KR101334012B1 - Manufacturing method of substrate for mask blank, and manufacturing method of mask blank and mask - Google Patents

Abstract

A process of polishing a mask blank substrate by moving the surface plate to which the polishing cloth is attached and the mask blank substrate relative to each other under a predetermined load, and then supplying a polishing liquid between the contact surface between the polishing cloth and the mask blank substrate. A method of manufacturing a mask blank substrate having a surface, wherein the surface plate to which the polishing cloth is attached has a groove on the surface of the polishing cloth attachment surface of the surface plate 1, and the cross-sectional shape of the groove has a predetermined shape at least at the opening circumference of the groove. And a polishing cloth 2 attached along the shape of the groove having the polishing cloth attachment plane of the surface plate 1 and the predetermined opening circumferential shape. A method for producing a mask blank substrate, wherein the mask blank substrate 4 is polished using a predetermined surface plate (3).

Description

MANUFACTURING METHOD OF SUBSTRATE FOR MASK BLANK, AND MANUFACTURING METHOD OF MASK BLANK AND MASK

BRIEF DESCRIPTION OF THE DRAWINGS It is typical sectional drawing for demonstrating one form of "the predetermined | prescribed surface plate which affixed the polishing cloth" which has the "prescribed groove | channel covered with the polishing cloth" of this invention.

It is typical sectional drawing for demonstrating one form of "the groove | channel which has the form of the predetermined opening peripheral part formed on the surface plate" of this invention.

FIG. 3: is a schematic cross section for demonstrating another form of the "prescribed groove | channel covered with the polishing cloth" formed reflecting the form of the "groove | channel which has the form of the predetermined opening peripheral part on the surface plate" of this invention.

It is typical sectional drawing for demonstrating the further another aspect of the "prescribed groove | channel covered with the polishing cloth" formed reflecting the form of the "groove | channel which has the predetermined | prescribed opening peripheral part shape on the surface plate" of this invention.

It is typical sectional drawing for demonstrating another form of "the groove | channel which has the form of the predetermined opening peripheral part formed on the surface plate" of this invention.

Fig. 6 is a schematic cross-sectional view for explaining a method of forming a “predetermined groove made of abrasion cloth” formed by reflecting the form of “a groove having a predetermined opening circumferential shape on a surface plate” of the present invention.

FIG. 7 is a schematic diagram for explaining a layout shape and the like of a "predetermined surface plate made by attaching abrasion cloth" having a "prescribed groove made of abrasion cloth" according to the present invention; (1) is a top view, and FIG. 7 (2) is sectional drawing along the AA line of FIG.

8 is a schematic plan view for explaining another embodiment of a layout shape in which the groove of the present invention is viewed in plan.

FIG. 9 is a schematic view for explaining a one-side polishing apparatus used in the embodiment of the present invention. FIG.

Fig. 10 is a schematic diagram for explaining the double-side polishing apparatus used in the embodiment of the present invention.

It is typical sectional drawing for demonstrating the grinding | polishing form of the board | substrate for small mask blanks.

It is typical sectional drawing for demonstrating the grinding | polishing form of the board | substrate for large mask blanks.

FIG. 13: is a schematic cross section for demonstrating grinding | polishing of the large sized mask blank board | substrate with the polishing cloth which has a groove | channel.

It is typical sectional drawing for demonstrating the shape of the polishing cloth at the time of grind | polishing the large sized mask blank substrate with the grooved polishing cloth.

FIG. 15 is a schematic cross-sectional view for explaining the experiment pattern using a large-sized mask blank substrate using a surface plate formed by attaching a polishing cloth along the upper surface and concave grooves of the surface plate or along the upper surface and V grooves of the surface plate.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a mask blank substrate, a method for manufacturing a mask blank, and a method for manufacturing a mask, and in particular, a method for manufacturing a mask blank substrate and a method for manufacturing a mask blank, which are suitable for the production of a substrate for a large mask blank. And a method for producing a mask.

At present, when manufacturing a semiconductor integrated circuit device, photolithography technology is applied in the process of forming a region other than wiring. In the photolithography process, a photomask used as an exposure master plate is formed with a patterned light shielding film on a transparent substrate, and the light shielding film pattern is transferred onto a semiconductor wafer through an exposure apparatus to manufacture a semiconductor integrated circuit device. The photomask is usually made of a mask blank in which a light shielding film is formed on a transparent substrate. If a defect (a scratch or a foreign substance, etc.) is present on the transparent substrate, a patterning defect is caused. Furthermore, the flatness is high from the recent request for miniaturization of the pattern. The board | substrate with high smoothness is calculated | required.

As described above, in order to complete the transparent substrate used for the mask blank with high flatness, high smoothness, and no defects such as scratches, a lapping process and a polishing (polishing) process are generally performed in a plurality of steps. A lapping process is made | formed in order to make uniform a process distortion layer, to adjust the dimension of plate | board thickness to a predetermined plate | board thickness dimension, and to improve flatness. The polishing step is carried out for the purpose of further improving the smoothness of the substrate surface while maintaining and improving the flatness obtained by the lapping step, and for the purpose of removing particles adhering to the substrate surface. In the polishing step, polishing is performed in a plurality of steps while decreasing the particle diameter of the abrasive grains in stages. For example, after polishing with abrasive grains of cerium oxide having an average particle diameter of 0.3 to 3 µm, fine polishing is performed by abrasive grains with colloidal silica having an average particle diameter of 300 nm or less (Japanese Patent Laid-Open No. 2002-). 127000)

In the polishing (polishing) step of the mask blank substrate, the polishing liquid 11 is supplied onto the polishing cloth 2 attached to the surface plate 1 as shown in FIG. (3 ') and the board | substrate 4 are performed by moving both relatively in the state which applied the fixed load between them. At this time, if the substrate is a glass mask for a small mask blank used for a photomask for IC manufacturing or the like, as shown in Fig. 11, the polishing liquid 11 supplied on the polishing cloth from the outer peripheral side of the substrate in the substrate advancing direction is sufficiently filled with the polishing cloth. The portion of the polishing cloth and the substrate 4 which are impregnated and the excess polishing liquid 11 'is collected on the polishing cloth 2 and the substrate 4 are relatively moved as shown in FIG. Polishing is performed in the state where an extremely thin layer 11 "of polishing liquid is interposed between the contact surfaces of the abrasion 2.

On the other hand, if the substrate is a large-sized mask blank glass substrate (330 mm x 450 mm or more) used for a liquid crystal display device (thin film transistor: TFT, etc.), a mask for manufacturing a color filter (CF), or the like, under a condition that emphasizes polishing efficiency (mainly a load) Under this large condition), as shown in FIG. 12, since the substrate 4 has a large area and a large weight, the polishing liquid 11 supplied from the substrate outer circumferential side A in the substrate advancing direction, On the opposite side to the supply side (A) (opposite to the advancing direction of the substrate; B), an extremely thin layer of polishing liquid interposed between the substrate surface and the contact surface of the polishing cloth surface with a decrease in the polishing liquid impregnated with the polishing cloth ( 11 "), the liquid amount (layer thickness) may decrease, and when the substrate is enlarged, the extremely thin layer 11" of the polishing liquid interposed between the surface of the substrate and the contact surface of the polishing cloth surface is extinguished ( There was a case). Due to these phenomena, the following disadvantages occur when polishing a large-sized mask blank substrate used for a liquid crystal mask, a CF mask, or the like.

(1) The contact resistance between the substrate and the polishing cloth becomes large, and as a result, the polishing resistance becomes very large.

(2) Since the size of the substrate to be processed is large, if the fresh polishing liquid is not always supplied as a whole between the contact surface between the substrate and the polishing cloth, the polishing liquid is exothermic and adhered, and the substrate is scratched, or The desired flatness cannot be obtained due to the uneven polishing rate due to the unbalance of the polishing liquid.

(3) The mask blank substrate of the large glass used for the mask for the liquid crystal manufacturing, the mask for the CF manufacturing, etc. is 330 mm x 450 mm or more in size, and is 8 to 15 mm in thickness compared to the large one, so that warpage is allowed to some extent, and at the time of polishing processing Is strongly adsorbed onto the polishing cloth. As a result, if sufficient polishing liquid is not supplied between the substrate and the contact surface between the polishing cloth, the frictional resistance is large, and a large load is generated in the rotary drive system of the polishing apparatus, causing vibration throughout the apparatus, which causes scratches on the substrate surface. In the worst case, the substrate itself is broken.

(4) After completion of polishing, the substrate is strongly adsorbed to the polishing cloth attached to the surface plate, which requires a great force for separation.

In order to avoid these disadvantages, polishing of a large-sized mask blank glass substrate used for a liquid crystal mask, a CF mask, or the like has been conventionally carried out at a low load. As a result, the polishing rate is lowered, so that the polishing time is long and the polishing efficiency is inevitably deteriorated.

An object of the present invention is to solve the problem relating to the polishing of the large substrate.

MEANS TO SOLVE THE PROBLEM This inventor tried to solve the subject regarding the said large sized substrate grinding | polishing by providing the groove | channel in the polishing cloth. Specifically, as shown in FIG. 13, a polishing cloth 2 having various patterns of grooves (for example, a lattice-shaped groove, a groove width of 2 mm, a groove pitch of 30 mm, and a groove depth of 1.5 mm) is placed on a commercially available plane. (1) was attempted to supply the polishing liquid (not shown) collected in the grooves 2a from the lower surface of the large substrate 4 through the grooves 2a of the polishing cloth 2, but expected effect Was not obtained. Specifically, as shown in Fig. 13, on the opposite side (B) from the supply side A of the polishing liquid 11, the polishing liquid on the polishing cloth was insufficient or the polishing liquid disappeared when viewed from a distance (as seen from the back). It was confirmed that the polishing resistance was high and the polishing efficiency was still high, such as the increase in the current value of the platen driving motor and the vibration of the entire apparatus. Therefore, the polishing efficiency could not be pursued.

