KR102368126B1 - Etching apparatus, etching method, substrate manufacturing method, and substrate - Google Patents

Abstract

The etching tank 110 which has the board|substrate carrying-in port 111 and the board|substrate carrying-out port 112, and the conveyance apparatus 120 which conveys the board|substrate 500 toward the board|substrate carrying-in port 112 from the board|substrate carrying-in port 111; , a nozzle 130 formed inside the etching bath 110 and injecting a reaction gas to the back surface 510 of the substrate 500 conveyed by the conveying device 120 , and the etching bath 110 inside A gap 131 between the nozzle 130 and the back surface 510 of the substrate 500 and the outside air that is formed and flowed into the etching tank 110 from the substrate inlet 111 and the substrate outlet 112 An etching apparatus (100) comprising an airflow control device (140) for suppressing inflow into the etchant.

Description

Etching apparatus, etching method, manufacturing method of a board|substrate, and board|substrate TECHNICAL FIELD

The present invention relates to an etching apparatus, an etching method, a method for manufacturing a substrate, and a substrate.

DESCRIPTION OF RELATED ART In manufacturing processes, such as a flat panel display, it is known that a board|substrate is electrically charged by static electricity which generate|occur|produces when a board|substrate contacts a stage etc.. Therefore, in order to suppress such charging, the surface on the side on which the substrate is placed on a stage or the like (hereinafter referred to as "rear surface") is etched with plasma containing an HF-based gas, and the substrate It is proposed to roughen the back surface of (for example, refer patent document 1). Further, there is known a method in which a fluorine-containing gas, water vapor, and plasma are reacted to generate a reactive gas containing an HF-based gas, and the reactive gas is sprayed onto the substrate to etch the substrate (see, for example, Patent Document 2). .

As an etching apparatus, the structure in which the board|substrate carrying-in port and the board|substrate export port were formed in the tank (henceforth "etching tank") to which the chemical process of a glass substrate was performed is known (for example, patent document 3 Reference). In order to continuously carry out the process from loading in the substrate to unloading the substrate, the substrate loading and unloading ports are opened, and the substrate is transported from the substrate loading port to the substrate unloading port from a nozzle installed on the substrate transport path. A reactive gas is sprayed on one surface of the substrate.

International Publication No. 2010/128673 Japanese Patent Laid-Open No. 2007-201067 Japanese Patent Laid-Open No. 2012-216581

The illuminance at each point in the back surface of the substrate is determined by two factors: the concentration of the reactive gas to which the point is exposed, and the cumulative time for which the point is exposed to the reactive gas. These factors are largely fluctuated by the disturbance of the airflow caused by the outside air flowing in from the substrate inlet and the substrate outlet. However, in the conventional etching apparatus, since the influence by the disturbance of an airflow could not fully be suppressed, the nonuniformity of roughness generate|occur|produced with inflow of external air into the inside of an etching tank. As a result, it has become difficult to reduce the amount of static electricity charged on the back surface of the substrate.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an etching apparatus and an etching method capable of suppressing the unevenness of the roughness accompanying the inflow of external air into the inside of the etching bath.

An etching apparatus according to an aspect of the present invention comprises: an etching tank having a substrate loading port and a substrate loading port; A nozzle for spraying a reaction gas on one surface of the substrate conveyed by the conveying device, and external air formed inside the etching tank and flowing into the etching tank from the substrate inlet and the substrate outlet, the substrate and an airflow control device for suppressing inflow into the gap between one surface of the nozzle and the nozzle.

In the etching apparatus which concerns on 1 aspect of this invention, the said airflow control apparatus is a 1st vent hole formed between the said board|substrate carrying-in opening and the said nozzle for the external air which flowed into the inside of the said etching tank from the said board|substrate carrying-in opening toward the said clearance gap. a first vent passage for introducing from the substrate, and a second vent passage for introducing external air introduced into the etching tank from the substrate ejection port toward the gap through a second vent hole formed between the substrate ejection port and the nozzle; can do.

The etching apparatus according to an aspect of the present invention may include a connection path for connecting the first vent passage and the second vent passage.

The etching apparatus according to an aspect of the present invention may include a suction device for sucking the outside air flowing into the connection path from the first and second ventilation passages.

In the etching apparatus according to an aspect of the present invention, the first ventilation passage is formed so as to block the front of the nozzle as viewed from the substrate loading port, and the second ventilation passage is viewed from the substrate carrying out port, It may be formed to block the front of the nozzle.

The etching method which concerns on one aspect of this invention conveys a board|substrate toward the said board|substrate carrying-out port from the said board|substrate carrying-in port of the etching tank which has a board|substrate carrying-in port and a board|substrate carrying-out port, The said etching from the said board|substrate carrying-in port and the said board|substrate carrying out port The reaction gas is injected from the nozzle to one surface of the substrate while suppressing the outside air introduced into the tank from flowing into the gap between the one surface of the substrate and the nozzle.

In the etching method according to one aspect of the present invention, external air flowing into the etching tank from the substrate loading port toward the gap is transferred from the first ventilation hole formed between the substrate loading port and the nozzle to the first ventilation passage. By inflowing, the external air introduced into the etching tank from the substrate loading port is suppressed from flowing into the gap, and the external air introduced into the etching tank from the substrate carrying out port toward the gap is reduced to the substrate carrying out port. By introducing the second vent through the second vent formed between the and the nozzle into the second vent, it is possible to suppress the external air flowing into the etching tank from the substrate discharge port from flowing into the gap.

In the etching method according to one aspect of the present invention, the external air flowing into the connection path connecting the first ventilation passage and the second ventilation passage can be sucked.

The manufacturing method of the board|substrate which concerns on one aspect of this invention is a manufacturing method of the board|substrate which has the process of etching a board|substrate by the said etching method.

A substrate according to an aspect of the present invention is a substrate having a first surface and a second surface opposite to the first surface,

The average value of the arithmetic mean surface roughness of the entire first surface is 0.3 to 1.5 nm, and the average value of the arithmetic mean surface roughness of the peripheral portion of the first surface is different from the average value of the arithmetic mean surface roughness of the central portion of the first surface, and The standard deviation of the arithmetic mean surface roughness of the entire first surface is 0.06 or less.

In the board|substrate which concerns on one aspect of this invention, 1500 mm x 1500 mm or more may be sufficient as the size of the said board|substrate.

In the substrate according to one aspect of the present invention, the difference between the arithmetic mean surface roughness of the central portion of the first surface and the average value of the arithmetic mean surface roughness of the entire first surface may be −0.13 or more and 0.13 or less.

ADVANTAGE OF THE INVENTION According to this invention, the nonuniformity of the roughness accompanying the inflow of external air to the inside of an etching tank can be suppressed.

1 is a side view schematically showing an etching apparatus according to a first embodiment of the present invention.
Fig. 2 is a cross-sectional view of a nozzle of the etching apparatus according to the first embodiment of the present invention.
3 : is a front view of the nozzle and airflow control apparatus seen from the board|substrate carrying-in port side.
Fig. 4 is a schematic diagram showing the flow of external air in the etching bath, and Fig. 4 (a) is a diagram showing the flow of external air when a first air passage and a second air passage are formed in the vicinity of the nozzle, Fig. 4(b) is a diagram showing the flow of outside air in the case where such a ventilation path is not formed in the vicinity of the nozzle.
Fig. 5 is a side view showing a part of a substrate manufacturing system including the etching apparatus according to the first embodiment of the present invention.
Fig. 6 is a diagram showing the atmospheric pressure fluctuation distribution around the nozzle when the etching bath does not include an airflow control device. Fig. 6(c) is a diagram of a state in which the substrate is transported from the substrate loading port to the substrate unloading port in the middle stage, and Fig. 6(c) is a diagram showing the state in which the rear end of the substrate is transported to the vicinity of the nozzle.
Fig. 7 is a diagram showing a calculation model of a numerical simulation related to the concentration distribution of a reaction gas. Fig. 7 (a) is a calculation model of a space below the substrate in the etching bath, and Fig. 7 (b) is a calculation model of the simulation space. It is an enlarged view of the gap between the nozzle and the substrate.
Fig. 8 is a diagram showing the suction pressure dependence of the numerical simulation result regarding the concentration distribution of the reactive gas, and Fig. 8 (a) is the concentration distribution of the reactive gas in the gap in the comparative example before the air flow control device is introduced. is a _diagram showing an example of the result of calculating It is a figure which shows the calculation result for an Example.
Fig. 9 is a diagram showing the suction pressure dependence of the numerical simulation result regarding the concentration distribution of the reaction gas, and Fig. 9 (a) is a diagram showing the calculation result of the comparative example, and Fig. 9(d) is a diagram showing the calculation results of Examples in the case of P _BB = -0.5 Pa, -1 Pa, and -1.5 Pa in order.

