Plasma etching apparatus and etching method using reusable mask

Abstract

A plasma etching apparatus using a reusable mask according to an embodiment disclosed herein comprises: a chamber; a substrate disposed inside the chamber; and a mask including a mask body, in which a plurality of holes are formed, and a lower electrode, which is coupled to a lower portion of the mask body and to which a voltage is applied. When the mask is attached to an upper portion of the substrate and a voltage is applied to the lower electrode, an etching process of the substrate is carried out by charged particles that pass through the holes.

Description

Plasma etching apparatus and etching method using a reusable mask

[0001] The present invention relates to a plasma etching technology using a reusable mask, and to an etching apparatus and etching method in which a detachable mask with a pattern formed thereon is attached to a substrate, and when a voltage is applied to an electrode, charged particles within the pattern are accelerated to perform etching.

[0002] Typically, in the photolithography process, a semiconductor manufacturing process, the mask pattern used is formed by repeatedly arranging identical shapes on a single mask. When such a mask is placed over a substrate coated with a photoresist and irradiated with ultraviolet light, the UV rays pass through the mask and react with the photoresist on the substrate, forming a pattern on the substrate that is identical in shape to the pattern on the mask. Generally, multiple masks with formed patterns are used to complete a single semiconductor device.

[0003] However, during the research phase, such as in corporate research institutes or university laboratories, a mask pattern of the same shape is not repeatedly formed across the entire mask; instead, a single mask pattern is formed on a single mask, or a portion of a substrate is cut out and used instead of the entire substrate. This is because, in the case of substrates made of new materials during the research stage—particularly expensive substrates like compound semiconductors—increased research costs make it impossible to conduct sufficient experiments with limited funds.

[0004] However, even if the cost of the substrate can be reduced by cutting out a portion of it in this way, the cost of manufacturing the mask remains the same. This is because completing a single semiconductor device requires multiple photolithography processes, and masks with different pattern shapes must be used for each photolithography process. Furthermore, since numerous trials and errors are involved during research, masks are required each time, ultimately resulting in a large number of masks.

[0005] In addition, since masks typically use expensive special materials such as glass or industrial quartz plates, this is also a factor that increases the cost of the photolithography process.

[0006] Therefore, a plasma etching apparatus and method for forming patterns without a photolithography process step are required.

[0007] In addition, in conventional methods, power is applied to the substrate to accelerate charged particles from the plasma to the substrate. However, in such methods, the entire substrate, rather than just the mask, is affected, so there is a risk that the mask may be damaged.

[0008] The present invention provides a plasma etching apparatus and method for forming a pattern without a photolithography process step.

[0009] The present invention provides an etching apparatus and an etching method that allow etching to proceed in a vertical direction without mask damage or distortion of the etching shape by applying voltage to the electrode layer of a mask.

[0010] The present invention provides an etching apparatus and an etching method in which the mask can be detached and removed after the etching process, thereby eliminating the need to remove residual resist after etching.

[0011] The present invention provides an etching apparatus and an etching method in which a mask removed from a substrate can be reused in the next wafer process.

[0012] A plasma etching apparatus using a reusable mask according to one embodiment of the present invention comprises: a chamber; a substrate disposed inside the chamber; and a mask including a mask body having a plurality of holes formed therein and a lower electrode coupled to the lower part of the mask body to which a voltage is applied; wherein the substrate is characterized in that when the mask is attached to the upper part of the substrate and a voltage is not applied to the lower electrode, an etching process of the substrate is carried out by charged particles penetrating the holes.

[0013] A plasma etching device using a reusable mask according to one embodiment of the present invention may be characterized by having an insulating film applied to the inner circumference of the hole to prevent damage caused by collision of the charged particles.

[0014] The mask of a plasma etching device using a reusable mask according to one embodiment of the present invention may further include a pad disposed below the lower electrode and detachably attached to the substrate.

[0015] A plasma etching device using a reusable mask according to one embodiment of the present invention may further include an upper electrode disposed on the upper part of the mask body; and a power control unit that controls the magnitude of the voltage applied to the upper electrode and the lower electrode.

[0016] The power control unit of a plasma etching device using a reusable mask according to one embodiment of the present invention may be characterized by applying voltage only to the lower electrode or the upper electrode.

[0017] The power control unit of a plasma etching device using a reusable mask according to one embodiment of the present invention may be characterized by controlling the length of the depth at which the substrate is etched by adjusting the size of the voltage applied to the upper electrode or the lower electrode.

