JP5790096B2 - Reflective photomask dust adhesion prevention jig, mounting method thereof, mounting apparatus thereof, and reflective photomask storage apparatus - Google Patents

Description

  The present invention relates to a jig for preventing dust adhesion of a reflective photomask, its mounting method, its mounting apparatus, and a reflective photomask storage apparatus, and more particularly to a reflective photomask used in a manufacturing process of an integrated circuit or the like. The present invention relates to a dust adhesion preventing jig for preventing dust from adhering to a mask, its mounting method, its mounting apparatus, and a reflection type photomask storage apparatus.

  In a photolithography technique for drawing an integrated circuit pattern on a silicon wafer, a technique for exposing a finer circuit pattern is required as the integration becomes higher. In recent years, in order to expose and transfer a fine circuit pattern, an exposure transfer technique using a reflective photomask using extreme ultraviolet (EUV) having a wavelength of 13.5 nm has been developed.

  On the other hand, conventionally, in order to prevent dust from adhering to the pattern formation surface of the EUV photomask, a method of attaching a protective film called a pellicle has been employed (see, for example, Patent Document 1). In this method, a frame (pellicle frame) to which a pellicle is attached is pasted to the peripheral portion of the photomask by glue, and the glue generates organic volatile gas, which causes the following problems.

  In EUV photomasks, light with a short wavelength of about 13.5 nm is irradiated in a high vacuum, so that volatile gas generated from the glue generates a photochemical reaction to generate dust, and the EUV photomask and exposure apparatus optics. It is assumed that the system will be contaminated.

  Further, in the EUV exposure apparatus, a gas that generates radicals such as oxygen radicals and hydrogen radicals in the exposure chamber in order to suppress dust accumulation caused by EUV photochemical reaction of a small amount of organic gas existing in the exposure chamber. A method of introducing is proposed. However, according to this method, the glue for attaching the pellicle frame is remarkably altered by such radicals, resulting in poor adhesion ability.

  Further, in the method of attaching the pellicle frame using glue, in the case of an EUV photomask that requires high pattern position accuracy and prevention of dust contamination on a high pattern, there are concerns about the following problems in addition to the above problems.

  That is, when the pellicle frame is fixed to the EUV photomask with glue, the flatness of the EUV photomask varies due to the stress, and the pattern position may move accordingly, and the pattern position accuracy may vary. Further, when the pellicle or the like is damaged and the pellicle is removed from the photomask, the pasting method using the glue may leave the glue on the photomask and contaminate the photomask.

Special table 2010-509774

  The present invention has been made in view of the above circumstances, and a dust adhesion preventing jig for a reflective photomask that does not contaminate the photomask, a mounting method therefor, a mounting device therefor, and a reflective photomask. An object of the present invention is to provide a storage device.

In order to solve the above problems, a first aspect of the present invention is a dust adhesion preventing jig for storing a reflective photomask having a pattern on one surface and preventing dust adhesion to the pattern. A frame including a base portion covering a peripheral end surface of one surface of the reflective photomask and a side wall portion covering a side surface of the reflective photomask, and a pattern of the reflective photomask spaced apart from each other by a predetermined interval. A protective film provided on the base of the frame so as to cover the upper end of the side wall of the frame together with the other surface of the reflective photomask, and fixed to the base of the frame; Elevating pins for supporting a peripheral end portion of one surface of the reflective photomask, which is provided in a photomask elevating means used when the reflective photomask is stored in a dust adhesion preventing jig. To provide a dust attachment prevention jig reflective photomask, characterized in that the lift pins passing hole for passing is provided.

  In such a dust adhesion preventing jig, an electrostatic chuck that electrostatically adsorbs the upper end of the side wall of the frame and the other surface of the reflective photomask can be used as the fixing member. In this case, an electrostatic adsorption layer made of a conductive material can be provided on the upper end of the side wall of the frame and the other surface of the reflective photomask. Cr or CrN can be used as the conductive material.