An embodiment of the present invention will be described with reference to Figs. FIG. 1 is a side view schematically showing an etching apparatus 100 . 2 is a cross-sectional view of the nozzle 130 . 3 : is a front view of the nozzle and airflow control apparatus seen from the board|substrate carrying-in port side. 4 : is a schematic diagram which shows the flow of the external air in an etching tank. Fig. 4 (a) is a diagram showing the flow of outside air when the first air passage 141 and the second air passage 142 are formed in the vicinity of the nozzle 130, and Fig. 4 (b) is the nozzle It is a diagram showing the flow of outside air in the case where such a ventilation path is not formed in the vicinity of (130). In Fig. 4 (a) and Fig. 4 (b), the flow of outside air is indicated by a thick arrow.

Hereinafter, the etching apparatus 100 which concerns on this embodiment is demonstrated using FIG.

As shown in FIG. 1 , the etching apparatus 100 includes an etching tank 110 , a conveying apparatus 120 , a nozzle 130 , and an airflow control apparatus 140 . The etching apparatus 100 performs a chemical treatment using atmospheric pressure plasma on one surface (eg, the back surface 510 ) of the substrate 500 . Thereby, one surface of the board|substrate 500 is roughened.

The board|substrate 500 is a glass substrate used for electronic devices, such as a flat panel display like a liquid crystal display and an organic electroluminescent display, organic electroluminescent lighting, a solar cell, and a storage battery, for example. The substrate 500 is cut out into a rectangle by a manufacturing process of the substrate 500 which will be described later. The size of the board|substrate 500 is 2880 mm in the width direction (direction orthogonal to the paper surface of FIG. 1), and 3130 mm in a conveyance direction (the left-right direction in the paper surface of FIG. 1), for example. Moreover, the thickness of the board|substrate 500 is 0.6 mm, for example. In addition, the size and thickness of the board|substrate 500 are not limited to these values. The shape of the substrate 500 is also not limited to a square shape, and may be a circular shape or a band shape.

The etching tank 110 has a board|substrate carrying-in port 111 and the board|substrate carrying-out port 112. As shown in FIG. As shown in FIG. 1, the board|substrate carry-in opening 111 and the board|substrate carrying-out port 112 are located at the same height. The board|substrate carry-in opening 111 and the board|substrate carrying out port 112 have the shape of the slit extended in the width direction of the board|substrate 500. As shown in FIG. The width (length in the direction perpendicular to the paper plane of FIG. 1 ) of the substrate inlet 111 and the substrate outlet 112 is slightly larger than the width of the substrate 500 so as to pass through the substrate 500 . do. Moreover, the height (length of the up-down direction in the paper of FIG. 1) of the board|substrate inlet 111 and the board|substrate carrying out port 112 is made into a value sufficiently larger than the thickness of the board|substrate 500. As shown in FIG. For example, the height of the board|substrate carrying-in opening 111 and the board|substrate carrying-out port 112 is 5-20 mm. The board|substrate carry-in opening 111 and the board|substrate carrying-out port 112 are always open, for example, while conveying the board|substrate 500 from the board|substrate carrying-in port 111 to the board|substrate carrying-out port 112.

The conveyance apparatus 120 conveys the board|substrate 500 toward the board|substrate carrying-out port 112 from the board|substrate carrying-in port 111. The conveying apparatus 120 is a roller conveyor which consists of several rollers 121, for example. The some rollers 121 are spaced apart suitably in the conveyance direction of the board|substrate 500, mutually parallel, and it is formed so that it may match with the height of the board|substrate carrying-in port 111 and the board|substrate carrying out port 112. From upstream in the conveyance direction of the board|substrate 500 by the some roller 121, it passes through the board|substrate carrying-in port 111 to the inside of the etching tank 110, and passes through the board|substrate carrying out port 112 to the etching tank ( A conveyance path which comes out of 110 and goes downstream in the conveyance direction of the board|substrate 500 is formed. The plurality of rollers 121 are conveying the substrate 500 while supporting the back surface 510 . For this reason, the surface 520 mentioned later does not come into contact with the roller 121, and the flaw caused by the roller 121 does not appear on the surface 520.

The plurality of rollers 121 rotate in synchronization with a drive control mechanism (not shown). When the some roller 121 rotates in the same direction (clockwise in FIG. 1) in synchronization, the board|substrate 500 is horizontally conveyed toward the board|substrate carrying-out port from the board|substrate carrying-in opening 111. In addition, the conveying apparatus 120 is not limited to a roller conveyor, For example, it can implement|achieve also by means like a belt conveyor and a robot arm.

The nozzle 130 injects a reaction gas to one surface (eg, the back surface 510 ) of the substrate 500 conveyed by the conveying device 120 . The nozzle 130 is formed inside the etching bath 110 .

Hereinafter, the detail of the structure of the nozzle 130 is demonstrated using FIGS.

The nozzle 130 includes, for example, a gas supply path 132 , a first gas suction path 133 , and a second gas suction path 134 as shown in FIG. 2 . The upper end of the nozzle 130 is flat. At the upper end of the nozzle 130 , the jet port 132a of the gas supply path 132 , the first suction port 133a of the first gas suction path 133 , and the second of the second gas suction path 134 . A suction port 134a is formed. The 1st suction port 133a is formed between the jet port 132a and the board|substrate carry-in port 111, and the 2nd suction port 134a is formed between the jet port 132a and the board|substrate export port 112. As shown in FIG. The gas supply path 132 , the first gas suction path 133 , and the second gas suction path 134 have constant cross sections in a direction orthogonal to the paper plane of FIG. 2 . The jet port 132a, the 1st suction port 133a, and the 2nd suction port 134a are slit-shaped extended in the direction orthogonal to the paper surface of FIG. The width (length in the direction orthogonal to the paper sheet in FIG. 2 ) of the jet port 132a , the first suction port 133a , and the second suction port 134a is set over the entire surface of the back surface 510 of the substrate 500 . It is slightly larger than the width|variety of the board|substrate 500 so that cotton can be implemented.

The gas supply path 132 is connected to a reactive gas generating device (not shown) formed outside the etching tank 110 . The reactive gas generating device generates a reactive gas from a source gas and supplies the reactive gas to the gas supply path 132 . Moreover, a source gas supply part (not shown) is provided in the reaction gas generating apparatus. The raw material gas supply unit supplies a raw material gas that is a raw material of the reaction gas. The source gas contains, for example, a fluorine-based source gas and a carrier gas.

The fluorine-based source gas is used to generate a fluorine-based reactive component that reacts with the surface of the substrate 500 . The fluorine-based reaction component can be produced by introducing a fluorine-based raw material gas and water molecules into plasma to react. A carrier gas is used in order to convey and dilute a fluorine-type raw material gas, and to implement plasma discharge. In the present embodiment, CF ₄ is used as the fluorine-based source gas and argon is used as the carrier gas. Hereinafter, hydrogen fluoride (HF) will be used as an example of the fluorine-based reaction component. In addition, the fluorine-based raw material gas is not limited thereto, and other perfluorocarbons such as C ₂ F ₆ and C ₃ F ₈ , CHF ₃ , CH ₂ F ₂ , and hydrofluorocarbons such as CH ₃ F , SF ₆ , NF ₃ , and other fluorine-containing compounds such as XeF ₂ may be used. In addition, the carrier gas is not limited to this, You may use other inert gas like helium, neon, and xenon.