The reason for this was ascertained, and as a result, the grooves 2a of the polishing cloth 2 were polished at the time of polishing as shown in FIG. Crushed and unable to maintain the cross-sectional shape of the grooves during polishing; (2) the grooves 2a of the polishing cloth 2 are crushed during polishing, so that the volume of the grooves becomes small and the amount of polishing liquid in the grooves is secured. (3) Since the thickness of the polishing cloth is limited to a thickness (usually 1 to 2 mm) having a predetermined elasticity (flexibility) in terms of predetermined polishing quality (flatness and mirror surface precision) and polishing efficiency, The main reason was that the limit of the depth (liquid amount) of the groove was limited. Therefore, increasing the width of the grooves, the depth of the grooves, the pitch of the grooves (gap between the grooves), the number of grooves, and the like to increase the amount of polishing liquid stored in the entire groove on the polishing cloth (increasing the total amount of groove volume) Attempted). In addition, an attempt was made to change the pattern when the groove was viewed in a plane (for example, application of an abrasive cloth having a spiral groove). As a result, although the improvement effect was seen, it did not come to solve the situation which still does not say that grinding | polishing resistance is high and polishing efficiency is good. This is because the grooved abrasive cloth has cracks in the grooves during processing, and there is a limit in increasing the total amount of the grooves due to the limitation of the thickness of the polishing cloth and the durability of the polishing cloth, etc. This was thought to be the main cause. Moreover, when the width of the grooves on the polishing cloth, the depth of the grooves, the pitch of the grooves, the number of grooves, etc. were increased, the durability of the polishing cloth was inferior, and it was also found that the practicality was insufficient because it could be used for only a short time.

Therefore, experiments were carried out using a surface plate formed by forming a concave groove having a rectangular cross section on the surface plate and attaching a polishing cloth along the surface surface surface and the surface surface grooves. It was elucidated that a reduction effect and an improvement in polishing efficiency could be obtained.

As a result of further research, as shown in FIG. 15 (1), the surface plate 3 formed by attaching the polishing cloth 2 along the upper surface and the concave groove of the surface plate 1, or the surface plate of FIG. In the experiment using the surface plate 3 formed by attaching the polishing cloth 2 along the V-shaped groove in the upper surface and the cross section of the surface plate 1 shown in 2), the shape of the groove 3a is maintained and the groove Although the polishing liquid supply action by (3a) is effected, the effect of scraping (removing) the intervening slurry at the edges (edges) of the grooves 3a acts more strongly, so there is a certain effect but the effect is as expected. No improvement was clarified.

Therefore, as shown in Fig. 1, a groove formed with an R (predetermined radius of curvature) at the opening periphery of the groove as seen in cross section, that is, a groove having a rounded shape (hereinafter referred to as 'R groove') is formed. Experiments were carried out using the surface plate 3 formed on the surface plate and affixed with the polishing cloth 2 along the upper surface of the surface plate 1 and the R grooves. Under one condition (mainly under a heavy load), the effect of reducing the polishing resistance is higher than that of the embodiment shown in FIG. 15, and thus, the effect of improving the polishing efficiency is high, and as a result, the productivity can be realized. It came to completion and completed this invention.

The reason is that since the polishing cloth 2 adhered along the upper surface of the surface plate 1 and the R groove is held (supported) from the lower side in the surface plate R groove, the R groove is hardly deformed, and thus, the grooves are hardly deformed. The "predetermined R groove made of abrasion cloth" 3a formed by reflecting the shape of the R groove on the surface plate, which is easy to secure the amount of liquid, and scrapes the polishing liquid (intervention slurry) from the substrate surface ( It is considered that the action of removing) is very small, and on the contrary, the action of adhering the polishing liquid to the substrate surface and the effect of effectively attaching the polishing liquid to the substrate surface are performed. The action of adhering (adhering) the polishing liquid to the substrate surface is the action of the polishing liquid (space) formed in the space 3a 'formed between the R portion of the predetermined R groove and the substrate surface by the centrifugal force according to the surface rotation. It is considered that the action according to the shape, the action of increasing the contact area between the surface of the substrate and the polishing liquid, the impregnation of the polishing liquid of the polishing cloth, the elastic action of the polishing cloth, and the like may be caused. That is, the present invention is less effective in scraping (removing) the polishing liquid from the surface of the substrate in the form of a "prescribed groove covered with abrasive cloth" formed by reflecting the shape of the predetermined groove on the surface plate. The action of adhering (adhering) the polishing liquid to the cross section (form) in which the action of the former is greater than the action of the former.

Moreover, it is technically difficult to have R (curvature radius) to have the opening periphery in the recessed groove in which the cross section formed in the polishing cloth itself is rectangular, and it is difficult to manufacture. Moreover, even if R is given to the periphery of the opening in the concave groove having a rectangular cross section formed on the polishing cloth itself, it is thought that a sufficient effect cannot be expected due to the reason that the groove is distorted as described above or the groove is deformed. do. However, as compared with the concave groove whose cross section formed in the polishing cloth itself shown in FIG. 14 is rectangular, it is thought that the effect | action as having R is exhibited similarly to this application.

The present invention has the following configuration.

(Configuration 1)

A process of polishing a mask blank substrate by moving the surface plate to which the polishing cloth is attached and the mask blank substrate relative to each other under a predetermined load, and then supplying a polishing liquid between the contact surface between the polishing cloth and the mask blank substrate. As a method of manufacturing a mask blank substrate having a

The surface plate to which the said polishing cloth was affixed,

A surface plate having a groove on the surface of the polishing cloth attached to the surface plate, the cross-sectional shape of the groove being formed in a curved or curved shape at least around the opening of the groove;

And a polishing cloth attached along the shape of the groove having the polishing cloth attachment plane of the surface plate and the predetermined opening circumference portion shape,

A method for producing a mask blank substrate, characterized in that the substrate for mask blank is polished using a predetermined surface on which the polishing cloth is attached.

(Composition 2)

The surface plate to which the polishing cloth is attached and the mask blank substrate are moved relatively in a state where a predetermined load is applied, and then the polishing liquid is supplied between the contact surface between the polishing cloth and the mask blank substrate to polish the mask blank substrate. As a manufacturing method of a mask blank substrate which has a process,

The surface plate to which the said polishing cloth was affixed,

A groove having a groove on the surface of the polishing cloth attached to the plate, the cross-sectional shape of the groove being formed in a predetermined shape at least around the opening of the groove;

A polishing cloth attached along the shape of the surface of the polishing cloth attaching surface of the surface plate and the groove having the shape of the predetermined opening,

The shape of the opening periphery in the "prescribed groove made of abrasion cloth" formed reflecting the form of "the groove having a predetermined opening periphery shape on the surface plate" is the opening of the "prescribed groove made of abrasion cloth". As a surface plate in which the action of adhering the polishing liquid to the surface of the substrate becomes relatively large with respect to the action of removing the polishing liquid from the surface of the substrate among the actions generated by the shape of the periphery,

By using a predetermined surface plate to which the polishing cloth is attached, using the action caused by the shape of the opening portion of the polishing liquid stored in the "prescribed groove made of abrasive cloth" and "prescribed groove made of abrasive cloth" A method for producing a mask blank substrate, comprising polishing the mask blank substrate.

(Composition 3)

The shape of the opening periphery in the "prescribed groove made of abrasion cloth" formed by reflecting the shape of the groove having the shape of the predetermined opening periphery on the surface plate is curved, curved or inclined in a cross-sectional direction. The manufacturing method of the board | substrate for mask blanks of the structure 2 characterized by the above-mentioned.

(Composition 4)

The mask blank substrate is placed on the surface plate to which the polishing cloth is affixed, and the surface plate and the mask blank substrate are relatively moved in a state where a certain load is applied from the surface plate to the mask blank substrate, and then the polishing liquid is A method for manufacturing a mask blank substrate, comprising: supplying between a contact surface between the polishing cloth and the mask blank to polish the mask blank substrate;

The surface plate to which the said polishing cloth was affixed,

A surface plate having a groove on the surface of the polishing cloth attached to the surface plate, the cross-sectional shape of the groove being formed in a shape in which at least the opening circumference of the groove is rounded;

Manufacture of a mask blank substrate, comprising a polishing plate attached to the surface of the surface of the polishing cloth and the shape of the groove, and polishing the mask blank substrate using a predetermined surface to which the polishing cloth is attached. Way.

(Composition 5)

The manufacturing method of the mask blank board | substrate which grinds the large mask substrate for mask blanks for display apparatus manufacture using the manufacturing method of the mask blank board | substrate in any one of the structures 1-4.

(Composition 6)

In the polishing step, the mask blank substrate is manufactured according to any one of Configurations 1 to 5, wherein a plurality of polishing steps are performed such that the surface of the mask blank substrate has a desired flatness and a desired smoothness. Way.

(Composition 7)

In the plurality of polishing steps, the mask blank substrate is sandwiched by an upper plate and a lower plate having a predetermined groove shape to which the polishing cloth is attached. On the other hand, the manufacturing method of the mask blank board | substrate in any one of the structures 1-6 characterized by grind | polishing both surfaces of the said mask blank board | substrate by moving the said lower plate relatively.

