An exposure method for a metal photomask assembly and a metal photomask substrate.

Abstract

This invention discloses a metal photomask assembly and an exposure method for a metal photomask substrate, comprising: a photomask having a first plane and a second plane, the first plane having a chamfer, the chamfer width D1 being less than half the photomask thickness T; and a gripper fixture fitted to the upper and lower end faces of the photomask, including a fixture body and a fitting portion disposed on one side of the fixture body and fitting the chamfer; the fixture body of the gripper fixture presses against the upper and lower end faces of the photomask, causing the photomask to form a small protrusion facing the first plane. This invention, by setting the chamfer and the corresponding gripper fixture, achieves the dispersion of the pressing force, and simultaneously causes the photomask to undergo directional small deformations, squeezing the air between the photomask and the substrate from the center outwards, reducing cavitation.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically to an exposure method for a metal mask assembly and a metal mask substrate. Background Technology

[0002] In existing technologies, metal photomask substrates are typically held in place by grippers during exposure. For example... Figure 1 As shown, the gripper fixture holds the upper and lower ends of the photomask and applies vertical pressure. This pressure causes the photomask to deform, resulting in uneven difference between the actual length and the designed length of the effective graphic area inside the FMM product after exposure and development and etching processes. Summary of the Invention

[0003] To solve the above technical problems, the present invention provides a metal mask assembly and an exposure method for a metal mask substrate. The method is characterized by a chamfer and a corresponding gripper fixture, which disperses the extrusion pressure and causes the mask to undergo directional micro-deformation, squeezing the air between the mask and the substrate outward from the center, thereby reducing the generation of cavitation bubbles.

[0004] The present invention adopts the following technical solution:

[0005] A metal photomask assembly includes: a photomask having a first plane and a second plane, the first plane having a chamfer, the width of the chamfer D1 being less than half the thickness T of the photomask; a gripper fixture fitted to the upper and lower end faces of the photomask, including a fixture body and a fitting portion disposed on one side of the fixture body and fitted to the chamfer; the fixture body of the gripper fixture presses against the upper and lower end faces of the photomask, causing the photomask to form a small protrusion facing the first plane.

[0006] Preferably, the chamfer height D2 is less than half of the photomask thickness T.

[0007] Preferably, the chamfer width D1 and height D2 are both greater than 2mm.

[0008] Preferably, the angle θ of the chamfer is less than or equal to 60 degrees.

[0009] Preferably, the angle θ of the chamfer is 45 degrees.

[0010] A method for exposing a metal photomask substrate involves using a metal photomask assembly to perform double-sided contact exposure close to the substrate, transferring the pattern on the photomask onto photoresist.

[0011] Preferably, the gripper fixture fits the photomask from the top and bottom and applies a certain amount of pressure, causing the photomask to form a small protrusion facing the first plane.

[0012] Preferably, the moving gripper fixture drives the photomask to move by friction, so that the small protrusion in the middle of the photomask contacts the substrate first, and the edge of the photomask contacts the substrate later.

[0013] Compared with the prior art, the present invention has the following advantages: The present invention provides an exposure method for a metal mask assembly and a metal mask substrate, which sets up a chamfer and a corresponding gripper fixture to achieve the dispersion of extrusion pressure. At the same time, it causes the mask to produce directional micro-deformation, squeezing the air between the mask and the substrate from the center outward, reducing the generation of cavitation bubbles, and improving the uniformity of the actual length of the effective pattern area generated by the subsequent processing of FMM. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a photomask assembly in the prior art.

[0015] Figure 2 This is a schematic diagram of the structure of a photomask in the prior art.

[0016] Figure 3 This is a schematic diagram of the structure under exposure conditions.

[0017] Figure 4 This is a schematic diagram of the effective graphic area of ​​the finished FMM.

[0018] Figure 5 This is a schematic diagram of the structure of the photomask assembly of the present invention.

[0019] Figure 6 This is a schematic diagram showing the photomask assembly of the present invention in use.

[0020] Figure 7 This is a structural comparison diagram between the embodiment and the comparative example.

[0021] In the figure, there is a photomask 1, a first plane 11, a second plane 12, a chamfer 13, a gripper fixture 2, a fixture body 21, and a fitting part 22. Detailed Implementation

[0022] To facilitate understanding of the technical solution of the present invention, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0023] Example 1

[0024] like Figure 5-6 As shown, a metal photomask assembly includes:

[0025] Photomask 1 has a first plane 11 and a second plane 12. The first plane 11 has a chamfer 13, and the width D1 of the chamfer 13 is less than half the thickness T of the photomask 1.

[0026] The photomask 1 has a rectangular cross-section, with the first plane 11 facing the substrate and the second plane 12 away from the substrate.

[0027] The gripper fixture 2 is attached to the upper and lower end faces of the photomask 1, and includes a fixture body 21 and a fitting part 22 disposed on one side of the fixture body 21 and attached to the chamfer 13.

[0028] The jig body 21 has a rectangular cross-section, and the fitting part 22 has a triangular structure with a fitting chamfer 13.

[0029] The gripper body 21 of the gripper 2 is pressed against the upper and lower end faces of the photomask 1, causing the photomask 1 to form a small protrusion facing the first plane 11.