  A second aspect of the present invention is a method for attaching a dust adhesion preventing jig for storing a reflective photomask having a pattern on one surface and preventing dust adhesion to the pattern, which is described above. Disposing the dust adhesion preventing jig under the reflective photomask, raising the photomask elevating means disposed under the dust adhesion preventing jig, and moving the elevating pin to the base of the frame A step of passing through a lifting pin passage hole provided in the surface and supporting a peripheral end portion of one surface of the reflective photomask at a tip portion thereof, lowering the photomask lifting means, and moving the lifting pin up and down Pulling out from the pin passage hole, storing the reflective photomask in the dust adhesion preventing jig, and the fixing means, the upper end of the side wall of the frame is connected to the other surface of the reflective photomask. To provide a mounting method of a reflective photomask dust attachment prevention jig, characterized by comprising the step of fixing the well.

  In such a method for attaching the dust adhesion preventing jig, the dust adhesion preventing jig and the reflective photomask can be brought into non-contact after the fixing step.

  A third aspect of the present invention is a method for storing a reflection type photomask having a pattern on one surface and attaching a dust adhesion preventing jig for preventing dust adhesion to the pattern to the reflection type photomask. An apparatus for attaching an adhesion preventing jig, the dust adhesion preventing jig supporting means for supporting the dust adhesion preventing jig described above under the reflection type photomask, and the lifting pin by moving up the base of the frame Is passed through an elevating pin passage hole provided at the top, and supports the peripheral end portion of one surface of the reflective photomask at the tip, and when lowered, the elevating pin is pulled out from the elevating pin passage hole, and reflected photo A photomask elevating means for storing the mask in the dust adhesion preventing jig, and a means for fixing the upper end of the side wall of the frame together with the other surface of the reflective photomask. To provide a mounting device for dust attachment prevention jig reflective photomask characterized.

  According to a fourth aspect of the present invention, there is provided a reflection type photomask storage device for storing a reflection type photomask having a pattern on one surface in a dust adhesion prevention jig for preventing dust adhesion to the pattern. A support pin for supporting the reflection type photomask at an inner corner, comprising a base portion covering a peripheral end surface of one surface of the reflection type photomask and a side wall portion covering a side surface of the reflection type photomask. A dust adhering jig provided with a protective film provided on a base of the frame so as to cover the frame of the reflective photomask at a predetermined interval, and an upper opening of the dust adhering preventing jig Provided is a reflection type photomask storage device comprising: a lid member that covers a surface; and a dust adhesion preventing jig support arm that supports the dust adhesion preventing jig.

  According to the present invention, there are provided a dust adhesion preventing jig for a reflective photomask that does not contaminate the photomask, its mounting method, its mounting device, and a reflective photomask storage device.

It is sectional drawing which shows the state which attached the jig | tool for dust adhesion prevention for reflective photomasks which concerns on one Embodiment of this invention to the EUV photomask. It is sectional drawing which extracts and shows the jig | tool for dust adhesion prevention shown in FIG. It is sectional drawing which shows the process which attaches the jig | tool for dust adhesion prevention to an EUV photomask in order of a process. It is sectional drawing which shows the process which attaches the jig | tool for dust adhesion prevention to an EUV photomask in order of a process. It is sectional drawing which shows the process which attaches the jig | tool for dust adhesion prevention to an EUV photomask in order of a process. It is sectional drawing which shows the process which attaches the jig | tool for dust adhesion prevention to an EUV photomask in order of a process. It is sectional drawing which shows the process which attaches the jig | tool for dust adhesion prevention to an EUV photomask in order of a process. It is sectional drawing which shows the process which attaches the jig | tool for dust adhesion prevention to an EUV photomask in order of a process. It is sectional drawing which shows the process which attaches the jig | tool for dust adhesion prevention to an EUV photomask in order of a process. It is sectional drawing which shows the process which attaches the jig | tool for dust adhesion prevention to an EUV photomask in order of a process.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a cross-sectional view showing a state in which a dust adhesion preventing jig for a reflective photomask according to an embodiment of the present invention is attached to an EUV photomask. In FIG. 1, both the dust adhesion preventing jig 1 and the EUV photomask 2 are electrostatically attached to an electrostatic chuck 3. That is, the dust adhesion preventing jig 1 is attached to the electrostatic chuck 3 so as to cover the surface and the periphery of the EUV photomask 2 attached to the electrostatic chuck 3 where the pattern 2a is formed. In this case, it is desirable that the dust adhesion preventing jig 1 and the EUV photomask 2 are not in contact with each other.

