Etching apparatus

Abstract

This invention provides an etching apparatus capable of forming a plurality of through-holes on an insulating substrate with high throughput. The etching apparatus 1 of this invention is an etching apparatus for forming a plurality of through-holes on an insulating substrate W. The etching apparatus 1 includes a chamber 2, a mask 3, a bias voltage application unit 4, and a plasma generation unit 5. The insulating substrate W is moved into the chamber 2. The mask 3 has a plurality of first openings 3a and faces the insulating substrate W. The bias voltage application unit 4 applies a negative voltage to the mask 3. The plasma generation unit 5 generates plasma and supplies the cations in the plasma to the insulating substrate W through the plurality of first openings 31a of the mask 3.

Description

[Technical Field]

[0001] This invention relates to an etching apparatus. [Previous Technology]

[0002] Previously, in the field of fan-out panel-level packaging, an interposer was provided between the chip and the substrate. The interposer was a glass-based substrate. A plurality of through-holes were formed in the glass-based substrate, and conductive members were filled in the through-holes. The interposer realized the electrical connection between the chip and the substrate.

[0003] A technique is proposed in which, during the manufacture of this interlayer, through-holes are formed on a glass substrate by laser processing and wet etching (Patent Documents 1-3). [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-530629 [Patent Document 2] Japanese Patent Application Publication No. 2020-66551 [Patent Document 3] Japanese Patent Application Publication No. 2017-61401 [Summary of the Invention]

[0005] [Problem to be Solved by the Invention] In laser processing, there is a risk of microcracks being generated in glass-based substrates. Therefore, it is ideal to process glass-based substrates at a low speed or to use pulsed lasers. However, in such methods, a relatively long time is required to form a plurality of through-holes. In particular, if the number of through-holes reaches millions or more, the throughput in laser processing is low.

[0006] Therefore, the object of the present invention is to provide an etching apparatus capable of forming a plurality of through-holes on an insulating substrate with high productivity. [Technical Problem Solved]

[0007] The first state is an etching apparatus for forming a plurality of through holes in an insulating substrate, comprising: a chamber for receiving the insulating substrate; a shield having a plurality of first openings and facing the insulating substrate; a bias application unit for applying a negative voltage to the shield; and a plasma generation unit for generating plasma and supplying cations in the plasma to the insulating substrate through the plurality of first openings of the shield.

[0008] The second state sample is the etching apparatus of the first state sample, wherein the mask includes an insulating plate having a plurality of second openings and a conductive film, the conductive film including a first conductive portion, the first conductive portion being disposed on the inner peripheral surface of each of the plurality of second openings in the insulating plate to form the first opening, and the bias voltage application portion applying the negative voltage to the conductive film.

[0009] The third state sample is an etching apparatus like the second state sample, wherein the conductive film includes a second conductive portion, which is formed on the first main surface of the insulating substrate side in the insulating plate, and the first conductive portions are connected to each other.

[0010] The fourth state sample is an etching apparatus like the second or third state sample, wherein a portion of the first conductive part protrudes more than the second main surface of the insulating plate that is opposite to the first main surface of the insulating substrate.

[0011] The fifth state sample is an etching apparatus like any of the second to fourth state samples, wherein the mask further includes a protective film facing the first conductive portion and protecting the first conductive portion from the influence of the plasma.

[0012] The sixth state sample is an etching apparatus like any of the second to fifth state samples, wherein the mask further includes a replacement part, which is disposed between the insulating plate and the insulating substrate and is configured to be detachable from the insulating plate and the conductive film. The replacement part has an opening, which together with the opening of the first conductive part forms the first opening. The diameter of the opening of the replacement part is smaller than the diameter of the opening of the first conductive part.

[0013] The seventh state sample is an etching apparatus like any of the second to sixth state samples, which further includes a heater that emits heating light toward the insulating substrate. The shield includes an absorption portion disposed between the insulating plate and the insulating substrate, and the absorption rate of the light is higher than that of the insulating substrate.

[0014] The eighth state sample is an etching apparatus like any of the first to seventh states, comprising a plurality of conductive rollers. These conductive rollers support the mask while simultaneously conveying the mask and the insulating substrate. The bias voltage application unit applies the negative voltage to the rollers. [Effects of the Invention]

[0015] According to the first state sample, a negative voltage is applied to the mask, thus enabling cations to be supplied to the insulating substrate more effectively. Therefore, the etching apparatus can form through-holes in the insulating substrate with higher efficiency.

[0016] According to the second state, cations can be concentratedly attracted to the first opening. Therefore, cations can be supplied to the insulating substrate through the first opening more efficiently.

[0017] According to the third state sample, the wear of the second conductive part generated by cations can be suppressed.

[0018] According to the fourth state, the lifespan of the conductive film and even the lifespan of the mask can be extended.

[0019] According to the fifth state, the lifespan of the mask can be extended.

[0020] According to the sixth state sample, the opening of the first conductive part is wider, thus allowing more cations to pass to the insulating substrate side. Furthermore, if the replacement part wears out, it can be replaced.

[0021] According to the seventh state, heat is generated in the absorbing portion by absorbing light. Since this heat is transferred to the insulating substrate, the insulating substrate can be heated more effectively.

[0022] According to the 8th state, negative voltage can be applied to the shield at multiple locations, thus making the potential distribution of the shield more uniform.

Implementation Method

[0024] Hereinafter, the embodiments will be described in detail with reference to the drawings. Furthermore, in the drawings, for ease of understanding, the dimensions or quantities of each part have been exaggerated or simplified as needed. Also, parts with the same structure and function are labeled with the same symbols, and repeated descriptions are omitted in the following description.

