JP4905263B2 - Surface processing method and surface processing apparatus - Google Patents

Description

  In the present invention, an etchant such as hydrofluoric acid (etching solution) is supplied to the surface of a workpiece such as a glass substrate or a semiconductor substrate by a processing head and sucked, whereby the gap between the processing head and the workpiece is constant. The present invention relates to a surface processing method and a surface processing apparatus that forms an etchant flow path that forms an etching area and processes the surface of a workpiece by, for example, scanning a processing head. The present invention relates to an improved surface processing method and a surface processing apparatus.

  A panel of a liquid crystal television or a personal computer monitor is composed of a TFT array and a color filter, and these are produced by repeatedly transferring a pattern drawn on a photomask using an exposure apparatus.

  In recent years, with the growing demand for large LCD TVs, the size of photomasks that support large panels has increased, and the display quality has been improved. It has been.

  An exposure apparatus having a size of 1220 mm × 1400 mm has been announced as a photomask size, and the size of the photomask will be further increased.

  Synthetic quartz glass having a small thermal expansion coefficient is used as the base material of the photomask, but the flatness of the base material greatly affects the exposure accuracy. When a base material with poor flatness is used, it is understood from experience that a high-definition product cannot be obtained due to pattern deviation, and a flatness of several μm is required.

  It is considered that it is very difficult to perform strict required performance such as flatness by a conventional mechanical polishing method such as a double-side polishing method or a single-side polishing method using water, polishing abrasive grains, and polishing cloth.

  In such a mechanical polishing method, the flatness of the substrate is improved by devising the uniforming of the relative movement speed between the polishing surface pressure and the polishing head and the workpiece, Since the entire surface of the substrate is flattened while being simultaneously polished, it is extremely difficult to control for flattening the partial shape.

  In view of this, a method for flattening the surface by performing local etching using plasma has been proposed as a processing method instead of machining. This is achieved by measuring the shape or thickness distribution of the workpiece in advance and then controlling the plasma scanning speed on the workpiece according to the distribution, thereby controlling the amount of etching removed and realizing high flatness. It is the correction processing method for doing.

  When this plasma etching method is applied to the processing of a glass substrate, the correction processing method by the plasma etching requires an increase in processing speed because the processing time becomes extremely long as the glass substrate becomes larger. In order to increase the processing speed, it is necessary to enlarge the processing area, that is, to increase the area of the plasma area. However, due to the difference in material properties, specifically, the relative permittivity and the difference in thermal conductivity, Becomes unstable, the amount of processing fluctuates, the input power increases, and heat accumulates on the glass substrate, making control difficult and worsening the surface roughness of the workpiece.

  In addition, the plasma etching method requires expensive devices such as a vacuum chamber and a gas exhaust device, and the processing of a large glass substrate has a problem that the cost for processing further increases.

  Therefore, the present applicant paid attention to the chemical etching method as a new processing method in place of the mechanical processing method and the plasma etching processing method described above (Patent Documents 1 and 2).

  The chemical etching method disclosed in Patent Document 1 uses an etching solution (etchant) that can take an active state and an inactive state depending on temperature, and is immersed in an inert etchant contained in a tank. The semiconductor substrate is moved relative to the etchant jet nozzle in a direction parallel to the main surface of the semiconductor substrate while an active etchant is applied to a part of the main surface of the semiconductor substrate by an etchant jet nozzle. The active etchant is applied to the entire surface, and the reacted etchant applied to the main surface of the semiconductor substrate is immediately discharged out of the tank through the etchant discharge pipe.

Patent Document 2 discloses a nozzle having a concentric tube structure in which a pipe having an introduction passage to which an etchant as a processing liquid is supplied and a discharge passage through which the etchant is discharged is disposed inside and outside, and the etchant is directed toward an object to be processed. Is supplied from the inner pipe, and the etchant supplied from the gap between the outer pipe and the inner pipe toward the object to be processed is supplied.
JP-A-11-045872 Japanese Patent Laid-Open No. 10-163153

  When the technique disclosed in Patent Document 1 described above is to be applied to a workpiece having a large size, a tank that can accommodate the workpiece is required, and the facility becomes very large, which is not realistic.

  On the other hand, in the technique disclosed in Patent Document 2, it is not necessary to immerse the substrate in a tank in which an inert etchant is accommodated. As a result of experiments on flattening, it was found that the target planar shape could not be obtained.

