JP3987761B2 - Transported substrate processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transfer substrate processing method used for manufacturing a glass substrate for a liquid crystal display device, and more specifically, etching for supplying an etching solution to the surface of a substrate while transferring the substrate in a horizontal direction in a horizontal posture. The present invention relates to a carrier type substrate processing method .
[0002]
[Prior art]
A glass substrate used in a liquid crystal display device is manufactured by repeatedly performing various chemical treatments such as etching of a material formed on the surface of a glass substrate as a material and peeling of a masking material. The processing apparatus is roughly classified into a dry type and a wet type, and the wet type is further classified into a batch type and a single wafer type. Further, the single wafer type is subdivided into a rotary type and a conveyance type such as roller conveyance.
[0003]
Among these substrate processing apparatuses, the transport type has a basic configuration that supplies the processing liquid to the surface of the substrate while transporting the substrate in the horizontal direction. Used for processing.
[0004]
In the transfer type substrate processing apparatus used for the etching process, an etching solution is sprayed from a large number of spray nozzles arranged in a matrix above the substrate transfer line, and the substrate is passed through the etching solution, thereby allowing the substrate to pass through the substrate. An etching solution is supplied to the entire surface. By this shower process, the surface of the substrate is selectively etched except for the portion where the masking material is applied. When the etching is finished, a cleaning process using a shower is subsequently performed.
[0005]
[Problems to be solved by the invention]
By the way, in the glass substrate for liquid crystal display devices, high definition of a circuit is progressing with the enlargement of the substrate. As a wiring material used for the substrate, Cr has been widely used in the past, but with recent high definition, conversion to Al or Al / Mo having a smaller specific resistance value is being attempted. For this reason, the etching solution for Al has begun to be used also in the transporting substrate processing apparatus for etching, but it has been found that the following problems occur with the use of this etching solution.
[0006]
As the etching solution for Al, one having phosphoric acid as a main component is used. In the Al etching process using this etching solution, many fine bubbles are often generated. When this bubble stays on the substrate, uneven etching occurs, but the shower process is effective in destroying this bubble.In addition, when a large number of spray nozzles are periodically swung to both sides, The effect of moving and discharging bubbles is also added, and the adverse effects of bubbles are effectively removed.
[0007]
In addition, the etching rate of the etching solution for Al is higher than the etching rate of Cr by the etching for Cr, and thereby high etching efficiency is obtained. When combined with shower treatment, particularly high etching efficiency is obtained. On the other hand, the side edge surface of the Al layer after etching becomes an inappropriate shape for the lamination of the next layer.
[0008]
FIG. 3 is a cross-sectional view showing the shape of the Al layer after Al etching. An Al layer 2 and an Mo layer 3 are formed on a glass substrate 1 as a material, and a masking material 4 is coated thereon. By etching, the Al layer 2 and the Mo layer 3 are removed at a portion not covered with the masking material 4, but the remaining side edge surfaces of the Al layer 2 and the Mo layer 3 are steep and sharp as shown by the solid line. It becomes a gentle slope. Then, the next layer is not stably placed on the Al layer 2 and the Mo layer 3. In order to stably place the next layer, it is necessary to make the inclination of the side edge surface gentle as shown by the alternate long and short dash line. The same tendency occurs when there is no Mo layer 3.
[0009]
In addition, the etching solution for Al has a higher viscosity than the etching for Cr, and the wettability with respect to the surface of the glass substrate 4 is poor. Further, as described above, the etching rate is high. For this reason, the portion where the fine droplets of the etching solution collide at the start of the shower process becomes uneven in the process and remains after the etching without disappearing even in the subsequent shower process.
[0010]
The object of the present invention is applied to a high-speed etching process in which the slope of the side edge surface does not become gentle in the shower process such as Al etching, and the side edge surface is formed on a gently inclined surface suitable for the lamination of the next layer. In addition, another object of the present invention is to provide a transportable substrate processing method capable of eliminating processing unevenness caused by an initial shower.
[0011]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the transfer type substrate processing method of the present invention provides an etching line for supplying an etching solution to the surface of the substrate while transferring the substrate in a substantially horizontal position in a substantially horizontal position, with an etching of a predetermined depth. An etching solution supplying means is provided for both the just-etched portion and the over-etched portion, and includes a just-etched portion for performing the processing and an over-etched portion for imparting an inclination to the side edge surface of the etching layer etched in the just-etched portion. As shown in the figure, slit nozzles that are arranged at right angles to one or more stages with respect to the substrate transport direction and each supply a processing liquid in the form of a film over the entire width direction of the substrate surface are provided . Both etching processes are performed by a chemical knife process using a slit nozzle .