(Composition 8)

The manufacturing method of the mask blank substrate of the structure 7 characterized by having the flatness measuring process of measuring the flatness of the said mask blank substrate surface during the said some grinding | polishing process.

(Composition 9)

Based on the measurement result obtained by the flatness measuring step, the mask is subjected to single side polishing using a predetermined surface to which the polishing cloth is attached so that the flatness of the surface of the mask blank substrate is the desired flatness. The manufacturing method of the mask blank substrate of the structure 8 characterized by grind | polishing the blank substrate.

(Configuration 10)

The thin film for mask patterns used as a mask pattern is formed in the surface of the mask blank substrate obtained by the manufacturing method of the mask blank substrate in any one of the structures 1-9, The manufacturing method of the mask blank characterized by the above-mentioned.

(Configuration 11)

The said mask pattern thin film in the mask blank obtained by the manufacturing method of the mask blank of the structure 10 is patterned, and the mask pattern is formed in the surface of the said mask blank substrate.

(Configuration 12)

A plate having an abrasive cloth attached thereto, means for relatively moving the mask blank substrate under a constant load applied thereto, and means for supplying the polishing liquid between the contact surface between the polishing cloth and the mask blank substrate. An apparatus for manufacturing a mask blank substrate, which is used in a polishing step of a mask blank substrate,

The surface plate to which the said polishing cloth was affixed,

A groove having a groove on the surface of the polishing cloth attached to the plate, the cross-sectional shape of the groove being formed in a predetermined shape at least around the opening of the groove;

And a polishing cloth attached along the shape of the groove having the polishing cloth attaching surface of the surface plate and the predetermined opening peripheral shape.

(Composition 13)

And a means for directly supplying a polishing liquid only to the "prescribed grooves covered with abrasive cloth" formed by reflecting the form of the "homes having a predetermined opening circumferential shape on the surface plate". Apparatus for producing a substrate for mask blanks.

(Composition 14)

The surface plate to which the polishing cloth is adhered is first attached to the surface of the surface of the surface plate with the polishing cloth, and then the portion of the polishing cloth spread over the top of the groove on the surface plate is pushed from the top into the groove. An apparatus for producing a mask blank substrate according to configuration 12 or 13, wherein a polishing cloth is attached along the inner surface of the film.

Hereinafter, the present invention will be described in detail.

According to the method for producing a mask blank substrate of the present invention, a surface plate having a polishing cloth adhered to the mask blank substrate is relatively moved in a state where a predetermined load is applied, and then the polishing liquid is brought into contact with the polishing cloth and the mask blank substrate. As a manufacturing method of a mask blank substrate which has a process of supplying between and grinding | polishing the board | substrate for mask blanks,

The surface plate to which the said polishing cloth was affixed,

A surface plate having a groove on the surface of the polishing cloth attached to the surface plate, the cross-sectional shape of the groove being formed in a curved or curved shape at least around the opening of the groove;

And a polishing cloth attached along the shape of the groove having the polishing cloth attachment plane of the surface plate and the predetermined opening circumference portion shape,

The substrate for mask blanks is ground using the predetermined surface plate which affixed the said polishing cloth (Structure 1).

Moreover, in the manufacturing method of the mask blank board | substrate of this invention, the said mask blank board is mounted on the surface plate on which the polishing cloth was affixed, and the said surface plate and the said board | substrate were applied to the said mask blank board | substrate in the state. A method for manufacturing a mask blank substrate, comprising moving the mask blank substrate relatively, and then supplying a polishing liquid between the contact surface between the polishing cloth and the mask blank to polish the mask blank substrate.

The surface plate to which the said polishing cloth was affixed,

A surface plate having a groove on the surface of the polishing cloth attached to the surface plate, the cross-sectional shape of the groove being formed in a shape in which at least the opening circumference of the groove is rounded;

And a polishing cloth attached along the shape of the polishing cloth attaching surface of the surface plate and the groove, and the substrate for mask blank is polished using a predetermined surface to which the polishing cloth is attached (Configuration 4).

In addition, the apparatus for manufacturing a mask blank substrate of the present invention includes a surface plate to which an abrasive cloth is attached, a means for relatively moving the mask blank substrate in a state where a predetermined load is applied therebetween, and the polishing liquid to the abrasive cloth and the mask. An apparatus for manufacturing a mask blank substrate, which is used in a polishing step of a mask blank substrate having a means for supplying a contact surface with a blank substrate,

The surface plate to which the said polishing cloth was affixed,

A surface plate having a groove on the surface of the polishing cloth attached to the surface plate, the cross-sectional shape of the groove being formed in a curved or curved shape at least around the opening of the groove;

And a polishing cloth attached along the shape of the groove having the polishing cloth attaching plane of the surface plate and the predetermined opening circumferential form (Configuration 5).

In the manufacturing method and the manufacturing apparatus of this invention, a surface plate has a groove | channel in the polishing cloth attachment surface of a surface plate. The cross-sectional shape of the groove is formed in a predetermined shape at least around the opening of the groove. The predetermined form is a rounded shape, that is, a curved shape, a curved surface, or an inclined shape when viewed in the cross-sectional direction (Configurations 1 to 4).

For example, in the present invention, as shown in FIG. 2, for example, the groove 1a is provided on the polishing cloth attaching surface 1b of the surface plate 1, and the cross-sectional shape of the groove 1a is at least the polishing cloth of the surface plate 1. At the site C where the attachment plane 1b and the side surface 1c of the groove 1a intersect, they are formed in a rounded shape, that is, curved, curved, or inclined when viewed in the cross-sectional direction.

In the manufacturing method and the manufacturing apparatus of the present invention, the polishing cloth is generally formed along the shape of the groove having the surface of the polishing cloth attached to the surface plate and the predetermined opening circumference shape (at least along the opening circumference, and generally the entire inner surface of the groove). Accordingly). Thereby, the "prescribed groove | channel covered with the polishing cloth" formed reflecting the form of "the groove | channel which has the form of the predetermined | prescribed opening peripheral part formed on the surface plate" is formed. At this time, the polishing cloth is integrally supported from the back surface side along the polishing cloth attachment plane of the surface plate and the inner surface of the groove. Then, the surface plate and the polishing cloth attached to the surface plate are integrated to form a predetermined surface plate made by attaching the polishing cloth having a predetermined groove formed by being covered with polishing cloth.

In the manufacturing method and the manufacturing apparatus of the present invention, the "polishing" formed by reflecting the form of "the groove which has the form of the predetermined opening periphery formed on a surface plate" and the "the groove which has the form of a predetermined opening periphery shape on a surface plate" The form of the "prescribed groove | channel covered with cloth" is the groove which made R (predetermined curvature) to have the simplest at least the periphery of the opening part of a groove | channel (refer FIG. 1).

In the manufacturing method and the manufacturing apparatus of the present invention, the "polishing" formed by reflecting the form of "the groove which has the form of the predetermined opening periphery formed on a surface plate" and the "the groove which has the form of a predetermined opening periphery shape on a surface plate" As shown in Fig. 3, for example, as shown in Fig. 3, the polishing cloth attachment plane 1b or the polishing cloth 2 is placed on the surface of the groove around the opening periphery D of the groove as shown in FIG. ) Is preferably a cross-sectional shape which is gently inclined (depressed) in the thickness direction of the surface plate 1 from the plane 2b. That is, the cross-sectional shape in which the space E whose cross section is substantially wedge-shaped is formed between the opening peripheral part of the groove | channel 3a and the surface of the board | substrate 4 which contact | connects this is preferable (FIG. 3). As shown in Fig. 3, the polishing liquid 11 is lumped into the space E having a substantially wedge shape by the action of centrifugal force due to the counterclockwise rotation as shown. The contact area between the lumped polishing liquid 11 and the surface of the substrate 4 is larger than the case where the space E having a substantially wedge-shaped cross section is not formed. Moreover, the space E whose cross section is substantially wedge-shaped is narrow toward the contact surface (line) of the surface of the board | substrate 4, and the polishing cloth 2. As shown in FIG. It is considered that the action of adhering (adhering) the polishing liquid to the substrate surface acts strongly by these actions. In addition, it is thought that the space E whose cross section is substantially wedge-shaped has very little effect of scraping off (removing) the polishing liquid (interposed slurry) which adhered to (attached) the substrate surface.

As described above, in the present invention, the polishing liquid is scraped (removed) from the surface of the substrate by removing the form of the "prescribed grooves covered with abrasive cloth" formed by reflecting the shape of the "grooves having a predetermined opening circumferential shape on the surface plate". It is preferable to set it as a cross-sectional shape (shape) which has little effect, and on the contrary, the action of adhering (adhering) the polishing liquid to the substrate surface strongly acts. That is, the shape of the opening periphery in the "prescribed groove | channel made with the polishing cloth" formed reflecting the board | substrate of "the groove | channel which has a predetermined | prescribed opening peripheral part shape on a surface plate" form the said predetermined groove | channel made with the polishing cloth " It is preferable that the action of adhering the polishing liquid to the substrate surface becomes relatively large in relation to the action of removing the polishing liquid from the substrate surface among the two actions caused by the shape of the opening periphery of the structure (constitution 2). Accordingly, the effect of reducing the polishing resistance is very high, and therefore the effect of improving the polishing efficiency is very high, and as a result, a significant improvement in productivity can be realized.