  Here, as a method of flattening the surface of the glass substrate or the like, the surface of the workpiece is intended based on the measurement data obtained by measuring the surface shape of the workpiece such as the glass substrate. The correction process of partially processing so that it may become a shape is used.

  Therefore, in order to apply the correction process to the above-described chemical etching type surface processing method to process the surface of the workpiece with high flatness, an etchant such as hydrofluoric acid (etching solution) is applied to the glass substrate by the processing head. Then, by supplying to the surface of the workpiece such as a semiconductor substrate and sucking, an etchant flow path that forms an etching area of a certain area is formed in the gap between the processing head and the workpiece, for example, the processing head is Scanning is performed at a scanning speed corresponding to the removal amount determined by the shape measurement data and the target shape. At that time, a machining trace shape (hereinafter referred to as a unit machining trace) as a unit is measured on the surface of the workpiece formed by the etching region with the machining head stationary, and based on the unit machining trace based on the measurement result. Thus, the removal amount to be removed by machining from the surface of the workpiece before machining and the scanning speed of the machining head are obtained, and the machining head is driven by this scanning speed.

  However, even if the processing head is driven at a predetermined scanning speed, the processing cannot be performed as calculated, and the target planar shape may not be obtained. One of the situations in which the desired planar shape cannot be obtained is the occurrence of the outer peripheral portion of the workpiece.

  The inventors of the present invention, as the reason why the target planar shape cannot be obtained at the outer peripheral portion of the workpiece, is that the gap between the processing head and the workpiece when the processing head reaches the outer peripheral portion of the workpiece. It has been found that the etching region to be formed protrudes outward from the outer peripheral edge of the workpiece, the etchant flow path forming the etching region is disturbed, and processing in the regular etching region cannot be performed.

  In general, in a mask substrate, a portion having a constant width (depending on the substrate size) from the outer peripheral edge to the inside is not a flatness guarantee portion. Therefore, a processing head having a small etching area is required to guarantee flatness inside this portion. Although it is conceivable to use it, it takes a long processing time to process a large mask substrate so as to obtain high flatness, which is not practical. Therefore, in order to shorten the time required for processing by increasing the etching region, it is necessary to process the outer peripheral portion of the workpiece with high flatness.

  The object of the present invention is made in view of such a viewpoint, and the surface of a workpiece is processed into a target shape including an outer peripheral portion, and a glass substrate or the like having a highly flat surface is processed. An object of the present invention is to provide a surface processing method and a surface processing apparatus capable of providing an object.

A first surface processing method that realizes the object of the present invention is to supply an etchant to the surface of a workpiece by a processing head and suck it, so that an etching region having a constant area is formed in the gap between the processing head and the workpiece. Forming a surface of the workpiece by scanning the processing head and the workpiece relative to a position where the etchant region exceeds the end of the workpiece. a machining method, wherein the combined surface position on the edge of the workpiece, said plate member to secure the flow path of the etchant formed by the machining head is brought into contact Rutotomoni, with the workpiece and the plate The processing head and the workpiece are processed while relatively scanning with the surface of the portion where the contact is made in a liquid-tight seal .

A second surface processing method for realizing the object of the present invention is the above-described workpiece, the processing head, and the processing head based on measurement data of the surface shape of the workpiece measured in advance in any of the above processing methods. The relative scanning speed is determined.

The third surface processing method for realizing the object of the present invention is the above-described third processing method, in which the relative scanning speed is determined based on the measurement data so as to coincide with the target surface shape, and flattened. It is characterized by processing.

According to a fourth surface processing method for realizing the object of the present invention, in any one of the above processing methods, the workpiece is a synthetic quartz glass having a rectangular flat plate shape.

According to a fifth surface processing method for realizing the object of the present invention, in the fifth surface processing method, the synthetic quartz glass is a glass substrate for a photomask.

A sixth surface processing method for realizing an object of the present invention is characterized in that, in the above-described sixth surface processing method, one side of the glass substrate for the photomask is 300 mm square or more.

According to a seventh surface processing method for realizing the object of the present invention, in any one of the surface processing methods described above, the workpiece is processed while being held in a vertical posture.