[0018] The mask of a plasma etching device using a reusable mask according to one embodiment of the present invention may be characterized in that the aspect ratio of the mask is formed to be 1:1 or greater so that the charged particles can vertically penetrate the hole.

[0019] The power control unit of a plasma etching device using a reusable mask according to one embodiment of the present invention may be characterized by including a DC (Direct Current) power source.

[0020] A plasma etching apparatus using a reusable mask according to another embodiment of the present invention may be characterized by comprising: a chamber; a substrate disposed inside the chamber; a mask including a mask body having a plurality of holes formed therein and a lower electrode coupled to the lower part of the mask body to which voltage is applied; and an insulating film on the inner surface of the holes to prevent damage caused by collision of charged particles, wherein the substrate is attached to the upper part of the mask and, when voltage is not applied to the lower electrode, an etching process of the substrate is performed by charged particles penetrating the holes.

[0021] The mask of a plasma etching apparatus using a reusable mask according to another embodiment of the present invention may further include a silicon pad disposed below the lower electrode and detachably attached to the substrate.

[0022] A plasma etching device using a reusable mask according to another embodiment of the present invention may further include an upper electrode disposed on the upper part of the mask body; and a power control unit that controls the magnitude of the voltage applied to the upper electrode and the lower electrode.

[0023] The power control unit of the plasma etching device using a reusable mask according to another embodiment of the present invention may be characterized by applying voltage only to the lower electrode or the upper electrode.

[0024] A plasma etching method using a reusable mask according to one embodiment of the present invention may be characterized by comprising the steps of: placing a mask having a hole formed on the upper surface of a substrate; injecting a reaction gas into a chamber; applying a voltage to a lower electrode using a power control unit; adjusting the voltage to control the etching depth of the substrate; and removing the mask from the substrate.

[0025] A plasma etching method using a reusable mask according to one embodiment of the present invention may be characterized in that an insulating film is applied to the inner surface of the hole to prevent damage caused by collision with charged particles.

[0026] The mask of the plasma etching method using a reusable mask according to one embodiment of the present invention may further include a pad disposed below the lower electrode and detachably attached to the substrate.

[0027] According to one embodiment, since the mask can be removed after the process is finished, the mask can be reused by placing it on another substrate on which a pattern is to be engraved.

[0028] In addition, according to one embodiment of the present invention, since a conventional photolithography process is not required, problems that may occur during the photolithography process can be prevented, and a pattern can be formed on a substrate without a photolithography process step.

[0029] According to one embodiment of the present invention, by applying voltage to the lower electrode layer of the mask, etching can proceed in the vertical direction without damage to the mask or distortion of the etching shape.

[0030] According to one embodiment of the present invention, since the mask removed from the substrate can be reused in the next wafer process, semiconductor production costs can be reduced.

[0031] The effects of the present invention are not limited to the technical problems mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below.

[0032] A brief description of each drawing is provided to help to better understand the drawings cited in the detailed description of the invention.

[0033] Figure 1 (a) is a schematic drawing of a substrate and a mask of an etching apparatus according to one embodiment of the present invention, and (b) is a drawing for explaining a mask structure of an etching apparatus according to one embodiment of the present invention.

[0034] FIG. 2 is a diagram showing an electric field simulation of an etching device according to one embodiment of the present invention.

[0035] FIGS. 3(a) to (e) are drawings sequentially illustrating a plasma etching process using a reusable mask according to one embodiment of the present invention.

[0036] FIGS. 4 (a) to (d) are drawings sequentially illustrating a plasma etching process of a mask and a substrate equipped with a pad according to an embodiment of the present invention.

[0037] Figure 5 (a) is a simulation showing the focus of an electric field within a pattern, and (b) is a photograph showing an example of etching in a vertical direction by applying voltage to the lower electrode of the mask.

[0038] Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted. Additionally, while embodiments of the present invention will be described below, the technical concept of the present invention is not limited or restricted thereto and can be modified and implemented in various ways by those skilled in the art.

[0039] Furthermore, the terms used in this specification are for describing embodiments and are not intended to limit or / or restrict the disclosed invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “having,” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0040] Additionally, throughout the specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected" but also cases where they are "indirectly connected" with other elements in between. Terms including ordinal numbers, such as "first," "second," etc., used in this specification may be used to describe various components, but the components are not limited by these terms.

[0041] Below, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. Additionally, parts of the drawings that are irrelevant to the description are omitted to clearly explain the invention.

[0042] Figure 1 (a) is a schematic drawing of a substrate and a mask of an etching apparatus according to one embodiment of the present invention, and (b) is a drawing for explaining a mask structure of an etching apparatus according to one embodiment of the present invention.