[0025] Furthermore, in the following descriptions, the same symbols are used to illustrate the same constituent elements, and their names and functions are also set to be the same. Therefore, detailed descriptions of them are sometimes omitted to avoid repetition.

[0026] Furthermore, in the following description, even if ordinal numbers such as "first" or "second" are sometimes used, such terms are for the convenience of users to easily understand the content of the implementation method and are not limited to the order that may be generated by such ordinal numbers.

[0027] When using expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.), unless otherwise specified, such expressions not only strictly indicate their positional relationship but also indicate the state after relative displacement with respect to angles or distances within the tolerance range or range where the same level of functionality can be obtained. When using expressions indicating equal states (e.g., "same," "equal," "homogeneous," etc.), unless otherwise specified, such expressions not only indicate a state of quantitatively strict equality but also indicate a state where there is a difference in tolerance or range where the same level of functionality can be obtained. When using expressions indicating shape (e.g., "quadrilateral shape" or "cylindrical shape," etc.), unless otherwise specified, such expressions not only strictly indicate the shape geometrically but also indicate a shape with concavity, convexity, or chamfers within the range where the same level of effect can be obtained. When the expression "equipped with", "including", "possessing", "comprises", or "has" a constituent element is used, the expression is not an exclusive expression excluding the presence of other constituent elements. When the expression "at least one of A, B, and C" is used, the expression includes: only A, only B, only C, any two of A, B, and C, and all of A, B, and C.

[0028] <First Embodiment> <Etching Apparatus> FIG1 is a side view schematically showing an example of the configuration of the etching apparatus 1 according to the first embodiment. The etching apparatus 1 is a dry etching apparatus for forming a plurality of through holes in an insulating substrate W. For example, the insulating substrate W is a glass substrate with a plate-like shape. The etching apparatus 1 performs dry etching on the insulating substrate W to form a plurality of through holes in the insulating substrate W. The etching apparatus 1 may also be referred to as a through hole forming apparatus. In a step after the etching apparatus 1, for example, a conductive member is provided in the through holes of the insulating substrate W to form an intermediate layer.

[0029] The etching apparatus 1 includes a chamber 2, a shield 3, a bias voltage application section 4, and a plasma generation section 5.

[0030] Chamber 2 has a hollow box shape. The internal space of chamber 2 corresponds to a processing chamber for etching the insulating substrate W. A transfer inlet 21 is formed in chamber 2. In the example of FIG1, a transfer inlet 21 is formed on the side wall of chamber 2. A passage 22 is connected to the transfer inlet 21. The untreated insulating substrate W is transferred into chamber 2 through passage 22. The insulating substrate W is etched in chamber 2. The treated insulating substrate W is removed from chamber 2 through passage 22.

[0031] In the example of Figure 1, a plurality of rollers 25 are provided in the chamber 2. The plurality of rollers 25 transport the insulating substrate W. The plurality of rollers 25 are arranged at intervals along the transport direction D1 of the insulating substrate W. In the example of Figure 1, the transport direction D1 is horizontal. Each roller 25 is configured to rotate about a rotation axis described below. The rotation axis is a horizontal width direction D2 orthogonal to the transport direction D1. Each roller 25 rotates synchronously by a roller rotation drive unit (not shown). The roller rotation drive unit includes, for example, a motor. The roller rotation drive unit is controlled by a control unit 9.

[0032] The insulating substrate W can be conveyed in a horizontal position. Here, "horizontal position" refers to the position where the thickness direction of the insulating substrate W is along the vertical direction. The insulating substrate W is supported by rollers 25. The lower surface of the insulating substrate W may contact the rollers 25, or a mounting plate (not shown) may be provided between the insulating substrate W and the rollers 25. In the latter case, the insulating substrate W is conveyed while mounted on the mounting plate. The roller rotation drive unit moves the insulating substrate W, which has been conveyed through the conveying inlet 21, to a processing position within the chamber 2 by simultaneously rotating multiple rollers 25 in the conveying direction. Figure 1 shows the insulating substrate W stopped at the processing position. On the other hand, the roller rotation drive unit removes the insulating substrate W from the chamber 2 through the conveying inlet 21 by simultaneously rotating multiple rollers 25 in the conveying direction opposite to the conveying direction.

[0033] The mask 3 faces the insulating substrate W in the vertical direction. The mask 3 has, for example, a plate-like shape and is positioned with its thickness direction along the vertical direction. In the example of FIG1, the mask 3 is positioned above the insulating substrate W. The mask 3 faces the insulating substrate W at least when the insulating substrate W is in the processing position. Here, as an example, the mask 3 and the insulating substrate W are transported together. That is, the mask 3 is fixed to the insulating substrate W, and the mask 3 and the insulating substrate W are transported integrally. The lower surface of the mask 3 may contact the upper surface of the insulating substrate W, or it may face it with a slight gap between them. In the latter case, a fixing member (e.g., a spacer) is provided to fix the relative position of the insulating substrate W and the mask 3.

[0034] A plurality of first openings 3a are formed in the mask 3. Each first opening 3a penetrates the mask 3 along its thickness direction. The first opening 3a may also be referred to as a through hole. The plurality of first openings 3a are distributed two-dimensionally in a top view. The top view here refers to observing the object with the line of sight along the vertical direction. Each first opening 3a has, for example, a circular shape in a top view. The diameter of the first opening 3a can be set to tens of μm (e.g., 30 μm) or less. The number of first openings 3a in the mask 3 is, for example, more than one million.