In addition, as an application of the aspect as shown in FIG. 3, in the aspect shown in FIG. 4, ie, in the vicinity of the opening circumference of the groove D, the polishing cloth 2 is attached to the surface of the polishing cloth attaching surface 1b or the surface plate. The slanted shape may be inclined smoothly and linearly in the thickness direction of the surface plate 1 from the flat surface 2b. In this case, the angle α formed between the surface 1b of the polishing cloth on the surface plate and the side surface 1c of the groove in the vicinity of the opening circumferential portion D of the groove is 120 ° or more, more preferably 150 ° or more. It is preferable from the viewpoint of effectively exhibiting the above-mentioned action.

The shape (shape) of a portion other than the opening circumference in the groove according to the present invention (the side of the bottom portion, the side of the bottom portion or the side except the opening portion) is not particularly limited, but the polishing liquid supply action by the centrifugal force, the polishing cloth In view of ease of attachment and the like, a curved shape (curved shape) is preferable.

In the present invention, the shape of the groove is preferably symmetrical when viewed in the cross section in the width direction from the viewpoint of the motion trajectory of the surface and the like.

In the present invention, the groove may have a uniform or substantially uniform widthwise cross section along the longitudinal direction of the groove, and may have a different cross section along the longitudinal direction of the groove.

In the manufacturing method and the manufacturing apparatus of the present invention, the "predetermined groove formed by polishing cloth" formed by reflecting the form of "the groove having the shape of a predetermined opening circumferential portion on the surface plate" has a groove width of 10 to 50 mm and a groove. Depth: 1 ~ 10mm is good

The thickness of the polishing cloth is a thickness that can satisfy a predetermined polishing quality (flatness, mirror surface precision) and polishing efficiency, and does not significantly damage the shape of the "groove having a predetermined opening periphery shape on the surface plate". The thickness along which the abrasive cloth can be attached reliably and easily is good.

As for the more preferable specific example of the cross-sectional shape of a groove | channel, the curved surface (3 in which the direction of R differs at least comprised by the curved surface 1c in the peripheral part of the groove | channel, and the curved surface d of the bottom part of a groove | channel, as shown in FIG. 5). Curved surfaces composed of two or more curved surfaces), and the like. Here, the radius of curvature R of the curved surface 1c at the opening circumference of the groove is 3 to 20 mm, the radius of curvature R 'of the curved surface 1d of the bottom of the groove is 10 to 50 mm, and the groove depth h is As for 1-10 mm and groove width w, 10-50 mm is preferable.

In the manufacturing method and the manufacturing apparatus of the present invention, the manufacturing method of the above-described "prescribed surface plate made by attaching the polishing cloth" is, for example, as shown in Fig. 6 (1), the groove 1a having a predetermined cross-sectional shape. (Polishing) is made on the polishing cloth attaching surface of the surface plate (1), and on a flat surface, place one polishing cloth of roughly the same size and uniform thickness on the surface of the polishing cloth attachment surface of the surface plate (1). Through the double-sided tape attached to the entire surface of the polishing cloth, the polishing cloth 2 is attached in a planar shape to the polishing cloth attaching plane of the surface plate 1. Subsequently, as shown in Fig. 6 (1), the portion of the polishing cloth spread over the groove on the surface plate is pressed into the groove from the upper portion thereof, and as shown in Fig. 6 (2), Along the inner surface of the groove using the stretching, elasticity and the adhesive action of the double-sided tape (constitution 7). It is preferable to use the jig | tool 30 which has a curved surface part in order to recess the part of the polishing cloth spread | diffused on the upper part of a groove | channel, and to attach a polishing cloth to the whole groove | channel surface along the inner surface form of a groove | channel. At this time, when the whole cross-sectional shape (profile) of a groove is comprised by the gentle curve, attachment of an abrasive cloth becomes easy. From the viewpoint of durability, it is preferable to attach one polishing cloth to the surface plate. As the jig having the curved portion, for example, a golf ball or the like can be used.

In order to attach the polishing cloth, the polishing cloth is attached to the upper surface and the groove of the surface plate in order, and both sides can be joined.

In the manufacturing method and the manufacturing apparatus of the present invention, the "polishing" formed by reflecting the form of "the groove which has the form of the predetermined opening periphery formed on a surface plate" and the "the groove which has the form of a predetermined opening periphery shape on a surface plate" The layout shape (design viewed from the plane) viewed from the plane of the "prescribed groove covered with cloth" is important for the following reasons.

(1) It relates to the total amount of the groove volume (proportion of the groove length, the groove depth, the number of grooves (area ratio between the non-groove portion and the groove portion in plan view), etc.).

(2) It relates to the function of holding (securing) a sufficient amount of the polishing liquid in the groove on the surface plate.

(3) In relation to the polishing liquid flowing out of the groove by the action of the centrifugal force due to the platen rotation, it relates to the function of holding (securing) a sufficient amount of the polishing liquid in the groove on the surface plate.

In the present invention, it is preferable that the layout shape (design viewed from the plane) viewed from the plane of the groove is a form that can sufficiently exhibit all of the following items.

As a specific plan view layout of the groove according to the present invention, the movement traces of the substrate and the surface plate in the one-side polishing apparatus and the double-side polishing apparatus used in the polishing process of the mask blank large substrate shown in Figs. From the standpoint of the interaction of the vortices, the vortex shape shown in Fig. 7 (1) is particularly preferable. In the double-side polishing apparatus, it is preferable to form grooves according to the present invention on both the upper and lower platen. In this case, when the groove of the lower plate is a vortex as shown in Fig. 7, the groove of the upper plate is preferably inverted vortex (vortex in a mirror-like relationship).

As a layout view seen from the other specific plane of the groove | channel which concerns on this invention, the aspect which laid out the circular arc-shaped groove | channel 3a shown in FIG. 8 from the disk center part to the disk circumferential edge part in multiple and radial layout. Can be mentioned.

As shown in these examples, the design seen from the plane such as drawing the polishing liquid supplied on the surface plate provided with the substrate into the grooves by the surface rotation action is preferable.

Moreover, in the layout shape seen from the plane, such as a parallelogram grid | lattice or a square grid | lattice, the polishing liquid in a groove | channel tends to flow out by the rotation action (centrifugal force) of a surface plate. In addition, in the layout shape viewed from these planes, it is difficult to obtain interaction with the motion trajectory of the substrate, and the effect of grooves (abrasion resistance suppression, scratch prevention, etc.) is reduced.

In the manufacturing method and manufacturing apparatus of the present invention, the width of the groove can be changed. For example, in the case of a vortex groove, since the amount of liquid decreases with the action of the centrifugal force in the outer periphery of the surface, the entire outer periphery is made by thickening the groove in the center of the swirl groove (reducing the line width from the center of the surface to the periphery). This is effective because the supply amount of the polishing liquid also increases in the groove in the groove.

In this invention, it is also possible to provide the height difference in the depth of a groove | channel.

In the present invention, as the means for supplying the polishing liquid, (1) means for supplying the polishing liquid on the surface plate to which the polishing cloth is affixed, and (2) directly supplying the polishing liquid only to at least the "prescribed grooves covered with abrasive cloth". Means (configuration 13), and the like. Although these polishing liquid supply means can use one independently or both, it is preferable to use both. In this case, it is preferable to mainly use the means for supplying the polishing liquid onto the surface plate to which the polishing cloth is attached, and to use the means for directly supplying the polishing liquid only to the "prescribed grooves covered with abrasive cloth".

In addition, it is possible to indirectly supply the polishing liquid to the "prescribed grooves covered with polishing cloth" by means for supplying the polishing liquid on the surface plate to which the polishing cloth is attached. Further, by means of directly supplying the polishing liquid only to the "prescribed grooves covered with abrasive cloth", the polishing liquid flows out from the "prescribed grooves covered with polishing cloth", and the polishing liquid is indirectly attached to the surface plate to which the polishing cloth is attached. It is possible to feed it.

In the manufacturing method and apparatus of the present invention, as a means for directly supplying the polishing liquid only to the "prescribed grooves covered with abrasive cloth", a vortex shape in which the planar shape of the grooves is shown in FIG. (Swirl centering on the center of the surface plate), as shown to (1) and (2) of FIG. 7, from the surface center, the grinding | polishing liquid is supplied to the edge part of the center side of the vortex groove | channel 3a. It is preferable to supply the polishing liquid through the furnace 14. The same applies to the upper surface plate in the double-side polishing apparatus, and it is preferable to supply the polishing liquid to both grooves formed in the upper and lower surface plates, respectively.

As a means for directly supplying the polishing liquid only to the "prescribed grooves covered with abrasive cloth", when the layout shape seen from the plane of the grooves is divided into a plurality of grooves, for example, as shown in Fig. 8, for example, The polishing liquid can be directly supplied only to each groove by forming a polishing liquid supply hole in a bottom portion of each groove divided into a plurality of grooves and supplying the polishing liquid through the polishing liquid supply passage connected thereto. . Even in the spiral groove, the polishing liquid supply hole is formed in a bottom portion of the groove at an arbitrary position of the groove, and the polishing liquid is supplied through the polishing liquid supply passage communicating with it. The polishing liquid can be supplied directly to the grooves.

In the production method of the present invention, the cross-sectional shape of the groove, the groove depth, the groove width, the layout shape seen from the plane of the groove, and the direct supply of the polishing liquid to the grooves, the supply of the polishing liquid onto the surface plate, the amount of each polishing liquid supply, It is preferable to be able to achieve the following matters by a composite action such as a platen rotation speed and a substrate rotation speed.