  FIG. 2 is a cross-sectional view showing only the dust adhesion preventing jig 1 shown in FIG. In FIG. 2, the dust adhesion preventing jig 1 has a structure in which a protective film for the pattern 2 a of the photomask 2, that is, a pellicle film 5 is attached to the opening surface of a rectangular frame 4. The frame 4 is preferably made of a material that generates little gas, for example, a metal such as aluminum or stainless steel.

  An electrostatic adsorption film 6 a is provided on the upper end of the frame 4, that is, on the attachment surface to the electrostatic chuck 3. An electrostatic adsorption film 6b is also provided on the surface opposite to the pattern formation surface of the EUV photomask 2 shown in FIG. These electrostatic adsorption films 6a and 6b are formed by depositing a conductive material such as CrN or Cr by sputtering. The thickness of the electrostatic adsorption films 6a and 6b is, for example, 30 nm to 200 nm.

  At the inner corner of the frame 4, for example, three to four support pins 7 are provided for supporting the EUV photomask 2 in a step in the middle of the attachment process of the dust adhesion preventing jig 1 described later. . These support pins 7 are tapered at the top, and support the end face of the EUV photomask 2.

  A first elevating pin passage hole 8 through which an EUV photomask elevating pin, which will be described later, penetrates, is provided at a portion where the pellicle film 5 of the frame 4 is attached. The first elevating pin passage hole 8 has a diameter of, for example, 0.3 to 2.0 mm, and a process for housing the EUV photomask 2 in the dust adhesion prevention jig 1 and the EUV photomask 2 and dust adhesion prevention. This is used for supporting and aligning the EUV photomask 2 in the process of attracting the jig 1 to the electrostatic chuck 3.

  3 to 10 are cross-sectional views showing the process of attaching the dust adhesion preventing jig 1 to the EUV photomask 2 in the order of steps, of which FIGS. 3 to 6 show the EUV photomask 2 as a dust adhesion preventing jig. 7 to 10 are processes for adsorbing the dust adhesion preventing jig 1 to the electrostatic chuck.

  First, a process for housing the EUV photomask 2 in the dust adhesion preventing jig 1 will be described with reference to FIGS.

  FIG. 3 shows a state before the EUV photomask 2 is stored in the dust adhesion preventing jig 1. The dust adhesion preventing jig 1 is supported by a dust adhesion preventing jig support arm 9. The dust adhesion preventing jig support arm 9 includes a dust adhesion preventing jig support pin 10 that supports the dust adhesion preventing jig 1 and a second lifting pin passing hole 11. The second elevating pin passage hole 11 is a hole through which the elevating pin 13 of the photomask elevating arm 12 arranged under the dust adhesion preventing jig support arm 9 passes.

  As a material of the dust adhesion preventing jig support arm 9, a metal such as aluminum or stainless steel can be used. The dust adhesion preventing jig support arm 9 is connected to a robot arm (not shown) or the like so as to be movable in the vertical and horizontal directions.

  A photomask raising / lowering arm 12 is disposed below the dust adhesion preventing jig 1 supported by the dust adhesion preventing jig support arm 9. The photomask elevating arm 12 includes elevating pins 13 that support the EUV photomask 2 and move it up and down. The photomask lifting arm 12 and the second lifting pin 13 can be made of metal such as aluminum or stainless steel.

  The thickness of the elevating pin 13 needs to be smaller than the diameters of the first elevating pin passage hole 8 and the second elevating pin passage hole 11, and is usually 0.2 to 1.9 mm in diameter. It is desirable that the elevating pins 13 have such a length that a slight gap in the vertical direction is formed between the EUV photomask 2 and the upper end of the frame 4 (attachment surface to the electrostatic chuck 3). . This is because when the EUV photomask 2 is stored in the dust adhesion prevention jig 1, a gap is necessary so that the EUV photomask 2 can be held and lowered by an arm (not shown). . However, when the EUV photomask 2 is supported from the back side by an electrostatic chuck or the like, it may be shorter. The photomask elevating arm 12 is connected to a robot arm (not shown) or the like so as to be movable in the vertical and horizontal directions.

