JP5696418B2 - Photomask manufacturing method - Google Patents

Description

The present invention relates to a full Otomasuku manufacturing method, full Otomasuku manufacturing method relating particularly suitable for only an arbitrary region for etching.

In the etching process in the dry etching, a material to be etched other than a region covered with a resist or the like and serving as an etching mask is dug.
Therefore, in the case where only an arbitrary region is dry-etched, the material to be etched must be covered with an etching mask such as a resist and patterned after being patterned by electron beam drawing.

Prior art relating to the manufacture of a phase shift mask will be described with reference to FIG.
As shown in FIG. 1A, a resist film 11 of a photomask blank in which a molybdenum silicide film 13, a chromium film 12 and a resist film 11 are sequentially laminated on a synthetic quartz substrate 14 is exposed by electron beam drawing and developed. To form a pattern.
Next, using the patterned resist film 11 shown in FIG. 1A as an etching mask, the chromium film 12 and the molybdenum silicide film 13 are etched as shown in FIG. 1B, and the resist film is also removed.

Next, as shown in FIG. 1C, the second resist film is formed on the upper surface of the chromium film 12, the etched portion of the chromium film 12 and the molybdenum silicide film 13, and the exposed surface of the synthetic quartz substrate 14 exposed by the etching. 15 is applied. Thereafter, the second resist film 15 is exposed by electron beam drawing, and development processing is performed to form a pattern as shown in FIG.
Thereafter, using the patterned second resist film 15 as an etching mask, the chromium film 12 is etched as shown in FIG. 1E, and the second resist film 15 is removed. As a result, the chromium film 12 remains on the outer peripheral portion, and the portion becomes a light shielding portion in the phase shift mask.

  The manufacturing process of such a phase shift mask has a longer process than the manufacturing process of a binary mask that does not require a light-shielding part because the light shielding part must be formed by peeling the chromium film of the main pattern. .

  Therefore, Patent Document 1 discloses a dry etching method capable of controlling pattern dimensions. The technique disclosed in Patent Document 1 is a plasma device including a shutter that can change a contact area between a chamber inner wall surface and plasma, and is generated from the plasma and the chamber inner wall surface by adjusting an opening area of the shutter. The reaction product is controlled and etching is performed with an optimum pattern dimension.

JP-A-10-233386

  However, the dry etching method described in Patent Document 1 still requires steps such as resist coating, electron beam drawing, and development when the main pattern chromium film is stripped in the phase shift mask manufacturing process.

The present invention is intended to solve the problems of the prior art as described above, and an object thereof is to provide a method for producing a full Otomasuku capable only an etching process arbitrary regions.

In order to achieve the above object, a first aspect of the present invention is a dry etching apparatus for etching a material to be etched placed on a cathode by generating plasma from an anode facing the material to be etched. A method of manufacturing a photomask by etching the material to be etched using the method, wherein the dry etching apparatus is disposed between the material to be etched and the anode, and has a size of an opening through which the plasma passes. The dry etching apparatus without applying a resist in the step of removing the light shielding film of the main pattern of the phase shift mask when forming the phase shift mask by etching the material to be etched. And removing the light-shielding film .

According to a second aspect of the present invention, in the photomask manufacturing method according to the first aspect , the shutter includes a plurality of plates arranged so as to be movable in a direction orthogonal to a direction of separating and approaching the material to be etched. And a support for supporting each of the plates in a movable manner, and a first moving means for moving the plates.

A third aspect of the present invention, in the photomask manufacturing method according to claim 2, wherein said shutter, said plate, said support, said first moving means moves said in a direction toward and away with respect to the material to be etched A second moving means is further provided.

According to a fourth aspect of the present invention, in the photomask manufacturing method according to the second or third aspect , the material of the plate and the support is either anodized or yttria.

According to a fifth aspect of the present invention, the material to be etched is etched using a dry etching apparatus that etches the material to be etched placed on the cathode by generating plasma from an anode facing the material to be etched. The dry etching apparatus includes a plurality of spacers disposed between the material to be etched and the anode, each having a different size of an opening through which the plasma passes , When the etching target material is etched to form the phase shift mask, the light shielding film is removed using the dry etching apparatus without applying a resist in the step of removing the light shielding film of the main pattern of the phase shift mask. Features.