The raw material gas contains water vapor, for example. The source gas supply unit includes a water addition unit that adds water to CF ₄ and argon in the present embodiment. The water addition unit is, for example, a humidifier that supplies liquid water as saturated water vapor. The amount of water to be added can be adjusted by controlling the temperature of the humidifier. By adjusting the amount of water added, it is possible to set the partial pressure of water vapor in the raw material gas. Thereby, the condensation temperature of the fluorine-based reaction component and water vapor generated in the plasma (that is, the temperature at which hydrofluoric acid reacts with the substrate is generated) can be changed.

In the reactive gas generating apparatus, a plasma generating unit (not shown) connected to the source gas supply unit is formed. The plasma generator includes a pair of electrodes. A pair of electrodes is arrange|positioned across the channel|path through which the source gas is supplied. One of the pair of electrodes is connected to a power source, and the other is grounded. When a high voltage is applied from the power source, an electric field is generated between the pair of electrodes, and discharge is performed. Thereby, plasma is generated between the pair of electrodes, and when the source gas is introduced into the plasma, CF ₄ and water molecules react to generate hydrogen fluoride that reacts with the surface of the substrate 500 . That is, the source gas becomes a reactive gas by being introduced into the plasma. The reaction gas is injected from the jet port 132a to the back surface 510 of the substrate 500 .

The top plate 135 opposes to the upper end of the nozzle 130, and is formed horizontally above the nozzle 130, as shown in FIGS. After the board|substrate 500 is carried in from the board|substrate carrying-in opening 111, it passes between the upper end of the nozzle 130, and the lower surface of the top plate 135, and is carried out from the board|substrate carrying out port 112. The distance between the upper end of the nozzle 130 and the lower surface of the top plate 135 is such that the substrate 500 can pass through the thickness of the substrate inlet 111 and the substrate outlet 112 (in the vertical direction in the paper of FIG. 1 ) length) is roughly equal to

While the substrate 500 passes between the upper end of the nozzle 130 and the lower surface of the top plate 135 , the reaction gas ejected from the ejection port 132a flows between the rear surface 510 of the substrate 500 and the nozzle 130 . fills the gap 131 (see FIG. 2) of While the backside 510 is exposed to the reactant gas, the backside 510 is roughened.

It is preferable that the arithmetic mean surface roughness of the back surface 510 is 0.3-1.5 nm. When the arithmetic mean surface roughness is 0.3 nm or more, peeling charging is less likely to occur when the substrate 500 is peeled from the stage. When arithmetic mean surface roughness is 1.5 nm or less, a roughening process does not take time, and there is also no possibility that the in-plane intensity|strength of the board|substrate 500 will become inadequate.

On the lower surface of the top plate 135, a plate-shaped heater (not shown) capable of freely controlling the temperature is formed. With this heater, a region located just below the top plate 135 of the surface (hereinafter referred to as a "surface") 520 on the opposite side to the back surface 510 of the substrate 500 can be heated. The width (length in the direction perpendicular to the paper plane in FIG. 2 ) of the heater is slightly larger than the width of the substrate 500 so that the entire surface 520 of the substrate 500 can be heated. When the back side 510 is defined as the first side, the surface 520 opposite to the first side is defined as the second side.

The temperature when the substrate 500 is loaded into the etching bath 110 and the temperature of the heater of the top plate 135 are appropriately set in accordance with the above-mentioned condensation temperature of hydrogen fluoride and water vapor. Accordingly, while the substrate 500 passes over the nozzle 130 , the temperature of the back surface 510 may be lower than or equal to the condensation temperature, and the temperature of the surface 520 may be higher than or equal to the condensation temperature. For this reason, hydrogen fluoride and water vapor are condensed only on the back surface 510 to form hydrofluoric acid. Thereby, even if a part of the reaction gas ejected from the ejection port 132a enters the gap between the top plate 135 and the front surface 520, etching of the substrate 500 can be selectively performed on only the back surface 510. . Therefore, the surface 520 in which an electronic member or wiring is formed can be maintained smooth, without roughening.

The first gas suction path 133 and the second gas suction path 134 are connected to the gas recovery device 600 outside the etching bath 110 (refer to FIG. 1 ). The gas recovery device 600 includes conventional suction means, for example, a rotary pump. The reaction gas supplied to the gap 131 is sucked from the first suction port 133a and the second suction port 134a, and passes through the first gas suction path 133 and the second gas suction path 134, , is recovered to the gas recovery device 600 .

Hereinafter, the airflow control apparatus 140 is demonstrated using FIG.1, FIG.3, and FIG.4.

The airflow control device 140 is provided inside the etching tank 110, as shown in FIG. As for the airflow control apparatus 140, the outside air which flowed into the inside of the etching tank 110 from the board|substrate carrying-in opening 111 and the board|substrate carrying-out port 112 is one surface (in this embodiment, the back surface 510) of the board|substrate 500. )) and the nozzle 130 to suppress the inflow into the gap 131 (refer to FIG. 2). As shown in FIG. 1 , the air flow control device 140 includes, for example, a first air passage 141 and a second air passage 142 .

The 1st ventilation path 141 has the 1st ventilation port 141c between the board|substrate carrying-in opening 111 and the nozzle 130. The first ventilation passage 141 is, as shown in FIG. inflow from Thereby, the 1st ventilation path 141 suppresses that the external air which flowed into the inside of the etching tank 110 from the board|substrate carrying-in opening 111 flows in into the clearance gap 131.

As shown in FIG. 1 , the first air passage 141 includes, for example, a first rear plate 141a and a first front plate 141b in order from the side close to the nozzle 130 . . The first back plate 141a and the first front plate 141b are provided, for example, with an interval of 50 to 100 mm. The first back plate 141a and the first front plate 141b are connected by a first side plate (not shown). The width of the first back plate 141a and the first front plate 141b is slightly longer than the width of the substrate 500 . The upper part of the space enclosed by the 1st back plate 141a, the 1st front plate 141b, and the 1st side plate is open, This open upper space serves as the 1st ventilation hole 141c.

As shown in FIG. 3, the 1st back plate 141a, the 1st front plate 141b, and the 1st side plate are the etching tank so that the front of the nozzle 130 may be blocked|blocked as seen from the board|substrate carrying-in opening 111. It is formed from the bottom surface of the 110 to a height close to the roller 121 . Thereby, the 1st ventilation path 141 functions as shielding means which shields the external air which flows in into the clearance gap 131 from the board|substrate carrying-in opening 111. The first front plate 141b is lower in height than the first rear plate 141a. Thereby, the 1st ventilation path 141 has the box-shaped shape long in the width direction in which the 1st ventilation hole 141c was opened toward the board|substrate carrying-in opening 111 side. For this reason, the external air which flowed in from the board|substrate carrying-in port 111 becomes easy to flow in into the 1st ventilation port 141c.

As shown in FIG. 1, the upper end of the 1st back plate 141a is provided so that it may enter between the adjacent two sets of rollers 121, for example. The upper end of the first back plate 141a is provided at a position as high as possible within a range that does not interfere with the substrate 500 conveyed by the conveying device 120 . Thereby, it can suppress that the external air which flowed in into the inside of the etching tank 110 from the board|substrate carrying-in opening 111 flows into the clearance gap 131. As shown in FIG. For example, the distance between the back surface 510 of the substrate 500 and the upper end of the first back plate 141a is set to be 1 to 10 mm. The position of the upper end of the first front plate 141b is set, for example, to a position 50 to 100 mm lower than the position of the upper end of the first rear plate 141a.

A first exhaust port 143 is opened on the bottom surface of the etching tank 110 in the portion where the first air passage 141 is provided. The first exhaust port 143 is formed, for example, in a slit shape in the width direction of the first air passage 141 , but the shape of the first exhaust port 143 is not limited to this.

The second ventilation passage 142 has a second ventilation hole 142c between the substrate discharge port 112 and the nozzle 130 . The second ventilation passage 142 is, as shown in Fig. 4(a), the external air introduced into the etching tank 110 from the substrate discharge port 112 toward the gap 131 through the second ventilation hole 142c. inflow from Thereby, the 2nd ventilation path 142 suppresses the outside air which flowed into the inside of the etching tank 110 from the board|substrate carrying-out port 112 from flowing into the clearance gap 131. As shown in FIG.

