JP2005195992A - Pellicle mounting jig, pellicle mounting method, pellicle mounting structure, and pellicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mount a pellicle mounting jig, a pellicle mounting method and a pellicle that can be securely and easily mounted on a photomask without deforming the bending shape of the pellicle plate when mounting the pellicle made of synthetic quartz glass on the photomask The purpose is to provide a mounting structure.
SOLUTION: A peripheral edge of a pellicle 2 made of synthetic quartz glass is pressed through an adhesive 3 to be attached to a photomask 1 and includes a pair of parallel pressing pieces 8 and a connecting piece 9 for connecting the pressing pieces 8 together. The pellicle mounting jig 4 includes a pellicle frame 5 having a rectangular frame and a pellicle plate 6 that is bent and bent in a convex shape. The piece 8 presses the peripheral edge of the two opposite sides 6b on the non-deflection side of the peripheral edge of the pellicle 2, and the connecting piece 9 is not in contact with the pellicle plate 6 when pressed.
[Selection] Figure 1

Description

The present invention is attached to a photomask or reticle (hereinafter referred to as a photomask) used in an integrated circuit manufacturing process such as printing a circuit pattern on a substrate such as a semiconductor element for the purpose of preventing foreign matter adhesion, in particular F _{The present} invention relates to a pellicle mounting jig, a pellicle mounting method, a pellicle mounting structure, and a pellicle suitable for photolithography using light of _two lasers (wavelength: 157.6 nm).

  In an optical lithography process used in an integrated circuit manufacturing process, a pattern is formed by exposing a semiconductor wafer coated with a resist material. If scratches / foreign matter are present on the photomask used at this time, the scratches / foreign matter are transferred onto the wafer together with the pattern, which may cause a short circuit or disconnection of the circuit. For this reason, a pellicle is mounted on one side or both sides of the photomask in order to prevent scratches and foreign matter contamination on the surface of the photomask on which the circuit pattern is formed.

  Conventionally, a pellicle has been used in which a pellicle film made of an organic resin such as nitrocellulose or fluorine resin is attached to a pellicle frame made of aluminum or the like with an adhesive, and this is used as a photomask. It was fixed to cover the upper pattern. However, a pellicle using such an organic resin film or the like is used for actual exposure because the optical energy is strong when the wavelength used to increase the exposure accuracy is shortened, and the aerial content is decomposed. It does not have sufficient durability with respect to the number of shots with energy, in other words, the usage time.

Therefore, in consideration of durability against exposure light using short-wavelength light such as an F ₂ laser with a wavelength of 157 nm due to recent pattern miniaturization and higher density, a pellicle plate made of synthetic quartz glass processed into a thin plate is used. To be considered.

FIG. 11 is a schematic view showing a pellicle mounting method using a conventional pellicle mounting jig.
As shown in the figure, a pellicle 72 is bonded via an adhesive 73 so as to cover a pattern (not shown) on the photomask 71, and the peripheral portion of the pellicle 72 is pressed by a mounting jig 74 having a rectangular frame. To do. The pellicle 72 is made of synthetic quartz glass, and is formed by attaching a pellicle plate 76 to a rectangular frame pellicle frame 75 with an adhesive 77. This synthetic quartz glass is made from, for example, substantially silicon oxide obtained by allowing a silicon source and an oxygen source to react in a gas phase to grow a porous material made of silicon oxide called soot and sintering the porous material. Glass. The pellicle plate 76 made of synthetic quartz glass is often provided with an antireflection film on one or both sides in order to improve transmission efficiency.

  Thus, when synthetic quartz glass is used as the pellicle plate, it is desirable that the thickness of the pellicle plate 76 is 0.01 to 2 mm. The pellicle plate having such a thickness is an organic resin. Unlike the pellicle film made of the above, there are cases where the optical path of the exposure light varies due to the birefringence inside the pellicle plate 76 or the warp of the pellicle plate 76.

  On the other hand, as a pellicle mounting structure for mounting a pellicle on a substrate (photomask), Patent Document 1 discloses a structure in which a groove is formed in a pellicle frame, and a plurality of U-shaped plate springs are engaged with the groove and the substrate. ing. However, the pellicle mounting structure described in Patent Document 1 must form a groove in the pellicle frame. When synthetic quartz glass is used as the pellicle frame, it is difficult to form a groove that can maintain sufficient strength. . Therefore, it is not suitable as a mounting structure for a pellicle made of synthetic quartz glass.