[0035] As described below, the cations in the plasma generated by the plasma generation unit 5 act on the insulating substrate W through the first opening 3a of the shield 3. Thereby, the insulating substrate W is etched directly below each of the first openings 3a.

[0036] The shield 3 is conductive. FIG2 is a cross-sectional view schematically showing an example of one component of the shield 3. FIG3 is a top view schematically showing an example of one component of the shield 3. In the examples of FIG2 and FIG3, the shield 3 includes an insulating plate 31 and a conductive film 32. The insulating plate 31 has a plate-like shape and is arranged with its thickness direction along the vertical direction. The insulating plate 31 is insulating, for example, formed of resin or glass. One of the main components of glass is, for example, silicon dioxide. Hereinafter, the two main surfaces of the insulating plate 31 will be referred to as the first main surface 31a and the second main surface 31b, respectively. The first main surface 31a is the main surface on the insulating substrate W side of the insulating plate 31, and the second main surface 31b is the surface opposite to the first main surface 31a. A plurality of second openings are formed in the insulating plate 31. Hereinafter, the inner peripheral surface of each second opening in the insulating plate 31 will be referred to as the inner peripheral surface 31c. One peripheral end of the inner peripheral surface 31c is connected to the first main surface 31a, and the other peripheral end of the inner peripheral surface 31c is connected to the second main surface 31b. In other words, the second opening penetrates the insulating plate 31 in its thickness direction.

[0037] In the example of FIG. 2, the conductive film 32 includes a first conductive portion 321 and a second conductive portion 322. The first conductive portion 321 is disposed on each inner peripheral surface 31c of the insulating plate 31. For example, the first conductive portion 321 has a cylindrical shape, and the outer peripheral surface of the first conductive portion 321 is joined to the inner peripheral surface 31c. Moreover, the inner peripheral surface of the first conductive portion 321 forms the first opening 3a of the shield 3. That is, the inner peripheral surface of the first conductive portion 321 is exposed in the chamber 2. Here, as an example, the second opening of the insulating plate 31 has a circular shape when viewed from above, and the first conductive portion 321 has a cylindrical shape.

[0038] A second conductive portion 322 is disposed on the first main surface 31a of the insulating plate 31. The second conductive portion 322 has a plate-like shape, and one of its main surfaces is joined to the first main surface 31a. The second conductive portion 322 electrically connects a plurality of first conductive portions 321 to each other. The second conductive portion 322 may be disposed on the entire surface of the first main surface 31a, or it may be disposed partially.

[0039] The conductive film 32 is conductive, for example, formed of a metal. The metal includes at least one of copper, silver, and aluminum. The conductive film 32 is disposed on the insulating plate 31, for example, by vapor deposition or plating. The conductive film 32 is disposed in a state bonded to the insulating plate 31.

[0040] The bias application section 4 applies a negative voltage to the mask 3. Specifically, the bias application section 4 applies a negative voltage to the mask 3 during the etching process of the insulating substrate W. In the example of FIG1, the bias application section 4 includes a contact member 41, a wiring 42, and a DC power supply 43. The contact member 41 is conductive and is disposed in the chamber 2. Specifically, the contact member 41 is disposed at a position that contacts the conductive film 32 of the mask 3 when it is stopped at the processing position. For example, the contact member 41 contacts a portion of the second conductive portion 322 of the mask 3. The contact member 41 may, for example, have a conductive brush. By contacting the conductive film 32 (e.g., the second conductive portion 322) with the brush, the contact member 41 is electrically connected to the conductive film 32. In the example of FIG1, the mask 3 is wider than the insulating substrate W when viewed from above. That is, the mask 3 extends further than the insulating substrate W in the horizontal direction. The second conductive portion 322 also has a portion in the shield 3 that extends further than the insulating substrate W, and the contact member 41 can contact the second conductive portion 322 at this portion.

[0041] Wiring 42 is connected to the contact member 41 and the low-potential output terminal of the DC power supply 43. The high-potential output terminal of the DC power supply 43 is grounded.

[0042] The DC power supply 43 outputs a DC voltage between the high-potential output terminal and the low-potential output terminal. Since the high-potential output terminal is grounded, a negative voltage is applied to the low-potential output terminal. The output of the DC power supply 43 is controlled by the control unit 9. The control unit 9 causes the DC power supply 43 to output a DC voltage while the contact member 41 is in contact with the shield 3. Thereby, a negative voltage is applied to the shield 3 (specifically, the conductive film 32) (e.g., 500 eV or less).

[0043] The plasma generation unit 5 generates plasma and supplies the cations in the plasma to the main surface (upper surface in FIG. 1) of the insulating substrate W through a plurality of first openings 3a of the shield 3. As shown in FIG. 1, a gas introduction unit 6 is also provided in the etching apparatus 1. The gas introduction unit 6 supplies plasma gas to the plasma generation unit 5. The plasma gas includes, for example, at least one of a fluorine-containing gas containing fluorine and a rare gas. The rare gas includes, for example, argon. The fluorine-containing gas includes, for example, at least one of carbon fluoride gas (CxFy) and sulfur fluoride gas (SFx).

[0044] In the example of Figure 1, the plasma generating unit 5 is disposed within the chamber 2, and the gas introducing unit 6 supplies gas into the chamber 2. In the example of Figure 1, the gas introducing unit 6 includes a gas introducing pipe 61 and a valve 62. The downstream end of the gas introducing pipe 61 opens into the chamber 2. The upstream end of the gas introducing pipe 61 is connected to a gas supply source (not shown). The valve 62 is disposed on the gas introducing pipe 61. The valve 62 is controlled by the control unit 9 to switch the opening and closing of the gas introducing pipe 61. When the control unit 9 opens the valve 62, gas is supplied into the chamber 2 through the gas introducing pipe 61. The gas is plasmaized by the plasma generating unit 5.

