be a plate that injects gas, and may be a DGDP (Distribution Gas Distributed Plate). A power source for applying power is connected to the lower electrode and the upper electrode, and the power source may be a DC power source, an AC power source, or an RF power source (including a pulse power source).

[0030] In the plasma processing apparatus for etching, when a wafer is placed on an electrostatic chuck in region B, gas can be introduced into a vacuum chamber through a gas injection plate (DGDP) or an upper electrode in region A. Then, power is applied to a lower electrode in region B to generate plasma in the chamber, and the plasma and the wafer in region B undergo a chemical reaction to perform an etching process on the wafer. At this time, the plasma also reacts with a metallic consumable part installed in region A of the chamber and exposed inside the chamber, and a by-product formed by the reaction between the metallic consumable part and the plasma acts like a conventional special gas additive and coats the side that should not be etched during etching of region B with the additive, which can contribute to improving the quality of a high aspect ratio etching process by performing an etching process in a vertical direction. FIG. 2 is a circuit diagram of the device with one power source connected to the consumable unit and a schematic diagram of the consumable unit.

[0031] 2 shows an etching plasma processing apparatus in which a consumable part is provided in region B including an edge ring around a substrate in addition to region A including a side wall of a chamber, and a power source is connected to the consumable part in region A in addition to a power source connected to an upper electrode and a power source connected to a lower electrode. The power source may be a DC power source, an AC power source, or an RF power source (including a pulsed power source), and the amount of by-products generated by etching the consumable part in region A can be controlled by the power source. The consumable part in region A may be the consumable part alone in region A, or may further include a dielectric between the side wall and the consumable part. FIG. 3 is a circuit diagram of the device with two power sources connected to the consumable unit and a schematic diagram of the consumable unit.

[0032] 3 shows an etching plasma processing apparatus in which a consumable part is provided in region B including an edge ring around a substrate in addition to region A including a side wall of the chamber, and in addition to a power source connected to an upper electrode and a power source connected to a lower electrode, a power source is further connected to both the consumable parts in region A and region B. The power source may be a DC power source, an AC power source, or an RF power source (including a pulsed power source), and the amount of by-products generated by etching the consumable parts can be controlled by the power source. In addition, the consumable parts in regions A and B may be present in region A alone, or may further include a dielectric between the side wall and the consumable parts.

[0033] 4 to 9 show how the consumable part configuration of the present invention is applied to various types of plasma processing procedures for etching. The following equipment includes a plasma source power supply, a bias power supply, an additional power supply, and a power supply connected to the consumable part. FIG. 4 is a structural diagram of a dual frequency Capacitively Coupled Plasma (CCP) device of the present invention.

[0034] Referring to FIG. 4, the showerhead of the dual frequency capacitively coupled plasma apparatus may include a consumable part, and the showerhead may be removable and replaceable. Although not shown in FIG. 4, the edge ring and sidewall of the apparatus may also include a consumable part that is removable and replaceable. In order to control etching of the showerhead, the apparatus may further include a consumable part connection power source (Power M), which may be connected to the showerhead and apply power to the consumable part provided on the showerhead. In addition to the consumable part connection power source, a source power source is connected to the upper electrode of the apparatus, and a bias and additional power source are connected to the lower part. Also, a dielectric may be included on the sidewall or under an electrostatic chuck (ESC). FIG. 5 is a structural diagram of a dual frequency Capacitively Coupled Plasma (CCP) device of the present invention.

[0035] Referring to FIG. 5, the showerhead of the dual frequency capacitively coupled plasma apparatus may include a consumable part, and the showerhead may be removable and replaceable. Although not shown in FIG. 5, the edge ring and sidewall of the apparatus may also include a consumable part that is removable and replaceable. In order to control etching of the showerhead, the apparatus may further include a consumable part connection power source (Power M), and the consumable part connection power source may be connected to an upper electrode to which the showerhead is attached and may apply power to the consumable part provided on the showerhead. In addition to the consumable part connection power source, a source and bias power source are simultaneously connected to the lower part of the apparatus, and an additional power source is connected to the source and bias power sources, making a total of three power sources. Also, a dielectric may be included on the sidewall or under an electrostatic chuck (ESC). FIG. 6 is a structural diagram of an inductively coupled plasma (ICP) device of the present invention.

[0036] Referring to FIG. 6, the showerhead of the inductively coupled plasma device may include a consumable part, and the showerhead may be removable and replaceable. Although not shown in FIG. 6, the edge ring and sidewall of the device may also include a consumable part that is removable and replaceable. In order to control etching of the showerhead, the device may further include a consumable part connection power source (Power M), which may be connected to the showerhead and apply power to the consumable part provided on the showerhead. In addition to the consumable part connection power source, a source power source is connected to an upper dielectric plate (ICP window) of the device, and a bias and additional power source are connected to a lower portion. A dielectric may also be included at the lower portion of the electrostatic chuck (ESC). FIG. 7 is a structural diagram of the microwave plasma device of the present invention.

[0037] Referring to FIG. 7, the sidewall of the electromagnetic plasma device may include a consumable part, and the consumable part provided on the sidewall may be removable and replaceable. Although not shown in FIG. 7, the edge ring of the device may also include a consumable part that is removable and replaceable. In order to control etching of the consumable part in the sidewall, the device may further include a consumable part connection power source (Power M), and the consumable part connection power source may be connected to the consumable part in the sidewall to apply power to the consumable part in the sidewall. In addition to the consumable part connection power source, bias and additional power sources are connected to the lower part of the device. The device may not have a source power source, but may be supplied with a plasma source via electromagnetic waves from the upper part of the device. Also, a dielectric may be included on the contact surface between the consumable part and the sidewall or on the lower part of the electrostatic chuck (ESC). FIG. 8 is a structural diagram of a remote plasma device of the present invention.