Japanese Patent Application Laid-Open No. 11-194481

  Since the pellicle 72 is mounted on the lower surface of the photomask 71 with the pellicle plate 76 facing downward, if the pellicle plate 76 bends by its own weight during use, the optical path of the exposure light is changed, which causes deterioration in exposure accuracy. Since exposure by the exposure apparatus is such that the photomask with a pellicle moves in one direction and transfers the pattern of the photomask onto the wafer, the variation of the pellicle plate 76 in the vertical direction can be expressed by a function of an even order. If it is a curvature, it can be corrected by an optical system, and this curvature only needs to be constant with respect to the moving direction of the photomask.

  Therefore, if the opposite side of the pellicle plate 76 parallel to the moving direction of the photomask 71 (arrow E) is bonded in parallel to the bonding surface of the pellicle frame 75 to the photomask 71, the moving direction of the photomask (arrow E). Even if the opposite side of the pellicle plate 76 is bent with respect to the pellicle frame 75, the deflection can be optically corrected to form a pattern on the semiconductor wafer.

  On the other hand, when the pellicle plate 76 is bent and a gap is formed between the pellicle frame 75, foreign matter or the like is mixed from the pellicle plate 75, preventing the pellicle function from protecting the photomask surface from being lost, In order to prevent the deflection amount from partially changing due to vibration generated when the photomask with the pellicle moves, the gap generated between the pellicle plate 76 and the pellicle frame 75 is sealed. At this time, the amount of deflection of the pellicle plate 76 is kept constant by interposing a spacer in the gap between the pellicle plate 76 and the pellicle frame 75 or using a sealing material such as an adhesive 77 (in the figure, sealed with the adhesive 77). Stop). Therefore, the pellicle plate 76 bends with a predetermined curvature and is line symmetric with respect to a line connecting the midpoints of the opposite sides of the bent side.

  When the pellicle 72 having the pellicle plate 76 bent in a convex shape is to be mounted on the photomask 71, the mounting jig 74 made of a rectangular frame presses the four sides of the pellicle plate 76 evenly. The gap between the opposite side of 76 and the pellicle frame 75 is compressed, resulting in partial deformation of the pellicle plate 76, which deteriorates the exposure accuracy in exposure light in which the deflection is optically corrected. .

  The present invention is based on the above prior art, and when a pellicle made of synthetic quartz glass is mounted on a photomask, it can be securely and easily mounted on the photomask without deforming the bending shape of the pellicle plate. A pellicle mounting jig, a pellicle mounting method, a pellicle mounting structure, and a pellicle are provided.

  In order to achieve the above object, according to the first aspect of the present invention, a peripheral edge of a pellicle made of synthetic quartz glass is pressed through an adhesive to be attached to a photomask, and a pair of parallel pressing pieces are connected to each other. A pellicle mounting jig comprising a connecting piece, wherein the pellicle includes a pellicle frame having a rectangular frame body and a pellicle plate bent and bent in a convex shape, and the pair of parallel pressing members A pellicle mounting jig is provided, wherein one of the peripheral edges of the pellicle peripheral edge of the pellicle is pressed against the opposite peripheral edges of the pellicle, and the connecting piece is not in contact with the pellicle plate when pressed. To do.

  The invention according to claim 2 is characterized in that an elastic member is provided on the pressing-side surface of the connecting piece, and the elastic member contacts the pellicle plate and presses elastically when pressed.

  In the invention of claim 3, the periphery of the pellicle made of synthetic quartz glass is pressed through an adhesive to be mounted on a photomask, and a pellicle mounting treatment comprising a pair of parallel pressing pieces and a connecting piece connecting the pressing pieces to each other. The pellicle includes a pellicle frame having a rectangular frame and a pellicle plate bent and bent in a convex shape, and the pair of parallel pressing pieces are used to form a pellicle peripheral portion. A pellicle mounting jig is provided, which presses the peripheral edges of two opposing sides on the non-deflection side, and the pressing side surface of the connecting piece is concavely curved with the same curvature as the pellicle plate. To do.