As shown in FIG. 1 , the second air passage 142 includes, for example, a second rear plate 142a and a second front plate 142b in order from the side close to the nozzle 130 . The second back plate 142a and the second front plate 142b are provided with an interval of, for example, 50 to 100 mm. The second back plate 142a and the second front plate 142b are connected by a second side plate (not shown). The width of the second back plate 142a and the second front plate 142b is slightly longer than the width of the substrate 500 . The upper part of the space surrounded by the second back plate 142a, the second front plate 142b, and the second side plate is open, and this open upper space serves as the second ventilation port 142c.

As shown in FIG. 3 , the second back plate 142a, the second front plate 142b and the second side plate are the etching tanks so as to block the front of the nozzle 130 as seen from the substrate discharge port 112 . It is formed from the bottom surface of the 110 to a height close to the roller 121 . Thereby, the 2nd ventilation path 142 functions as a shielding means which shields the external air which flows in into the clearance gap 131 from the board|substrate carrying-out port 112. The second front plate 142b is lower in height than the second rear plate 142a. Thereby, the 2nd ventilation path 142 has a box-like shape long in the width direction in which the 2nd ventilation hole 142c was opened toward the board|substrate carrying-out port 112 side. For this reason, the outside air which flowed in from the board|substrate carrying-out port 112 flows in easily into the 2nd ventilation port 142c.

As shown in FIG. 1, the upper end of the 2nd back plate 142a is provided so that it may enter between the adjacent two sets of rollers 121, for example. The upper end of the second back plate 142a is provided at a position as high as possible within a range that does not interfere with the substrate 500 conveyed by the conveying device 120 . Thereby, it can suppress that the external air which flowed into the inside of the etching tank 110 from the board|substrate carrying-out port 112 flows into the clearance gap 131. As shown in FIG. For example, the distance between the back surface 510 of the substrate 500 and the upper end of the second back plate 142a is set to be 1 to 10 mm. The position of the upper end of the second front plate 142b is set, for example, to a position 50 to 100 mm lower than the position of the upper end of the second rear plate 142a.

A second exhaust port 144 is opened in the bottom surface of the etching tank 110 in the portion where the second air passage 142 is provided. The second exhaust port 144 is formed, for example, in a slit shape in the width direction of the second air passage 142 , but the shape of the second exhaust port 144 is not limited to this.

The 1st airflow path 141 and the 2nd airflow path 142 are connected by the connection path 150 outside the etching tank 110, for example, as shown in FIG. The connection path 150 is connected to the first exhaust port 143 through the first exhaust port 143 formed at the bottom of the first air passage 141 and the second exhaust port 144 formed at the bottom of the second air passage 142 . It communicates with the inner space of the ventilation passage 141 and the inner space of the second ventilation passage 142 .

The first ventilation passage 141 , the connection passage 150 , and the second ventilation passage 142 form a bypass for diverting the outside air toward the gap 131 . The outside air which flowed into the inside of the etching tank 110 from the board|substrate carrying-in port 111 or the board|substrate carrying-in port 112 flows out to the board|substrate carrying-in port 112 side or the board|substrate carrying-in port 111 side through this bypass. For this reason, it is suppressed that the external air which flowed into the inside of the etching tank 110 directly flows into the clearance gap 131. As shown in FIG.

A suction device 160 is connected to the connection path 150 . The suction device 160 includes conventional suction means, for example, a rotary pump. By operating the suction device 160 , the gas inside the connection passage 150 and the gas inside the first ventilation passage 141 and the second ventilation passage 142 can be exhausted. It is not always necessary to move the suction device 160, and what is necessary is just to make it actuate as needed, such as a case where the external air which flows in into the etching tank 110 increases.

Hereinafter, the structure of the board|substrate manufacturing system 1000 containing the etching apparatus 100 is demonstrated using FIG. 5 is a side view showing a part of the substrate manufacturing system 1000 . In FIG. 5 , reference numeral 1030 corresponds to the etching bath 110 shown in FIG. 1 . In FIG. 5, the code|symbol shown in FIG. 1 is put together and described next to the code|symbol of each component which comprises the etching tank 1030.

The substrate manufacturing system 1000 includes a first cleaning tank 1010 , a first buffer tank 1020 , an etching tank 1030 , a second buffer tank 1040 , and a second cleaning tank 1050 , , and a conveying device 1070 .

The conveying apparatus 1070 conveys the board|substrate 500 toward the right side of illustration from the left side of illustration. The conveying apparatus 1070 is a roller conveyor which consists of several rollers 1071, for example. The first cleaning tank 1010 , the first buffer tank 1020 , the etching tank 1030 , and the second buffer tank 1040 from the upstream side of the first cleaning tank 1010 by the plurality of rollers 1071 . , and the second cleaning tank 1050 sequentially passing through, and a conveyance path toward the downstream side of the second cleaning tank 1050 is formed.

Although illustration is abbreviate|omitted, the apparatus by which shaping|molding and grinding|polishing of the board|substrate 500 are performed is provided in the upstream of the 1st washing tank 1010, for example. On the downstream side of the second cleaning tank 1050 , for example, an apparatus for drying and inspecting the substrate 500 is provided.

Each of the first cleaning tank 1010 , the first buffer tank 1020 , the second buffer tank 1040 , and the second cleaning tank 1050 includes a substrate inlet and a substrate outlet. The board|substrate carrying-in opening and board|substrate carrying-out port of each group are formed in the same height as the board|substrate carrying-in opening 1031 of the etching tank 1030, and the board|substrate carrying-out port 1032, and the same magnitude|size. The board|substrate carrying-out port of each set is sequentially connected to the board|substrate carrying-in port of the set adjacent to the downstream of a conveyance direction.

Hereinafter, the manufacturing process of the board|substrate 500 is demonstrated using FIG.

The substrate 500 is formed into a ribbon shape by, for example, a float method, then a cutting step of cutting into a substrate 500 of a desired size, a chamfering step of chamfering the cross section of the substrate 500, and the substrate 500 ), is transferred to the first cleaning tank 1010 through a polishing step of polishing the surface (surface 520 ). As a grinding|polishing method, the method of supplying a slurry to a board|substrate and grinding|polishing is used, for example. A slurry is a dispersion liquid in which abrasive grains are dispersed in a liquid such as water or an organic solvent. As the abrasive grain, for example, cerium oxide is used.

The polished substrate 500 is transferred to the first cleaning tank 1010 by the transfer device 1070 . In the first cleaning tank 1010 , abrasive grains are removed from the surface of the substrate 500 . In the 1st cleaning tank 1010, for example, the board|substrate 500 is shower-cleaned first, and the abrasive grain of the surface of the board|substrate 500 is wash|cleaned with water. Thereafter, the substrate 500 is subjected to slurry cleaning. Slurry cleaning is a cleaning method in which the abrasive grains that cannot be removed by shower cleaning are removed using cleaning means such as a disk brush while spraying a cleaning slurry from a nozzle to a substrate. As the cleaning slurry, for example, a dispersion in which cerium oxide, calcium carbonate, or magnesium carbonate is dispersed in a liquid such as water or an organic solvent is used.

The board|substrate 500 is carried out from the 1st washing tank 1010 by the conveyance apparatus 1070, and is carried in to the 1st buffer tank 1020. The first buffer tank 1020 is formed in order to prevent the reaction gas from leaking from the substrate carrying-in port 1031 to the first cleaning tank 1010 . Accordingly, the cleaning step performed in the first cleaning tank 1010 is not contaminated by the reaction gas.

The first buffer tank 1020 has, for example, a fan filter unit FFU1 on a ceiling and an exhaust port EXH1 on a floor surface. Fan filter unit FFU1 filters outside air, introduce|transduces it into the inside of the 1st buffer tank 1020, and makes the inside of the 1st buffer tank 1020 a positive pressure state. The outside air introduced from the fan filter unit FFU1, together with dust and gas inside the first buffer tank 1020, is outside the first buffer tank 1020 having a relatively low pressure from the exhaust port EXH1. is emitted as

The board|substrate 500 is carried out from the 1st buffer tank 1020 by the conveyance apparatus 1070, and is carried in into the etching tank 1030. In the etching tank 1030 , a reactive gas is injected from the nozzle 1080 ( 130 in FIG. 1 ) to the back surface 510 of the substrate 500 , and the back surface 510 of the substrate 500 is roughened.