The first configuration of the surface processing apparatus that realizes the object of the present invention is to supply an etchant to the surface of the workpiece by the processing head and suck it, thereby providing a constant area in the gap between the processing head and the workpiece. An apparatus for processing a surface of a workpiece by forming an etchant flow path forming an etching region and relatively scanning the processing head and the workpiece to hold the workpiece. A plate member that secures the flow path of the etchant formed by the machining head by aligning the surface position of the workpiece with the surface of the holding member is disposed around the workpiece, and an end of the workpiece A sealing member for sealing the contact portion in a liquid-tight manner is provided on the upper surface of the contact surface with the plate material .

According to a second configuration of the surface processing apparatus for realizing the object of the present invention, in the first configuration described above, the seal member is a tape member or a filling member.

A third configuration of the surface processing apparatus that achieves the object of the present invention is characterized in that, in any of the above-described configurations of the surface processing apparatus, the workpiece is held in a vertical posture.

In the state where the work piece is held in a vertical posture, when the step generated when the end surface of the work piece protrudes from the plate member is expressed as minus, the step is sealed with a seal member. In the range of −0.2 mm or less, the variation of the processing amount at the end portion of the workpiece can be reduced, and the surface of the workpiece can be processed with the target flatness.

  According to the present invention, when the processing head processes the end of a workpiece such as a glass substrate, the flow path of the etchant forming the etching region is not disturbed by the presence of the plate material. A glass substrate such as synthetic quartz glass for photomasks processed with the processing amount of can be provided, and even if a large processing head is used with the large size of the glass substrate, the flow path of the etchant is disturbed. There can be provided a glass substrate for a large photomask whose surface has high flatness.

In addition, since the workpiece is held in a vertical posture, the workpiece is prevented from being distorted due to its own weight, and the workpiece is corrected to a desired shape with higher accuracy. Can be processed.

Further, as the seal member, for example shea Rutepu, also it can be sealed with a high sealing property of the joint between the workpiece and the plate material by the filling material, the etchant etching regions of the workpiece and the plate member It is possible to prevent the etchant from entering the joint, and the flow path of the etchant forming the etching region is not disturbed, and the deterioration of the surface roughness of the end face and the back surface of the glass due to the entered etchant can be prevented.

  Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

  FIG. 1 is a view showing a chemical etching type surface processing apparatus (abbreviated as a wet etching processing apparatus) according to the present invention, and FIG. 2 is a substrate holder for holding the processing head of FIG. 1 and a glass substrate as a workpiece in a vertical posture. It is a figure which shows the relationship.

  A wet etching processing apparatus 1 shown in FIG. 1 includes an etchant circulation device 1A surrounded by a broken line and a processing head 2 connected to the etchant circulation device 1A, and the processing head 2 with respect to the surface of a glass substrate 3 as a workpiece. And a processing head scanning device 1B that moves the two in two directions orthogonal to each other. Examples of the glass substrate 3 as a workpiece include a synthetic quartz glass plate, a photomask substrate, a large photomask substrate, and the like, and the large substrate is one having a side of 300 mm square or more. Further, the workpiece is not limited to a glass substrate, but may be a silicon wafer or the like.

  In the etchant circulation device 1A, an etchant 5 such as hydrofluoric acid is accommodated in an etchant tank 4 having a sealed structure, and the etchant 5 in the etchant tank 4 is supplied to the processing head 2 by an etchant supply system 6. Further, the processing head 2 and the etchant tank 4 are connected by an etchant recovery tube 7, and the etchant 5 supplied to the surface of the glass substrate 3 from the processing head 2 is sucked and returned from the etchant recovery tube 7 to the etchant tank 4.

  A gas exhaust pipe 8 is connected to the etchant tank 4, and the gas in the etchant tank 4 is exhausted by a gas exhaust pump 9 that also serves as a suction pump. When the concentration of the etchant 5 in the etchant tank 4 is reduced or increased, or when the amount of the etchant is reduced, water 11 and the etchant 5 are individually or mixed from the concentration controller 10 and supplied into the supply pipe in the etchant tank 4. 12 is supplied. As the etchant, hydrofluoric acid (hydrofluoric acid), a mixed liquid of hydrofluoric acid and ammonium fluoride, or the like can be used.

  The etchant supply system 6 includes, in order from the etchant tank 4 side, a liquid feed pump 13, a heat exchanger 14, a temperature measuring body 15 for measuring the temperature of the sent etchant 5, and the flow rate of the sent etchant 5. A flow rate adjusting valve 16 for adjusting, a flow meter 17 for measuring the flow rate of the etchant 5 to be fed, and a hydrofluoric acid concentration sensor 18 are arranged, and a supply pipe 19 comprising a flexible pipe provided downstream from the hydrofluoric acid concentration sensor 18. Is connected to the machining head 2.