[0043] Referring to FIG. 1, a plasma etching apparatus (10) using a reusable mask according to one embodiment of the present invention includes a chamber (100), a substrate (200), and a mask (300). In addition, the present invention may be characterized in that the mask (300) is attached to the upper surface of the substrate (200), and when a voltage is applied to an electrode, the substrate (200) is etched by charged particles that penetrate the hole (hereinafter referred to as h) of the mask (300).

[0044] First, the plasma etching apparatus (10) according to the present invention may include a chamber (100) into which a reaction gas is injected. Meanwhile, a plasma source for generating plasma exists in the chamber (100), but the type or location of the source is irrelevant. A substrate (200) on which a mask (300), to be described later, is placed may be disposed on the bottom surface of the chamber (100).

[0045] The chamber (100) may include a gas inlet (not shown) so that reaction gases can be injected into the chamber (100).

[0046] In addition, the present invention may be configured such that a vacuum pump (not shown) for providing vacuum to the chamber (100) is connected to the lower part of the chamber (100) and a vacuum sensor (not shown) is also attached to the chamber (100).

[0047] The mask (300) of the present invention may include a mask body (310), a lower electrode (320), an insulating layer (330), and a pad (340). Additionally, the aspect ratio of the mask (300) may be 1:1 or greater.

[0048] The mask (300) of the present invention may further include a lower electrode (320) attached to the lower part of the mask body (310) and a pad (340) for attaching and detaching from the substrate (200).

[0049] Specifically, the mask body (310) of the present invention may have a plurality of holes (h) formed so that charged particles can pass through in a vertical direction. The plurality of holes of the mask body may be formed with the same diameter and may be formed in rows and columns in the longitudinal and transverse directions.

[0050] The mask (300) may further include an insulating film (330) to prevent collisions of charged particles focused in the direction of the hole (h).

[0051] Referring to FIG. 2, when voltage is applied to the lower electrode (320) or to the upper electrode (400), an etching process can be performed in the direction of the hole (h) of the mask body (310).

[0052] In the mask body (310) of the present invention, holes (h) are formed at regular intervals, and the substrate (200) is shielded in the area where holes (h) are not formed, and etching can be performed only in the area of ​​the substrate where holes (h) are formed.

[0053] The mask (300) of the present invention may further include a lower electrode (320) disposed at the lower part of the mask body (310). The lower electrode (320) is located between the pad (340) and the mask body (310) and may be configured to be attached to the mask body (310).

[0054] In addition, the lower electrode (320) of the present invention may include a material such as copper, silicon, or TiN, and may be formed in the same shape as the mask body (310).

[0055] Accordingly, the present invention enables the focusing of an electric field perpendicular to the pattern and can be configured so that charged particles can be accelerated only within the hole (h) of the mask body (310).

[0056] That is, the effect is achieved that a pattern can be accurately formed on the substrate (200) and damage to the mask body (310) can be prevented.

[0057] Meanwhile, conventionally, Extreme Ultraviolet (EUV, 13.4 nm), which has a very short wavelength, is used to implement fine patterns. EUV is a very expensive piece of equipment, and problems such as Sn (tin) deposition on the mask and mirror or the formation of bubbles occur.

[0058] Therefore, in the present invention, fine patterns can be formed without a photolithography process step, thereby significantly reducing process time and costs.

[0059] An upper electrode (400) may be disposed on the upper part of the mask body (310) of the present invention.

[0060] Specifically, the upper electrode (400) is located at the top of the internal space of the chamber (100) and is positioned parallel to the lower electrode (320). When a voltage is applied by the power control unit, the charged particles inside the chamber can move downward according to the voltage difference.

[0061] Additionally, the upper electrode (400) may include the lower electrode (320) and materials such as copper, silicon, and TiN.

[0062] Meanwhile, the power control unit according to the present invention can control the magnitude and duration of the voltage applied to the upper electrode (400) or the lower electrode (320). Depending on the implementation, the power control unit can supply power to both the upper electrode (400) and the lower electrode (320).

[0063] Conventionally, electrodes were placed on the underside of the substrate and power was supplied to them. Consequently, it is difficult to focus the electric field in the vertical direction, leading to distortion of the etching shape and frequent damage to the mask.

[0064] However, in the present invention, since the lower electrode (320) is located on the upper part of the substrate, when voltage is applied to the lower electrode (320), charged particles (ions or electrons) can be concentrated in a vertical direction.