  According to a fourth aspect of the present invention, there is provided a pellicle mounting method in which a pellicle made of synthetic quartz glass is pressed and mounted on a photomask, wherein the pellicle is curved into a rectangular frame pellicle frame and a convex shape attached to the pellicle frame. A pellicle mounting method comprising: a pellicle plate in a bent state, wherein at least a pair of opposite sides of the pellicle frame has a protruding surface protruding from an outer peripheral edge of the pellicle plate, and the protruding surface is pressed. To do.

  The invention according to claim 5 is a pellicle mounting structure in which a pellicle made of synthetic quartz glass with a pellicle plate bent and bent in a convex shape on a pellicle frame of a rectangular frame is mounted on a photomask, At least one pair of opposite sides of the pellicle frame has a substantially L-shaped cross section with a protruding piece formed on the outside, and the pellicle mounting is characterized in that the protruding piece and the photomask are sandwiched and fixed to each other Provide structure.

  According to a sixth aspect of the present invention, there is provided a pellicle composed of a rectangular frame pellicle frame made of synthetic quartz glass and a pellicle plate made of synthetic quartz glass bent in a convex shape and attached to the pellicle frame. The pellicle frame is characterized in that at least a pair of opposite sides of the pellicle frame protrude outward from the outer peripheral edge of the pellicle plate.

  According to the first aspect of the present invention, when the two opposite sides of the pellicle mounting jig, each of which has no deflection, are pressed with a pair of parallel pressing pieces of a pellicle mounting jig comprising a pressing piece and a connecting piece, the connecting piece is convex. Therefore, the pellicle can be securely mounted on the photomask without deforming the bent shape of the pellicle plate when the pellicle is mounted.

  According to the second aspect of the present invention, when the pellicle is mounted on the photomask with the pellicle mounting jig, the elastic member provided on the connecting piece elastically presses the pellicle plate. There is no deformation, and the pressing effect can be enhanced and mounting can be ensured.

  According to the invention of claim 3, since the pressing side surface of the connecting piece is curved concavely with the same curvature corresponding to the convex curved shape of the pellicle plate, there is no deflection of the periphery of the pellicle with a pair of parallel pressing pieces. Even when the connecting piece comes into contact with the pellicle plate when the two opposite sides are pressed, the pellicle plate is not deformed, and the pellicle can be securely attached to the photomask.

  According to the invention of claim 4, at least a pair of opposite sides of the pellicle frame has a protruding surface formed wider outside the outer peripheral edge of the pellicle plate in a state where the pellicle plate is attached, and presses the protruding surface. Therefore, the pellicle can be mounted on the photomask without contacting the pellicle plate, and the pellicle can be securely mounted on the photomask without deforming the bending shape of the pellicle plate.

  According to the invention of claim 5, at least a pair of opposite sides of the pellicle frame protrude outward to form a protruding piece, and the protruding piece and the photomask are sandwiched by the holding member, so that the pellicle can be held without contacting the pellicle plate. The pellicle can be mounted on the photomask, and the pellicle can be securely mounted on the photomask without deforming the bending shape of the pellicle plate. In addition, since the pellicle is sandwiched and fixed by the holding member, it is easy to attach and remove, and the photomask is less likely to be scratched or soiled, and the pellicle can also be recycled and is economical. It can be said that.

  According to the invention of claim 6, since at least a pair of opposite sides of the pellicle frame constituting the pellicle protrudes outward from the outer peripheral edge of the pellicle plate, the protruding portion is pressed or sandwiched between the photomask and the pellicle plate Since the pellicle can be attached to the photomask without contact, it is possible to obtain a pellicle that can be reliably attached to the photomask without deforming the bending shape of the pellicle plate.

FIG. 1 is a schematic view showing a pellicle mounting jig according to the present invention.
As shown in the figure, a pellicle 2 is bonded via an adhesive 3 so as to cover a pattern (not shown) on the photomask 1, and the peripheral portion of the pellicle 2 is pressed by a mounting jig 4 having a rectangular frame (shown in the figure). (Down) The pellicle 2 is made of synthetic quartz glass, and is formed by attaching a pellicle plate 6 to a pellicle frame 5 having a rectangular frame shape via an adhesive 7. The pellicle plate 6 is formed by bending a pair of opposite sides (first side 6a) with a predetermined curvature, and can be corrected by an optical system at the time of exposure. The gap between the convex pellicle plate 6 and the pellicle frame 5 is filled with an adhesive 7 and sealed to fix the bent shape. The bending shape may be fixed by sandwiching a member such as a spacer between the pellicle plate 6 and the pellicle frame 5.