(1) At the time of surface rotation (during polishing), it is preferable not to become a liquid amount in which some of the grooves have dropped the polishing liquid or the polishing liquid supply action is lost.

(2) At the time of surface rotation (during polishing), by the surface rotation action and the gravity action (action in the direction of removing the difference of the water level) in each of the grooves of some of the grooves or the grooves, It is desirable that the polishing liquid be in the entire groove, at a certain level or more (about half or more) on average, regardless of the passage of time.

(3) It is preferable that a plurality of grooves are provided on the contact surface between the large substrate and the polishing cloth so that fresh polishing liquid can be supplied from here and there (for example, FIG. 1).

(4) It is preferable to grind in the state where the groove | channel is always interposed in the contact surface of a large substrate and a polishing cloth (refer FIG. 1).

(5) In this invention, it is preferable to be able to grind | polish in the state which always interposes a thin layer of slurry between a polishing cloth and the whole surface of a large board | substrate from grinding start to completion.

The manufacturing method of the present invention utilizes the action brought about by the shape of the opening circumference in the "prescribed groove made of abrasion cloth" formed to reflect the shape of the "groove having the shape of the predetermined opening circumference on the surface plate". It is a manufacturing method of the mask blank board | substrate characterized by grind | polishing a board | substrate, (constitution 2). In addition, the method of the present invention is a method for producing a mask blank substrate, characterized in that the substrate is polished using the action of the polishing liquid stored in the " prescribed groove formed by polishing cloth " (holding).

Moreover, the manufacturing method of this invention has the effect | action brought about by the form of the opening peripheral part in the "prescribed groove | channel covered with the polishing cloth" formed reflecting the form of "the groove | channel which has a predetermined opening peripheral shape on a surface plate", In other words, the polishing of the mask blank substrate is performed using the action of scraping off (removing) the polishing liquid from the surface of the substrate, compared with other forms described above (Fig. 13, Fig. 15, etc.). It is a manufacturing method.

Moreover, the manufacturing method of this invention has the effect | action brought about by the form of the opening peripheral part in the "prescribed groove | channel covered with the polishing cloth" formed reflecting the form of "the groove | channel which has a predetermined opening peripheral shape on a surface plate", In other words, the polishing is performed while the action of scraping off (removing) the polishing liquid from the surface of the substrate is reduced relative to the effect of adhering (adhering) the polishing liquid to the substrate surface described above. It is a manufacturing method of the mask blank substrate.

Moreover, the manufacturing method of this invention has the effect | action brought about by the form of the opening peripheral part in the "prescribed groove | channel covered with the polishing cloth" formed reflecting the form of "the groove | channel which has the form of the predetermined opening peripheral part on a surface plate." That is, a mask blank characterized in that polishing is carried out by utilizing the action of adhering (adhering) the polishing liquid to the surface of the substrate described above, which is stronger than that of the other forms (Fig. 13, Fig. 15, etc.). It is a method of manufacturing a substrate for use.

In the manufacturing method of the present invention, during polishing (from the start of polishing to the end of polishing) by the above-described actions, the effect of effectively adhering the polishing liquid to the substrate surface, i.e., the large polishing resistance at the time of polishing the large substrate is reduced, resulting in higher It is a manufacturing method of the mask blank substrate which grinds, using the effect | action which supplies the surface of a board | substrate with the quantity of polishing liquid which can fully achieve the objective and the subject which were polished efficiently by the load.

According to the manufacturing method and manufacturing apparatus of the present invention, the following operational effects can be obtained.

(1) The polishing resistance can be reduced, and the polishing speed (processing efficiency) can be improved. For this reason, the objective and the subject of this invention which are improved so that the large grinding | polishing resistance at the time of the grinding | polishing of a large sized board | substrate may become small efficiently, and can grind efficiently with a higher load can be fully achieved.

(2) After processing, it is easy to separate the substrate from the polishing cloth by reducing the area adsorbed by the polishing cloth and by supplying a large amount of fluid such as polishing liquid (slurry) or water that suppresses adsorption between the substrate and the polishing cloth. Lose.

(3) It is possible to reduce machining resistance and reduce mechanical vibration.

(4) The heat generation of the polishing surface can be suppressed, the solidification of the instant abrasive can be suppressed, and the occurrence of scratches can be prevented.

(5) Since the polishing liquid on the polishing cloth in contact with the polishing surface of the substrate can be prevented from being insufficient or the polishing liquid disappears, the variation in polishing speed in the substrate surface is suppressed and the substrate having high flatness Can be obtained.

(6) In the " prescribed surface plate made by attaching the polishing cloth " of the present invention described above, even if the thickness of the polishing cloth decreases in proportion to the use time, the form of the " prescribed groove covered with the polishing cloth " is maintained. It is possible to achieve and maintain a problem that the polishing resistance is low and the polishing is carried out with higher weighting efficiency until the polishing cloth is replaced. It can also be used any number of times only by replacing the polishing cloth. In addition, the use of expensive commercially available grooved abrasive cloth is unnecessary.

Moreover, in the "prescribed surface plate which affixed the polishing cloth", the groove | channel more than the thickness of an abrasive cloth can be formed. In contrast, in the prior art in which grooves are formed in the polishing cloth itself, it is impossible to form grooves in the polishing cloth that are thicker than the thickness of the polishing cloth. As described above, in the " prescribed plate made by applying the polishing cloth " of the present invention, the degree of freedom in designing the groove increases.

(7) As the substrate is enlarged, there is a tendency that the adsorption force that the substrate adsorbs on the polishing cloth increases.

In the present invention, the form of the "prescribed grooves covered with abrasive cloth" is maintained, and the "prescribed grooves covered with abrasive cloth" is adhered closely to the surface plate to which the substrate and the abrasive cloth are adhered, such as air or polishing liquid or water. Means for escaping the fluid having the effect of removing the sinter are secured, and an area which is not adsorbed in the portion of the "prescribed groove formed by polishing cloth" is secured, so that the substrate is easily separated from the polishing cloth attached to the surface plate. . On the other hand, in the prior art in which the grooves are formed in the polishing cloth itself, the grooves formed in the polishing cloth itself may be crushed and exhibit the same action as the sucker, so that the substrate can be easily separated from the polishing cloth attached to the surface plate. The effect is small.

In the present invention, for example, when the "prescribed groove formed by polishing cloth" is formed in the top plate, there is an effect of easily separating the substrate from the polishing cloth attached to the top plate. Similarly, when a "prescribed groove made of abrasive cloth" is formed in the lower platen, there is an effect of easily separating the substrate from the polishing cloth attached to the lower platen.

In the present invention, for example, if the layout shape seen from the plane of the groove is a vortex shape (a vortex shape centered on the surface center) shown in Fig. 7, even if a large substrate is placed, the entire groove is not covered with the substrate. Since a hole for air to escape is secured sufficiently, it is easy to separate the substrate from the upper and lower platen.

As is apparent from the above-described effects, the manufacturing method and the manufacturing apparatus of the present invention are particularly for large mask blanks for manufacturing display devices (e.g., display panel components) such as liquid crystal displays (TFTs) and color filters (CF). It is particularly suitable for producing substrates (configuration 5). The large-sized mask blank substrate includes a large-sized mask blank transparent substrate in addition to the large-sized mask blank glass substrate.

In the present invention, the action (method) of easily separating the substrate from the polishing cloth attached to the surface plate is provided on the groove and the surface plate in addition to the action of easily separating the substrate exerted by the above-mentioned "prescribed groove formed by the polishing cloth". It can adjust by adjusting supply amount of polishing liquid.

In the case where the substrate is further enlarged and the amount of polishing liquid is relatively insufficient, in addition to the above method, the separation of the substrate is facilitated due to the floating peeling of the surface shown in (1) to (6) below. Cooperating with the method (Japanese Patent Laid-Open No. 2002-127000) is effective as a method for making it easier to separate the substrate.

(1) The substrate 20 held by the substrate carrier 21 shown in FIG. 10 is sandwiched and held on the upper and lower surface plates 22 and 23 made up of a “predetermined surface plate formed by attaching abrasion cloths”. 22 and 23 are rotated on an axis a perpendicular to the working surface of the substrate 20, and the substrate carrier 21 is rotated on an axis perpendicular to the working surface of the substrate 20. In the substrate polishing method of performing a double-side polishing process on the substrate 20 by rotating the substrate 20, the polishing process of the substrate 20 is finished, and before the rotation of the upper and lower plates 22 and 23 is stopped, the upper plate ( 22) the predetermined amount is raised in a range smaller than the thickness of the substrate 20.

As described above, the upper plate 22 is raised by a predetermined amount in a range smaller than the thickness of the substrate 20, thereby bringing the upper plate 22 and the substrate 20 to their own weight. Peeling action is made.

(2) In the substrate polishing method, the predetermined amount is 1/4 to 3/4 of the thickness of the substrate 20.

As a result, the rising amount of the upper platen 22 is not so small that the upper platen 22 is easily brought into contact with the substrate 20. In addition, the rising amount of the upper platen 22 is too large so that the substrate 20 is rotated when the carrier 21 is rotating. It doesn't stick out.

(3) In the substrate polishing method, the lower plate 23 acting on the substrate 20 by varying the rotation speed of the upper plate 22 and the lower plate 23 before the upper plate 22 rises. The frictional resistance of the side is made larger than the frictional resistance of the upper platen side 22.