[0045] In the example of FIG1, the plasma generating unit 5 includes a conductive member 51. The conductive member 51 is disposed within the chamber 2. Specifically, the conductive member 51 is disposed in the vertical direction opposite to the shield 3 which is stopped at the processing position. That is, the conductive member 51 is disposed on the side opposite to the insulating substrate W relative to the shield 3. In other words, the shield 3 is located between the conductive member 51 and the insulating substrate W. In the example of FIG1, the conductive member 51 is disposed above the shield 3. A plasma voltage is applied to the conductive member 51. By applying this voltage, plasma is generated in the gas surrounding the conductive member 51.

[0046] In the example of FIG1, the plasma generating unit 5 generates plasma by inductive coupling. Specifically, the conductive member 51 functions as an inductively coupled antenna. In the example of FIG1, the conductive member 51 has a U-shaped form. The conductive member 51 is positioned with the bottom of its U-shape facing the shield 3, and both ends of the conductive member 51 penetrate the cavity 2. In the example of FIG1, both ends of the conductive member 51 penetrate the top wall of the cavity 2.

[0047] In the example of Figure 1, the downstream outlet of the gas inlet pipe 61 of the gas inlet section 6 is positioned vertically closer to the conductive member 51 than the shield 3. That is, the downstream outlet of the gas inlet pipe 61 is positioned higher than the loading / unloading inlet 21. Furthermore, the downstream outlet of the gas inlet pipe 61 is positioned in a position aligned horizontally with the conductive member 51. In this way, the plasma gas flowing out from the downstream outlet of the gas inlet pipe 61 can easily flow to the vicinity of the conductive member 51.

[0048] The conductive member 51 is connected to the high-frequency power supply 54 via an impedance matching circuit 53. More specifically, one end of the conductive member 51 is connected to the first output terminal of the high-frequency power supply 54 via the impedance matching circuit 53, and the other end of the conductive member 51 is connected to the second output terminal of the high-frequency power supply 54. In the example of FIG1, the second output terminal is grounded. The high-frequency power supply 54 is controlled by the control unit 9 and outputs a high-frequency voltage of, for example, 13.56 to 60 MHz.

[0049] A high-frequency voltage is applied to both ends of the conductive member 51 by a high-frequency power supply 54, thereby generating a high-frequency induced magnetic field for plasma generation around the conductive member 51. This magnetic field acts on the plasma gas, causing the gas to ionize and plasmaize. This inductively coupled plasma is a high-density plasma with an electron spatial density of 3×10¹⁰ electrons / cm³ or higher.

[0050] In the example of Figure 1, a plurality of conductive members 51 are provided. The plurality of conductive members 51 are arranged in a horizontal direction. As shown in Figure 1, the plurality of conductive members 51 can be arranged in the conveying direction D1. Alternatively, the plurality of conductive members 51 can also be arranged in the width direction D2. In this way, the plasma generating unit 5 can generate plasma over a larger area. As shown in Figure 1, the conductive members 51 can be arranged with their two ends aligned in the conveying direction D1.

[0051] In the example of FIG1, the plasma generating unit 5 also includes a dielectric member 52. The dielectric member 52 is disposed correspondingly to the conductive member 51. The dielectric member 52 covers the conductive member 51 and protects the conductive member 51 from the influence of plasma. The dielectric member 52 has a U-shaped hollow shape, and the conductive member 51 is disposed in its hollow portion.

[0052] In the example of FIG. 1, a pressure reduction unit 7 is provided in the etching apparatus 1. The pressure reduction unit 7 includes a suction tube 71 and a suction unit 72. The upstream opening of the suction tube 71 is open in the chamber 2. In the example of FIG. 1, the upstream opening of the suction tube 71 is provided in the sidewall of the chamber 2 opposite to the downstream opening of the gas inlet tube 61 and opposite to the conductive member 51. The suction unit 72 is provided in the suction tube 71. The suction unit 72 is controlled by the control unit 9 and draws gas from the chamber 2 through the suction tube 71. The suction unit 72 includes, for example, a pump (vacuum pump). By activating the suction unit 72 by the control unit 9, the pressure in the chamber 2 can be reduced to a pressure range suitable for etching.

[0053] In the example of Figure 1, a heater 8 is provided in the etching apparatus 1. The heater 8 is controlled by the control unit 9 to heat the insulating substrate W. The heater 8 adjusts the temperature of the insulating substrate W to a specified temperature range suitable for etching. In the example of Figure 1, the heater 8 is positioned vertically aligned with the insulating substrate W and is located on the side opposite to the mask 3 (lower in the figure) relative to the insulating substrate W. Also, in the example of Figure 1, the heater 8 is located lower than the bottom of the chamber 2. The heater 8 is, for example, an optical heater (radiation heater).

[0054] The control unit 9 controls various configurations of the etching apparatus 1. The control unit 9 is, for example, a general-purpose computer with circuitry. As an example, the control unit 9 includes a CPU (Central Processing Unit) as a central processing unit for performing various arithmetic operations (data processing), a ROM (Read Only Memory) for storing basic programs, a RAM (Random Access Memory) as the operating area for the CPU to perform specified processing (data processing), a memory device composed of non-volatile memory devices such as flash memory and hard disk drives, and bus lines connecting these to each other. The program for the processing executed by the control unit 9 can be stored in the memory device or RAM. In this case, for example, by causing the CPU to execute the program, the control unit 9 can control each part of the etching apparatus 1, and the processing specified by the program can be executed in the etching apparatus 1. That is, the control unit 9 can implement circuitry for performing the processing specified by the program by causing the CPU to execute the program. Of course, some or all of the control performed by the control unit 9 can also be executed (implemented) by dedicated logic circuits or other hardware (some or all of the circuit implemented by the control unit 9). Furthermore, the control unit 9 may include a plurality of control components composed of arithmetic units and memory units. That is, a plurality of control components can also cooperate to realize the function of the control unit 9.