  The mounting jig 4 is a rectangular frame composed of a pressing piece 8 and a connecting piece 9. The connecting piece 9 is thinner than the pressing piece 8, and the difference D is larger than the maximum deflection amount F of the pellicle plate 6. The Therefore, a space is formed on the side of the connecting piece 9 in the pressing direction (the lower side in the figure), and when the pellicle 2 is pressed by the mounting jig 4, the pressing piece 8 is opposite to the side of the pellicle plate 6 that is not bent (second side 6b). ) And the opposite side of the bent side does not contact the connecting piece 9. As a result, the pellicle 2 can be securely attached to the photomask 1 without changing the amount of deflection of the pellicle plate 6. The pressing piece 8 is preferably longer than the second side 6b, but may be shorter, or the surface of the pressing piece 8 on the pressing direction side is an uneven shape, and the difference in thickness from the connecting piece 9 is a convex portion. May be secured to press the second side 6b. Further, the mounting jig 4 is not limited to the rectangular frame shape formed of the pressing piece 8 and the connecting piece 9, and has a shape in which one or a plurality of connecting pieces 9 are bridged in the center of the pair of parallel pressing pieces 8. Also good.

FIG. 2 is a schematic view showing another pellicle mounting jig according to the present invention.
As illustrated, the elastic member 10 is provided on the side of the connecting piece 9 in the pressing direction (the lower side in the figure). Since the compression elastic coefficient of the elastic member 10 is larger than that of the adhesive 7 that holds the deflection amount of the first side 6 a of the pellicle plate 6, the pellicle plate 6 and the elastic member are pressed when the pellicle 2 is pressed by the mounting jig 4. Even when 10 is in contact, the pressure is absorbed, so that the pellicle 2 can be securely mounted on the photomask 1 without changing the amount of deflection of the first side 6a of the pellicle plate 6. The elastic member 10 may protrude in the direction perpendicular to the longitudinal direction of the connecting piece 9. Other configurations, operations, and effects are the same as those in FIG.

FIG. 3 is a schematic view showing still another pellicle mounting jig according to the present invention.
As shown in the drawing, the surface of the connecting piece 9 on the pressing direction side (the lower side in the figure) is formed following the bending shape of the pellicle plate 6. That is, the difference in thickness between the connecting piece 9 and the pressing piece 8 is equal to the amount of deflection of the pellicle plate 6 at each position in the longitudinal direction. Therefore, when the pellicle 2 is pressed by the pellicle mounting jig 4, the connecting piece 9 can securely mount the pellicle 2 on the photomask 1 without changing the curvature of the first side 6 a of the pellicle plate 6. Other configurations, operations, and effects are the same as those in FIG.

FIG. 4 is a schematic view showing an example of a pellicle mounting method according to the present invention.
A pellicle 2 is mounted via an adhesive 3 so as to cover a pattern (not shown) on the photomask 1. The pellicle 2 is made of synthetic quartz glass, and is formed by attaching a pellicle plate 6 to a pellicle frame 5 having a rectangular frame shape via an adhesive 7. The pellicle plate 6 has a pair of opposite sides (first side 6a) having a predetermined curvature, and can be corrected by an optical system during exposure. The gap between the convex pellicle plate 6 and the pellicle frame 5 is filled with an adhesive 7 and sealed to fix the bent shape. The bending shape may be fixed by sandwiching a member such as a spacer between the pellicle plate 6 and the pellicle frame 5.

  The pellicle frame 5 has a protruding surface 11 with a pair of opposite sides protruding outward. In the pellicle mounting method according to the present invention, the protruding surface 11 is pressed to mount the pellicle 2 on the photomask 1. By pressing the protruding surface 11 in this manner, the pellicle 2 can be mounted on the photomask 1 without contacting the pellicle plate 6, and the pellicle 2 can be reliably attached to the photomask 1 without changing the amount of deflection of the pellicle plate 6. Can be installed.