According to a sixth aspect of the present invention, in the photomask manufacturing method according to the fifth aspect, the dry etching apparatus further includes a spacer arrangement mechanism, and the spacer arrangement mechanism includes a storage shelf for storing the plurality of spacers, and the cover. A stage provided between the etching material and the anode and capable of supporting the spacer; selecting one of the plurality of spacers from the storage shelf; and placing the spacer on the stage. And a loading / unloading mechanism for returning the storage shelf.

According to a seventh aspect of the present invention, in the photomask manufacturing method according to the sixth aspect , the dry etching apparatus further includes a moving means for moving the spacer and the stage in a direction approaching and separating from the material to be etched. It is characterized by that.

The invention according to claim 8 is the photomask manufacturing method according to claim 6 or 7, wherein the spacer and the material of the stage are either anodized or yttria.

According to full Otomasuku production method of the present invention, it is possible to etching only an arbitrary region of the material to be etched.

It is a schematic cross section which shows the process order of the prior art regarding phase shift mask manufacture. It is a schematic sectional drawing which shows embodiment of the dry etching apparatus with a shutter concerning this invention. It is a top view for demonstrating operation | movement of the shutter of the dry etching apparatus concerning this Embodiment. It is a schematic sectional drawing which shows embodiment of the dry etching apparatus with a spacer concerning this invention. It is a top view of the stage concerning embodiment of this invention. It is a top view of the spacer concerning this Embodiment. It is a figure which shows the etching process result of the chromium film | membrane by the conventional method. It is a figure which shows the etching process result of the chromium film | membrane by the dry etching apparatus with a shutter of this invention. It is a figure which shows the etching process result of the chromium film | membrane by the dry etching apparatus with a spacer of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the dry etching apparatus with a shutter 20 according to the embodiment of the present invention will be described in detail with reference to FIG.

  As shown in FIG. 2, the dry etching apparatus 20 with a shutter according to the present embodiment is disposed opposite to a chamber 21 having a gas supply port 24 and an exhaust port 25 at the upper and lower portions in the chamber 21. An anode (anode) 23 and a cathode (cathode) 22; an RF (high frequency) power source (high frequency oscillator) 28 connected between the cathode 22 and ground via a blocking capacitor 26 and an impedance matching unit (MB) 27; The shutter 21 is disposed between the material to be etched 10 in the chamber 21 and the anode 23, and includes a shutter 30 capable of changing the size of the opening through which the plasma from the anode 23 passes.

The shutter 30 has a plurality of, for example, four plates 30a (see FIG. 3) arranged so as to be movable in a direction orthogonal to the direction of separating and approaching the material to be etched 10, and each of the plates 30a can be moved. A support 29 to be supported and a first moving means 301 for moving the plate 30a are provided.
Furthermore, the shutter 30 includes a second moving unit 302 that moves the plate 30 a, the support 29, and the first moving unit 301 in a direction approaching and separating from the material to be etched 10.

In the dry etching apparatus 20 configured as described above, after the chamber 21 is evacuated to a predetermined degree of vacuum, the reactive gas is supplied from the gas supply port 24, and the reactive gas is exhausted through the exhaust port 25. Thereby, the inside of the chamber 21 is controlled to a predetermined pressure (about 0.1 mTorr to several hundreds mTorr). The material to be etched 10 is placed on the cathode 22. RF (high frequency) power is supplied to the cathode 22 from the RF (high frequency) power source 28 through the impedance matching unit 27 and the blocking capacitor 26 into the gas in the chamber 21.
Further, before the plasma processing, the area of the opening 30b formed by the four shutter plates 30a is adjusted by the first moving means 301 so that only an arbitrary region of the material to be etched 10 can be etched, and further, the second The distance (height) of the plate 30 a from the material to be etched 10 is adjusted by the moving means 302.

  As described above, by adjusting the distance (height) and opening area of the shutter 30 with respect to the material to be etched 10 before the plasma processing, the plasma contact area can be freely changed with respect to the material to be etched, and the material to be etched It is possible to etch only an arbitrary region.

  In the photomask manufacturing method according to the embodiment of the present invention, plasma processing is performed without performing steps such as resist coating, electron beam drawing, and development, which are necessary when the main pattern chromium film is stripped in the phase shift mask manufacturing process. By adjusting the height and opening area of the shutter 30 before, the plasma contact area is varied with respect to the material to be etched, and only an arbitrary region is etched. As a result, the etching area can be easily varied according to process requirements, and the productivity of the photomask can be improved.

Next, examples of the present invention will be described.
Example 1
The etching apparatus 20 shown in the first embodiment will be described with reference to a method of etching only an arbitrary region using a shutter 30 that can move between the material to be etched 10 and the anode 23, as shown in FIG.