Thus, since the frictional resistance of the lower platen 23 side acting on the substrate 20 is made larger than the frictional resistance of the upper platen side 22, the substrate 20 is attached to the lower platen 23, The upper plate 22 and the substrate 20 are prevented from adhering.

(4) In the substrate polishing method, the number of rotations of the upper surface plate 22 is made larger than the number of rotations of the lower surface plate 23 before the upper surface plate 22 rises.

Thereby, the frictional force on the lower platen 23 side acting on the substrate 20 can be made larger than the frictional force on the upper platen 22 side.

 (5) In the substrate polishing method, the ratio of the rotation speed of the upper surface plate 22 to the rotation speed of the lower surface plate 23 is 1: 4 or more.

Thereby, the peeling success rate which shows the probability that peeling of a board | substrate from a top plate succeeds can be raised.

(6) In the substrate polishing method, the ratio of the rotational speed of the upper surface plate 22 to the rotational speed of the lower surface plate 23 is 1: 4-7.

Thereby, there is no worry that it will become difficult to perform roughness control control, without reducing peeling success rate.

In the present invention, examples of the polishing cloth (polishing pad) include artificial leather, expanded urethane, unsaturated polyester fibers, and the like. The polishing cloth includes a polishing cloth having a base layer and a foamed resin layer.

As the polishing liquid, a suspension (slurry) of the abrasive particles and water is preferable.

In the polishing step using cerium oxide (CeO 2) as the abrasive grain (for example, the first polishing step described later), the polishing resistance due to the abrasive grain is a polishing step using colloidal silica (SiO 2) (for example, described later). Since it is large compared with the 3rd polishing process, the effect of this invention is large.

In addition, the action and principle of the "prescribed surface plate formed by adhering abrasion cloths" having the "prescribed grooves covered with abrasion cloth" of the present invention can be applied to a substrate having a large area. However, in the case of small electronic device substrates (mask blank substrates, liquid crystal display substrates, information recording medium substrates, etc.), polishing is carried out using a polishing cloth without grooves under the present conditions. As mentioned above, there is no problem that the polishing resistance is increased.

Moreover, in the manufacturing method of this invention, it is efficient to manufacture the mask blank substrate (constitution 6) through several grinding | polishing processes so that the surface of a mask blank substrate may obtain desired flatness and desired smoothness, and a mask blank substrate will be obtained. It is preferable at the point. Further, in the plurality of polishing steps, the mask blank substrate is sandwiched by an upper plate and a lower plate having a predetermined groove shape to which an abrasive cloth is attached, and the mask blank substrate, the upper plate and the lower plate move relatively. It is preferable that both surfaces of the mask blank substrate are polished on both sides to produce a mask blank substrate (constitution 7). In addition, during a plurality of polishing steps, the flatness of the surface of the mask blank substrate is measured (constitution 8), and the flatness of the surface of the mask blank substrate is desired based on the measurement result obtained by the measurement of the flatness. It is preferable to manufacture the mask blank substrate by the single-side polishing (constitution 9) using the predetermined surface plate to which the polishing cloth was attached as much as possible, and it is preferable at the point which can obtain the mask blank substrate with high yield.

Moreover, the manufacturing method of the mask blank of this invention is characterized by forming the mask pattern thin film used as a mask pattern on the surface of the mask blank substrate obtained by the manufacturing method of said mask blank substrate (constitution 10) ). The mask blank produced in this way can obtain the mask blank without defect, maintaining the flatness high. As a mask blank of this invention, the mask blank in which the light shielding film | membrane was formed on the mask blank substrate, the gray-tone mask blank etc. which formed the semi-transmissive film and the light shielding film in order on the mask blank substrate etc. are mentioned. In addition, the upper layer of the light shielding film may have an antireflection film having an antireflection function.

As the material of the light-shielding film, chromium, chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium oxide carbide, chromium oxynitride carbide, chromium nitride carbide, chromium fluoride, and at least one of them The material is preferred. The light shielding film may be a single layer or a plurality of layers. In the case where a material containing chromium is used as the material of the light shielding film, a material containing nitrogen in all the layers constituting the light shielding film is preferable in terms of film stress reduction. In addition, as a light shielding film, it is not limited to the material containing chromium. The material of the light-shielding film is not limited to a MoSi-based material composed of Mo and Si, and metals and silicon (transition metals such as MSi, M: Mo, Ni, W, Zr, Ti, Ta, Cr), and oxynitride metals And silicon (MSiON), oxidized carbon and silicon (MSiCO), oxynitride carbonized metal and silicon (MSiCON), oxidized metal and silicon (MSiO), nitrided metal and silicon (MSiN), and the like.

As a material of a semi-transmissive film, the material which has the light-shielding film mentioned above and etching selectivity with respect to the etchant used when manufacturing a mask is preferable. When the material of the light-shielding film is a material containing chromium, the material of the semi-transmissive film is not limited to the MoSi-based material composed of Mo and Si, and may include metal and silicon (MSi, M: Mo, Ni, W, Zr, Ti, Transition metals such as Ta and Cr), oxynitride metals and silicon (MSiON), oxycarbonized metals and silicon (MSiCO), oxynitride carbonized metals and silicon (MSiCON), oxidized metals and silicon (MSiO), nitride Metal and silicon (MSiN).

The method for manufacturing a mask of the present invention is further characterized by forming a mask pattern on the surface of the mask blank substrate by patterning the thin film for a mask pattern in the mask blank obtained by the method for manufacturing a mask blank described above ( Configuration 11). The mask produced as described above has a good positional accuracy of the mask pattern, and a mask having no pattern defect is obtained.

desirable Example  Explanation

(Example)

Next, an Example of this invention is given and this invention is demonstrated in detail.

(Example 1)

The manufacturing process of the mask blank board | substrate consists of (1) rough lapping process, (2) shape processing process, (3) precision lapping process, (4) 1st polishing process, (5) 2nd polishing process, and (6) agent 3 polishing steps, (7) washing step, and (8) evaluation step. Hereinafter, each process is explained in full detail.

(1) rough lapping process

First, it cut out from the grinding glass from the sheet glass which consists of synthetic quartz glass, and obtained the rectangular large-sized mask blank board | substrate (330 mm x 450 mm or more: 800 mm x 920 mm, thickness 10 mm).

Next, the lapping process was performed to the mask blank substrate. The lapping step is intended to improve the dimensional accuracy and the shape precision. The lapping process was performed using the double-sided lapping apparatus, and the grain size of the abrasive grain was performed at # 400. In detail, the load L was set to about 100 kg using the alumina abrasive grain of particle size # 400, and both surfaces of the mask blank substrate accommodated in the carrier were finished to predetermined precision.

(2) Shape processing process

Next, after the outer peripheral cross section was ground and the outer dimensions were adjusted, predetermined chamfering was performed on the outer peripheral end face and the inner peripheral face.

(3) Precision Lapping

Next, by changing the particle size of the abrasive grain to # 1000 and wrapping the surface of the mask blank substrate, both surfaces of the mask blank substrate were finished to a predetermined precision. The mask blanking substrate which completed the said precision lapping process was immersed in each washing tank of neutral detergent and water in order, and it cleaned.

(4) First Polishing Process

Next, the polishing process was performed. The polishing step was carried out using a double-side polishing apparatus for a large-sized mask blank shown in FIG. 10 for the purpose of removing scratches and distortions remaining in the lapping step described above. Specifically, the "predetermined surface plate made by attaching abrasion cloth" (3) formed by forming a spiral groove (a swirl groove in a clockwise direction from the center of the surface plate) centered on the surface center shown in FIG. As shown in Fig. 7 (1) and (2), the polishing liquid was supplied from the lower plate center to the end portion of the center side of the vortex through the polishing liquid supply passage 14. Similarly, from the center of the top plate, a "predetermined plate made by abrasion cloths" formed by forming a spiral groove (a counterclockwise vortex groove from the base center) is formed as the top plate. The polishing liquid was supplied to the end of the vortex center side through the polishing liquid supply passage. In addition, in the double-side polishing apparatus for large-sized mask blanks shown in FIG. 10, the distance between the rotating shaft a of the upper and lower platen 22, 23, and the rotating shaft b of the board | substrate 20 makes the board | substrate 20 rotate the rotating shaft b. Even in the case of rotating about the axis, it is preferable that no part of the substrate 20 passes through the part of the rotating shaft a, and this is applied in the apparatus shown in FIG.

The cross-sectional shape of the grooves formed on the surface plate is the shape shown in Fig. 5, wherein R: 10 mm of the curved surface 1c at the opening circumference of the groove, R ': 25 mm, the groove of the curved surface 1d at the bottom of the groove. Depth (h): 1.5 mm, groove width (w): 20 mm. The thickness of the polishing cloth was 2 mm.

Using a hard polisher as a polisher, it was carried out under the following polishing conditions.

Polishing liquid: Free abrasive grains with water added to cerium oxide (average particle diameter 2-3 μm)

Grinding cloth: soft polisher (suede type), thickness 2mm

Amount of polishing liquid supplied directly to the groove only: 5ℓ / min

Polishing liquid supplied on the surface plate: 2ℓ / min

Upper plate rotation speed: 1 ~ 50rpm (rotate clockwise when viewed from the top of the device)

Lower plate rotation speed: 1 ~ 50rpm (rotate counterclockwise when viewed from the top of the device)

Carrier (mask blank substrate) rotation speed: 1 ~ 50rpm (rotate counterclockwise when viewed from the top of the device)

Load (Negative pressure): 80 ~ 100g / ㎠

Polishing time: 30 ~ 100 minutes

Removal amount: 35 ~ 75㎛

The mask blank substrate which completed the said polishing process was immersed in each washing tank of neutral detergent, pure water, pure water, IPA, and steam-drying | cleaning, and washed. In addition, ultrasonic waves were applied to each cleaning tank. In addition, this washing | cleaning process can also be abbreviate | omitted when the polishing liquid used by a 2nd polishing process is the same.

