JP6908489B2 - Etching device - Google Patents

Description

The present invention relates to an apparatus for dry etching a substrate to be processed such as a glass or a wafer containing a silicon-containing substance with a chemically active reaction gas containing a fluorine-based reaction component, and particularly to an element forming surface or the like on the substrate to be processed. The present invention relates to an etching apparatus suitable for lightly roughening a surface to be treated to prevent contact electrification while suppressing contact of a reaction gas with the non-treated surface.

It is known that a silicon-containing substrate such as glass is etched with a reaction gas containing hydrogen fluoride (see Patent Documents 1 to 4 and the like).
In Patent Document 1, of the pair of upper and lower facing surfaces forming a flat processing space through which a glass substrate can pass, a reaction gas supply portion and an exhaust portion are provided on the lower facing surface, and the upper facing surface is provided. By providing the outside air intake port in the center, an outside air intake flow is formed on the upper surface side of the glass substrate, and the reaction gas is prevented from coming into contact with the upper surface of the glass substrate.
In Patent Document 2, an inert gas that does not contribute to the reaction such as nitrogen is allowed to flow on the upper surface side of the glass substrate, and the lower surface (surface to be treated) of the glass substrate is etched while diluting or eliminating the reaction gas that wraps around the upper surface side. Processing is being performed.

Japanese Unexamined Patent Publication No. 2014-125414 Japanese Unexamined Patent Publication No. 2012-191001

In Patent Document 1, hydrogen fluoride in the reaction gas in the treatment space may be diluted by drawing the outside air into the outside air suction port provided on the upper facing surface, and the treatment performance may be deteriorated. In addition, there is a concern that hydrogen fluoride may wrap around the upper surface of the glass substrate due to the drawing flow.
In Patent Document 2, by appropriately adjusting the flow rate of the inert gas according to the transport speed of the glass substrate, it is possible to prevent the above-mentioned performance deterioration, but the flow rate is adjusted incorrectly and exhausted. If more than the amount of inert gas is pushed into the treatment space, hydrogen fluoride may leak to the outside of the treatment space.
In view of the above considerations, the present invention can perform stable etching processing by suppressing turbulence of the reaction gas on the surface side of the substrate to be processed such as a glass substrate, and react on the non-processed surface side opposite to the surface to be processed. It is an object of the present invention to provide an etching apparatus capable of suppressing the wraparound of gas and suppressing etching.

In order to solve the above problems, the present invention is an apparatus for etching the surface to be treated of a substrate to be treated containing a silicon-containing substance with a reaction gas containing a fluorine-based reaction component.
A nozzle portion having a nozzle surface on which the outlet and suction port of the reaction gas are formed, and
An opposing member having an opposing surface facing the nozzle surface in the opposite direction and defining a flat processing space between the nozzle surface and the nozzle portion.
A transport means for passing the substrate to be processed with the surface to be processed facing the nozzle surface into the processing space along a transport direction orthogonal to the facing direction.
It is characterized in that it is provided with a movable partition member that projects from the facing surface of the facing member toward the nozzle surface and is movable in the transport direction together with the substrate to be processed.

According to the etching apparatus, when the substrate to be processed is passed through the processing space, the protruding end portion of the movable partition member is in close proximity to or in contact with the tip portion of the substrate to be processed in the transport direction (hereinafter referred to as “transport tip portion”). Then, a blocking space is defined by the non-processed surface of the substrate to be processed, the facing surface of the facing member, and the movable partition member. While the cutoff space is communicated with the external space of the nozzle part, it is almost cut off from the reaction space part filled with the reaction gas in the processing space. Therefore, since the reaction gas is restricted or prevented from entering the cutoff space, it is possible to suppress or prevent the non-processed surface of the substrate to be processed from being etched. The outside air outside the nozzle section enters the blocking space.
Since the surface to be processed of the treated substrate faces the reaction space and is in contact with the reaction gas, the etching process can be performed reliably.
Examples of the silicon-containing material include SiO ₂ , SiN, Si, SiC, SiOC and the like.
The fluorine-based reaction component is a compound capable of reacting with the silicon-containing substance, and examples thereof include HF and COF ₂ .

It is preferable that the movable partition member protrudes to the passing height of the substrate to be processed.
In this case, when the substrate to be processed is passed through the processing space, the transport tip portion of the substrate to be processed abuts against the movable partition member. The movable partition member and the substrate to be processed are moved together while being abutted against each other. As a result, it is possible to surely prevent the reaction gas from entering the cutoff space, and it is possible to surely prevent the non-treated surface from being etched.