FIG. 3A shows a state where the area of the opening 30 b formed by the four shutter plates 30 a is maximized by the first moving means 301. FIG. 3B shows a state where the area of the opening 30 b formed by the four shutter plates 30 a is reduced by the first moving means 301. Since the plate 30a and the support 29 of the shutter 30 are exposed to plasma during the etching process, they are made of alumite or yttria, which is a plasma resistant material.
As the material to be etched 10, a photomask similar to that shown in FIG. 1B in which molybdenum silicide 13 and chromium 12 are patterned on a synthetic quartz substrate 14 was used.

The etching apparatus 20 etches the entire surface of the material to be etched when the area of the opening 30b of the shutter 30 is maximum. Further, if the shutter plate 30a is operated by the first moving means 301 to reduce the area of the opening 30b of the shutter 30, the area of the opening through which the plasma passes can be freely changed with respect to the material to be etched. Further, by adjusting the height of the shutter 30 with the second moving means 302, it is possible to finely adjust the opening area through which the plasma with respect to the material to be etched passes.
As described above, by adjusting the opening area through which the plasma passes through the material to be etched by the shutter 30, only an arbitrary region can be etched.

  As described above, by using the present etching apparatus 20, it is possible to vary the etching area according to the process requirements. For example, the height and opening area of the shutter 30 are adjusted before the plasma processing without performing the steps such as resist coating, electron beam drawing, and development necessary for stripping the chromium film of the main pattern in the phase shift mask manufacturing process. As a result, it is possible to etch only an arbitrary region by changing the opening area through which the plasma passes through the material to be etched.

  FIG. 7 shows the result of etching the chromium film of the main pattern in the conventional process (FIGS. 1A to 1E) in the phase shift mask manufacturing process using a conventional dry etching apparatus. The positional deviation shown in FIG. 7 indicates the deviation amount between the main pattern area and the light shielding area.

  In the manufacturing process of the phase shift mask using the dry etching apparatus 20 having the shutter shown in FIG. 2 of the present invention, instead of the steps of FIGS. Adjust the opening area to pass through. FIG. 8 shows the result of the etching process of FIG.

  As is apparent from FIG. 8, the etching results using the conventional process and the shutter were the same. As a result, the etching area can be easily changed according to process requirements, and the productivity of the photomask can be improved.

(Example 2)
As shown in FIG. 4, the etching apparatus 40 shown in the second embodiment is provided in a chamber 21 configured similarly to the case shown in FIG. 2 so that it can move between the material to be etched 10 and the anode 23. Stage 41 and a spacer 44 placed on the stage 41 are provided.
The spacer 44 has a quadrangular shape, and a square-shaped opening 44 a through which plasma irradiated from the anode 23 to the material to be etched 10 passes is formed at the center. Further, a plurality of such spacers 44 are provided, and the sizes of the openings 44a are different.

Further, the etching apparatus 40 includes a storage shelf 42 for storing a plurality of spacers 44 provided in the chamber 21, and the spacer 44 is unloaded from the storage shelf 42 and placed on the stage 44, or a spacer on the stage 41. A loading / unloading mechanism 43 for loading 44 into the storage shelf 42 is provided. Hereinafter, a method for etching only an arbitrary region using the etching apparatus 40 including these will be described.
The stage 41, the storage shelf 42, and the carry-in / out mechanism 43 constitute a spacer arrangement mechanism described in the claims.

As shown in FIG. 5, the stage 41 has a cavity 41 a with a central portion penetrating in a square tube shape. Further, as shown in FIG. 6, the opening 44a of the spacer 44 sets an opening area through which the plasma passes through the material to be etched, and the plurality of spacers are the smallest as in the case shown in FIG. The structure is divided into steps from the opening area to the maximum opening area. The opening area of each spacer 44 is designed to be smaller than the opening area of the cavity 41 a of the stage 41. Since the stage 41 and the spacer 44 are exposed to plasma during the etching process, the stage 41 and the spacer 44 are made of alumite or yttria, which is a plasma resistant material.
As the material to be etched 10, a photomask similar to that shown in FIG. 1B in which molybdenum silicide 13 and chromium 12 are patterned on a synthetic quartz substrate 14 was used.