  Further, there is an advantage that deformation of the pressure-sensitive adhesive 3 on the pellicle plate due to pressing and distortion of the pellicle frame 5 are small. Note that the protruding surfaces 11 formed on the pellicle frame 5 may be provided on a pair of opposite sides different from the drawing, or may be provided on the entire circumference of the four sides. Further, the pellicle frame 5 may be provided intermittently in the longitudinal direction of each side. In this case, since various alignment marks, identification symbols, numbers, and the like are written on the outer peripheral edge of the photomask 1, the protruding surface 11 has a size that does not cover them.

  As a method of pressing the protruding surface 11, it is preferable to use the mounting jig 12 as shown in the figure. For example, the mounting jig 12 is a rectangular frame composed of a pressing piece 13 and a connecting piece 14. The pressing piece 13 protrudes downward as compared with the connecting piece 14, and the protruding length is longer than the length from the protruding surface 11 to the maximum deflection portion of the pellicle plate 6 (the middle point of the first side 6a). By using the mounting jig 12 to press the protruding surface 11 of the pellicle frame 5, the above-described effects can be obtained.

5 to 7 are sectional views in the vicinity of a pellicle frame using the pellicle mounting method according to the present invention. Note that the protruding surface 11 is provided on the side of the pellicle frame 5 corresponding to the second side 6 b of the pellicle plate 6.
As shown in FIG. 5, the lower surface of the pellicle frame 5 is protruded to form a protruding surface 11. The effect mentioned above can be acquired by pressing this protrusion surface 11. FIG. Moreover, as shown in FIG. 6, the upper surface of the pellicle frame 5 may be cut out to form a step 15 for adhering and attaching the pellicle plate 6, and the protruding surface 11 may be formed outside the step 15. The effect mentioned above can be acquired by pressing this protrusion surface 11. FIG. Further, as shown in FIG. 7, the width of the pellicle frame 5 may be made larger than that of the pellicle plate 6 to form the protruding surface 11. In this case, the protruding surface 11 may be formed using a pellicle plate 6 that is smaller than the width of the pellicle frame 5. The effect mentioned above can be acquired by pressing this protrusion surface 11. FIG.

FIG. 8 is a schematic view showing a pellicle mounting structure according to the present invention.
As shown in the figure, a pellicle 2 is placed on the photomask 1. The pellicle frame 5 has a protruding piece 16 protruding outward, and the holding member 17 sandwiches the protruding piece 16 and the photomask 1 to mount the pellicle 2 on the photomask 1. The holding member 17 is a clip having a substantially U-shaped cross section, and has elasticity in a direction of being held inside. Since the protruding piece 16 of the pellicle frame 5 and the photomask 1 are sandwiched and held in this manner, the pellicle 2 can be mounted on the photomask 1 without contacting the pellicle plate 6, and the amount of deflection of the pellicle plate 6 is not changed. The pellicle 2 can be reliably attached to the photomask 1. Further, since the pellicle 2 is sandwiched and fixed by the holding member 17, it is easy to detach and attach the pellicle 2, and damage to the photomask 1 such as scratches and dirt is small, and the pellicle 2 can also be recycled. It can be said that it is economical.

  In the figure, no adhesive is interposed between the pellicle frame 5 and the photomask 1, but in this case, the adhesive surface (lower surface) of the pellicle frame 5 that has been processed with high precision is in direct contact with the photomask 1. This is preferable in that the parallelism between the pellicle plate 6 and the photomask 1 can be maintained without being affected by uneven thickness of the adhesive. However, an elastic body having a function as a sealing material or a gasket may be applied and sandwiched between the both in order to prevent the purge gas from leaking due to scratches on the contact surfaces of the two or foreign matter and the deformation of the pellicle frame 5. Further, for the purpose of preventing the pellicle frame 5 and the photomask 1 from being damaged, a buffer material may be placed on the contact portion with the holding member 17. Other configurations, operations, and effects are the same as those in FIG.

FIG. 9 is a schematic view showing another pellicle mounting structure according to the present invention.
As shown in the figure, the projecting piece 16 and the photomask 1 may be sandwiched and fixed using a clamp as the holding member 18, and the pellicle 2 may be attached to the photomask 1. In this case, the upper surface of the protruding piece 16 and the lower surface of the photomask 1 are sandwiched between two plate materials 19, and the interval between the two plate materials 19 is tightened with screws 20 to be sandwiched. Other configurations, operations, and effects are the same as those in FIG.