  Next, as shown in FIG. 4, the photomask elevating arm 12 is raised, and the elevating pins 13 are moved to the second elevating pin passage hole 11 of the dust adhesion preventing jig support arm 9 and the first elevating of the frame 4. The pin passes through the pin passage holes 8 sequentially and stops at a position where it comes into contact with the dust adhesion prevention jig support arm 9.

  Next, the EUV photomask 2 supported by another arm or the electrostatic chuck is lowered, and the EUV photomask 2 is supported from below by the lift pins 13 of the photomask lift arm 12 as shown in FIG. Become.

  Thereafter, the photomask elevating / lowering arm 12 is lowered, and the EUV photomask 2 is also lowered accordingly, and the elevating / lowering pin 13 of the photomask elevating / lowering arm 12 is moved to the second elevating / lowering pin passage hole 11 of the dust adhesion preventing jig supporting arm 9. As shown in FIG. 6, the EUV photomask 2 is supported by the support pins 7 at the inner corners of the frame 4.

  At this time, the height H of the frame 4 is set so that the level of the upper surface of the EUV photomask 2 and the level of the upper end of the frame 4 (surface attached to the electrostatic chuck 3) are higher in the latter. Is desirable. For example, when the thickness of the EUV photomask 2 is 6.35 mm, it is desirable that H is 6.4 mm or more. In this state, the dust adhesion preventing jig 1 and the EUV are gripped by an arm (not shown) in the gap between the dust adhesion preventing jig 1 and the photomask lifting arm 12. It is also possible to move the photomask 2.

  As described above, the process of storing the EUV photomask 2 in the dust adhesion preventing jig 1 is completed. In addition, with the EUV photomask 2 stored in the dust adhesion prevention jig 1, the upper opening of the dust adhesion prevention jig 1 is covered, and this is stored in another dust prevention case. It can also be stored. That is, in another embodiment of the present invention, the EUV photomask 2 is accommodated in this manner, and the dust adhesion preventing jig 1 with the upper opening covered is supported by the dust adhesion preventing jig support arm 9. An EUV photomask storage device having a structure is provided.

  Next, the process of adsorbing the dust adhesion preventing jig 1 to the electrostatic chuck will be described with reference to FIGS.

  FIG. 7 shows a state in which the EUV photomask 2 is housed in the dust adhesion preventing jig 1, and the electrostatic chuck 3 is disposed above.

  As shown in FIG. 8, when the electrostatic chuck 3 is lowered, the electrostatic chuck 3 is electrostatically attracted to the electrostatic adsorption film 6 a at the upper end of the frame 4 located slightly above the upper surface of the EUV photomask 2. Next, after the photomask elevating arm 12 is raised and the elevating pins 13 are in contact with the EUV photomask 2, the photomask elevating arm 13 is pushed upward, and the electrostatic chucking film 6 b of the EUV photomask 2 is attached to the electrostatic chuck 3 as shown in FIG. As a result, the EUV photomask 2 is electrostatically attracted to the electrostatic chuck 3. At this time, the gap D between the pattern forming surface of the EUV photomask 2 and the inner peripheral surface of the frame 4 is preferably as narrow as 0.3 to 1.0 mm. The reason is that when dust is mixed from the first lifting pin passage hole 8, the gap D is narrowed to the above extent to suppress the passage of the dust gap D, and the dust reaches the pattern forming portion. This is to prevent it.

  Thereafter, the photomask elevating arm 12 and the dust adhesion preventing jig support arm 9 are sequentially lowered, and the process of adsorbing the dust adhesion preventing jig 1 to the electrostatic chuck is completed (FIG. 10).

  As described above, according to the present embodiment, the dust adhesion preventing jig 1 and the EUV photomask 2 are fixed by a fixing means such as an electrostatic chuck, whereby the dust adhesion preventing jig 1 is fixed to the EUV photomask 2. To solve all the problems caused by pasting the pellicle frame to the photomask with glue, such as a decrease in adhesion capability, pattern contamination, and variations in pattern position accuracy. did it.