The roughened board|substrate 500 is carried out from the etching tank 1030 by the conveyance apparatus 1070, and is carried in to the 2nd buffer tank 1040. The second buffer tank 1040 is formed to prevent the reaction gas from leaking from the substrate discharge port 1032 to the second cleaning tank 1050 . Accordingly, the cleaning step performed in the second cleaning tank 1050 is not contaminated by the reaction gas.

The second buffer tank 1040 has, for example, a fan filter unit FFU2 on a ceiling and an exhaust port EXH2 on a floor surface. The fan filter unit FFU2 filters outside air and introduces it into the inside of the 2nd buffer tank 1040, and makes the inside of the 2nd buffer tank 1040 into a state of a positive pressure. The outside air introduced from the fan filter unit FFU2 is discharged from the exhaust port EXH2 with the dust or gas inside the second buffer tank 1040 to the outside of the second buffer tank 1040 having a relatively low pressure. .

The board|substrate 500 is carried out from the 2nd buffer tank 1040 by the conveyance apparatus 1070, and is carried in into the 2nd washing tank 1050. The second washing tank 1050 includes a high-pressure shower 1051 . In the 2nd cleaning tank 1050, both surfaces of the board|substrate 500 are wash|cleaned, and the glass cullet, etching by-product, etc. which generate|occur|produced by roughening are removed. The washing|cleaning method is not specifically limited, For example, high pressure shower washing|cleaning, brush washing|cleaning, ultrasonic washing|cleaning, or a combination thereof, etc. are mentioned. The cleaned substrate 500 is carried out from the second cleaning tank 1050 by the transfer device 1070 , and is supplied to the drying step and the inspection step.

Hereinafter, the function of the airflow control device 140 will be described with reference to FIGS. 4 to 6 . 6 : is a figure which showed the atmospheric pressure fluctuation distribution around the nozzle 1080 in the case where the etching tank 1030 does not include the airflow control apparatus 140. As shown in FIG.

As shown to Fig.4 (a), the back surface 510 of the board|substrate 500 is roughened by the reaction gas ejected from the nozzle 130. As shown in FIG. The illuminance at each point in the back surface 510 of the substrate 500 is determined by two factors: the concentration of the reaction gas to which the point is exposed, and the cumulative time the point is exposed to the reaction gas. These factors greatly fluctuate with the disturbance of the airflow generated in the gap 131 between the substrate 500 and the nozzle 130 . The disturbance of the airflow is caused by the outside air flowing into the etching tank 110 through the substrate inlet 111 and the substrate outlet 112 .

The inflow of outside air originates in the pressure difference occurring between the first buffer tank 1020 and the second buffer tank 1040 shown in FIG. 5 . In particular, it became clear by the inventor's examination that this pressure difference generate|occur|produces remarkably when the size of the board|substrate 500 is large enough to extend to the length of a plurality of sets. Moreover, it became clear by the examination of the inventor that the inflow degree of external air fluctuates with time accompanying conveyance of the board|substrate 500.

The cause of which a pressure difference generate|occur|produces between the 1st buffer tank 1020 and the 2nd buffer tank 1040 can be considered in various ways. For example, a different device operating in the first cleaning tank 1010 and the second cleaning tank 1050 may be one cause.

In the 1st cleaning tank 1010, shower cleaning and slurry cleaning are performed until the board|substrate 500 is carried out, for example. However, even if these apparatuses operate, a large fluctuation does not occur in the distribution of the broad-spectrum atmospheric pressure inside the first washing tank 1010 . On the other hand, when the substrate 500 is loaded into the second cleaning tank 1050 , high-pressure shower cleaning by the high-pressure shower 1051 is performed. When the high-pressure shower 1051 is operated, the wide-area distribution of atmospheric pressure inside the second washing tank 1050 is greatly changed. This fluctuation fluctuates the internal pressure of the adjacent 2nd buffer tank 1040 through the board|substrate carrying-in opening of the 2nd washing tank 1050. In particular, when the size of the substrate 500 is large, a state in which the substrate 500 extends from the etching bath 1030 to the second cleaning bath 1050 occurs. In this case, since a portion of the substrate 500 is roughened in the etching bath 1030, while another portion of the substrate 500 is subjected to high-pressure shower cleaning in the second cleaning bath 1050, the pressure during roughening Fluctuations occur and the inflow of outside air occurs. Such a situation arises when the board|substrate 500 is longer than the length from the jet port of the nozzle 1080 to the board|substrate carrying-in port of the 2nd washing tank 1050 in the conveyance direction of the board|substrate 500.

Other causes of the pressure difference between the first buffer tank 1020 and the second buffer tank 1040 can be considered.

For example, as shown in FIG. 6 , when the size of the substrate 500 is large, the first buffer tank 1020 and the second buffer tank ( 1040), there is a difference in atmospheric pressure. As a result, a pressure distribution occurs inside the etching bath 1030 to generate an airflow before and after the nozzle 1080 . The large size of the substrate 500 is the length from the jet port 132a of the nozzle 1080 to the substrate loading port of the first buffer tank 1020 in the conveyance direction of the substrate 500 or longer, or the nozzle 1080. It means a substrate having a length equal to or greater than the length from the ejection port 132a of the second buffer tank 1040 to the substrate ejection port of the second buffer tank 1040 .

For example, as shown in FIG. 6( a ), when the tip of the substrate 500 reaches the vicinity of the nozzle 1080 , the first buffer tank 1020 is divided into the upper and lower spaces by the substrate 500 . do. At this time, when the fan filter unit FFU1 introduces outside air, the space above the first buffer tank 1020 becomes a positive pressure. Since the introduced external air is blocked by the substrate 500 , the space below the first buffer tank 1020 becomes relatively negative pressure. On the other hand, as for the 2nd buffer tank 1040, when fan filter unit FFU2 introduces external air, the whole space becomes a positive pressure. As for the etching tank 1030, the space between the board|substrate carrying-in opening 1031 and the nozzle 1080 is partitioned by the board|substrate 500. Since the space under the board|substrate 500 is connected with the space under the 1st buffer tank 1020 via the board|substrate carrying-in opening 1031, it becomes a negative pressure. On the other hand, since the space between the nozzle 1080 and the board|substrate discharge port 1032 is connected via the board|substrate discharge port 1032 with the whole space of the 2nd buffer tank 1040, it becomes a positive pressure. As a result, the airflow toward the board|substrate carrying-in port 1031 from the board|substrate carrying-out port 1032 inside the etching tank 1030 generate|occur|produces.

As shown in Fig. 6(c), when the rear end of the substrate 500 is conveyed to the vicinity of the nozzle 1080, since the substrate 500 does not exist in the first buffer tank 1020, the fan filter unit ( FFU1) When the outside air is introduced, the entire space of the first buffer tank 1020 becomes a positive pressure. On the other hand, the second buffer tank 1040 is divided into upper and lower spaces by the substrate 500 . At this time, when the fan filter unit FFU2 introduces outside air, the space above the second buffer tank 1040 becomes a positive pressure. Since the introduced external air is blocked by the substrate 500 , the space below the second buffer tank 1040 becomes a relatively negative pressure. In the etching tank 1030 , the space between the nozzle 1080 and the substrate discharge port 1032 is partitioned by the substrate 500 . Since the space under the board|substrate 500 is connected with the space under the 2nd buffer tank 1040 via the board|substrate carrying-out port 1032, it becomes a negative pressure. On the other hand, since the space between the nozzle 1080 and the board|substrate carrying-in opening 1031 is connected through the whole space of the 1st buffer tank 1020, and the board|substrate carrying-in opening 1031, it becomes a positive pressure. As a result, in the etching tank 1030, the airflow toward the board|substrate carrying-in port 1032 from the board|substrate carrying-in port 1031 arises.

In addition, as shown to FIG.6(b), in the stage in the middle of the board|substrate 500 being conveyed from the board|substrate carrying-in port 1031 to the board|substrate carrying-out port 1032, the 1st buffer tank 1020 and the 2nd buffer tank Depending on whether the substrate 500 divides the space of 1040 , various distributions of atmospheric pressure are realized.