(5) second polishing process

Next, the 2nd polishing process was implemented using the single-side polishing apparatus for large mask blanks shown in FIG.

Specifically, by using the "prescribed surface plate made by attaching abrasion cloth" (3) in which a vortex groove (a vortex groove clockwise from the surface center) is formed around the center of the surface plate shown in FIG. As shown in Fig. 7 (1) and (2), the polishing liquid was supplied from the lower plate center to the end portion of the center side of the vortex through the polishing liquid supply passage 14. In the large-scale mask blank single-side polishing apparatus shown in FIG. 9, the distance between the rotation axis a of the lower plate 23 and the rotation axis b of the substrate 20 is such that the substrate 20 rotates the rotation axis b. Even in the case of rotating about the axis, it is preferable that no part of the substrate 20 passes through the part of the rotating shaft a, and this is applied in the apparatus shown in FIG.

The cross-sectional shape of the groove formed on the surface plate is the shape shown in Fig. 5, and the radius of curvature R of the curved surface 1c at the opening circumference of the groove is 10 mm and the radius of curvature of the curved surface 1d of the bottom of the groove. (R '): 25 mm, groove depth (h): 1.5 mm, groove width (w): 20 mm. The thickness of the polishing cloth was 2 mm.

Using a super soft polisher as a polisher, it was carried out under the following polishing conditions.

Polishing liquid: Glass abrasive grains with water added to colloidal silica (average particle diameter 50 ~ 80nm)

Grinding cloth: Super soft polisher (suede type), thickness 2mm

Amount of polishing liquid supplied directly to the groove only: 5ℓ / min

Polishing liquid supplied on the surface plate: 2ℓ / min

Lower plate rotation speed: 1 ~ 50rpm (rotate counterclockwise when viewed from the top of the device)

Carrier (mask blank substrate) rotation speed: 1 ~ 50rpm (rotate counterclockwise when viewed from the top of the device)

Load (Negative pressure): 80 ~ 100g / ㎠

Polishing time: 30 ~ 50 minutes

Removal amount: 35 ~ 45㎛

(6) Third polishing process (mirror polishing process)

Next, using the double-side polishing apparatus for large-sized mask blanks shown in FIG. 10, the 3rd polishing process (mirror polishing process; final polishing) was performed as a polisher, changing from a hard polisher to a soft polisher.

Specifically, the "prescribed surface plate made by attaching abrasion cloth" (3) formed by forming a spiral groove (a swirl groove in a clockwise direction from the center of the surface plate) centered on the surface plate center shown in FIG. As shown in (1) and (2) of FIG. 7, the polishing liquid was supplied from the lower plate center to the end portion of the center side of the vortex through the polishing liquid supply passage 14. Similarly, using the "predetermined surface formed by attaching abrasion cloth" in which a spiral groove (a counterclockwise vortex groove is formed from the surface center) is formed as the upper surface plate from the center of the upper surface plate. The polishing liquid was supplied to the end of the vortex center side through the polishing liquid supply passage. In the double-side polishing apparatus for large-sized mask blanks shown in FIG. 10, the distance between the rotation shaft a of the upper and lower platen 22 and 23 and the rotation shaft b of the substrate 20 is such that the substrate 20 is the rotation shaft b. Even in the case of rotating around the axis, it is preferable that no part of the substrate 20 passes through the part of the rotation axis a, and this is applied in the apparatus shown in FIG.

The cross-sectional shape of the groove formed on the surface plate is the shape shown in Fig. 5, and the radius of curvature R of the curved surface 1c at the opening circumference of the groove is 10 mm and the radius of curvature of the curved surface 1d of the bottom of the groove. (R '): 25 mm, groove depth (h): 1.5 mm, groove width (w): 20 mm. The thickness of the polishing cloth was 2 mm.

Using a super soft polisher as a polisher, it was carried out under the following polishing conditions.

Polishing liquid: Glass abrasive grains with water added to colloidal silica (average particle diameter 50 ~ 80nm)

Grinding cloth: Super soft polisher (suede type), thickness 2mm

Amount of polishing liquid supplied directly to the groove only: 5ℓ / min

Polishing liquid supplied on the surface plate: 2ℓ / min

Upper plate rotation speed: 1 ~ 50rpm (rotate clockwise when viewed from the top of the device)

Lower plate rotation speed: 1 ~ 50rpm (rotate counterclockwise when viewed from the top of the device)

Carrier (mask blank substrate) rotation speed: 1 ~ 50rpm (rotate counterclockwise when viewed from the top of the device)

Load (Negative pressure): 80 ~ 100g / ㎠

Polishing time: 30 ~ 50 minutes

Removal amount: 35 ~ 45㎛

(7) cleaning process

The mask blank substrate which completed the said 3rd polishing process was immersed in alkali (NaOH), sulfuric acid in order, and it wash | cleaned. In addition, ultrasonic waves were applied to each cleaning tank. In addition, it was immersed in each washing tank of neutral detergent, pure water, pure water, IPA, and IPA (vapor drying), and washed.

(8) Evaluation process

The mask blank substrate thus obtained had high flatness (11 μm) and high smoothness, and was free of defects such as scratches.

Further, in the first to third polishing processes, the object and the object of the present invention can be sufficiently achieved to improve such that the large polishing resistance at the time of polishing a large substrate becomes small and to efficiently polish with a higher load. In addition, in these processes, a large substrate was polished with a high load, and no vibration occurred at all of the apparatus portions and the apparatus as a whole. In addition, in these processes, the board | substrate could be easily isolate | separated from the upper and lower predetermined surface plate.

Moreover, the light shielding film etc. were formed on the obtained large sized mask blank substrate, and the large sized mask blank could be manufactured efficiently.

(Example 2)

In Example 1, both main surfaces of the substrate 20 under the same conditions as the first polishing process, using the large-area mask blank double-side polishing apparatus shown in Fig. 10, for the mask blank substrate obtained through the lapping process. Was polished on both sides.

When the flatness of both main surfaces of the double-sided polishing substrate 20 was measured, the surface was 5.3 µm and the rear surface was 11.4 µm.

Next, similarly to Example 1, the 2nd polishing process was performed with respect to the back surface using the single-side polishing apparatus for large mask blanks shown in FIG.

In addition, the cross-sectional shape of the grooves formed on the surface plate of the single-side polishing apparatus and the thickness of the polishing cloth were the same as those in Example 1, and the polishing conditions (lower platen speed, carrier rotation speed, load under which the flatness was about 5 µm) were used. And polishing time) were set appropriately for polishing.

It was 6.2 micrometers when the flatness of the back surface of the board | substrate 20 was measured.

Finally, similarly to Example 1, using the double-sided polishing apparatus for large-sized mask blanks shown in FIG. 10, the load is reduced from 50 to 50 so that the flatness of the substrate 20 obtained by the second polishing process is maintained or improved. A third polishing step was performed in the same manner as in Example 1 except that the amount was changed to 85 g / cm 2.

When the flatness of both main surfaces of the obtained board | substrate 20 was measured, the surface was 4.7 micrometers and the back surface was 6.2 micrometers very favorable. In addition, the smoothness of the surface was in a mirror state without any marks due to polishing, which was good. Moreover, it was satisfactory without defects such as scratches, cracks, and debris.

A chromium nitride film, a chromium nitride carbide film, and a chromium oxynitride film were laminated on the surface of the substrate 20 thus obtained, and a light shielding film with an antireflection film containing nitrogen was formed by sputtering in the entire depth direction of the film by sputtering. Blanks and large mask blanks for CF production were obtained. The obtained large mask blank maintained high flatness with little change from the flatness of the substrate 20, and was also free from defects.

A resist film was formed on the light shielding film in the above-mentioned large mask blank, a desired pattern was drawn on the resist film, and then developed to form a resist pattern. Next, the resist pattern was used as a mask, the light shielding film was wet etched with a wet etching solution to form a light shielding film pattern, and then the resist film was peeled off to obtain a mask for TFT manufacture and a mask for CF manufacture. The mask thus obtained was also good in pattern position accuracy and good without pattern defects.

(Comparative Examples 1 and 2)

In the first to third polishing steps of Example 1, a surface plate (Comparative Example 1) having a grooved polishing cloth attached to the surface plate or a surface plate having a grooved polishing cloth attached to the surface plate (Comparative Example 2) Except for the use, polishing was carried out in the same manner as in Example 1 to prepare a mask blank substrate.

In these cases, as described in FIG. 13, in the first to third polishing steps, the polishing liquid on the polishing cloth is insufficient on the side B opposite to the supply side A of the polishing liquid 11 when viewed from a distance. In other words, it was confirmed that the polishing liquid had fallen off, the current value of the surface plate driving motor was increased, and vibration occurred in the entire apparatus.

Therefore, in the first to third polishing steps, polishing was carried out with a small load. As a result, the polishing rate is lowered, so that the polishing time is long, and the polishing efficiency is inevitably deteriorated to 1/5 as compared with Example 1. In addition, in such a process, it was not easy to separate a board | substrate from the upper and lower surface plates.