[0065] In addition, when voltage is applied to both the upper electrode (400) and the lower electrode (320), there is an advantage in that the energies of the incident charged particles can be precisely controlled.

[0066] In addition, by preventing the problem of distortion of the mask (300) due to the etching shape, damage to the mask (300) can be significantly reduced.

[0067] Therefore, the etching device according to the present invention brings about the effect of significantly reducing process time as well as reducing manufacturing costs.

[0068] Additionally, the hole (h) of the mask (300) of the present invention is formed in the mask body (310), and the process may be configured such that charged particles pass through the hole (h) of the mask and etch the substrate (200). In the present invention, an insulating film (330) may be applied to the inner surface of the hole (h) of the mask (300).

[0069] Specifically, an insulating film (330) may be applied to the inner surface of the hole (h) of the mask to prevent damage to the mask body (310) and the lower electrode (320) due to collision with charged particles.

[0070] Referring to FIG. 1(b), the insulating film (330) of the present invention may be positioned adjacent to the mask body (310), lower electrode (320), and pad (340) to be described later of the mask (300), and may be applied to surround the inner surface of the hole (h). In addition, since at least one hole (h) is formed, the insulating film (330) may also include at least one so as to correspond to the number of holes (h).

[0071] In this way, damage to the mask body (310), lower electrode (320), and pad (340) can be prevented through the insulating film (330).

[0072] Additionally, although not shown, a thin insulating film may also be deposited on the upper electrode (400). The insulating film described above may be configured to protect the electrode (320, 400) and to concentrate the electric field within the pattern in a vertical direction.

[0073] The mask (300) of the present invention may further include a pad (340) disposed below the lower electrode (320). The pad (340) may be provided with a material that is detachable from the substrate (200), and in the present invention, silicon (or Si, SiO2) may be adopted, but any material that is detachable from the substrate (200) may be used.

[0074] In addition, the present invention enables a structure that is detachable from the substrate (200) due to the pad (340) of the mask (300), thereby allowing the mask (300) to be reused.

[0075] For example, in the present invention, a mask (300) is placed on a substrate (200) to perform an etching process, and then the area where the pad (340) and the substrate (200) are attached is removed from the substrate (200), and a mask is placed on another substrate to be performed next to perform the etching process once more.

[0076] The power control unit of the present invention is characterized by selectively adjusting the magnitude of the voltage applied to the upper electrode (400) and the lower electrode (320). Specifically, by adjusting the magnitude of the voltage applied to the upper electrode (400) and the lower electrode (320) of the present invention, the depth of etching of the substrate (200) on which the etching process is performed by charged particles can be adjusted.

[0077] In the following, the plasma etching process using the reusable mask of the present invention will be described in more sequential and detailed steps.

[0078] FIGS. 3(a) to (e) are drawings sequentially illustrating a plasma etching process using a reusable mask according to one embodiment of the present invention.

[0079] Referring to FIGS. 3 (a) to (e), a mask with holes formed therein is placed on a substrate (a). Then, a process is performed in which a reaction gas is injected into the chamber through a gas inlet, or the reaction gas is injected in the direction of the upper electrode and a voltage is applied to the lower electrode (b).

[0080] In the present invention, power may be applied to both the upper electrode and the lower electrode using a power control unit, or power may be supplied to only one of the upper electrode or the lower electrode. Here, the height (or length) to be formed within the substrate can be adjusted by controlling the voltage of the upper electrode or the lower electrode. At this time, the operator determines the desired height by controlling the voltage.

[0081] Afterwards, a pattern can be formed on the substrate due to the etching process (c). The mask is removed from the substrate (d). Next, the mask is placed on the substrate to be etched with the pattern, and the plasma etching process is performed again (e).

[0082] FIGS. 4 (a) to (d) are drawings sequentially illustrating a plasma etching process of a mask and a substrate equipped with a pad according to an embodiment of the present invention.

[0083] Referring to FIG. 4 (a) to (d), a mask with attached pads is attached to a substrate (a). Then, a process is performed in which a reaction gas is injected into the chamber through a gas inlet or a voltage is applied to the lower electrode (b). Using a power control unit, a pattern is formed on the substrate by applying voltage to both the upper and lower electrodes, or by applying voltage to only one of the upper or lower electrodes (c). Then, the pads attached to the substrate are detached to remove the mask (d). Although the subsequent process is not illustrated, a mask is attached to a new substrate on which a pattern is to be etched, and the plasma etching process is performed again.

[0084] Figure 5 (a) shows a simulation process showing the focus of an electric field within a pattern, and (b) is a photograph showing an example of etching in a vertical direction by applying voltage to the lower electrode of the mask.