The movable partition member may be freely movable in the transport direction.
After the transfer tip of the substrate to be processed hits the movable partition member, the movable partition member is pushed and moved by the movable partition member as the substrate to be processed is conveyed while maintaining the abutted state. .. In this case, a mobile drive unit is not required, the device configuration can be simplified, and the device cost can be reduced.

The movable partition member may be moved in the transport direction in synchronization with the substrate to be processed by the moving drive unit. In this case, it is possible to avoid applying a load for pushing and moving the movable partition member on the substrate to be processed.

According to the present invention, on the surface side of a substrate to be processed such as a glass substrate, by suppressing the inflow of outside air, turbulence of the reaction gas can be suppressed and the etching process can be performed stably. By ensuring that the outside air flows in on the side opposite to the surface to be treated, it is possible to suppress the wraparound of the reaction gas and suppress the etching.

FIG. 1 shows a schematic configuration of an etching apparatus according to a first embodiment of the present invention, and is a side sectional view of a state before the glass substrate is introduced into the processing space. FIG. 2 is a side sectional view showing a schematic configuration of the etching apparatus in a state where the glass substrate passes through the processing space. FIG. 3 is a front sectional view taken along the line III-III of FIG. FIG. 4 shows an embodiment when the width of the glass substrate is small, and is a front sectional view corresponding to FIG. FIG. 5 is a side sectional view showing a schematic configuration of an etching apparatus according to a second embodiment of the present invention in a state where a glass substrate passes through a processing space.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
1 and 2 show the first embodiment of the present invention. As shown in FIG. 1, the substrate to be processed according to the present invention is a glass substrate 9 for a liquid crystal panel. The glass substrate 9 contains a silicon-containing substance such as _{SiO 2.} The back surface (lower surface in FIG. 1) of the glass substrate 9 for which contact electrification should be suppressed is the surface to be processed 9a. By chemically etching the surface to be processed 9a with the etching apparatus 1, desired surface roughness (unevenness) is imparted to the surface to be processed 9a.
The surface of the glass substrate 9 (upper surface of FIG. 1) is an element forming surface on which an element such as a TFT is formed, and is a non-processed surface 9b that is not desired to be etched.

The etching apparatus 1 includes a conveying means 2, a reaction gas generating unit 3, and a processing unit 4.
The transport means 2 is composed of, for example, a roller conveyor having a disk-shaped roller 2c. The glass substrate 9 is conveyed along the conveying direction (left-right direction in FIG. 1) by the conveying means 2. In the glass substrate 9 being conveyed, the surface to be processed 9a is directed downward and the non-processed surface 9b is directed upward.

Although detailed illustration is omitted, the reaction gas generating unit 3 has a pair of electrodes facing each other. A fluorinated reaction gas is generated by forming a glow discharge near atmospheric pressure in the discharge space between these electrodes and introducing a fluorinated raw material gas into the discharge space.
The discharge type is not limited to glow discharge, and may be arc discharge, corona discharge, or the like.
In the present specification, the vicinity of atmospheric pressure means ^{a range of 1.013 × 10 4 to} 50.663 × 10 ^{4 Pa, and 1.333 × 10 4 in} consideration of facilitation of pressure adjustment and simplification of device configuration. ~ 10.664 × 10 ⁴ Pa is preferable, and 9.331 × 10 ^{4 to} 10.397 × 10 ⁴ Pa is more preferable.

The fluorine source gas, and a fluorine-containing gas, and water (H 2 _O), a carrier gas.
Fluorine-containing gases include PFCs (perfluorocarbons) such _{as CF 4} , C ₂ F ₄ , C ₂ F ₆ , C ₃ F ₈ , and HFCs (hydrofluorocarbons) such as _{CHF 3} , CH ₂ F ₂ , and CH _{3 F.} Examples include SF ₆ , NF ₃ , XeF ₂ , and other fluorine-containing compounds. _{Here, CF 4} is used as the fluorine-containing gas.
Examples of the carrier gas include rare gases such as helium, argon, neon, and xenon, nitrogen, and other inert gases. Here, for example, nitrogen (N ₂ ) is used as the carrier gas.
When the fluorine-based raw material gas is turned into plasma (including excitation, activation, radicalization, ionization, etc.) in the discharge space, the fluorine-containing gas (CF ₄ ) is decomposed, and the fluorine-based reaction component, which is a fluorine-based reaction component, is decomposed. Hydrogen fluoride (HF) is produced. As a result, a reaction gas containing hydrogen fluoride is generated from the fluorine-based raw material gas. The reaction formula for producing hydrogen fluoride is, for example, the following formula.
CF ₄ + 2H ₂ O → 4HF + CO ₂ (Equation 1)