FIG. 10 is a schematic view showing still another pellicle mounting structure according to the present invention.
As shown in the figure, the upper surface of the protruding piece 16 may be provided at an acute angle with respect to the side surface of the pellicle frame 5. As a result, the holding member 17 is caught in the corner of the protruding piece 16, and the pellicle 2 and the photomask 1 are easily clamped. Other configurations, operations, and effects are the same as those in FIG.

Schematic which shows the pellicle mounting jig which concerns on this invention. Schematic which shows another pellicle mounting jig which concerns on this invention. Schematic which shows another pellicle mounting jig which concerns on this invention. Schematic which shows an example of the pellicle mounting method which concerns on this invention. Sectional drawing of the pellicle frame vicinity using the pellicle mounting method which concerns on this invention. Sectional drawing of the pellicle frame vicinity using the pellicle mounting method which concerns on this invention. Sectional drawing of the pellicle frame vicinity using the pellicle mounting method which concerns on this invention. Schematic which shows the pellicle mounting structure which concerns on this invention. Schematic which shows another pellicle mounting structure based on this invention. Schematic which shows another pellicle mounting structure which concerns on this invention. Schematic which shows the mounting method of the pellicle using the conventional pellicle mounting jig.

Explanation of symbols

1: photomask, 2: pellicle, 3: adhesive, 4: mounting jig, 5: pellicle frame, 6: pellicle plate, 7: adhesive, 8: pressing piece, 9: connecting piece, 10: elastic member, 11: protruding surface, 12: mounting jig, 13: pressing piece, 14: connecting piece, 15: step, 16: protruding piece, 17: holding member, 18: holding member, 19: plate material, 20: screw.

Claims (6)

A pellicle mounting jig consisting of a connecting piece that connects a pair of parallel pressing pieces and pressing pieces to each other by pressing the peripheral edge of the pellicle made of synthetic quartz glass through an adhesive and mounting it on a photomask,
The pellicle is composed of a pellicle frame having a rectangular frame and a pellicle plate bent and bent in a convex shape.
The pair of parallel pressing pieces press the opposing peripheral edges of the pellicle peripheral edge on the non-deflection side,
The pellicle mounting jig, wherein the connecting piece is not in contact with the pellicle plate when pressed. An elastic member is provided on the pressing-side surface of the connecting piece,
2. The pellicle mounting jig according to claim 1, wherein the elastic member is elastically pressed by contacting the pellicle plate when pressed. A pellicle mounting jig consisting of a connecting piece that connects a pair of parallel pressing pieces and pressing pieces to each other by pressing the peripheral edge of the pellicle made of synthetic quartz glass through an adhesive and mounting it on a photomask,
The pellicle is composed of a pellicle frame having a rectangular frame and a pellicle plate bent and bent in a convex shape.
The pair of parallel pressing pieces press the opposing peripheral edges of the pellicle peripheral edge on the non-deflection side,
The pellicle mounting jig, wherein a surface on the pressing side of the connecting piece is concavely curved with the same curvature as the pellicle plate. A pellicle mounting method for pressing a pellicle made of synthetic quartz glass and mounting it on a photomask,
The pellicle is composed of a pellicle frame having a rectangular frame and a pellicle plate that is bent and bent in a convex shape.
At least a pair of opposite sides of the pellicle frame has a protruding surface protruding from an outer peripheral edge of the pellicle plate,
A pellicle mounting method comprising pressing the projecting surface. A pellicle mounting structure in which a pellicle made of synthetic quartz glass with a pellicle plate bent and bent in a convex shape on a pellicle frame of a rectangular frame is mounted on a photomask,
At least a pair of opposite sides of the pellicle frame has a substantially L-shaped cross section with a protruding piece formed on the outside,
A pellicle mounting structure, wherein the projecting piece and the photomask are clamped by a holding member and fixed to each other. A rectangular frame pellicle frame made of synthetic quartz glass;
A pellicle constructed by sticking a pellicle plate made of synthetic quartz glass in a convexly curved and bent state to the pellicle frame,
At least a pair of opposite sides of the pellicle frame protrude outward from an outer peripheral edge of the pellicle plate.

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