  The heat exchanger 14 heats or cools the etchant 5 by the temperature control unit 20 so that the temperature of the etchant 5 fed based on the temperature measurement information of the temperature measuring body 15 becomes a predetermined temperature. Further, the flow rate adjusting valve 16 adjusts the flow rate so that the flow rate of the etchant 5 sent based on the flow rate information of the flow meter 17 becomes a predetermined flow rate. The hydrofluoric acid concentration sensor 18 feeds back the measured concentration value to the concentration controller 10 and controls the inside of the etchant tank 4 to a set concentration.

  A gas exhaust pump 9 also serving as a suction pump sucks and exhausts the gas in the etchant tank 4 to bring the inside of the etchant tank 4 into a negative pressure state, and the etchant 5 supplied between the processing head 2 and the glass substrate 3. The gas vaporized from a part of the etchant 5 is sucked from the processing head 2 and recovered into the etchant tank 4 through the recovery pipe 7. If the gas vaporized from a part of the etchant 5 supplied to the surface of the glass substrate 3 is diffused, the surface of the glass substrate 3 is corroded and the surface roughness is deteriorated. The surface roughness on the surface of the glass substrate 3 can be increased by sucking and exhausting.

  The various controls described above in the etchant circulation device 1A are executed by a control device (not shown).

As shown in FIG. 2, the processing head scanning device 1B fixes a substrate holding table (not shown) that holds a glass substrate 3 as a workpiece in a vertical posture to an apparatus base 31 and is held by the substrate holding table. along the surface of the glass substrate 3 mounting a machining head 2 in the vertical direction and the horizontal direction orthogonal two directions movable in two directions moving stage 32 of the main scanning speed of moving the machining head 2 in the horizontal direction, vertical The processing head scanning speed control unit 33 controls the feed amount in the sub-scanning direction to be fed at a predetermined pitch in the direction. The substrate holding table and the two-way moving stage 32 excluding the processing head scanning speed control unit 33 are provided. Covered by the apparatus cover 34, the etchant 5 is scattered in the room and the vaporized gas is prevented from being diffused.

The two-way moving stage 32 has a linear movement guide mechanism 37 attached to a pair of vertical frame members 36 constituting an aluminum vertical frame 35 formed in a gate shape and extending in the vertical direction, and the pair of linear movement guide mechanisms 37. A horizontal frame member 38 is attached to the horizontal frame member 38 so that the horizontal frame member 38 can be moved in the vertical direction with extremely high accuracy. Further, a ball screw 39 for driving in the main scanning direction is attached to the horizontal frame member 38 along the scanning direction, and the machining head 2 is attached to a nut portion of the ball screw 39. Further, a ball screw 40 for the sub-scanning direction is attached between the pair of vertical frame members 36 along the vertical direction, and a horizontal frame member 38 is attached to a nut portion of the ball screw 40.

  The ball screw 39 for driving in the main scanning direction and the ball screw 40 for driving in the sub scanning direction have motors (not shown) that rotationally drive the respective screw members, and these motors are driven and controlled by the machining head scanning speed control unit 33. ing.

  The machining head 2 is formed by integrating a disk-shaped nozzle block body 41 and a disk-shaped back block body 42 joined to the back side of the nozzle block body 41 with a fixing screw 43 to form an overall disk shape. The configuration is as follows.

  As shown in FIG. 1B, the nozzle block body 41 forms a supply nozzle portion 44 that supplies an etchant at the center position, and sucks the etchant on the same circumference centering on the supply nozzle portion 44. A plurality of discharge holes 45 for discharging are formed at an equal pitch. On the back side of the nozzle block body 41, a first circumferential groove 46 that opens to the back side corresponding to the plurality of discharge holes 45 is formed, and the plurality of discharge holes 45 communicate with the circumferential groove 46. .

  The back block body 42 is formed in a donut shape having an opening 47 in the center, and a second circumferential groove 48 having the same inner and outer diameter as the first circumferential groove 46 is formed on the front surface. When joined to the block body 41, the first circumferential groove 46 and the second circumferential groove 48 form an annular collection portion that collects the etchant from the plurality of discharge holes 45 at one place. In addition, the diameter of the discharge hole 45 was 1 mm or less, and the space | interval of the discharge hole 45 was 0.5 mm or less.