The processing unit 4 is connected to the reaction gas generation unit 3 via the reaction gas supply path 3b.
The processing unit 4 includes a nozzle unit 10 and an opposing member 21.
The nozzle portion 10 has a container shape extending in the width direction along the direction orthogonal to the paper surface of FIG. The upper surface of the nozzle portion 10 constitutes the nozzle surface 19. A blowout port 11 and a pair of suction ports 12 and 13 are formed on the nozzle surface 19. The air outlet 11 is provided at the center of the nozzle surface 19 in the transport direction (left-right direction in FIG. 1). The air outlet 11 has a slit shape extending in the width direction (direction orthogonal to the paper surface in FIG. 1). The length of the air outlet 11 is about the same as or slightly larger than the width dimension of the glass substrate 9 (dimension in the direction orthogonal to the paper surface in FIG. 1).

Although not shown, a rectifying unit is provided inside the nozzle unit 10. The rectifying unit includes a chamber, a slit, a perforated plate, and the like. The reaction gas from the reaction gas generation unit 3 is made uniform in the width direction of the nozzle unit 10 (orthogonal direction on the paper surface in FIG. 1) by passing through the rectifying unit, and then is evenly blown upward from the outlet 11. Will be done.

A pair of suction ports 12 and 13 are provided on both sides of the nozzle surface 19 with the air outlet 11 in the transport direction. The suction port 12 is arranged on the outer end side (right end side in FIG. 1) upstream of the air outlet 11 on the nozzle surface 19. The suction port 13 is arranged on the outer end side (left end side in FIG. 1) downstream of the air outlet 11 on the nozzle surface 19. Each of the suction ports 12 and 13 extends in a slit shape in the width direction (direction orthogonal to the paper surface in FIG. 1). Although detailed illustration is omitted, these suction ports 12 and 13 are connected to a suction means such as a vacuum pump or an abatement means via a suction path 17.

The facing member 21 is arranged above the nozzle portion 10 at a distance. The facing member 21 is formed in a horizontal plate shape and extends in the width direction (direction orthogonal to the paper surface in FIG. 1) in parallel with the nozzle portion 10. The lower surface of the facing member 21 constitutes the facing surface 29. A flat processing space 31 is defined between the facing surface 29 and the nozzle surface 19. The air outlet 11 is communicated with the central portion of the processing space 31 in the transport direction (left-right direction in FIG. 1), and the suction ports 12 and 13 are communicated with both side portions.

A communication opening 34 is formed between one end of the nozzle surface 19 and the opposite surface 29 in the transport direction (the right end in FIG. 1). A communication opening 35 is formed between the other ends (left end in FIG. 1) of the nozzle surface 19 and the facing surface 29 in the transport direction.
Both ends of the processing space 31 in the transport direction are connected to the space outside the nozzle portion 10 via these communication openings 34 and 35.

As shown in FIG. 3, both end portions (left and right end portions in FIG. 3) in the width direction of the processing space 31 are closed by a pair of side walls 14. The width of the glass substrate 9 in FIG. 3 (dimensions in the left-right direction in FIG. 3) is substantially equal to the distance between the pair of side walls 14, that is, the width of the processing space 31. Substantially means that the width of the glass substrate 9 may be smaller than the width of the processing space 31 by a small clearance that allows the glass substrate 9 to move relative to each other.

As shown in FIG. 4, when the width of the glass substrate 9 is somewhat or considerably smaller than the width of the processing space 31 (distance between the pair of side walls 14), a pair of side partitions in the processing space 31. The members 15 may be provided so that the distance between the side partition members 15 is substantially equal to the width of the glass substrate 9.
The side partition member 15 is fixed in position with respect to the nozzle portion 10.

The glass substrate 9 is introduced into the processing space 31 from the communication opening 34 while being conveyed along the conveying direction (the direction connecting the suction ports 12 and 13 and the air outlet 13) by the conveying means 2, and is introduced into the processing space 31. It is passed through and derived from the communication opening 35.

A movable partition member 41 is provided on the facing surface 29 of the facing member 21. The movable partition member 41 extends along the width direction (direction orthogonal to the paper surface in FIG. 1) over almost the entire processing space 41, and protrudes from the facing surface 29 toward the nozzle surface 19 below. The protruding end (lower end) of the movable partition member 41 is located at the passing height of the substrate to be processed.

The movable partition member 41 can freely move in the transport direction. Although not shown, the facing member 21 is provided with a guide rail extending in the transport direction. The movable partition member 41 is provided with a slider that is slidably engaged with the guide rail.