As described above, when a substrate of a particularly large size is used, a different pressure distribution occurs before and after the nozzle 1080 in the etching bath 1030 according to the relative positions of the substrate 500 and the etching bath 1030 . Since the some board|substrate 500 is conveyed sequentially and continuously through the board|substrate inlet 1031 and the board|substrate carrying out port 1032, the pressure difference in the front and back of the nozzle 1080 fluctuates with time.

As shown in FIG.4(b), when the airflow control apparatus 140 is not provided in the etching tank 110, the external air which flowed in from the board|substrate inlet 111 and the board|substrate export port 112 is almost Without being blocked, the gap 131 between the back surface 510 of the substrate 500 and the nozzle 130 is reached. For this reason, the concentration distribution of the reaction gas filled in the gap 131 is directly influenced by the disturbance of the airflow. As a result, non-uniformity arises in the roughness of the back surface 510 of the substrate 500 .

On the other hand, when the airflow control device 140 is formed in the etching tank 110 as shown in FIG. It flows into the bypass formed by the 1st ventilation path 141, the connection path 150, and the 2nd ventilation path 142, and it is suppressed from reaching|attaining the clearance gap 131 directly. In addition, since the pressure inside the first vent passage 141 and the second vent passage 142 always tends to be equalized by the connection passage 150, the first buffer tank 1020 and the second buffer tank ( 1040), the effect of the time fluctuation of the pressure difference between them is also alleviated. Thereby, the concentration distribution of the reactive gas filled in the gap 131 is less affected by the disturbance of the airflow, and the uniformity of the illuminance of the back surface 510 of the substrate 500 is improved.

Moreover, when moving the suction device 160, the internal pressure of the connection path 150 is always maintained by negative pressure (for example, -1 to -2 Pa). Thereby, even if a pressure difference (for example, about ± 3 Pa at most) is generated between the first buffer tank 1020 and the second buffer tank 1040 , the flow of outside air mostly flows through the substrate inlet 111 and the second buffer tank 1040 . It occurs between the first vent 141c and between the substrate discharge port 112 and the second vent 142c. Accordingly, in the gap 131 between the rear surface 510 of the substrate 500 and the nozzle 130 , the influence of the inflow of external air is reduced. Moreover, since the 1st vent 141c and the 2nd vent 142c open toward the side opposite to the nozzle 130, by operating the suction device 160, the airflow of the clearance gap 131 is large. There is no case of blurring.

As described above, in the etching apparatus of this embodiment, as shown in FIG. The board|substrate 500 is conveyed toward the board|substrate discharge port 112 from the board|substrate 500, and the reactive gas is injected to the back surface 510 of the board|substrate 500 from the nozzle 130. The reaction gas is injected into a gap ( 131) while suppressing the inflow.

For example, in order to suppress that the external air which flowed into the inside of the etching tank 110 from the board|substrate carrying-in opening 111 flows into the clearance gap 131, as shown in FIG.4(a), the board|substrate carrying-in opening 111 ) to the first vent passage 141 from the first vent 141c formed between the substrate loading port 111 and the nozzle 130 for external air introduced into the etching tank 110 toward the gap 131 from the bring in

In order to suppress the outside air flowing into the interior of the etching tank 110 from the substrate discharge port 112 from flowing into the clearance gap 131, as shown in Fig. 4(a), a clearance gap ( External air flowing into the etching tank 110 toward the 131 is introduced into the second ventilation passage 142 from the second ventilation hole 142c formed between the substrate discharge port 112 and the nozzle 130 .

Therefore, the non-uniformity of the roughness in the back surface 510 of the board|substrate 500 which generate|occur|produced with inflow of external air into the etching tank 110 inside can be suppressed.

As mentioned above, although the preferred embodiment which concerns on this invention was demonstrated referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. The various shapes, combinations, etc. of each structural member shown in the above-mentioned example are an example, In the range which does not deviate from the main point of this invention, various changes are possible based on a design request etc.

For example, in the above embodiment, although the first ventilation passage 141 and the second ventilation passage 142 are connected to the common suction device 160, the first ventilation passage 141 and the second ventilation passage ( 142) may be connected to different suction devices, respectively. In this case, the outside air which flowed into the inside of the etching tank 110 from the board|substrate carrying-in port 111, and the outside air which flowed into the inside of the etching tank 110 from the board|substrate export port 112 are exhausted independently, respectively. Even in this case, it is possible to suppress the outside air flowing into the etching bath 110 from flowing into the gap 131 between the back surface 510 of the substrate 500 and the nozzle 130 . As a result, the non-uniformity of the illuminance in the back surface 510 of the board|substrate 500 can be suppressed.

In addition, in the method for manufacturing a substrate according to an embodiment of the present invention, after being molded into a ribbon shape by a float method or a fusion method, a cutting step of cutting into a substrate 500 of a desired size, the cross section of the substrate 500 For the substrate 500 that has undergone a chamfering process for chamfering, and a polishing process for grinding the surface (surface 520) of the substrate 500, a process of etching the back surface 510 by the etching method described in the above embodiment is included. do. As a result, the board|substrate 500 in which the nonuniformity of the illumination intensity in the back surface 510 was suppressed can be obtained.

Further, in the substrate of one embodiment of the present invention, the average value of the arithmetic mean surface roughness of the entire back surface 510 is 0.3 to 1.5 nm, and the average value of the arithmetic mean surface roughness of the periphery of the back surface 510 and the back surface 510 ), the arithmetic mean surface roughness of the central portion is different, and the standard deviation of the arithmetic mean surface roughness of the entire back surface 510 is 0.06 or less.

When the board|substrate 500 is divided|segmented into 9 areas|regions by 3 length and width each, let the area|region in the center be a center part, and let the area|region around the center part other than that be a periphery part. The peripheral edge portion is an area in a range of 500 mm from the side. The average value of the arithmetic mean surface roughness of a peripheral part is an average value of the arithmetic mean surface roughness of eight areas except a center part. Although the arithmetic mean surface roughness of the central portion and the peripheral portion does not become the same, by setting the deviation of the arithmetic mean surface roughness of the entire back surface 510 to 0.06 or less as a standard deviation, the amount of peeling charge can be effectively suppressed, and peeling can be effectively suppressed. Damage to the substrate caused by charging can be suppressed. In addition, the arithmetic mean surface roughness of a central part may be higher than the arithmetic mean surface roughness of a peripheral part.

Further, the larger the size of the substrate, the higher the possibility that the substrate will be damaged by peeling charging when placed on the vacuum adsorption stage for a certain period of time. Therefore, in the substrate of one embodiment of the present invention, it is preferable that the size of the substrate is 1500 mm x 1500 mm or more, since suppression of the amount of peeling charge becomes more effective. Furthermore, it is more effective that the size of a board|substrate is 2000 mm x 2000 mm or more.

In addition, if the value obtained by subtracting the average value of the arithmetic mean surface roughness of the entire back surface 510 from the arithmetic mean surface roughness of the central portion of the back surface 510 is -0.13 or more and 0.13 or less, the amount of peeling charge can be more effectively suppressed. .

Example

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 7 to 9 . 7 is a diagram showing a calculation model and an example of a calculation result of a numerical simulation related to a concentration distribution of a reaction gas. 8 and 9 are diagrams showing the pressure absorption dependence of the numerical simulation results regarding the concentration distribution of the reaction gas.

7 shows a calculation model of a numerical simulation regarding the concentration distribution of a reaction gas. Here, the simulation of the flow of the reaction gas in the clearance gap between a nozzle and a board|substrate was performed. Fluid calculation was performed by the direct method using ANSYS (trademark) (product name: ANSYS FLUENT, version: 14.5, manufactured by ANSYS, Inc.) as calculation software.

Fig. 7(a) shows a calculation model of the space 700 below the substrate 750 in the etching bath. In the calculation of the embodiment, with respect to the nozzle 730 , a first airflow path (airflow control device) 741 is formed on the upstream side (left side in the drawing) of the substrate 750 in the conveying direction, and the second airflow path (airflow control device) 741 is formed on the downstream side (right side) Two ventilation passages (airflow control device) 742 are formed. In the calculation of the comparative example, the first air passage 741 and the second air passage 742 are not formed.