[0030] The gripper fixtures 2 at both ends hold the photomask 1 and apply pressure to the upper and lower surfaces of the photomask 1. Due to the presence of the fitting part 22, part of the pressure is applied to the inclined surface of the chamfer 13, reducing the force directly acting on the upper and lower surfaces of the photomask 1. At the same time, due to the chamfer 13, when the pressure applied by the gripper fixtures 2 acts on the upper and lower surfaces of the photomask 1, it will cause the photomask 1 to form a small protrusion facing the first plane 11. In this way, during exposure, the small protrusion in the middle will contact the substrate surface first, squeezing the air between the photomask and the substrate from the center outward, reducing the generation of cavitation bubbles, and improving the uniformity of the actual length of the effective pattern area generated by the FMM in the later processing.

[0031] Specifically, the height D2 of the chamfer 13 is less than half the thickness T of the photomask 1; this paper defines tanθ = D1 / D2, the smaller the θ angle, the more conducive it is to the dispersion of the extrusion force in the vertical direction, and the smaller the irregular deformation of the photomask.

[0032] As a preferred embodiment, the width D1 and height D2 of the chamfer 13 are both greater than 2mm.

[0033] As a preferred embodiment, the angle θ of the chamfer 13 is less than or equal to 60 degrees, and preferably 45 degrees.

[0034] Currently, the standard photomask thickness T for metal photomasks is 4.8mm. Therefore, in this embodiment, the width D1 and height D2 are both less than 2.4mm.

[0035] In addition, in the prior art, the photomask clamping fixture is mainly used to prevent the photomask from falling during the horizontal movement of the contact exposure. It relies entirely on friction to prevent it from falling, which can easily generate dust particles due to friction. In this embodiment, by setting the chamfer 13, the horizontal contact area between the clamping fixture 2 and the photomask 1 is reduced, the friction is reduced, and the dust particles generated by friction can be effectively reduced, avoiding the deviation of the exposure pattern caused by the light blocking of dust particles.

[0036] like Figure 6As shown, an exposure method for a metal mask substrate involves using a metal mask assembly to perform double-sided contact exposure close to the substrate, transferring the pattern on the mask 1 onto the photoresist.

[0037] During use, the gripper fixture 2 adheres to the photomask 1 from the top and bottom and applies a certain squeezing force, causing the photomask 1 to form a small protrusion facing the first plane 11; the moving gripper fixture 2 drives the photomask 1 to move by friction, so that the small protrusion in the middle contacts the substrate first, and the edge of the photomask 1 contacts the substrate later, squeezing the air between the photomask and the substrate from the center outward, reducing the generation of cavitation bubbles, and improving the uniformity of the actual length of the effective graphic area generated by the FMM in the later processing.

[0038] like Figure 7 As shown, in this embodiment, the width D1 and height D2 of the photomask chamfer 13 are both 2.2mm. Compared with the photomask of the prior art, it can be concluded that after using the chamfer 13 in this embodiment, the uniformity of the actual length of the effective graphic area generated by the subsequent processing of the FMM is significantly improved.

[0039] like Figure 2 , 4 As shown, C1 to C5 are the designed lengths of the effective graphic area on the A-side of the photomask, and E1 to E5 are the actual lengths of the effective graphic area of ​​the finished FMM.

[0040] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention shall be determined by the scope defined in the claims. Any improvements and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall also be considered as within the scope of protection of the present invention.

Claims

1. A method for exposing a metal photomask substrate, characterized in that, A metal mask assembly is used to perform double-sided contact exposure close to the substrate to transfer the pattern on the mask (1) onto the photoresist. The metal mask assembly includes: a mask (1) having a first plane (11) and a second plane (12), the first plane (11) having a chamfer (13), the width D1 of the chamfer (13) being less than half the thickness T of the mask (1); The gripper fixture (2) is attached to the upper and lower end faces of the photomask (1), including the fixture body (21) and the fitting part (22) provided on one side of the fixture body (21) and attached to the chamfer (13). The gripper body (21) of the gripper fixture (2) is pressed against the upper and lower end faces of the photomask (1), causing the photomask (1) to form a small protrusion facing the first plane (11). During exposure, the small protrusion in the middle will first contact the surface of the substrate, squeezing the air between the photomask and the substrate from the center outward, reducing the generation of cavitation bubbles.

2. The exposure method for a metal photomask substrate according to claim 1, characterized in that, The gripper fixture (2) attaches to the photomask (1) from the top and bottom sides and applies a certain squeezing force, so that the photomask (1) forms a small protrusion facing the first plane (11).

3. The exposure method for a metal photomask substrate according to claim 2, characterized in that, The moving gripper fixture (2) drives the photomask (1) to move by friction, so that the small protrusion in the middle contacts the substrate first, and the edge of the photomask (1) contacts the substrate later.

4. The exposure method for a metal photomask substrate according to claim 1, characterized in that, The height D2 of the chamfer (13) is less than half the thickness T of the photomask (1).

5. The exposure method for a metal photomask substrate according to claim 4, characterized in that, The width D1 and height D2 of the chamfer (13) are both greater than 2mm.

6. The exposure method for a metal photomask substrate according to claim 1, characterized in that, The angle θ of the chamfer (13) is less than or equal to 60 degrees.

7. The exposure method for a metal photomask substrate according to claim 6, characterized in that, The angle θ of the chamfer (13) is 45 degrees.

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