CN218446368U - Light shield - Google Patents

Abstract

The utility model provides an optical mask, the optical mask includes stratum basale, metal rete, dustproof rete and frame, the metal rete is located on the stratum basale, the frame is fixed in on the stratum basale, the frame is hollow structure, hollow structure is used for filling the macromolecular granule that absorbs the ammonia radical ion, set up a window on the frame at least, including first dust screen, first ammonia radical ion absorption region and second dust screen in the window, first ammonia radical ion absorption region is located first dust screen with between the second dust screen, the first ammonia radical ion absorption region of window department with the frame is the hollow structure intercommunication, the diameter of second dust screen is less than the diameter of the macromolecular granule of first ammonia radical ion absorption region, the second dust screen is used for preventing the ammonia radical ion with the macromolecular granule of first ammonia radical ion absorption region gets into in the dustproof rete. The effect of preventing the light shield from being atomized is improved.

Description

Light shield

Technical Field

The utility model relates to a lithography technique field, in particular to photomask.

Background

In a semiconductor integrated circuit manufacturing process, a photolithography process is one of the most important steps. The process of the photoetching technology is to accurately transfer a device or a circuit pattern prefabricated on a mask plate to a photoresist layer pre-coated on the surface of a wafer or a dielectric layer according to a required position through an exposure system. The photoresist at the exposed pattern part is removed or reserved by a developing process so as to achieve the purpose of accurately forming a device or a circuit pattern prefabricated on the mask plate on the surface of the wafer or the dielectric layer. The quality of the photoetching process directly affects the characteristic dimension and the product quality of a semiconductor device, wherein a mask plate is a standard and a blueprint of a photoetching copy pattern, and any defect on the mask plate can seriously affect the precision of a final pattern.

The mask plate is also called as a photomask, in the photoetching process, water molecules in the environment and sulfate radicals and ammonia radicals on the surface of the photomask generate chemical reaction under the exposure action to form ammonium sulfate crystals, the crystals are continuously enlarged to finally cause the light transmittance of the area to be poor and further react on a projected pattern, if the crystals are not processed in time, the product yield is seriously influenced, and meanwhile, the online production of products is interrupted due to the fact that the photomask with the atomization problem is washed, and the production efficiency is influenced. In particular, in the 193nm light source etching process of ArF and immersion (immersion) tools, the light source energy is high, which leads to the acceleration of the photomask atomization process and the serious defect of photomask atomization.

In the prior art, in the aspect of preventing the problem of Haze of the photomask, the photomask is mainly cleaned by using a cleaning solution without sulfur (S), and the control of sulfate radicals (SO 4+, SO3+, SO 2) and ammonia radicals (NH 4 +) in the environment is enhanced by using a chemical filter, SO that the two substances are prevented from being enriched on the surface of the photomask and further generating Haze defects (Haze defects) on the surface of the photomask. But the optimization and control of the mask itself is less.

The photomask generally comprises a quartz substrate layer, a chromium metal layer (a MoSi layer is also present in the case of a phase transfer photomask) and a dustproof film layer. The dustproof film layer is composed of a light-permeable film and a square metal (generally aluminum alloy) frame with a certain height, and the film can block tiny dust and volatile gaseous molecules. In the prior art, a small window is arranged on the side surface of a metal frame, and a dustproof net is tightly attached to the periphery of the small window and is used for maintaining the balance of air pressure inside and outside a dustproof film of a main body and preventing large-particle dust from entering the dustproof film but not blocking gaseous molecules. A few existing solutions will add a micro-filter outward from the small window to block small particle dust and large particle gaseous molecules. However, keeping the inner and outer air paths unobstructed and effectively blocking the particles are mutually opposite, and a proper balance needs to be found.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a light shield to solve the light shield and atomize and lead to the pattern on the light shield to produce and warp, and then lead to the problem that the product warp.