The following are set as boundary conditions regarding pressure. The pressure in the board|substrate carrying-in opening 711 is equivalent to atmospheric|air pressure P _LD of a 1st buffer tank. The pressure at the substrate discharge port 712 is equivalent to the atmospheric pressure P _NT of the second buffer tank. The pressure inside the first air passage 741 and the second air passage 742 is equal to the atmospheric pressure of the connection passage (suction pressure of the suction device) P _BB .

Fig. 7(b) is an enlarged gap between the nozzle 730 and the substrate 750 in the simulation space. In this simulation, the size d _A of the jet port 732a is 2 mm, the size d _B of the first suction port 733a is 7 to 10 mm, and the size d _C of the second suction port 734a is 2 mm. ) was set to 7 to 10 mm. Moreover, the space|interval d _D of the clearance gap 731 was 2-5 mm. Further, the distance l ₁ from the center of the air outlet 732a to the center of the first suction port 733a is 70 mm, and the distance l from the center of the air outlet 732a to the center of the second suction port 734a is l ₂ ) was set to 70 mm. For the mesh size, an appropriate value was selected for each location in the simulation space within the range of 0.1 to 4 mm.

As for the parameters d _B , d _C , and d _D , several values were selected within the above range, and calculations were performed for each value. However, the conclusion that the uniformity of the illuminance can be improved using the airflow control device and the conclusion that the uniformity of the illuminance can be easily increased by operating the suction device is not changed. 8 and 9, the calculation results when d _B = 7 mm, d _C = 10 mm, and d _D = 4 mm are shown.

The reaction gas passes through the gas supply passage 732 and is ejected from the ejection port 732a to the gap 731 . The reaction gas is sucked from the first suction port 733a to the first gas suction path 733 . In addition, the reaction gas is sucked from the second suction port 734a to the second gas suction path 734 . In order to express this, the boundary condition that the inflow rate of the reaction gas in the gas supply path 732 takes a constant value is set. In addition, a boundary condition was set in which the internal pressure of each of the first gas suction path 733 and the second gas suction path 734 takes a constant negative value. In this simulation, the reaction gas inflow velocity of the gas supply path 732 was set to 0.07 m/s. Moreover, the pressure inside the 1st gas suction path 733 was -1.9 Pa, and the pressure inside the 2nd gas suction path 734 was -1.9 Pa.

In the clearance gap 731, the board|substrate 750 is conveyed from left to right (in the direction of the arrow shown in FIG.7(b)). In order to express this, a moving boundary condition is placed that the back surface 751 of the substrate 750 has a constant speed in the right direction. In this simulation, the moving speed of the back surface 751 of the substrate 750 is set to 167 mm/s.

The concentration distribution of the reaction gas in the gap 731 was calculated by changing the conditions. The conditions to change are atmospheric pressure P _LD of a 1st buffer tank, atmospheric pressure P _NT of a 2nd buffer tank, and atmospheric pressure (suction pressure of a suction device) P _BB of a connection path.

For the given P _BB , several combinations of P _LD and P _NT were changed, and the concentration distribution of the reactive gas in the gap 731 , in particular, how the maximum value changes was investigated. The difference between P _LD and P _NT is considered to correspond to the magnitude of the flow of external air flowing into the etching bath. Therefore, it is possible to grasp how sensitively the concentration distribution of the reaction gas in the gap 731 reacts to the inflow of external air from this simulation.

The illuminance on the back surface 751 of the substrate 750 is determined by two factors: the concentration of the reaction gas to which the back surface 751 of the substrate 750 is exposed, and the cumulative time for exposure to the reaction gas. The accumulation time is mainly determined by the speed at which the substrate 750 is conveyed. In this simulation, as described above, the speed at which the substrate 750 is conveyed is set to a constant value of 167 mm/s. Therefore, the illuminance on the back surface 751 of the substrate 750 is mainly determined by the maximum value of the concentration distribution (the greater the maximum value, the greater the illuminance). Therefore, it is possible to grasp how strongly the illuminance on the back surface 751 of the substrate 750 is affected by the inflow of external air from this simulation.

8( a ) shows an example of the result of calculating the concentration distribution of the reaction gas in the gap 731 in the comparative example before the airflow control device was introduced. The horizontal axis (Position (m)) is the position in the nozzle 730, and the vertical axis ([HF] (ppm)) is the concentration of the reaction gas. The position in the nozzle 730 is expressed by coordinates with the jet port 732a as the origin, negative on the first suction port 733a side, and positive on the second suction port 734a side. Reflecting that the substrate 750 is conveyed from the left to the right in the figure, the reaction gas is also attracted to the substrate 750 and has a concentration distribution on the right side (Position > 0) of the jet port 732a.

Corresponding to each combination of P _LD and P _NT described above, a plurality of concentration distribution curves are obtained. The meaning of the legend is as follows.

As interpreted from FIG. 8(a) , when P _LD < P _NT , the peak tends to be high, and when P _LD > P _NT , the peak tends to be low. On the other hand, the position of the peak is almost unchanged and exists in the vicinity of the second suction port 734a.

In the embodiment after the air flow control device was introduced, when the combination of P _LD and P _NT is changed under the given P _BB , pay attention to the size of the range in which the height of the peak fluctuates (hereinafter referred to as “peak fluctuation range”) do. The magnitude of the peak fluctuation range corresponds to the magnitude of the influence of the inflow of external air on the roughening of the substrate 750 . The inventor studied the relationship between P _BB and the peak fluctuation range based on this simulation.

Fig. 8(b), Fig. 8(c), and Fig. 8(d) show an embodiment when P _BB = -0.5 Pa, -1 Pa, -1.5 Pa in order (forming the airflow control device of the present invention) Calculation results for one etching apparatus) are shown. The horizontal axis, the vertical axis, and the legend are the same as in FIG. 8(a). In Fig. 8(a), Fig. 8(b), Fig. 8(c), and Fig. 8(d) , the magnitude of the peak fluctuation range is 272 ppm, 114 ppm, 75 ppm, and 23 ppm, respectively.

As the absolute value of P _BB is increased sequentially from zero, the peak fluctuation range gradually decreases. This suggests that the influence of the inflow of the external air with respect to the roughening of a board|substrate can be reduced by sucking the external air which flowed into the etching tank with the suction device.

Fig. 9 shows peak values of a plurality of concentration distribution curves obtained by changing combinations of P _LD and P _NT under the given P _BB . The horizontal axis (ΔP (Pa)) represents the difference between P _LD and P _NT (ΔP = P _LD -P _NT ). The vertical axis is the peak value ([HF] _max (ppm))) of each concentration distribution. When ΔP is equal for different combinations of P _LD and P _NT , such as (P _LD , P _NT ) = (-1 Pa, 0 Pa) and (P _LD , P _NT ) = (0 Pa, +1 Pa) there is For this reason, in FIG. 9 , a plurality of (three points in FIG. 9 ) data points are plotted for the same ΔP value. Fig. 9(a) shows the calculation result of the comparative example. Fig. 9(b), Fig. 9(c), and Fig. 9(d) show the calculation results of Examples in the case where P _BB = -0.5 Pa, -1 Pa, and -1.5 Pa in order. The numbers assigned to the data points in the drawing correspond to the following, respectively.

As shown in FIG. 9 , when the absolute value of P _BB is increased sequentially from zero, the peak values gradually become substantially equal. Therefore, if the suction device of the airflow control device according to the present invention is used, the concentration distribution of the reactive gas in the gap can be a normal distribution irrespective of the time fluctuations in the pressures of the first buffer tank and the second buffer tank. This suggests that it becomes easy to improve the uniformity of illumination intensity by operating a suction device.

Table 1 and Table 2 show the result of measuring the in-plane distribution of the roughness (arithmetic mean surface roughness Ra (JIS B 0601-2013)) of the roughened board|substrate with the atomic force microscope. Table 1 shows the measurement results in the case where the airflow control device of the present invention is not introduced into the etching bath. Table 2 shows the measurement results when the airflow control device of the present invention is introduced into the etching bath. The production conditions are as follows. Etching bath size: 850 mm, substrate: alkali-free glass (product name: AN100, manufactured by Asahi Glass Co., Ltd.), substrate size: width 2880 mm × length 3130 mm in transport direction, substrate transport speed: 10 m/min, composition of reaction gas: CF ₄ , N ₂ , water vapor, and the reaction gas discharge flow rate from the nozzle part: 0.07 m/sec.