  Further, as the material for the nozzle block body 41 and the back block body 42, it is desirable to select a material that has excellent etchant resistance and excellent mechanical properties such as bending strength and hardness. In particular, a fluororesin such as polytetrafluoroethylene, hard vinyl chloride, ABS, polyethylene, polypropylene, polycarbonate, methylpentene, PEEK and the like are used.

  A plurality of discharge passages 49 communicating with the second circumferential groove 48 are formed in the body portion of the back block body 42, and the recovery pipe 7 of the etchant circulation device 1 </ b> A is connected to the discharge end portions of these discharge passages 49. The supply pipe 19 of the etchant circulation device 1A is connected to the etchant supply nozzle section 44 of the nozzle block body 41 through the opening 47 of the back block body 42.

  The etchant 5 continuously supplied from the etchant supply nozzle portion 44 of the processing head 2 to the surface of the glass substrate 3 is supplied to a plurality of discharge holes 45 provided on the circumference of the radius R around the etchant supply nozzle portion 44. Since suction and discharge are continuously performed, an etching region, which is a constant region in which an etchant flow path is formed between the head and the surface of the workpiece, is formed with a radius R.

Further, the processing head 2 having the above-described configuration is moved from one end side in the horizontal direction toward the other end side of the upper end of the glass substrate 3 held in the vertical posture by the two-way moving stage 32 as indicated by an arrow in FIG. When the main scanning is performed horizontally and the predetermined position on the other end is reached, the sub-scan is sent downward by a predetermined amount, and then the main scanning is performed toward the one end. Do. Note that the scan order may be reversed from the bottom to the top.

  In the above-described control of the main scanning speed, when correction processing is assumed, the shape of the surface of the glass substrate 3 is measured in advance, and the shape before processing and the processing head 2 are set so as to be closest to the target shape based on the measurement result. The amount of machining removal and the main scanning speed of the machining head are calculated from the shape of the static machining trace formed by machining. For example, the main scanning speed of the processing head 2 is controlled so that a large convex portion has a large etching amount, and a small convex portion or a concave portion has a small etching amount. The scanning speed after the processing head 2 passes through the glass substrate 3 is not particularly defined, but it is preferable to increase the scanning speed in consideration of the processing time.

  The shape of the surface of the glass substrate 3 can be measured using a non-contact method using a laser or the like, or a contact method such as a stylus. In addition, since the measurement is performed with the glass substrate 3 held in a vertical posture, the influence of the self-weight deflection of the glass substrate 3 can be eliminated.

In the present embodiment, as shown in FIG. 4, the substrate holder 50 that holds the glass substrate 3 in a vertical posture is formed to have an outer diameter size larger than the outer diameter size of the glass substrate 3, and the glass substrate 3 is centered. It is held so as to be placed in the part. And the dummy member 51 is arrange | positioned so that it may contact | abut to four sides of the glass substrate 3 of a rectangular planar shape, and may surround the perimeter of the glass substrate 3. FIG.

As shown in the reference example of FIG. 5A, the dummy member 51 is configured so that there is no step in the thickness direction with respect to the end surface in contact with the glass substrate 3 in the state of being arranged on the substrate holding table 50. . Further, there is no gap between the end face of the glass substrate 3 and the dummy member 51, and the glass substrate 3 and the dummy member 51 surrounding the glass substrate 3 over the entire circumference are as if one. The substrate holding table 50 is held in a vertical posture so as to form a single substrate.

  Here, when the processing head 2 is scanned in a state where the dummy member 51 is not disposed and the processing head 2 reaches the outer peripheral portion of the glass substrate 3, it is formed in the gap between the processing head 2 and the glass substrate 3. The etching region protrudes outward from the outer peripheral edge of the glass substrate 3, the etchant flow path forming the etching region is disturbed, and processing in the regular etching region cannot be performed.

On the other hand, as in this embodiment, the etchant region formed by the processing head 2 is formed at the end of the glass substrate 3 by surrounding the glass substrate 3 with the dummy member 51 without gaps and without causing a step. Even if it approaches and exceeds the end of the glass substrate 3, the dummy member 51 is extended from the end of the glass substrate 3, so that the flow path of the etchant forming the etching region is not disturbed. That is, the dummy member 51 plays a role of securing a flow path for the etchant formed by the processing head 2.

  For this reason, it becomes possible to process the edge part of the glass substrate 3 according to the target shape.