[0012]
In the etching process that generates bubbles, such as Al etching, the shower process is considered to be indispensable for just etching because of the purpose of removing the bubbles. For this reason, as described above, the slope of the side edge surface of the remaining etching layer does not become gentle. Under such circumstances, the present inventors examined a method of gradual inclination of the side edge surface of the remaining etching layer. As a result, the following was found.
[0013]
First, etching is performed on a substrate to be transported by chemical knife processing in which a processing liquid is supplied in the form of a film across the width direction of the substrate surface by slit nozzles arranged at right angles to the substrate transport direction in one or more steps. It has been found that when the paddle state in which the liquid is thinly mounted is realized after just etching, the inclination of the side edge surface of the etching layer becomes gentle.
[0014]
Secondly, it has been found that this chemical knife treatment has an unexpectedly large striking force and can secure a high liquid replacement function by adjusting the flow rate.
[0015]
Thirdly, in the paddle processing after just etching, the reaction area is small, the amount of bubbles generated is small, and the generated bubbles do not become a major obstacle to imparting the slope of the side edge surface, and there is a problem due to bubbles. It turned out not to be obvious.
[0016]
The transportable substrate processing method of the present invention has been completed based on such knowledge, and an etching line includes a just-etched portion that performs an etching process at a predetermined depth, and a side of an etching layer that is etched in the just-etched portion. The overetched portion that imparts an inclination to the edge surface, and both the just-etched portion and the overetched portion are arranged on the substrate surface by slit nozzles arranged substantially perpendicularly to one or more steps with respect to the substrate transport direction. By supplying the processing liquid in the form of a film over the entire width direction and performing chemical knife processing, in the just-etched part, by setting conditions that promote liquid replacement, adverse effects due to bubbles are eliminated and efficient uniform etching is performed. . In the overetch portion following the just etch, the remaining etching layer gradually proceeds from the surface due to the condition setting for restricting the liquid replacement, the side edge surface is gradually inclined, and the problem due to bubbles does not become obvious.
[0017]
The condition for promoting liquid replacement in the just-etched portion is basically realized by increasing the flow rate of the etching liquid. The condition for limiting the liquid replacement in the overetched portion is basically realized by reducing the flow rate of the etching liquid. However, when the present inventors conducted a detailed study on these conditions, there are places where both conditions overlap, and the flow rate of the slit nozzle in the just-etched portion and the flow rate of the slit nozzle in the over-etched portion are determined. Even if it is the same, it was found that the purpose was achieved. It goes without saying that the flow rate adjustment and the device structure are simplified by making the respective flow rates the same.
[0018]
In the transport type substrate processing method of the present invention, a chemical knife process using a slit nozzle is performed at the entrance of the etching line, and the substrate enters the etching solution falling film. For this reason, the surface of a board | substrate gets wet uniformly. Once wetted evenly, processing unevenness does not occur unless drying occurs thereafter. Therefore, processing unevenness due to the initial shower is also eliminated.
[0019]
The transfer type substrate processing method of the present invention is particularly suitable for Al etching, but as with Al etching, it can be applied to etching processing in which the slope of the side edge surface does not become gentle in shower processing.
[0020]
A transport type substrate processing apparatus in which only slit nozzles are arranged in the entire etching line is described in FIGS. 10 and 11 of Japanese Patent Application Laid-Open No. 2000-114221. However, the transfer-type substrate processing apparatus described here is an inclined transfer type that transfers a substrate in a horizontal direction in a posture in which the substrate is inclined to the side. In addition, the plurality of slit nozzles are arranged in parallel to the substrate transport direction on the higher side of the substrate. That is, the transport type substrate processing apparatus described in FIGS. 10 and 11 of Japanese Patent Laid-Open No. 2000-114221 has slits parallel to a plurality of side edges arranged along one side edge of the substrate inclined sideways. From the nozzle, the etching solution is caused to flow laterally along the inclination of the substrate. According to this, liquid replacement is promoted, and bubbles are effectively removed. However, overetching that makes the inclination of the side edge surface gentle is not feasible. This is because this type of inclined transfer type substrate processing apparatus always requires a large flow rate in order to prevent partial drying of the surface due to running out of liquid, and gentle etching that makes the inclination of the side edge surface gentle. This is because processing is impossible. Therefore, it is fundamentally different not only in the structure but also in the function from the transport type substrate processing apparatus of the present invention.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a transfer substrate processing apparatus used in an embodiment of the transfer substrate processing method of the present invention, and FIG. 2 is a side view of the main part of the substrate processing apparatus.