[0085] As shown in Fig. 5(a), when a voltage is applied to the lower electrode of the mask, it can be seen that the electric field is focused into the internal space of the hole.

[0086] Subsequently, as shown in Figure (b), when a voltage is applied to the lower electrode of the mask, ions are focused vertically only within the pattern (the internal space of the hole), and a pattern can be formed on the substrate.

[0087] So far, through the drawings, we have examined the plasma etching apparatus and etching method using a reusable mask according to an exemplary embodiment of the present invention.

[0088] According to one embodiment, since the mask can be removed after the process is finished, the mask can be reused by placing it on another substrate to be patterned, and since the conventional photolithography process is not required, problems that may occur during the photolithography process can be prevented, and a pattern can be formed on the substrate without a photolithography process step.

[0089] In addition, according to one embodiment, the removed mask can be reused in the next wafer process, which can reduce semiconductor production costs.

[0090] The effects of the present invention are not limited to the technical problems mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below.

[0091] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or if the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents. Therefore, other implementations, other embodiments, and equivalents to the claims below are also within the scope of the claims.

Claims

1. Chamber; A substrate disposed inside the chamber; and A mask comprising a mask body having a plurality of holes formed therein and a lower electrode coupled to the lower part of the mask body to which voltage is applied; and The above substrate Characterized by the fact that when the above mask is attached to the upper part of the substrate and voltage is not applied to the lower electrode, the etching process of the substrate is carried out by charged particles penetrating the hole. Plasma etching device using a reusable mask.

2. In Paragraph 1, The inner surface of the above hole is characterized by having an insulating film applied thereon to prevent damage caused by collision of the charged particles. Plasma etching device using a reusable mask.

3. In Paragraph 1, The above mask is, A pad disposed below the lower electrode and detachably attached to the substrate; further comprising Plasma etching device using a reusable mask.

4. In Paragraph 1, It further includes an upper electrode disposed on the upper part of the above mask body. A power control unit that adjusts the magnitude of the voltage applied to the upper electrode and the lower electrode; further characterized by comprising Plasma etching device using a reusable mask.

5. In Paragraph 4, The above power control unit is, Characterized by applying voltage only to the lower electrode or the upper electrode. Plasma etching device using a reusable mask.

6. In Paragraph 4, The above power control unit is, Characterized by controlling the length of the depth at which the substrate is etched by adjusting the size of the voltage applied to the upper electrode or the lower electrode. Plasma etching device using a reusable mask.

7. In Paragraph 1, The above mask is, Characterized by the aspect ratio of the mask being formed to be 1:1 or greater so that the charged particles can vertically penetrate the hole. Plasma etching device using a reusable mask.

8. In Paragraph 4, The above power control unit is characterized by including a DC (Direct Current) power source. Plasma etching device using a reusable mask.

9. Chamber; A substrate disposed inside the chamber; A mask comprising a mask body having a plurality of holes formed therein and a lower electrode coupled to the lower part of the mask body to which voltage is applied; and The inner surface of the above hole includes an insulating film that prevents damage caused by collisions with charged particles, and The above substrate Characterized by the fact that when the above mask is attached to the upper part of the substrate and voltage is not applied to the lower electrode, the etching process of the substrate is carried out by charged particles penetrating the hole. Plasma etching device using a reusable mask.

10. In Paragraph 9, The above mask is, Characterized by further including a silicon pad disposed below the lower electrode and detachably attached to the substrate. Plasma etching device using a reusable mask.

11. In Paragraph 9, It further includes an upper electrode disposed on the upper part of the above mask body. A power control unit that adjusts the magnitude of the voltage applied to the upper electrode and the lower electrode; further characterized by comprising Plasma etching device using a reusable mask.

12. In Paragraph 11, The above power control unit is, Characterized by applying voltage only to the lower electrode or the upper electrode. Plasma etching device using a reusable mask.

13. A step of placing a mask with a hole formed on the upper part of the substrate; Step of injecting reaction gas into the chamber; A step of applying voltage to the lower electrode using a power control unit; A step of controlling the etching depth of the substrate by adjusting the above voltage; and A step of removing the mast from the substrate; and Plasma etching method using a reusable mask.

14. In Paragraph 13, The inner surface of the above hole is characterized by having an insulating film applied to prevent damage caused by collision of charged particles. Plasma etching method using a reusable mask.

15. In Paragraph 13, The above mask is, A pad disposed below the lower electrode and detachably attached to the substrate; further comprising Plasma etching method using a reusable mask.

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