[0055] Next, an example of the operation of the etching apparatus 1 will be summarized. The operation described below is achieved by the control unit 9. First, an untreated insulating substrate W without through holes is moved into the chamber 2. Specifically, the untreated insulating substrate W is moved to the processing position by a plurality of rollers 25 rotating synchronously in the loading direction. Here, as an example, the mask 3 and the insulating substrate W are transported together in a facing state. With the insulating substrate W and the mask 3 in the processing position, the contact member 41 of the bias application unit 4 contacts the conductive film 32 of the mask 3.

[0056] Next, the bias application unit 4 applies a negative voltage to the shield 3. Furthermore, the pressure reduction unit 7 draws in the gas inside the chamber 2, thereby reducing the pressure inside the chamber 2. The pressure reduction unit 7 adjusts the pressure inside the chamber 2 to a predetermined pressure range until etching is complete. Additionally, the heater 8 heats the insulating substrate W. The heater 8 adjusts the temperature of the insulating substrate W to a predetermined temperature range until etching is complete.

[0057] Subsequently, the gas inlet 6 supplies gas to the plasma generation unit 5, which plasmaizes the gas. Cations in the plasma (e.g., argon ions or fluoride ions) are attracted to the shield 3 side by the negative voltage of the shield 3. Figure 4 is a schematic diagram showing the movement of cations. As shown in Figure 4, cations are concentratedly attracted to the first conductive portion 321. That is, because a DC negative voltage is applied to the first conductive portion 321 exposed in the chamber 2, cations in the plasma are attracted to the first conductive portion 321 by a greater electro-attraction force. Therefore, the cations move towards the shield 3 side at a relatively high speed, and a portion of them act on the insulating substrate W through each of the first openings 3a. The cations can physically etch the insulating substrate W. In the case of fluoride ions, the cations can also chemically etch the insulating substrate W. Thus, the insulating substrate W is etched directly below the plurality of first openings 3a.

[0058] This allows a plurality of through holes to be formed on the insulating substrate W. When the insulating substrate W has been sufficiently etched, the etching apparatus 1 stops etching. For example, the etching apparatus 1 stops etching when a predetermined etching time has elapsed since the start of etching. Specifically, the plasma generation unit 5 stops operating, the gas introduction unit 6 stops introducing gas, and the pressure reduction unit 7, heater 8, and bias application unit 4 also stop operating. Then, the plurality of rollers 25 rotate synchronously in the conveying direction, causing the processed insulating substrate W with the plurality of through holes and the shield 3 to be integrally conveyed from the chamber 2. This separates the contact member 41 of the bias application unit 4 from the conductive film 32 of the shield 3.

[0059] As described above, the etching apparatus 1 can form a plurality of through holes in the insulating substrate W. Furthermore, in the etching apparatus 1, the bias application unit 4 applies a negative DC voltage to the mask 3. Therefore, the etching apparatus 1 can etch the insulating substrate W at a higher etching rate (capacity). That is, the conductive film 32 of the mask 3 (especially the first conductive portion 321) can function as a DC electrode for plasma, attracting cations with greater electroattraction. Therefore, the capacity can be increased. For example, according to this etching apparatus 1, the etching rate can be increased to the μm / min level.

[0060] Furthermore, in the above example, the second conductive portion 322 of the conductive film 32 is disposed on the first main surface 31a of the insulating substrate W side in the insulating plate 31. Therefore, cations are less likely to act on the second conductive portion 322. Therefore, the lifespan of the second conductive portion 322 and even the lifespan of the shield 3 can be improved.

[0061] On the other hand, the first conductive portion 321 of the conductive film 32 may wear down due to collisions between cations and the first conductive portion 321. In the above example, the mask 3 is transported integrally with the insulating substrate W, so the mask 3 is easy to replace. That is, the operator can replace the worn mask 3 with a new mask 3 from outside the chamber 2. Therefore, the workload is reduced.

[0062] <First Other Example of Mask> Figure 5 is a cross-sectional view schematically showing a first other example of the structure of the mask 3. The mask 3 in the first other example differs from the mask 3 in Figure 2 in terms of the structure of the conductive film 32. In the first other example, a portion of the first conductive portion 321 of the conductive film 32 protrudes further than the second main surface 31b of the insulating plate 31. That is, a portion of the first conductive portion 321 is located on the side opposite to the first main surface 31a (the conductive member 51 side) relative to the second main surface 31b of the insulating plate 31.

[0063] In the example of Figure 5, the conductive film 32 also includes a plurality of third conductive portions 323. Each third conductive portion 323 can be disposed one-to-one with a first conductive portion 321. Each third conductive portion 323 has an annular shape in top view, and its inner periphery is connected to the corresponding first conductive portion 321. Each third conductive portion 323 is disposed around the second opening in the second main surface 31b of the insulating plate 31. Each third conductive portion 323 is bonded to the second main surface 31b of the insulating plate 31.