[0022]
The transport type substrate processing apparatus of this embodiment is an etching apparatus that performs Al etching processing on a glass substrate 100 for liquid crystal display devices (hereinafter simply referred to as a substrate 100). As shown in FIG. 1, the substrate processing apparatus includes a straight first line A, a second line B connected at right angles to the first line A, and a first line A connected at right angles to the second line B. A U-turn layout in combination with the third line C in parallel with each other is adopted.
[0023]
The first line A is configured by linearly connecting the receiving unit 10, the liquid repellent unit 20, and the etching unit 30. The second line B is a water washing unit 40 equipped with a shower unit 41 that sprays washing water on the surface of the substrate 100. The third line C is configured by linearly connecting the water washing part 50, the final rinse part 60, the drying part 70 and the take-out part 80 using an air knife. The drying unit 70 is equipped with two inclined slit nozzles 71 and 71 for an air knife.
[0024]
The first line A and the second line B include a large number of transport rollers arranged in parallel in the transport direction at a predetermined interval in order to transport the substrate 100 in the line longitudinal direction. Each transport roller is a horizontal roll perpendicular to the transport direction. A turning mechanism 42 that changes the traveling direction of the substrate 100 by 90 degrees is provided in the second line B, that is, the entrance of the water washing section 40.
[0025]
The substrate 100 subjected to the Al etching process is carried into the receiving unit 10 by the transfer device 90. The substrate 100 enters the etching portion 30 from the liquid repellent portion 20 by the roller conveyance, and is subjected to an etching process while passing through this portion. The substrate 100 that has passed through the etching unit 30 subsequently enters the washing unit 40 by roller conveyance, changes the traveling direction by 90 degrees, moves the washing unit 40, and further changes the traveling direction by 90 degrees to another washing unit. 50 is moved, and a water washing process is received during the movement.
[0026]
The substrate 100 exiting the water washing section 50 is conveyed to the drying section 70 through the final rinse section 60. The substrate 100 which has been dried by the drying unit 70 is transported to the take-out unit 80 and further transported out of the apparatus by the transport device 90.
[0027]
In the transfer type substrate processing apparatus of the present embodiment, the etching unit 30 has a particularly great feature point. As shown in FIG. 2, the etching unit 30 includes a transport roller 31 that transports the substrate 100 in the horizontal direction. The transport roller 31 supports the substrate 100 by points with large diameter portions provided at a plurality of positions in the axial direction of the drive shaft, and instructs the substrate 100 and positions the substrate 100 in the width direction with flanges provided on both sides.
[0028]
The etching unit 30 is functionally divided into two in the substrate transport direction. The upstream side is a just-etched portion 30A that etches the Al layer to a predetermined depth, and the downstream side is an over-etched portion 30B that imparts an inclination to the side edge surface of the Al layer after the just-etched. In the just etch portion 30A, two slit nozzles 33a and 33b positioned above the transport line of the substrate 100 are arranged in two stages along the traveling direction of the substrate 10, and the first-stage slit nozzle 33a. Is located in the vicinity of the entrance of the etching unit 30. In the overetch portion 30B, four slit nozzles 33c to 33f positioned above the transport line of the substrate 100 are arranged in four stages at a relatively dense pitch along the traveling direction of the substrate 10.
[0029]
Each of the six slit nozzles 33a to 33f is a horizontal nozzle perpendicular to the direction of travel of the substrate 100. By flowing the Al etching solution into a film wider than the entire width of the substrate 10, the etching solution A part of the surface of the substrate 10 is supplied linearly over the entire width in a part in the traveling direction. The flow rates of the slit nozzles 33a to 33f are set to be the same here, and specifically, set to such an extent that the etching solution supplied to the surface of the substrate 100 slightly overflows to both sides.
[0030]
The lengths of the just-etched portion 30 </ b> A and the over-etched portion 30 </ b> B are larger than the length of the substrate 100, and the intervals between the slit nozzles 33 a to 33 f are smaller than the length of the substrate 100. The distance from the last-stage slit nozzle 33b in the just-etched portion 30A to the first-stage slit nozzle 33c in the over-etched portion 30B is made larger than the length of the substrate 100 in order to maintain the independence of each process. It is preferable. Here, the number of slit nozzles in the just-etched portion 30A and the over-etched portion 30B is two and four, but is appropriately selected based on the amount of etching solution required, the number of times of liquid replacement, and the like.
[0031]
On the further downstream side of the slit nozzles 33 a to 33 f, a slit-type air nozzle 34 is disposed in the vicinity of the outlet of the etching unit 30. The air nozzle 34 is a liquid draining device that removes the etching solution from the surface of the substrate 10 by blowing air linearly over the entire width of a part of the surface of the substrate 10 in the traveling direction.
[0032]
In the transport type substrate processing apparatus of the present embodiment having such a configuration, the etching process for the substrate 100 is performed as follows.