In the above embodiment, the electrostatic chuck is used as means for fixing the photomask and the dust adhesion preventing jig. However, the present invention is not limited to this, and other means may be used. An example of such means is a vacuum fixing means.
The invention described in the original claims is appended below.
[1]
A dust adhesion prevention jig for storing a reflection type photomask having a pattern on one surface and preventing adhesion of dust to the pattern, the peripheral end surface of one surface of the reflection type photomask being A frame composed of a base portion covering and a side wall portion covering a side surface of the reflective photomask; and a protective film provided on the base portion of the frame so as to cover the pattern of the reflective photomask with a predetermined interval. The upper end of the side wall portion of the frame is fixed together with the other surface of the reflective photomask by a fixing member.
[2]
The dust adhesion preventing jig according to [1], wherein the fixing member is an electrostatic chuck that electrostatically attracts an upper end of a side wall portion of the frame and the other surface of the reflective photomask. .
[3]
The dust adhering prevention according to [2], wherein an electrostatic adsorption layer made of a conductive material is provided on an upper end of the side wall portion of the frame and the other surface of the reflective photomask. jig.
[4]
The dust adhesion preventing jig according to [3], wherein the conductive material is Cr or CrN.
[5]
The base of the frame supports a peripheral end portion of one surface of the reflective photomask, which is provided in a photomask lifting / lowering means used when the reflective photomask is stored in a dust adhesion prevention jig. The dust adhesion preventing jig according to any one of [1] to [4], wherein a lifting pin passage hole through which the lifting pin passes is provided.
[6]
A method for attaching a dust adhesion prevention jig that houses a reflection type photomask having a pattern on one side and attaches a dust adhesion prevention jig to the reflection type photomask to prevent dust adhesion to the pattern. There,
Disposing the dust adhesion preventing jig according to [5] below the reflective photomask;
The photomask raising / lowering means is raised, the raising / lowering pins are passed through the raising / lowering pin passage holes provided in the base of the frame, and the peripheral end of one surface of the reflective photomask is supported at the tip thereof. Process,
Lowering the photomask elevating means, pulling the elevating pin out of the elevating pin passage hole, and storing the reflective photomask in the dust adhesion preventing jig; and
Fixing the upper end of the side wall of the frame together with the other surface of the reflective photomask by the fixing means;
A method of attaching a jig for preventing dust adhesion of a reflective photomask, comprising:
[7]
The method for attaching a dust adhesion preventing jig according to [6], wherein the dust adhesion preventing jig and the reflective photomask are not in contact with each other after the fixing step.
[8]
A dust adhesion prevention jig mounting device that houses a reflection type photomask having a pattern on one surface and attaches a dust adhesion prevention jig to the reflection type photomask to prevent dust adhesion to the pattern. There,
A dust adhesion preventing jig supporting means for supporting the dust adhesion preventing jig according to [5] below the reflective photomask;
The elevating pin passes through an elevating pin passing hole provided in the base of the frame by ascending, supports the peripheral end of one surface of the reflective photomask at the tip, and the elevating pin is moved by lowering A photomask lifting / lowering means for pulling out the lifting pin passage hole and storing the reflective photomask in the dust adhesion preventing jig; and
Means for fixing the upper end of the side wall portion of the frame together with the other surface of the reflective photomask
An apparatus for mounting a jig for preventing dust adhesion of a reflective photomask, comprising:
[9]
A reflection type photomask storage device for storing a reflection type photomask having a pattern on one side in a dust adhesion prevention jig for preventing adhesion of dust to the pattern,
A frame having a base that covers a peripheral end surface of one surface of the reflective photomask and a side wall that covers a side surface of the reflective photomask, and a support pin that supports the reflective photomask at an inner corner; and A dust adhesion preventing jig comprising a protective film provided at the base of the frame so as to cover the pattern of the reflective photomask at a predetermined interval
A lid member covering an upper opening surface of the dust adhesion preventing jig, and
Dust adhesion prevention jig support arm for supporting the dust adhesion prevention jig
A reflection type photomask storage device comprising:

  DESCRIPTION OF SYMBOLS 1 ... Dig adhesion prevention jig, 2 ... EUV photomask, 3 ... Electrostatic chuck, 4 ... Frame, 5 ... Pellicle film, 6a, 6b ... Electrostatic adsorption film, 7 ... Support pin, 8 ... First raising / lowering Pin passing hole, 9... Dust supporting jig supporting arm, 10. Dust supporting jig supporting pin, 11. Second lifting pin passing hole, 12. Photomask lifting arm, 13.