The etching apparatus 1 surface-treats the glass substrate 9 as follows.
The reaction gas containing hydrogen fluoride (HF) generated in the reaction gas generation unit 3 is sent to the processing unit 4 via the reaction gas supply path 3b, and is supplied to the processing space 31 from the outlet 11 (reaction gas supply). Process).

As shown in FIG. 1, the movable partition member 41 is arranged at the end of the facing surface 29 on the communication opening 34 side. Then, the glass substrate 9 is inserted into the communication opening 34 from the transfer upstream side (right side in FIG. 1) of the nozzle portion 10 by the transfer means 2 (convey step). Then, the transport tip portion (left end portion in FIG. 1) of the glass substrate 9 abuts on the protruding end portion of the movable partition member 41.
After that, the glass substrate 9 is further moved to the downstream side (left side in FIG. 1) in the transport direction by the transport means 2, and the movable partition member 41 is pushed and moved by the glass substrate 9. That is, the movable partition member 41 is moved together with the glass substrate 9 while maintaining the state of being abutted against the glass substrate 9.

As shown in FIG. 2, the glass substrate 9 is introduced into the processing space 31 by the movement. As a result, the reaction gas g0 in the processing space 31 comes into contact with the surface to be processed 9a of the glass substrate 9. Then, an etching reaction occurs between hydrogen fluoride (HF) in the reaction gas and the silicon-containing substance on the surface to be treated 9a (etching step). As a result, the surface to be treated 9a can have a desired surface roughness Ra. The reaction formula is, for example, the following formula.
SiO ₂ + 4HF + H ₂ O → SiF ₄ + 3H ₂ O (Equation 2)

The reaction gas that has flowed to the suction ports 12 and 13 without reacting or the gas generated by the reaction is sucked into the suction ports 12 and 13 and discharged. Further, the outside air (air) outside the nozzle portion 10 is drawn into the communication opening 34 and sucked into the suction ports 12 and 13. This drawing flow of outside air can prevent the reaction gas from leaking to the outside.

On the other hand, the blocking space 42 is defined by the non-processed surface 9b of the glass substrate 9, the facing surface 29 of the facing member 21, and the movable partition member 41. In other words, the processing space 31 is separated from the reaction space portion 31a excluding the blocking space 42 and the blocking space 42. The reaction space portion 31a is filled with the reaction gas.
The blocking space 42 communicates with the external space of the nozzle portion 10 via the upper portion 34b of the communication opening 34. As a result, outside air g0 (air) enters the cutoff space 42. Further, when the movable partition member 41 abuts on the glass substrate 9, the reaction gas g1 is restricted or prevented from entering the blocking space 41. Thereby, it is possible to suppress or prevent the non-treated surface 9b from being etched.

Further, as shown in FIG. 3, in the glass substrate 9 having a substantially equal width to the processing space 31, both ends of the glass substrate 9 in the width direction are substantially in contact with the side wall 14, and the glass substrate 9 and the side wall 14 are substantially in contact with each other. There is almost no gap between and. Therefore, even at both ends in the width direction, the reaction space portion 31a and the blocking space 42 are separated from each other, and the reaction gas can be prevented from wrapping around. Therefore, it is possible to suppress or prevent etching treatment at both ends of the non-treated surface 9b of the glass substrate 9 in the width direction.

As shown in FIG. 4, in the glass substrate 9 having a width smaller than the processing space 31, by installing the side partition member 15, it is possible to prevent the reaction gas from wrapping around at both ends in the width direction as in the case of FIG. , Both ends of the non-treated surface 9b in the width direction can be suppressed or prevented from being etched.

The movable partition member 41 may be detached from the facing member 21 when it reaches the end on the downstream side of the transport of the facing member 21 (the left end in FIG. 2), and further, the facing member 21 is transported by a robot or human power. It may be returned to the upstream end (right end in FIG. 2).
The glass substrate 9 is moved to the downstream side of the transport as it is, passes through the processing space 31, and is led out from the communication opening 35. As a result, the entire area of the surface to be processed 9a is etched.

According to the etching apparatus 1, the outside air drawing portion of Patent Document 1 and the inert gas supply portion of Patent Document 2 are unnecessary. Therefore, the device cost can be reduced and the running cost can be suppressed. In addition, there is no risk of the reaction gas leaking due to the excessive supply of the inert gas, which improves safety.