[0033]
The substrate 100 that has entered the etching unit 30 from the liquid repellent unit 20 first sequentially passes under the slit nozzles 33a and 33b provided in the upstream portion of the just etch unit 30A. As a result, the Al etching solution flows down from the slit nozzles 33a and 33b in sequence, and the etching solution is sequentially supplied from the tip portion onto the surface of the Al etching solution, and is held in a paddle state with liquid replacement.
[0034]
When the etching solution for Al is suddenly showered on the surface of the substrate 100, the portion that first received the droplet remains as processing unevenness, but the substrate 100 passes through the film of the etching solution that flows down from the slit nozzle 33a from the beginning. . Thereby, since the etching solution is supplied onto the surface of the substrate 100 without any unevenness, processing unevenness associated with the shower process of the etching solution is prevented.
[0035]
The Al layer or the Al / Mo layer formed on the surface of the substrate 100 is selectively etched by the first paddle process with the chemical knife using the slit nozzles 33a and 33b in the just etch part 30A. In this chemical knife processing, even when a large number of bubbles are generated in the etching process due to the impact of the etching solution for Al flowing down from the slit nozzles 33a and 33b, drainage to both sides, liquid replacement, etc., these bubbles are also generated. Is destroyed or removed. For this reason, the etching nonuniformity by a bubble is also prevented.
[0036]
In this chemical knife treatment, the remaining side edge surface of the Al layer or Al / Mo layer becomes a steep inclined surface that is inappropriate for stacking the next layer. However, at the over-edge portion 30b following the just-etched portion 30A, the Al etching solution flowing down in the form of a film from the slit nozzles 33c to 33f is sequentially supplied again to the surface of the substrate 100, and held in a paddle state on the surface. Is done. During this second paddle process, the etching process proceeds slowly, and the side edge surface of the remaining Al layer or Al / Mo layer is suitable for stacking the next layer, as shown by the one-dot chain line in FIG. It becomes a gentle slope. Here, as described above, the problem of bubbles does not become obvious.
[0037]
The second paddle processing time in the overetch portion 30B is preferably 30 to 70%, particularly preferably 50 to 60% of the total processing time with the etching solution. If the paddle treatment time is too short, the inclination of the side edge surface is not sufficiently relaxed. However, if the paddle treatment time is too long, the etching becomes excessive and the required wiring dimensions cannot be obtained.
[0038]
In the first paddle process and the second paddle process, the processing time can be secured by reciprocating or stopping the substrate 100.
[0039]
【The invention's effect】
As described above, according to the transportable substrate processing method of the present invention, the etching line is inclined between the just-etched portion for performing the etching process at a predetermined depth and the side edge surface of the etching layer etched at the just-etched portion. A film is formed over the entire width direction of the substrate surface by slit nozzles that are arranged at right angles to one or more stages in the substrate transport direction in both the just etch section and the over etch section. By applying a treatment solution in the form of a chemical knife and performing a chemical knife process, it is applied to a high-speed etching process in which the slope of the side edge surface does not become gentle in the shower process, such as Al etching. It can be formed on a gently sloping surface suitable for lamination, and processing unevenness caused by the initial shower can also be eliminated.
[Brief description of the drawings]
FIG. 1 is a plan view of a transport type substrate processing apparatus showing an embodiment of the present invention.
FIG. 2 is a side view of the main part of the substrate processing apparatus.
FIG. 3 is a cross-sectional view showing the shape of an Al layer after etching.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Receiving part 20 Liquid prevention part 30 Etching part 30A Just etch part 30B Over etch part 33a-33f Slit nozzle 34 Air nozzle 40 Water washing part 41 Shower unit 50 Water washing part 60 Final rinse part 70 Drying part 80 Extraction part 90 Conveyance apparatus 100 Substrate

Claims (2)

An etching line that supplies an etching solution to the surface of the substrate while transporting the substrate in a substantially horizontal position in a substantially horizontal direction, a just etch portion that performs an etching process of a predetermined depth, and an etching layer etched in the just etch portion And an over-etched portion that imparts an inclination to the side edge surface of the substrate. Both the just-etched portion and the over-etched portion are arranged as an etching solution supply means substantially perpendicularly to one or more steps with respect to the substrate transport direction. Each is provided with a slit nozzle that supplies a processing liquid in a film shape over the entire width direction of the substrate surface, and both the just edge portion and the over-etched portion are etched by chemical knife processing using the slit nozzle. A transporting substrate processing method . The transport type substrate processing method according to claim 1, wherein the flow rate of the slit nozzle in the just-etched portion is substantially the same as the flow rate of the slit nozzle in the over-etched portion.

Images