  In the present embodiment, as shown in FIG. 4, four dummy members 51 are arranged in combination so as to abut against one side of the glass substrate 3, but the arrangement configuration of the dummy members 51 is the configuration of FIG. 4. For example, a configuration in which a rectangular opening in which the glass substrate 3 is disposed at the center of a rectangular flat plate is formed, a configuration using two sets of planar L-shaped dummy members, and the like can be exemplified. .

  Further, in order to bring the dummy member 51 and the end surface of the glass substrate 3 into contact with each other without a gap, as shown in FIG. 5A, the end surface of the glass substrate 3 is formed in advance on a C-plane which is a convex curved surface. In some cases, the dummy member 51 and the glass substrate 3 can be brought into contact with each other without a gap by forming the concave surface portion 51a having a shape matching the C surface on the upper surface side of the end surface of the dummy member 51.

Further, when the end surface of the glass substrate 3 is formed at a right angle as in the embodiment shown in FIG. 5C, the end surface of the dummy member 51 is also formed at a right angle according to this, and the glass substrate 3 and the end face of the dummy member 51 are affixed with a resin tape 52 to seal the contact surface in a liquid-tight manner so as to securely close the contact surface. By preventing penetration, it is effective in preventing surface erosion of the contacted part.

Furthermore, as in the embodiment shown in FIG. 5B, when the end surface of the glass substrate 3 is formed on the C surface, the end surface of the dummy member 51 is formed at a right angle, and the recess formed on the abutting surface is formed. A resin sealant 53 may be filled to improve the sealability against the etchant.

  In the present embodiment, the dummy member 51 is a resin plate material having corrosion resistance to the etchant, for example, a fluorine resin such as polytetrafluoroethylene (PTFE), ABS, polyethylene, polyvinyl chloride, polycarbonate, methylpentene. , PEEK (trademark), and the resin tape 52 may be any adhesive and tape that can withstand the etchant, and examples of the tape material include polyester, fluororesin, and polyimide. Further, the material of the resin sealant 53 is not particularly limited as long as it can withstand the etchant, but fluorine rubber is preferable.

  The above description is based on the premise that there is no step between the dummy member 51 and the glass substrate 3. However, as shown in FIG. 5D, for example, when the end surface of the dummy member 51 is a right angle, the glass substrate. When the resin tape 52 is pasted, the resin tape 52 creates a level difference. When the resin sealant 53 is filled, the resin sealant 53 has a level difference. produce.

  Such a step substantially disturbs the etchant flow path forming the etchant region within a range of −0.2 mm in a state where the glass substrate 3 is held in a vertical posture and the step is sealed with a seal member. The end portion of the glass substrate 3 can be processed into a target shape.

FIG. 6B shows a comparison of processing line cross-sectional areas in which the horizontal axis is the distance from the end of the glass substrate to the inside, and the vertical axis is the ratio to the processing amount at the 75 mm position. The ratio with the processing amount at the 75 mm position is the ratio of the line processing cross-sectional area from the end of the glass substrate 3 to the end of the glass substrate 3 with respect to the line processing cross-sectional area at 75 mm, and this is the vertical axis. In addition to changing the level difference, a condition including the presence or absence of a seal is added. Then, as shown in FIG. 6 (a), the periphery of the glass substrate 3 is surrounded by a dummy member 51 on a rectangular flat plate, and the processing head 2 is reciprocated to obtain the cross-sectional area of one line processed on the glass substrate. It was. The processing was performed under the following processing conditions.
Processing conditions Processing head etching area: Diameter 15mm
Hydrofluoric acid concentration: 25 wt%
Distance between processing head and substrate: 250μm
Hydrofluoric acid circulation flow rate: 28L / h
Suction flow rate: 31.4L / min
Hydrofluoric acid temperature: 25 ° C
Substrate holding posture: vertical holding Processing head scanning speed: 200 mm / min
FIG. 6B shows a case where a seal is applied between the dummy member 51 and the glass substrate, the step is +0.12 mm, and the step is −0.15 mm, and a case where the seal is applied but the step is −0.3 mm. The line processing sectional area at 75 mm from the edge of the substrate 3 was obtained. In addition, it processed beyond the end of the glass substrate 3, and the measurement position of the outermost end is 5 mm from the end. The ratio of the line cross-sectional area at each position to the line cross-sectional area at 75 mm was taken as the vertical axis.