[0064] Furthermore, if cations collide with the first conductive portion 321, the first conductive portion 321 will gradually wear down. Therefore, the volume of the first conductive portion 321 may gradually decrease. However, in the first other example, a portion (protruding portion) of the first conductive portion 321 is located closer to the conductive member 51 than the second main surface 31b. Therefore, the lifespan of the first conductive portion 321, and even the lifespan of the shield 3, can be extended.

[0065] Furthermore, in the above example, a third conductive portion 323 is provided. Therefore, the protruding portion of the first conductive portion 321 is fixed to the second main surface 31b of the insulating plate 31 via the third conductive portion 323. Therefore, the strength of the first conductive portion 321 can be improved.

[0066] Furthermore, in the above example, the third conductive portion 323 is only disposed around the second opening in the second main surface 31b of the insulating plate 31. That is, the plurality of third conductive portions 323 are separated from each other on the second main surface 31b side. Therefore, compared with the structure in which the third conductive portion 323 is disposed on the entire surface of the second main surface 31b of the insulating plate 31, cations can be more concentratedly attracted to the first opening 3a of the shield 3.

[0067] <Second Other Example of Mask> Figure 6 is a cross-sectional view schematically showing a second other example of the structure of the mask 3. The mask 3 in the second other example differs from the mask 3 in Figure 2 in the presence or absence of a protective film 33. In the second other example, the mask 3 further includes a protective film 33. The protective film 33 faces the first conductive portion 321 of the conductive film 32. The protective film 33 is disposed on the side opposite to the insulating substrate W (the conductive member 51 side) relative to the first conductive portion 321. The protective film 33 has a plate-like shape, and in plan view, for example, has an annular shape. The protective film 33 is disposed one-to-one with the first conductive portion 321. Each protective film 33 surrounds the first opening 3a in plan view. In the example of Figure 6, the inner peripheral portion of the protective film 33 faces the first conductive portion 321, and the outer peripheral portion of the protective film 33 faces the second main surface 31b of the insulating plate 31. The protective film 33 is in contact with the first conductive portion 321 and the second main surface 31b of the insulating plate 31. The plurality of protective films 33 are separated from each other when viewed from above.

[0068] The protective film 33 may be insulating or conductive. When the protective film 33 is conductive, it is electrically connected to the first conductive portion 321. Therefore, a negative voltage is also applied to the protective film 33. The material of the protective film 33 may be a material that is less susceptible to etching than the material of the conductive film 32. For example, yttrium may be used as the material of the protective film 33. The protective film 33 may be formed, for example, by vapor deposition or plating.

[0069] The protective film 33 can protect a portion of the first conductive part 321 from the influence of cations. Therefore, the lifespan of the mask 3 can be extended. If the protective film 33 is made of a material that is less susceptible to etching than the first conductive part 321, the lifespan of the mask 3 can be further extended.

[0070] Furthermore, in the above example, the plurality of protective films 33 are separated from each other on the second main surface 31b. Therefore, when the protective film 33 is conductive, it is possible to concentrate and attract cations to the first opening 3a of the shield 3.

[0071] <Third Other Example of Mask> Figure 7 is a schematic diagram showing a third other example of the structure of the mask 3. The mask 3 in the third other example differs from the mask 3 in Figure 2 in the presence or absence of a replacement part 35. In the third other example, the mask 3 further includes a replacement part 35. The replacement part 35 is disposed on the side closer to the insulating substrate W than the conductive film 32. Specifically, the replacement part 35 has a plate-like shape and is disposed between the conductive film 32 and the insulating substrate W. The replacement part 35 is disposed with its thickness direction along the vertical direction. The replacement part 35 is an independent entity from the conductive film 32 and is configured to be separable from the conductive film 32. That is, the replacement part 35 is not bonded to the conductive film 32.

[0072] The replacement part 35 has an opening 35a, which communicates in the vertical direction with an opening 321a formed on the inner peripheral surface of the first conductive portion 321 of the conductive film 32. Openings 35a and 321a are provided one-to-one. Each opening 35a penetrates the replacement part 35 in its thickness direction. The size of the opening 35a in the replacement part 35, viewed from above, is smaller than the size of the opening 321a. That is, in view from above, the inner peripheral surface of the opening 35a forming the replacement part 35 is located further inward than the inner peripheral surface of the first conductive portion 321. When both openings 321a and 35a have a circular shape in view from above, the diameter of opening 321a is smaller than the diameter of opening 35a.

[0073] The replacement part 35 may be insulating or conductive. The replacement part 35 may be formed of, for example, resin or metal. Yttrium may be used as an example of metal. When the replacement part 35 is conductive, the replacement part 35 is electrically connected to the conductive film 32.

[0074] In this type of shield 3, cations collide with the main surface of the insulating substrate W through the opening 321a of the first conductive portion 321 and the opening 35a of the replacement portion 35. Therefore, the replacement portion 35 also functions as a shield. That is, the opening 35a and the opening 321a form the first opening 3a.

[0075] According to the third other example of the shield 3, the opening 321a of the first conductive portion 321 is relatively large, thus allowing more cations to pass through to the replacement portion 35. Furthermore, a portion of the cations collides with the replacement portion 35, while the remaining portion collides with the main surface of the insulating substrate W. The insulating substrate W is etched by the action of the cations on it. On the other hand, the replacement portion 35 gradually wears down due to the collisions between the cations and the replacement portion 35. This replacement portion 35 is not bonded to the conductive film 32 and can be detached from the insulating plate 31 and the conductive film 32. Therefore, the replacement portion 35 worn down during the processing of the insulating substrate W can be removed from the chamber 2 and replaced with a new replacement portion 35.