Next, other embodiments of the present invention will be described. In the following embodiments, the same reference numerals are given to the drawings for configurations that overlap with the above-described embodiments, and the description thereof will be omitted.
<Second Embodiment>
FIG. 5 shows a second embodiment of the present invention. In the etching apparatus 1B of the second embodiment, the moving drive unit 43 is connected to the movable partition member 41. Although detailed illustration is omitted, the moving drive unit 43 has a motor, a slide guide, and the like, and moves the movable partition member 41 in the transport direction (left-right direction in FIG. 5).
Moreover, the moving drive unit 43 is driven in synchronization with the transport means 2. As a result, the movable partition member 41 is kept in contact with the transport tip portion (left end portion in FIG. 5) of the glass substrate 9, and at the same speed as the glass substrate 9 by the driving force of the moving drive portion 43. It is moved to the downstream side of the transport. Therefore, it is possible to avoid applying a load for pushing and moving the movable partition member 41 on the glass substrate 9.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the second embodiment, the movable partition member 41 and the substrate 9 to be processed are subjected to the driving force of the moving drive unit 43 in a state where the movable partition member 41 is close to the transfer tip portion of the substrate 9 to be processed, that is, slightly separated from the transfer tip portion. It may be moved quickly. If it is in a state of being slightly separated, the reaction gas hardly enters the cutoff space 43.
When the movable partition member 41 reaches the communication opening 35 downstream of the transfer, the movable drive unit 43 raises the movable partition member 41 or removes it from the opposing member 21, so that the substrate 9 to be processed is further downstream of the transfer. The movable partition member 41 may not be an obstacle when it is moved to the side.
Further, the movable partition member 41 may be returned to the communication opening 34 upstream of the transfer by the moving drive unit 43. Then, when the transport rear end portion (right end portion in FIG. 5) of the substrate 9 to be processed enters the communication opening 34, the movable partition member 41 is attached to the transport rear end portion and together with the substrate 9 to be processed. The movable partition member 41 may be moved to the downstream side of the transfer. By doing so, it is possible to reliably suppress or prevent etching treatment of the portion of the non-processed surface 9b of the substrate 9 to be processed on the rear end side (right side in FIG. 5) of the transfer.
The protruding end portion (lower end portion) of the movable partition member 41 may be arranged at a height slightly above the non-processed surface 9b of the substrate 9 to be processed.

The present invention can be applied to, for example, surface treatment of a glass substrate for a flat panel.

1,1B Etching device 2 Conveying means 3 Reaction gas generating part 4 Processing part 9 Glass substrate 9a Processed surface 9b Non-processed surface 10 Nozzle part 11 Air outlet 12, 13 Suction port 14 Side wall 15 Side partition member 19 Nozzle surface 21 Opposing member 29 Facing surface 31 Processing space 31a Reaction space part 34 Communication opening 34b Upper part 35 Communication opening 41 Movable partition member 42 Blocking space 43 Moving drive part g0 Outside air g1 Reaction gas

Claims (4)

A device that etches the surface to be treated of a substrate to be treated containing a silicon-containing substance with a reaction gas containing a fluorine-based reaction component.
A nozzle portion having a nozzle surface on which the outlet and suction port of the reaction gas are formed, and
An opposing member having an opposing surface facing the nozzle surface in the opposite direction and defining a flat processing space between the nozzle surface and the nozzle portion.
A transport means for passing the substrate to be processed with the surface to be processed facing the nozzle surface into the processing space along a transport direction orthogonal to the facing direction.
It projects from the facing surface of the facing member toward the nozzle surface, and is close to or in contact with the tip end portion of the substrate to be processed in the transport direction when the protruding end portion is passed through the processing space. , etching apparatus, characterized in that said a movable partition member movable into the conveying direction together with the substrate to be processed. The etching apparatus according to claim 1, wherein the movable partition member can freely move in the transport direction. A device that etches the surface to be treated of a substrate to be treated containing a silicon-containing substance with a reaction gas containing a fluorine-based reaction component.
A nozzle portion having a nozzle surface on which the outlet and suction port of the reaction gas are formed, and
An opposing member having an opposing surface facing the nozzle surface in the opposite direction and defining a flat processing space between the nozzle surface and the nozzle portion.
A transport means for passing the substrate to be processed with the surface to be processed facing the nozzle surface into the processing space along a transport direction orthogonal to the facing direction.
It projects from the facing surface of the facing member toward the nozzle surface, and is close to or near the front end or rear end of the substrate to be processed in the transport direction when the protruding end is passed through the processing space. A movable partition member that is abutted and can move together with the substrate to be processed in the transport direction.
The movable partition is connected to the member, and synchronously driven with said conveying means, said movable partition member, wherein Before moving the conveying direction in the substrate to be treated and the constant speed of moving by the transfer means, A moving drive unit different from the transport means,
An etching device characterized by being equipped with. The etching apparatus according to any one of claims 1 to 3, wherein the movable partition member projects to a passing height of the substrate to be processed.

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