In order to solve the technical problem, the utility model provides a light shield, the light shield includes stratum basale, metal membranous layer, dustproof membranous layer and frame, the metal membranous layer is located on the stratum basale, the frame is fixed in on the stratum basale, the frame is used for fixing dustproof membranous layer, the frame is hollow structure, hollow structure is used for filling the macromolecular granule who absorbs the ammonia radical ion, set up a window at least on the frame, including first dust screen, first ammonia radical ion absorption area and second dust screen in the window, first ammonia radical ion absorption area is located first dust screen with between the second dust screen, the first ammonia radical ion absorption area of window department with the frame is hollow structure intercommunication, first dust screen is used for keeping apart impurity, sulfate radical ion and partial ammonia radical ion, first ammonia radical ion absorption area is used for absorbing and passes through the ammonia radical ion of first dust screen, the diameter of second dust screen is less than the diameter of the macromolecular granule in first ammonia radical ion absorption area, the second dust screen is used for preventing ammonia radical ion with the first ammonia radical ion absorption area get into the macromolecular granule in situ.

Optionally, a window is formed in the frame, and the length of the window is less than two thirds of one side length of the frame.

Optionally, the frame includes four sides, each side is provided with a plurality of windows, and the total length of the plurality of windows is less than two-thirds of one side length of the frame.

Optionally, the diameter of the second dust screen is smaller than the diameter of the first dust screen.

Optionally, the first dust screen, the first ammonia radical ion absorption region and the second dust screen in the window have the same width, and are one third of the width of the frame.

Optionally, the first ammonia radical ion absorbing region and the hollow structure of the frame comprise activated carbon.

Optionally, the first ammonia radical ion absorption region and the hollow structure of the frame comprise a bond of activated carbon and sepiolite.

Optionally, the width of the frame is 3 mm-15 mm.

Optionally, the first dust screen and the second dust screen are bonded to the frame through a colloid.

Optionally, the window is rectangular or square in shape.

The utility model provides an among the light shield, through inciting somebody to action the frame sets up to hollow structure, hollow structure is used for filling the macromolecular granule that absorbs the ammonia radical ion, and set up a window on the frame at least, including first dust screen, first ammonia radical ion absorption area and second dust screen in the window, first ammonia radical ion absorption area is located first dust screen with between the second dust screen, first dust screen is used for keeping apart impurity, sulfate ion and partial ammonia radical ion, first ammonia radical ion absorption area is used for absorbing and passes through the ammonia radical ion of first dust screen, the diameter of second dust screen is less than the diameter of the macromolecular granule of first ammonia radical ion absorption area, the second dust screen is used for preventing the ammonia radical ion with the macromolecular granule of first ammonia radical ion absorption area gets into in the dust screen, the frame sets up to hollow structure, hollow structure is used for filling the macromolecular granule that absorbs the ammonia radical ion, can fill more and be used for absorbing the ammonia radical ion, has improved the effect that prevents atomizing.

Drawings

Those skilled in the art will appreciate that the drawings are provided for a better understanding of the invention and do not constitute any limitation on the scope of the invention. Wherein:

FIG. 1 is a schematic structural diagram of a photomask according to an embodiment of the present invention;

FIG. 2 is a top view of a cross-sectional structure of a window formed in a frame of a photomask according to an embodiment of the present invention;

FIG. 3 is a top view of a cross-sectional structure of a mask having a plurality of windows;

fig. 4 is a schematic cross-sectional view of the window along line AA' of fig. 2 according to an embodiment of the present invention;

fig. 5 is a schematic cross-sectional view of the frame of fig. 2 along line BB' according to an embodiment of the present invention;

fig. 6 is a schematic cross-sectional view of the window along line CC' in fig. 2 according to an embodiment of the present invention;

in the drawings:

11-a base layer; 12-a metal film layer; 13-a frame; 13 a-a second ammine ion absorption zone; 14-a dustproof film layer; 15-window; 15 a-a first dust screen; 15 b-a first ammine ion absorption zone; 15 c-a second dust screen; 15 d-colloid; 16-spacer ring.

Detailed Description

To make the objects, advantages and features of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments. It is to be noted that the drawings are in simplified form and are not to scale, but rather are provided for the purpose of facilitating and distinctly claiming the embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings are intended to show different emphasis, sometimes in different proportions.