The etching apparatus 40 prepares a spacer 44 and sets it on the stage. During the etching process, the plasma is cut off in the region other than the opening region of the spacer 44, and the plasma contact area is limited to the material to be etched. Further, the stage 41 of the etching apparatus 40 includes a moving unit 411 that adjusts the height of the spacer 44 from the material to be etched. By adjusting the height of the stage 41 on which the spacer 44 is placed with the moving means 411 with respect to the material to be etched, it is possible to finely adjust the opening area through which the plasma passes through the material to be etched.
As described above, by adjusting the opening area through which the plasma passes through the material to be etched by the spacer 44, only an arbitrary region can be etched.

  By using the etching apparatus 40, the etching area can be varied according to the process requirements. For example, the steps such as resist coating, electron beam drawing, and development necessary for stripping the main pattern chromium film in the phase shift mask manufacturing process are not performed, and the height of the stage 41 on which the spacer 44 is placed before the plasma processing is increased. The spacer 44 having a desired opening area is selected from the storage shelf 42 by the carry-in / out mechanism 43 and set on the stage 41. This makes it possible to etch only an arbitrary region by changing the opening area through which plasma passes through the material to be etched.

  In the manufacturing process of the phase shift mask using the dry etching apparatus 40 having the spacer shown in FIG. 4, the plasma passes through the material to be etched using the spacer 44 as an alternative process of FIGS. 1C and 1D. Adjust the opening area. FIG. 9 shows the result of the etching process shown in FIG.

  As is apparent from FIG. 9, the etching result using the conventional process and the spacer was the same. As a result, the etching area can be easily changed according to process requirements, and the productivity of the photomask can be improved.

  DESCRIPTION OF SYMBOLS 10 ... Material to be etched, 11 ... Resist film, 12 ... Chromium film, 13 ... Molybdenum silicide film, 14 ... Synthetic quartz substrate, 15 ... Second resist film, 20 ... Etching apparatus, 21 ... Chamber, 22 ... Cathode, 23 ... Anode 24 ... Gas supply port 25 ... Exhaust port 26 ... Blocking capacitor 27 ... Impedance matching device 28 ... RF (high frequency) power supply 29 ... Shutter support 301 ... First moving means 302 ... Second moving Means 30 ... Shutter 40 ... Etching apparatus 41 ... Stage 411 ... Moving means 42 ... Storage shelf 43 ... Loading / unloading mechanism 44 ... Spacer

Claims (8)

A method for manufacturing a photomask by etching a material to be etched placed on a cathode by etching the material to be etched by generating plasma from an anode facing the material to be etched. Because
The dry etching apparatus is provided between the material to be etched and the anode, and includes a shutter capable of changing a size of an opening through which the plasma passes ,
Removing the light shielding film using the dry etching apparatus without applying a resist in the step of removing the light shielding film of the main pattern of the phase shift mask when forming the phase shift mask by etching the material to be etched;
A photomask manufacturing method characterized by the above. The shutter moves a plurality of plates arranged to be movable in a direction orthogonal to a direction approaching and separating from the material to be etched, a support body that can move the plates, and the plate. The photomask manufacturing method according to claim 1, further comprising first moving means. 3. The photo according to claim 2 , wherein the shutter further includes second moving means for moving the plate, the support, and the first moving means in directions toward and away from the material to be etched. Mask manufacturing method . 4. The photomask manufacturing method according to claim 2 , wherein the material of the plate and the support is either anodized or yttria. A method for manufacturing a photomask by etching a material to be etched placed on a cathode by etching the material to be etched by generating plasma from an anode facing the material to be etched. Because
The dry etching apparatus is provided between the material to be etched and the anode, and includes a plurality of spacers having different sizes of openings through which the plasma passes ,
Removing the light shielding film using the dry etching apparatus without applying a resist in the step of removing the light shielding film of the main pattern of the phase shift mask when forming the phase shift mask by etching the material to be etched;
A photomask manufacturing method characterized by the above. The dry etching apparatus further includes a spacer arrangement mechanism, and the spacer arrangement mechanism is provided at a location between a storage shelf for storing the plurality of spacers and the material to be etched and the anode, and supports the spacer. And a loading / unloading mechanism that selects one of the plurality of spacers from the storage shelf, places the spacer on the stage, and returns the spacer into the storage shelf. Item 6. A photomask manufacturing method according to Item 5. The photomask manufacturing method according to claim 6 , wherein the dry etching apparatus further includes moving means for moving the spacer and the stage in a direction approaching and separating from the material to be etched. The photomask manufacturing method according to claim 6 or 7, wherein a material of the spacer and the stage is either anodized or yttria.

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