[0076] <Fourth Other Example of Mask> Figure 8 is a schematic diagram showing a fourth other example of the structure of the mask 3. The mask 3 in the fourth other example differs from the mask 3 in Figure 2 in the presence or absence of the absorption portion 34. In the fourth other example, the mask 3 further includes the absorption portion 34. The absorption portion 34 is disposed on the side closer to the insulating substrate W than the conductive film 32. Specifically, the absorption portion 34 has a plate-like shape and is disposed between the conductive film 32 and the insulating substrate W. The absorption portion 34 is disposed with its thickness direction along the vertical direction.

[0077] The absorption portion 34 has an opening 34a, which communicates in the vertical direction with an opening formed on the inner peripheral surface of the first conductive portion 321 of the conductive film 32. The opening 34a extends through the absorption portion 34 in its thickness direction. The openings 34a of the absorption portions 34 and the openings 321a of the conductive film 32 form the first opening 3a of the shield 3.

[0078] The absorption section 34 can be configured to be separable from the conductive film 32, or it can be attached to the conductive film 32.

[0079] Here, heater 8 is an optical heater (in other words, a radiation heater) that directs heating light toward the insulating substrate W. The heating light is, for example, infrared light. In the example of FIG1, heater 8 is located further outward than the bottom of chamber 2. Therefore, a material with high transmittance for heating light is used at the bottom of chamber 2. This bottom is, for example, formed of glass.

[0080] On the other hand, sometimes the transmittance of the insulating substrate W is also relatively high. For example, when the insulating substrate W is made of glass, the insulating substrate W allows light for heating to pass through. Therefore, the light for heating is incident on the absorption portion 34. The transmittance of the insulating substrate W may be, for example, 60% or more, 80% or more, or 90% or more.

[0081] On the other hand, the absorption rate of the absorbing portion 34 for heating light is higher than the absorption rate of the insulating substrate W. Furthermore, the absorption rate of the absorbing portion 34 is higher than the absorption rate of the conductive film 32. For example, the light absorption rate of the absorbing portion 34 can be 40% or more, 60% or more, 80% or more, or even 90% or more. For example, the absorbing portion 34 is formed of cobalt-like carbon. The absorbing portion 34 is provided, for example, by sputtering or the like.

[0082] The light used for heating from the heater 8 is absorbed by the absorption section 34 and converted into heat. This heat is transferred to the insulating substrate W. Therefore, the insulating substrate W can be heated effectively. In the example of FIG8, the absorption section 34 is in contact with the insulating substrate W, so the heat emitted by the absorption section 34 is easily transferred to the insulating substrate W.

[0083] Furthermore, since the absorption portion 34 is disposed between the conductive film 32 and the insulating substrate W, it is in contact with the main surface of the insulating substrate W on the side where the cations in the insulating substrate W collide. Therefore, the temperature of the main surface of the insulating substrate W to be etched can be raised more effectively. Thus, the temperature of the main surface of the insulating substrate W can be raised to a suitable etching temperature more quickly, thereby enabling the etching process to begin at an earlier time.

[0084] The reflectivity of the conductive film 32 (especially the second conductive portion 322) to the light used for heating can be higher than that of the absorption portion 34. For example, the reflectivity of the conductive film 32 can be 60% or more, 80% or more, or 90% or more. As a result, a portion of the light used for heating that passes through the absorption portion 34 is reflected by the conductive film 32 and passes through the absorption portion 34 again. Therefore, the amount of light absorbed by the absorption portion 34 can be increased, thereby increasing the amount of heat generated in the absorption portion 34. Therefore, the insulating substrate W can be heated more effectively.

[0085] Furthermore, in FIG7, when the absorption rate of the replacement part 35 is higher than the absorption rate of the insulating substrate W, the replacement part 35 can function as the absorption part 34.

[0086] <Second Embodiment> FIG9 is a side view schematically showing an example of the configuration of the etching apparatus 1 according to the second embodiment. The etching apparatus 1 of the second embodiment differs from the etching apparatus 1 of the first embodiment in terms of the position of each component. In the example of FIG9, the roller 25 is in contact with the mask 3, and the insulating substrate W is disposed above the mask 3. For example, the insulating substrate W is placed on the mask 3. The plasma generating part 5 is disposed on the side opposite to the insulating substrate W relative to the mask 3, and therefore, in the example of FIG9, it is disposed below the mask 3. Also, in the example of FIG9, the gas inlet pipe 61 is disposed below the passage 22, and the downstream outlet of the gas inlet pipe 61 is disposed below the mask 3. For example, the downstream outlet of the gas inlet pipe 61 is disposed in a position arranged horizontally with the conductive member 51. On the other hand, the heater 8 is disposed above the insulating substrate W, and in the example of FIG9, it is disposed above the top wall of the chamber 2. When the heater 8 emits light for heating, the top wall of the chamber 2 is transparent to that light. Also, in the example of Figure 9, the upstream opening of the suction tube 71 is located further below the roller 25.

[0087] Figure 10 is a diagram showing an example of the configuration of the roller 25, the shield 3, and the insulating substrate W. Figure 10 shows the roller 25, the shield 3, and the insulating substrate W as viewed with the line of sight along the conveying direction D1. As shown in Figure 10, a pair of rollers 25 are arranged in the width direction D2. One roller 25 is connected to one end of the shield 3 in the width direction D2, and the other roller 25 is connected to the other end of the shield 3 in the width direction D2. A plurality of such pairs of rollers 25 are arranged in the conveying direction D1. A plurality of first openings 3a of the shield 3 are provided in the area between the pair of rollers 25 in the width direction D2. Conversely, the rollers 25 are provided in positions that avoid this area.