As used in this application, the singular forms "a," "an," and "the" include plural referents, the term "or" is generally employed in a sense including "and/or," the terms "a number of" are generally employed in a sense including "at least one," the terms "at least two" are generally employed in a sense including "two or more," and moreover, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to imply that the number of technical features indicated are present. Thus, features defined as "first", "second", "third" may explicitly or implicitly include one or at least two of such features, the term "proximal" is typically the end near the operator, the term "distal" is typically the end near the patient, "end" with "another end" and "proximal" with "distal" are typically the corresponding two parts, which include not only end points, the terms "mounted", "connected" and "connected" are to be understood broadly, e.g., they may be fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. Furthermore, as used in the present application, the disposition of an element with another element generally only means that there is a connection, coupling, fit, or drive relationship between the two elements, and the connection, coupling, fit, or drive between the two elements may be direct or indirect through intermediate elements, and is not to be understood as indicating or implying any spatial relationship between the two elements, i.e., an element may be in any orientation within, outside, above, below, or to one side of another element unless the content clearly dictates otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The inventor researches and discovers that before the exposure operation is carried out on the photomask, the photomask to be used is taken out from a photomask storage device and placed in a photomask storage unit (waiting table), an operator of the photomask storage unit carries out inspection and pretreatment before exposure on the photomask, and then the photomask in the photomask storage unit is transported to a photomask exposure operation table (retiring) through a mechanical arm to carry out the exposure operation. In the prior art, a better drying process exists for a photomask exposure operation platform, a better environment drying process does not exist in a photomask storage unit, and the storage time ratio of the photomask to the photomask exposure operation platform and the photomask storage unit is 1.5, so that the problem that the photomask is easy to atomize when the photomask is stored in the photomask storage unit for a long time is solved. Mask fogging (haze) refers to a phenomenon in which crystals of a misty compound such as ammonium sulfate, ammonium carbonate, or ammonium phosphate are generated on the surface of a mask. In the photolithography process, a common reticle haze is ammonium sulfate. Mask fogging can cause mask pattern distortion, ultimately resulting in product distortion.

Therefore, the core idea of the present invention is to provide a photomask, wherein the frame is configured as a hollow structure, the hollow structure is used for filling macromolecular particles for absorbing ammonia ions, and at least one window is formed in the frame, the window includes a first dust screen, a first ammonia ion absorption area and a second dust screen, the first ammonia ion absorption area is located between the first dust screen and the second dust screen, the first dust screen is used for isolating impurities, sulfate ions and part of ammonia ions, the first ammonia ion absorption area is used for absorbing ammonia ions passing through the first dust screen, the diameter of the second dust screen is smaller than that of the macromolecular particles in the first ammonia ion absorption area, the second dust screen is used for preventing the ammonia ions and the macromolecular particles in the first ammonia ion absorption area from entering the dust-proof film layer, the frame is configured as a hollow structure, the hollow structure is used for filling macromolecular particles for absorbing ammonia ions, so that more ammonia ions can be filled, and the effect of preventing fogging of the photomask is improved.

Specifically, fig. 1 is a schematic structural diagram of a photomask according to an embodiment of the present invention; FIG. 2 is a top view of a cross-sectional structure of a window formed in a frame of a photomask according to an embodiment of the present invention; fig. 4 is a schematic cross-sectional view along line AA' of the window in fig. 2 according to the embodiment of the present invention; as shown in fig. 1, fig. 2 and fig. 4, the utility model provides a photomask, the photomask includes stratum basale 11, metal film 12, dustproof film 14 and frame 13, metal film 12 is located on stratum basale 11, frame 13 is fixed in on the stratum basale 11, frame 13 is used for fixing dustproof film 14, set up a window 15 on the frame 13 at least, including first dust screen 15a, first ammonia radical ion absorption region 15b and second dust screen 15c in the window 15, first ammonia radical ion absorption region 15b is located first dust screen 15a with between the second dust screen 15c, first dust screen 15a is used for keeping apart impurity, sulfate radical ion and partial ammonia radical ion, first ammonia radical ion absorption region 15b is used for absorbing the ammonia radical ion through first dust screen, the diameter of second dust screen 15c is less than the diameter of the macromolecular granule of first ammonia radical ion absorption region 15b, second dust screen 15c is used for preventing ammonia radical ion with the first ammonia radical ion absorption region gets into in the dustproof film 14.