  When the step is +0.12 mm and the step is −0.15 mm by applying a seal, the cross-sectional area ratio is approximately 1. This indicates that there is almost no variation in the processing amount, and it was confirmed that the same processing shape was obtained up to the end of the glass substrate 3.

  However, even if there is a seal, dripping occurs when the step is -0.3 mm.

(A) is the schematic of the wet etching processing apparatus which shows 1st Embodiment of this invention, (b) is a front view of the processing head shown to (a). The AA arrow directional view of FIG. The figure which shows the scanning order in the process head scanning apparatus of FIG. (A) is a top view which shows the arrangement | positioning state of a dummy member, (b) is a side view of (a). (A)-(d) is a figure which respectively shows the contact part of the glass substrate shown in FIG. 4, and a dummy member , (a) is a reference example, (b) (d) shows embodiment . (A) The figure which shows the scanning direction of the processing head for calculating | requiring the line cross-sectional shape with respect to the glass substrate enclosed by the dummy member, (b) is a figure which shows the ratio of a line processing cross-sectional area in relation to distance from the glass substrate end. .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wet etching processing apparatus 1A Etchant circulation apparatus 1B Processing head scanning apparatus 2 Processing head 3 Glass substrate (workpiece)
4 Etchant Tank 5 Etchant 6 Etchant Supply System 7 Etchant Recovery Pipe 8 Gas Exhaust Pipe 9 Gas Exhaust Pump 10 Concentration Controller 11 Water 12 Supply Pipe 13 Liquid Pump 14 Heat Exchanger 15 Temperature Sensor 16 Flow Control Valve 17 Flowmeter 18 Foot Acid concentration sensor 19 Supply pipe 20 Temperature control unit 31 Device base 32 Two-way moving stage 33 Processing head scanning speed control unit 34 Device cover 35 Vertical frame 36 Vertical frame member 37 Linear movement guide mechanism 38 Horizontal frame member 39 Main scanning direction drive Ball screw 40 Ball screw 41 for sub-scanning direction Nozzle block body 42 Back block body 43 Fixing screw 44 Supply nozzle portion 45 Discharge hole 46 First circumferential groove 47 Opening 48 Second circumferential groove 49 Discharge path 50 Substrate holder 51 Dummy member 52 Resin tape 53 Resin sealant

Claims (10)

An etchant is supplied to the surface of the workpiece by the machining head and sucked to form an etchant flow path that forms an etching region of a certain area in the gap between the machining head and the workpiece, and the machining head and the workpiece A surface processing method for processing a surface of a workpiece by relatively scanning the workpiece to a position where the etchant region exceeds the end of the workpiece,
The combined end to the surface position of the workpiece, the processing is brought into contact with the plate member to secure the flow path of the etchant formed by the head Rutotomoni, the surface locations between the workpiece and the plate is in contact A surface processing method characterized in that processing is performed by relatively scanning the processing head and the workpiece in a state in which the surface is liquid-tightly sealed . The surface processing method according to claim 1, wherein a relative scanning speed between the workpiece and the processing head is determined based on measurement data of a surface shape of the workpiece measured in advance. The surface processing method according to claim 2 , wherein flattening is performed by determining the relative scanning speed based on the measurement data so as to match a target surface shape. The workpiece, the surface processing method according to any one of claims 1 to 3, characterized in that the synthetic quartz glass of the rectangular plate shape. The surface processing method according to claim 4 , wherein the synthetic quartz glass is a glass substrate for a photomask. The surface processing method according to claim 5 , wherein one side of the glass substrate for the photomask is 300 mm square or more. The workpiece surface processing method according to any one of claims 1 to 6, characterized in that to be processed is held in a vertical posture. An etchant is supplied to the surface of the workpiece by the machining head and sucked to form an etchant flow path that forms an etching region of a certain area in the gap between the machining head and the workpiece, and the machining head and the workpiece A surface processing apparatus for processing a surface of a workpiece by relatively scanning the workpiece,
A plate member that secures the flow path of the etchant formed by the processing head is arranged around the workpiece by aligning the surface position of the workpiece with the holding member that holds the workpiece , A surface processing apparatus, wherein a sealing member for sealing the contact portion in a liquid-tight manner is provided on the upper surface of the contact surface between the end of the workpiece and the plate member . The surface processing apparatus according to claim 8 , wherein the seal member is a tape member or a filling member. The surface processing apparatus according to claim 8, wherein the workpiece is held in a vertical posture.

Images