Moreover, the obtained mask blank substrate was able to confirm the tendency that the board thickness becomes smooth gradually from the outer periphery of a board | substrate to a board | substrate center part as seen from the cross section. In contrast, in Example 1, this tendency could not be confirmed. Moreover, when the flatness of both main surfaces of the mask blank substrates in Comparative Examples 1 and 2 was measured, Comparative Example 1 had a surface of 35 µm, a rear surface of 48 µm, and Comparative Example 2 also had a surface of 37 µm and a rear surface. The flatness standard of the mask blank substrate for TFT manufacture was 20 micrometers or less, and the flatness standard of the mask blank substrate for CF manufacture was 30 micrometers or less at 45 micrometers.

According to the present invention, the present invention relates to a method for manufacturing a mask blank substrate, a method for manufacturing a mask blank, and a method for manufacturing a mask, in particular, a method for manufacturing a mask blank substrate and a mask blank, which are suitable for producing a large mask blank substrate. A method and a method of manufacturing a mask can be provided.

Claims (19)

The surface plate to which the polishing cloth was affixed, and the mask blank substrate having a size of 330 mm x 450 mm or more were relatively moved under a predetermined load, and the polishing liquid was then moved to the polishing cloth and the mask blank substrate. A method of manufacturing a mask blank substrate, which comprises a step of supplying between contact surfaces of the substrate to polish the mask blank substrate. The surface plate to which the above polishing cloth is attached has a groove on the surface of the polishing cloth attachment surface of the surface plate, The groove has a curved or curved cross-sectional shape at least at the opening circumference of the groove, The groove is formed on the polishing cloth attaching surface of the surface plate in a vortex-like layout, and the width of the groove in the plane-viewed layout becomes smaller from the center side of the surface plate to the outer circumferential side. And The polishing cloth is attached along the shape of the groove having the surface of the polishing cloth attachment plane and the predetermined opening circumference of the surface plate, In the process of polishing the mask blank substrate, the surface plate rotates about a rotation axis provided at the center of the surface plate, and the rotation direction of the surface plate is the same as the vortex direction in the layout seen from the vortex-shaped plane of the groove. , A method for producing a mask blank substrate, characterized in that a polishing liquid is supplied from a polishing liquid supply path provided at the center of the surface plate to a central side end portion of the groove having a swirl shape. delete delete A mask blank substrate having a size of at least 330 mm × 450 mm is placed on a surface plate to which an abrasive cloth is attached, and the surface plate and the mask blank substrate are placed in a state where a predetermined load is applied to the mask blank substrate from the surface plate. A method of manufacturing a mask blank substrate, comprising the steps of relatively moving the substrate, and then supplying a polishing liquid between the contact surface between the polishing cloth and the mask blank to polish the mask blank substrate. The surface plate to which the above polishing cloth is attached has a groove on the surface of the polishing cloth attachment surface of the surface plate, The groove has a cross-sectional shape in which at least the opening circumference of the groove is rounded, The groove is formed on the polishing cloth attaching surface of the surface plate in a vortex-like layout, and the width of the groove in the plane-viewed layout becomes smaller from the center side of the surface plate to the outer circumferential side. And The polishing cloth is composed of the polishing cloth attached to the surface plate and the polishing cloth attached along the shape of the groove, the polishing cloth is attached, In the process of polishing the mask blank substrate, the surface plate rotates about a rotation axis provided at the center of the surface plate, and the rotation direction of the surface plate is the same as the vortex direction in the layout seen from the vortex-shaped plane of the groove. , A method for producing a mask blank substrate, characterized in that a polishing liquid is supplied from a polishing liquid supplying path provided at the center of the surface plate to a central side end portion of the groove having a swirl shape. The surface plate attached with the polishing cloth and the mask blank substrate having a size of 330 mm x 450 mm or more are relatively moved under a predetermined load, and then the polishing liquid is moved between the contact surface between the polishing cloth and the mask blank substrate. A method for producing a mask blank substrate, which comprises a step of supplying to a substrate to polish the mask blank substrate, The surface plate to which the above polishing cloth is attached has a groove on the surface of the polishing cloth attachment surface of the surface plate, The groove has a cross-sectional shape inclined in the thickness direction of the surface plate from the polishing cloth attaching surface at the opening circumference portion, The groove is formed on the polishing cloth attaching surface of the surface plate in a vortex-like layout, and the width of the groove in the plane-viewed layout becomes smaller from the center side of the surface plate to the outer circumferential side. And The polishing cloth is attached along the polishing cloth attaching plane of the surface plate and the shape of the groove, In the process of polishing the mask blank substrate, the surface plate rotates about a rotation axis provided at the center of the surface plate, and the rotation direction of the surface plate is the same as the vortex direction in the layout seen from the vortex-shaped plane of the groove. , A method for producing a mask blank substrate, characterized in that a polishing liquid is supplied from a polishing liquid supplying path provided at the center of the surface plate to a central side end portion of the groove having a swirl shape. The surface plate attached with the polishing cloth and the mask blank substrate having a size of 330 mm x 450 mm or more are relatively moved under a predetermined load, and then the polishing liquid is moved between the contact surface between the polishing cloth and the mask blank substrate. A method for producing a mask blank substrate, which comprises a step of supplying to a substrate to polish the mask blank substrate, The surface plate to which the above polishing cloth is attached has a groove on the surface of the polishing cloth attachment surface of the surface plate, The groove has a cross-sectional shape that is inclined linearly in the thickness direction of the surface plate from the polishing cloth attachment surface at the opening circumference portion, The groove is formed on the polishing cloth attaching surface of the surface plate in a vortex-like layout, and the width of the groove in the plane-viewed layout becomes smaller from the center side of the surface plate to the outer circumferential side. And The polishing cloth is attached along the polishing cloth attaching plane of the surface plate and the shape of the groove, In the process of polishing the mask blank substrate, the surface plate rotates about a rotation axis provided at the center of the surface plate, and the rotation direction of the surface plate is the same as the vortex direction in the layout seen from the vortex-shaped plane of the groove. , A method for producing a mask blank substrate, characterized in that a polishing liquid is supplied from a polishing liquid supplying path provided at the center of the surface plate to a central side end portion of the groove having a swirl shape. The method according to claim 6, The groove is a manufacturing method of a mask blank substrate, characterized in that the angle formed between the polishing cloth attaching surface at the opening circumference and the side surface of the groove is 120 degrees or more. The surface plate attached with the polishing cloth and the mask blank substrate having a size of 330 mm x 450 mm or more are relatively moved under a predetermined load, and then the polishing liquid is moved between the contact surface between the polishing cloth and the mask blank substrate. A method for producing a mask blank substrate, which comprises a step of supplying to a substrate to polish the mask blank substrate, The surface plate to which the above polishing cloth is attached has a groove on the surface of the polishing cloth attachment surface of the surface plate, The groove has a curved surface formed of at least a curved surface formed in the periphery of the opening and a curved surface formed in the bottom portion, The groove is formed on the polishing cloth attaching surface of the surface plate in a vortex-like layout, and the width of the groove in the plane-viewed layout becomes smaller from the center side of the surface plate to the outer circumferential side. And The polishing cloth is attached along the polishing cloth attaching plane of the surface plate and the shape of the groove, In the process of polishing the mask blank substrate, the surface plate rotates about a rotation axis provided at the center of the surface plate, and the rotation direction of the surface plate is the same as the vortex direction in the layout seen from the vortex-shaped plane of the groove. , A method for producing a mask blank substrate, characterized in that a polishing liquid is supplied from a polishing liquid supplying path provided at the center of the surface plate to a central side end portion of the groove having a swirl shape. 9. The method of claim 8, The groove is a mask blank substrate manufacturing method, characterized in that the entire cross-sectional shape is composed of a curve. delete Polishing the large substrate for mask blank for display device manufacturing using the method for manufacturing a mask blank substrate according to any one of claims 1, 4, 5, 6, and 8. A method of manufacturing a mask blank substrate, characterized in that. The method according to any one of claims 1, 4, 5, 6, and 8, The polishing step is a manufacturing method of a mask blank substrate, characterized in that for performing a plurality of polishing steps to obtain a desired flatness and the desired smoothness of the surface of the mask blank substrate. 13. The method of claim 12, In the plurality of polishing steps, the mask blank substrate is sandwiched by an upper plate and a lower plate having a predetermined groove shape to which the polishing cloth is attached. The half surface plate is moved relatively, and both surfaces of the said mask blank substrate are polished on both surfaces, The manufacturing method of the mask blank substrate characterized by the above-mentioned. 14. The method of claim 13, And a flatness measuring step of measuring the flatness of the mask blank substrate surface during the plurality of polishing steps. 15. The method of claim 14, Based on the measurement result obtained by the flatness measuring step, the mask is subjected to single side polishing using a predetermined surface to which the polishing cloth is attached so that the flatness of the surface of the mask blank substrate is the desired flatness. A method for producing a mask blank substrate, comprising polishing the blank substrate. The mask pattern which becomes a mask pattern on the surface of the mask blank substrate obtained by the manufacturing method of the mask blank substrate of any one of Claims 1, 4, 5, 6, and 8. A method for producing a mask blank, characterized in that a thin film for forming is formed. The mask manufacturing method of Claim 16 which forms the mask pattern on the surface of the said mask blank substrate by patterning the said thin film for mask patterns in the mask blank obtained by the manufacturing method of the mask blank of Claim 16. delete delete

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