Referring to fig. 2, a window 15 is opened on the frame 13, and the length of the window 15 is less than two thirds of a side length of the frame. The window is, for example, rectangular or square in shape. In this embodiment, the frame includes four sides. The material of the frame 13 is, for example, metal, and in the present embodiment, the frame 13 is, for example, an aluminum frame. The metal film 12 is, for example, a metal chromium film, a pattern required by a photolithography process is formed on the metal film 12, the base layer 11 is, for example, quartz glass, the base layer 11 and the metal film 12 have the same size, since the edge of the metal film 12 is provided with an alignment mark, the size of the dustproof film 14 is smaller than the size of the base layer 11 and the metal film 12, and when the frame 13 for supporting the dustproof film 14 is connected with the base layer 11, the frame 13 cannot be connected with the metal film 12, an isolation ring 16 needs to be etched on the metal film 12, and the isolation ring 16 isolates a pattern area of the metal film 12 from a peripheral area of the metal film 12, so that the pattern area of the metal film 12 is not in contact with the peripheral area of the metal film 12, and static charge conduction does not occur. The frame 13 is connected to the substrate layer 11 by means of a spacer ring 16. The anti-dust film layer 14 is located on the metal film layer 12 and there is a gap between the anti-dust film layer 14 and the metal film layer 12 because the anti-dust film layer 14 must be higher than the metal film layer 12 to allow light to diffract to bypass the particles on the metal film layer 12.

Fig. 3 is a top view of a cross-sectional structure of a photomask according to an embodiment of the present invention, wherein a plurality of windows are formed in a frame of the photomask; as shown in fig. 3, the frame 13 includes four sides, a plurality of windows 15 may be disposed on each side, and the total length of the plurality of windows 15 is less than two-thirds of one side of the frame 13. An excessive overall length of the window 15 may affect the degree of support of the frame 13. The window is, for example, rectangular or square in shape.

Referring to fig. 4, fig. 4 is a schematic cross-sectional view taken along line AA' in fig. 2 according to an embodiment of the present invention; the first dust-proof screen 15a, the first ammonia radical ion absorption region 15b and the second dust-proof screen 15c in the window 15 have the same width, and are one third of the width of the frame 13. The width of the frame 13 is, for example, 3mm to 15mm. The first dust-proof net 15a and the second dust-proof net 15c are bonded to the frame 13 by a colloid. The diameter of the second dust screen 15c is smaller than the diameter of the first dust screen 15a. The material of the first dust-proof net 15a is, for example, one or more of Polytetrafluoroethylene, expanded Polytetrafluoroethylene (ePTFE), polytetrafluoroethylene PTFE, and polyethersulfone PES, and the first dust-proof net 15a is used for isolating impurities, sulfate ions, and a part of ammonium ions. The first ammonia radical ion absorption region 15b includes therein macromolecular particles or macromolecular groups such as activated carbon or a binder of activated carbon and sepiolite. The first ammine ion absorption region 15b is used for absorbing the ammine ions passing through the first dust-proof screen. The second dust-proof net 15c is made of one or more of Polytetrafluoroethylene (PTFE), expanded Polytetrafluoroethylene (ePTFE), polytetrafluoroethylene (PTFE), and polyether sulfone (PES), for example. The diameter of the second dust-proof net 15c is smaller than the diameter of the macromolecular particles of the first ammonia radical ion absorption region 15b, and the second dust-proof net 15c is used for preventing the ammonia radical ions and the macromolecular particles of the first ammonia radical ion absorption region from entering the dust-proof film layer 14.

Fig. 5 is a schematic cross-sectional view of the frame of fig. 2 along line BB' according to the embodiment of the present invention; as shown in fig. 5, a cross-sectional view of the frame 13 in the non-window region is a hollow frame. The hollow structure of the frame 13 is a second ammonia radical ion absorption region 13a, and the second ammonia radical ion absorption region 13a includes macromolecular particles or macromolecular groups, such as activated carbon or a binding compound of activated carbon and sepiolite. The first ammonia ion absorption region 15b and the second ammonia ion absorption region 13a are in communication. Therefore, more macromolecular particles for absorbing the ammonia radical ions can be filled to absorb more ammonia radical ions, and the anti-fogging effect of the photomask is improved. The width of the hollow structure is not more than one third of the width of the frame 13 so as not to affect the supporting strength of the frame 13.