Claims (8)

A dust adhesion prevention jig for storing a reflection type photomask having a pattern on one surface and preventing adhesion of dust to the pattern, the peripheral end surface of one surface of the reflection type photomask being A frame composed of a base portion covering and a side wall portion covering a side surface of the reflective photomask; and a protective film provided on the base portion of the frame so as to cover the pattern of the reflective photomask with a predetermined interval. The upper end of the side wall of the frame is fixed together with the other surface of the reflective photomask by a fixing member , and the reflective photomask is stored in a dust adhesion preventing jig at the base of the frame. JP further comprising photomask lifting means used in, the lifting pins pass through apertures elevating pins penetrate to support the peripheral edge portion of one surface of the reflective photomask is provided Dust attachment prevention jig reflective photomask to.   2. The dust adhesion preventing jig according to claim 1, wherein the fixing member is an electrostatic chuck that electrostatically attracts an upper end of a side wall portion of the frame and the other surface of the reflective photomask. .   The dust adhering prevention according to claim 2, wherein an electrostatic adsorption layer made of a conductive material is provided on an upper end of the side wall portion of the frame and the other surface of the reflective photomask. jig.   4. The dust adhesion preventing jig according to claim 3, wherein the conductive material is Cr or CrN. A method for attaching a dust adhesion prevention jig that houses a reflection type photomask having a pattern on one side and attaches a dust adhesion prevention jig to the reflection type photomask to prevent dust adhesion to the pattern. There,
Disposing the dust adhesion preventing jig according to any one of claims 1 to 4 under the reflective photomask;
The photomask raising / lowering means is raised, the raising / lowering pins are passed through the raising / lowering pin passage holes provided in the base of the frame, and the peripheral end of one surface of the reflective photomask is supported at the tip thereof. Process,
Lowering the photomask elevating means, pulling out the elevating pins from the elevating pin passage holes, and storing the reflective photomask in the dust adhesion preventing jig; and A method for attaching a jig for preventing dust adhesion to a reflective photomask, comprising: fixing the upper end of the part together with the other surface of the reflective photomask. 6. The method for attaching a dust adhesion preventing jig according to claim 5 , wherein the dust adhesion preventing jig and the reflective photomask are not in contact with each other after the fixing step. A dust adhesion prevention jig mounting device that houses a reflection type photomask having a pattern on one surface and attaches a dust adhesion prevention jig to the reflection type photomask to prevent dust adhesion to the pattern. There,
Dust adhesion preventing jig support means for supporting the dust adhesion preventing jig according to any one of claims 1 to 4 under the reflective photomask,
The elevating pin passes through an elevating pin passing hole provided in the base of the frame by ascending, supports the peripheral end of one surface of the reflective photomask at the tip, and the elevating pin is moved by lowering Pull out from the elevating pin passage hole, and fix the photomask elevating means for storing the reflective photomask in the dust adhesion preventing jig, and the upper end of the side wall of the frame together with the other surface of the reflective photomask. An apparatus for attaching a jig for preventing dust adhesion of a reflection type photomask, characterized in that said means is provided. A reflection type photomask storage device for storing a reflection type photomask having a pattern on one side in a dust adhesion prevention jig for preventing adhesion of dust to the pattern,
A frame having a base that covers a peripheral end surface of one surface of the reflective photomask and a side wall that covers a side surface of the reflective photomask, and a support pin that supports the reflective photomask at an inner corner; and A dust adhesion preventing jig comprising a protective film provided at the base of the frame so as to cover the pattern of the reflective photomask at a predetermined interval
A reflective photomask storage device comprising: a lid member that covers an upper opening surface of the dust adhesion prevention jig; and a dust adhesion prevention jig support arm that supports the dust adhesion prevention jig. .

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