[0088] In the second embodiment, the roller 25 is conductive and is in contact with the conductive film 32 of the shield 3. In the example of FIG10, the conductive film 32 further includes a fourth conductive portion 324 and a fifth conductive portion 325. In the example of FIG10, the fifth conductive portion 325 is disposed on the second main surface 31b of the insulating plate 31 and is in contact with the roller 25. Thereby, the fifth conductive portion 325 is electrically connected to the roller 25. In the example of FIG10, a pair of fifth conductive portions 325 are respectively in contact with a pair of rollers 25. The fifth conductive portion 325 can extend along the conveying direction D1. That is, the fifth conductive portion 325 can have a strip-shaped form with the conveying direction D1 as its length direction when viewed from above.

[0089] The fourth conductive portion 324 penetrates the insulating plate 31 in its thickness direction, connecting the second conductive portion 322 and the fifth conductive portion 325. The fourth conductive portion 324 may, for example, have a cylindrical shape. The fourth conductive portion 324 may function as a through hole.

[0090] The bias application section 4 applies a negative voltage to the roller 25. This applies a negative voltage to the conductive film 32 in contact with the roller 25. The bias application section 4 may include, for example, a conductive contact member (e.g., a brush) that contacts the roller 25. This contact member is connected to the low-potential output terminal of the DC power supply 43 via wiring 42. Furthermore, in this example, since the roller 25 is in contact with the conductive film 32 of the shield 3, the roller 25 functions as a contact member 41 of the bias application section 4. A negative voltage can be applied to all of the rollers 25, or it can be applied to several rollers 25.

[0091] As described above, in the second embodiment, the conductive roller 25 is in contact with the conductive film 32 of the mask 3, and therefore the roller 25 is used to apply a negative voltage. When a negative voltage is applied to a plurality of rollers 25, a negative voltage can be applied to the mask 3 at a plurality of locations (rollers 25). Therefore, the potential distribution of the mask 3 can be made more uniform. Furthermore, the etching apparatus 1 can etch the insulating substrate W more uniformly.

[0092] The etching apparatus 1 has been described in detail above, but the above description is illustrative in all respects and the present invention is not limited thereto. Furthermore, the various variations described above can be combined and applied as long as they do not contradict each other. Moreover, it should be understood that multiple variations not illustrated may be assumed without departing from the scope of the present invention. [Simplified Explanation of the Diagram]

[0023] FIG1 is a side view schematically showing an example of the configuration of the etching apparatus according to the first embodiment. FIG2 is a cross-sectional view schematically showing an example of a component of the mask. FIG3 is a top view schematically showing an example of a component of the mask. FIG4 is a diagram schematically showing the movement of cations. FIG5 is a cross-sectional view schematically showing a first other example of the configuration of the mask. FIG6 is a cross-sectional view schematically showing a second other example of the configuration of the mask. FIG7 is a diagram schematically showing a third other example of the configuration of the mask. FIG8 is a diagram schematically showing a fourth other example of the configuration of the mask. FIG9 is a side view schematically showing an example of the configuration of the etching apparatus according to the second embodiment. FIG10 is a diagram showing an example of the configuration of the roller, the mask, and the insulating substrate.

Claims

1. An etching apparatus for forming a plurality of through holes in an insulating substrate, comprising: a chamber for receiving the insulating substrate; a shield having a plurality of first openings and facing the insulating substrate; a bias application unit for applying a negative voltage to the shield; and a plasma generation unit for generating plasma and supplying cations in the plasma to the insulating substrate through the plurality of first openings of the shield, the shield comprising an insulating plate having a plurality of second openings and a conductive film, the conductive film comprising a first conductive portion disposed on the inner peripheral surface of each of the plurality of second openings in the insulating plate to form the first opening, and the bias application unit applying the negative voltage to the conductive film.

2. The etching apparatus of claim 1, wherein the conductive film includes a second conductive portion formed on a first main surface of the insulating substrate side in the insulating plate, and the first conductive portions are connected to each other.

3. The etching apparatus of claim 1 or 2, wherein a portion of the first conductive part protrudes further than the second main surface of the insulating plate, which is opposite to the first main surface of the insulating substrate.

4. The etching apparatus of claim 1 or 2, wherein the mask further includes a protective film facing the first conductive portion and protecting the first conductive portion from the influence of the plasma.

5. The etching apparatus of claim 1 or 2, wherein the mask further includes a replacement part disposed between the insulating plate and the insulating substrate and configured to be detachable from the insulating plate and the conductive film, the replacement part having an opening that, together with the opening of the first conductive portion, forms the first opening, the diameter of the opening of the replacement part being smaller than the diameter of the opening of the first conductive portion.

6. The etching apparatus of claim 1 or 2, further comprising a heater that emits heating light toward the insulating substrate, the shield comprising an absorption portion disposed between the insulating plate and the insulating substrate, the absorption portion having an absorption rate of the light higher than that of the insulating substrate.

7. An etching apparatus for forming a plurality of through holes in an insulating substrate, comprising: a chamber for receiving the insulating substrate; a shield having a plurality of first openings and facing the insulating substrate; a bias application unit for applying a negative voltage to the shield; a plasma generation unit for generating plasma and supplying cations in the plasma to the insulating substrate through the plurality of first openings of the shield; and a plurality of conductive rollers supporting the shield and conveying the shield and the insulating substrate, wherein the bias application unit applies the negative voltage to the shield via the rollers.

8. The etching apparatus of claim 7, wherein the plurality of conductive rollers convey the mask and the insulating substrate along a conveying direction, the mask including a conductive portion in contact with the rollers having an elongated shape with the conveying direction as its length direction.

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