Fig. 6 is a schematic cross-sectional view taken along line CC' in fig. 2 according to an embodiment of the present invention; as shown in fig. 6, the frame 13 is connected to the second dust-proof net 15c through a glue 15d, and the frame 13 surrounds the second dust-proof net 15c, as seen in a longitudinal section along the frame of the window region. Similarly, when the section is cut to an area including the first dust-proof net 15a, the frame 13 is connected to the first dust-proof net 15a through the adhesive 15d, and the frame 13 surrounds the first dust-proof net 15a. When cut to include the first ammonia ion absorption region 15b, the frame 13 surrounds the first ammonia ion absorption region 15b.

In summary, the utility model provides an in the light shield, through with the frame sets up to hollow structure, hollow structure is used for filling the macromolecular granule that absorbs the ammonia radical ion, and set up a window on the frame at least, include first dust screen, first ammonia radical ion absorption region and second dust screen in the window, first ammonia radical ion absorption region is located first dust screen with between the second dust screen, first dust screen is used for keeping apart impurity, sulfate ion and partial ammonia radical ion, first ammonia radical ion absorption region is used for absorbing the ammonia radical ion through first dust screen, the diameter of second dust screen is less than the diameter of the macromolecular granule of first ammonia radical ion absorption region, the second dust screen is used for preventing the ammonia radical ion with the macromolecular granule of first ammonia radical ion absorption region gets into in the dust proof membrane layer, the frame sets up to hollow structure, hollow structure is used for filling the macromolecular granule that absorbs the ammonia radical ion, can fill more be used for absorbing the ammonia radical ion, has improved the effect of preventing the light shield from atomizing.

It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention will still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. The utility model provides an optical mask, its characterized in that, the optical mask includes stratum basale, metal membranous layer, dustproof membranous layer and frame, the metal membranous layer is located on the stratum basale, the frame is fixed in on the stratum basale, the frame is used for fixing dustproof membranous layer, the frame is hollow structure, hollow structure is used for filling the macromolecular granule who absorbs the ammonia radical ion, set up a window at least on the frame, including first dust screen, first ammonia radical ion absorption region and second dust screen in the window, first ammonia radical ion absorption region is located first dust screen with between the second dust screen, first ammonia radical ion absorption region of window department with the frame is hollow structure intercommunication, first dust screen is used for keeping apart impurity, sulfate radical ion and partial ammonia radical ion, first ammonia radical ion absorption region is used for absorbing the ammonia radical ion through first dust screen, the diameter of second dust screen is less than the diameter of the macromolecular granule of first ammonia radical ion absorption region, the second dust screen is used for preventing ammonia radical ion with the first ammonia radical ion absorption region gets into in the macromolecular granule in the dust screen.

2. The mask of claim 1, wherein the frame defines a window, and wherein the window has a length less than two-thirds of a side length of the frame.

3. The mask of claim 1, wherein the frame comprises four sides, each side defining a plurality of the windows, the total length of the plurality of windows being less than two-thirds of a side length of the frame.

4. The optical cover according to claim 1, wherein the diameter of the second dust screen is smaller than the diameter of the first dust screen.

5. The mask according to claim 1, wherein the first dust-proof screen, the first ammonia radical ion absorption region and the second dust-proof screen in the window have the same width and are one third of the width of the frame.

6. The mask of claim 1, wherein the first ammine ion absorbing region and the hollow structure of the frame comprise activated carbon.

7. The mask of claim 1, wherein the first ammine ion absorbing region and the hollow structure of the frame comprise a bond of activated carbon and sepiolite.

8. The optical cover according to claim 1, wherein the frame has a width of 3mm to 15mm.

9. The optical cover according to claim 1, wherein the first dust-proof screen and the second dust-proof screen are bonded to the frame by a glue.

10. The mask of claim 1, wherein the window is rectangular or square in shape.

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