A measurement point is a total of 9 points|pieces of 3 rows and 3 columns in the conveyance direction of a board|substrate in the width direction of a board|substrate. The rows of measurement points are arranged in order at positions 500 mm from the leftmost end, the center portion, and 500 mm from the rightmost end along the width direction of the substrate (hereinafter, “first row”, “second row”, “ third row”). Rows of measurement points are arranged in order at positions 500 mm from the front end, the center portion, and 500 mm from the rear end along the conveyance direction of the substrate (hereinafter, “first row”, “second row”, “ 3rd row”).

The measurement was performed by the following method. First, the sample of width 5mm x length 5mm including each measurement point was cut out from the roughened board|substrate. Next, the roughened surface of each sample was observed using the atomic force microscope (product name: SPI-3800N, the Seiko Instruments make). As the cantilever, SI-DF40P2 was used. Observation was performed at a scan rate of 1 Hz using the dynamic force mode for a scan area of 5 µm × 5 µm (the number of data in the area: 256 × 256). Based on this observation, the arithmetic mean surface roughness Ra at each measurement point was computed. As the calculation software, the software attached to the atomic force microscope (soft name: SPA-400) was used.

In Table 1 and Table 2, the arithmetic mean surface roughness Ra (unit: nm) at each measurement point is shown in matrix form. Each column in Tables 1 and 2 corresponds to the first column, the second column, and the third column of the measurement points in order from the left. Each row of Tables 1 and 2 corresponds to the first row, the second row, and the third row of the measurement points in order from the top.

As shown in Table 1, when the airflow control device was not introduced, the illuminance had low uniformity, and the illuminance at the center of the substrate was smaller than the average value. Specifically, the average value of Ra was 0.43 and the standard deviation was 0.073, and the difference between Ra and the average value in the central portion of the substrate was -0.144. On the other hand, as shown in Table 2, when the airflow control device was introduced, both the uniformity of the illuminance and the illuminance at the center of the substrate could be improved. Specifically, the average value of Ra was 0.45 and the standard deviation was 0.057, and the difference between Ra and the average value at the center of the substrate was +0.11.

The measurement of the peeling charge amount was performed by the following method. First, a sample having a width of 410 mm and a length of 510 mm is cut out from a roughened substrate. Next, the sample is placed on the vacuum adsorption stage for a certain period of time. The sample is peeled from the vacuum adsorption stage using a lift pin. The amount of charge of the sample immediately after peeling was measured with a surface electrometer (product name: MODEL 341B, manufactured by Trek Japan).

The measurement was performed about the Example, the comparative example 1, and the comparative example 2. An Example is the glass substrate which roughened using the etching apparatus provided with the airflow control apparatus of this invention. Comparative example 1 is the glass substrate which roughened using the etching apparatus which is not equipped with the airflow control apparatus of this invention. Comparative Example 2 is a commercially available glass substrate. About Example and Comparative Example 1, production conditions are as follows. Etching bath size: 850 mm, substrate: alkali-free glass (product name: AN100, manufactured by Asahi Glass Co., Ltd.), substrate size: width 2880 mm × length 3130 mm in transport direction, substrate transport speed: 10 m/min, composition of reaction gas: CF ₄ , N ₂ , water vapor, and the reaction gas discharge flow rate from the nozzle part: 0.07 m/sec.

The measured peeling charge amount was a relative comparative value, and was Example: Comparative Example 1: Comparative Example 2 = 0.84: 1: 0.91. The amount of charge in Examples was reduced compared to Comparative Examples 1 and 2. As shown in Table 1 and Table 2, this is because the uniformity of roughening improved by roughening with the etching apparatus which concerns on this invention.

As shown in the above examples, the concentration distribution of the reaction gas in the gap between the nozzle and the one surface to be roughened by the present invention is almost normal regardless of the pressure fluctuations in the first buffer tank and the second buffer tank. distribution can be done. Thereby, the nonuniformity of the roughness in the back surface of a board|substrate can be suppressed. As a result, the amount of peeling electrification of the substrate can be reduced.

This application is based on Japanese Patent Application No. 2014-084732 for which it applied on April 16, 2014, The content is taken in here as a reference.

100: etching device
110: etching tank
111: substrate inlet
112: board exit port
120: conveying device
130: nozzle
140: airflow control device
141: first air passage
141c: first vent
142: second air passage
142c: second vent
150: access path
160: suction device
500: substrate

Claims (12)

an etching tank having a substrate inlet and a substrate outlet;
a conveying apparatus which conveys a board|substrate from the said board|substrate carrying-in port toward the said board|substrate carrying out port;
a nozzle formed in the etching tank and spraying a reactive gas on one surface of the substrate conveyed by the conveying device;
It is formed inside the etching bath, and includes an airflow control device that suppresses the outside air flowing into the etching bath from the substrate loading port and the substrate exit port from flowing into the gap between the one surface of the substrate and the nozzle, and ,
The conveying device is a roller conveyor comprising a plurality of rollers,
The airflow control device includes: a first ventilation passage for introducing external air flowing into the etching tank from the substrate loading port toward the gap through a first ventilation hole formed between the substrate loading port and the nozzle;
and a second ventilation passage for introducing external air introduced into the etching tank from the substrate discharge port toward the gap through a second ventilation port formed between the substrate discharge port and the nozzle;
The first ventilation passage includes a first back plate formed so as to extend from the bottom surface of the etching tank toward the conveying device so as to block the front of the nozzle when viewed from the substrate loading port, and from the nozzle from the first back plate. a first front plate remote and lower than the first back plate;
The second ventilation passage includes a second back plate formed to extend from the bottom surface of the etching tank toward the conveying device so as to block the front of the nozzle when viewed from the substrate discharge port, and from the nozzle from the second back plate. a second front plate remote and lower than the second back plate;
The upper ends of the first and second rear plates are provided so as to be inserted between a pair of adjacent rollers, the etching apparatus. The method of claim 1,
and a connection path connecting the first vent passage and the second vent passage. 3. The method of claim 2,
and a suction device for sucking the outside air flowing into the connection path from the first vent passage and the second vent passage. A substrate is conveyed by a roller conveyor comprising a plurality of rollers from the substrate loading port of the etching bath having a substrate loading port and a substrate loading port toward the substrate loading port, and from the substrate loading port and the substrate loading port of the etching bath While suppressing the outside air introduced into the interior from flowing into the gap between the one surface of the substrate and the nozzle, injecting a reactive gas from the nozzle to one surface of the substrate,
Outside air flowing into the etching tank from the substrate loading port toward the gap is introduced into the first ventilation passage through the first ventilation port formed between the substrate loading port and the nozzle, thereby forming the inside of the etching bath from the substrate loading port. It suppresses the external air introduced into the gap from flowing into the gap, and the external air introduced into the etching tank from the substrate outlet port toward the gap is discharged from the second vent hole formed between the substrate outlet port and the nozzle. By flowing into the vent, the outside air introduced into the etching tank from the substrate outlet is suppressed from flowing into the gap,
The first ventilation passage includes a first back plate formed to extend from the bottom surface of the etching bath toward the roller conveyor so as to block the front of the nozzle when viewed from the substrate loading port, and from the nozzle rather than the first back plate. a first front plate remote and lower than the first back plate;
The second ventilation passage includes a second back plate formed to extend from the bottom surface of the etching bath toward the roller conveyor so as to block the front of the nozzle when viewed from the substrate discharge port, and from the nozzle from the second back plate. a second front plate remote and lower than the second back plate;
The etching method, characterized in that the upper ends of the first and second rear plates are installed so as to be inserted between a pair of adjacent rollers. 5. The method of claim 4,
An etching method for sucking the outside air flowing into a connection path connecting the first vent path and the second vent path. The manufacturing method of a board|substrate which has a process of etching a board|substrate by the etching method of Claim 4 or 5. delete delete delete delete delete delete

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