[0038] Referring to FIG. 8, the metal member (Metal in the drawing) disposed on the upper inner wall adjacent to the inlet of the plasma source injection passage of the remote plasma device may include a consumable part, and the metal member (Metal in the drawing) may be removable and replaceable. Although not shown in FIG. 8, the grid located in the plasma source injection passage of the device, the edge ring of the device, and the side wall may also include a consumable part that is removable and replaceable. In order to control the etching of the metal member (Metal in the drawing), the device may further include a consumable part connection power source (Power M), and the consumable part connection power source may be connected to the metal member (Metal in the drawing) and apply power to the consumable part provided on the metal member (Metal in the drawing). The remote plasma device does not include any additional power sources (source power source, bias power source, and additional power source) except the consumable part connection power source in the device, since the plasma source is supplied by an external plasma source supply source. Also, a dielectric may be included in a form covering the grid of the injection passage of the device or below the electrostatic chuck (ESC).

[0039] FIG. 9 is a structural diagram of one embodiment of the present invention using a self DC bias, and FIG. 10 is a structural diagram of another embodiment of the present invention using a self DC bias.

[0040] Referring to FIG. 9, the apparatus includes a gas supply device at an upper portion and a gas exhaust device at a lower portion, and may perform a plasma etching process of a wafer on a substrate support member, preferably an electrostatic chuck (ESC), as in the apparatuses of the other embodiments. The apparatus performs a plasma etching process by using a self DC bias, and may control the amount of etching and the amount of by-products generated by applying power to a consumable part exposed to plasma in a chamber of the apparatus, as in the apparatuses of the other embodiments. In FIG. 9, the consumable part may be in the form of metals (Metal 1 and Metal 1') connecting the upper and lower parts of a sidewall separated by a vacuum seal O-ring (O-ring), or in the form of a showerhead attached to an upper gas supply device. In order to control the etching of the consumable parts of the sidewall and the showerhead, the apparatus may further include a consumable part connection power source (Power M), and the consumable part connection power source may be connected to the consumable part of the sidewall and the showerhead to apply power to the consumable part. In addition to the power supply connected to the consumables section, a source power supply is connected to the upper dielectric plate of the apparatus, and bias and additional power supplies are connected to the lower part of the apparatus, preferably to an electrostatic chuck (ESC).The upper gas supply device of the apparatus may be entirely in the form of a dielectric plate (ICP window). FIG. 10 has a structure similar to that of FIG. 9, except that the dielectric is not on the top in the form of a plate, but is instead located on the sidewalls.

[0041] Referring to FIG. 10, the apparatus includes a gas supply device at an upper portion and a gas exhaust device at a lower portion, and may perform a plasma etching process of a wafer on a substrate support member, preferably an electrostatic chuck (ESC), as in the apparatuses of the other embodiments. The apparatus performs a plasma etching process by using a self DC bias, and may control the amount of etching and the amount of by-products generated by applying power to a consumable part exposed to plasma in a chamber of the apparatus, as in the apparatuses of the other embodiments. In FIG. 10, the consumable part may be in the form of metals (Metal 1 and Metal 1') connecting the upper and lower portions of a sidewall separated by a vacuum seal O-ring (O-ring), or in the form of a showerhead attached to an upper gas supply device. In order to control the etching of the consumable parts of the sidewall and the showerhead, the apparatus may further include a consumable part connection power source (Power M), and the consumable part connection power source may be connected to the consumable part of the sidewall and the showerhead to apply power to the consumable part. In addition to the power supply connected to the consumable section, a source power supply is connected to an upper portion of the device, and bias and additional power supplies are connected to a lower portion of the device, preferably an electrostatic chuck (ESC).The device may also include a dielectric on its upper sidewall.

[0042] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that the present invention can be modified and changed in various ways without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. A vacuum chamber; a substrate support member disposed within the chamber; a gas supply member for injecting gas into the chamber; a consumable unit disposed within the chamber and configured to generate metal by-products including ions or radicals of a first metal when plasma is generated within the chamber; a first electrode to which power is applied to generate a plasma within the chamber; a second electrode facing the first electrode; a power source that supplies power to the first and second electrodes, The ions or radicals of the first metal are bonded to a polymer material that is plasma-deposited on the substrate and deposited on the substrate; The consumable part includes a silicon (Si) compound or mixture containing the first metal, and is provided in a shower head located in an upper portion of the chamber and having one or more gas ejection holes. Plasma treatment procedure for etching.

2. The consumable part is provided on an edge ring disposed in a lower part of the chamber so as to surround an edge part of the substrate disposed on the substrate support member. The etching plasma processing method of claim 1.

3. The consumable part is provided on an inner wall of the chamber, The etching plasma processing method of claim 1.

4. the first metal comprises one or more of niobium (Nb), molybdenum (Mo), tantalum (Ta), tungsten (W), rhenium (Re), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), zinc (Zr), technetium (Tc), rubidium (Rb), rhodium (Rh), hafnium (Hf), osmium (Os), and iridium (Ir); The etching plasma processing method of claim 1.

5. a power source connected to the consumable unit for applying power to the consumable unit to promote generation of ions or radicals of the first metal; The etching plasma processing method of claim 1.

6. The device is any one of a dual frequency capacitively coupled plasma (CCP) device, an inductively coupled plasma (ICP) device, a microwave plasma device, a helicon plasma device, an electron cyclotron resonance (ECR) plasma device, and a remote plasma device; The etching plasma processing method of claim 1.

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