JP2012079853A - Transfer mask, manufacturing method of transfer mask, transfer mask housing body, and manufacturing method of transfer mask housing body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer mask housing body where a transfer mask is housed in a mask holder with high location accuracy.SOLUTION: A mask holder 30 has a concave housing part 33 for housing a transfer mask 20, and an inner surface 34 formed in the concave housing part 33. The transfer mask 20 has a thin film 2 in which an opening pattern 3 is formed, and a support frame 1 consisting of silicon and supporting the thin film 2. At the end 5 of the thin film 2, a guide surface which is etched simultaneously with formation of the opening pattern 3 and regulates movement of the transfer mask in the mask holder 30 is formed. The transfer mask is housed in the mask holder 30 with the guide surface of the transfer mask facing the inner surface 34 formed in the concave housing part 33 of the mask holder.

Description

  The present invention relates to a charged particle beam exposure mask (transfer mask) such as an electron beam, and more particularly to a transfer mask container and a transfer mask manufacturing method.

  In electron beam lithography, in which pattern exposure is performed using an electron beam, various elemental patterns that appear repeatedly in the exposure pattern can be partially exposed by a transfer method using a mask. An exposure method called partial batch exposure (sometimes called block exposure or cell projection exposure) that enables rapid exposure of a desired pattern by combining transfer is known, and the drawing time is short and mass productivity is known. It is possible to draw ultrafine patterns.

  A charged particle beam exposure mask (transfer mask) used for charged particle beam exposure such as partial batch exposure by the electron beam described above is generally a through (opening) pattern that allows a charged particle beam to pass through a thin film supported by a support frame. This is a so-called perforated mask (Stencil mask). That is, the open region must be penetrated as a region through which the charged particle beam can be transmitted satisfactorily. If this penetrating pattern is formed on a thick substrate or the like, the charged particle beam passing therethrough is affected by the side wall of the penetrating pattern and cannot be accurately transferred. Therefore, the portion for forming the penetrating pattern (opening pattern forming region) is a thin film. And shall be. Further, in order to support the thin film on which such a penetrating pattern is formed while maintaining the planar accuracy, a support frame having a predetermined strength is required.

  Transfer masks used for such partial batch exposure have been manufactured by various methods. However, from the viewpoint of workability and strength, a silicon substrate (commercially available silicon wafer, etc.) has been developed using lithography technology or micromachine processing technology. It is common to make use of it. Specifically, for example, a silicon substrate is etched to form a support frame and a thin film supported by the support frame, and through holes are formed in the thin film to produce a transfer mask.

Further, in this case, an SOI (Silicon on Insulator) substrate having a structure in which _two silicon plates are bonded together via a SiO ₂ layer is used as the substrate, and a silicon thin film is used with the SiO ₂ layer as an etching stop layer (etching stopper layer). Many methods of forming are used.

  Here, the transfer mask used for the partial batch exposure described above has a small outer dimension of about 5 to 50 mm □, and is not easy to handle. In addition, these transfer masks have a structure in which the thin film and the support frame are integrated, and thus are very vulnerable to external impacts.

  Therefore, usually, the transfer mask is accommodated in a mask holder made of a good conductor of an electron such as metal to cope with these problems, thereby facilitating handling and protecting the transfer mask from external impact. ing. In addition, the mask holder containing this transfer mask is used as it is attached to an electron beam exposure device, etc., and the heat and charge generated in the transfer mask during electron beam irradiation are released through the mask holder and antistatic (preventing charge-up prevention). ) Acts.

JP 2001-007005 A

  By the way, when replacing the transfer mask housed in the mask holder, which is mounted in the exposure apparatus, with the mask holder, the transfer mask is accurately placed at the specified position of the mask holder in order to save the trouble of adjusting the alignment of the transfer mask. It needs to be well-contained. Conventionally, if the alignment of the transfer mask stored in the mask holder is poor and adjustment is not possible even if the alignment adjustment mechanism of the apparatus is used, it is necessary to reattach the transfer mask stored in the mask holder to the apparatus. There was. Further, in this case, in some cases, it is necessary to perform a very complicated operation such as releasing the vacuum of the apparatus and then evacuating it again to remount the transfer mask accommodated in the mask holder.

The work of attaching the transfer mask to the mask holder with high precision is a delicate and time-consuming work that is a burden on the operator. In Patent Document 1, a positioning pattern is formed on the support frame of the transfer mask. Thus, an electron beam exposure mask excellent in alignment accuracy with the mask holder is disclosed. According to the disclosure of Patent Document 1, since the formation of the pattern of the opening of the transfer mask and the pattern for positioning the support frame are performed by different photolithography processes, the relative positional accuracy between the two is determined by each photolithography process. A total of processing errors is included, and an alignment shift between both processes is further added as an error. For this reason, the method of Patent Document 1 has an accuracy limit. Also, in the photolithography process for forming the support frame positioning pattern, wet etching is employed because of the necessity of efficiently processing a silicon substrate having a thickness exceeding several hundred μm. In this processing, it is difficult to carry out fine etching management with an accuracy of several μm, and there is a problem that sufficient processing accuracy in the positioning pattern cannot be obtained.

  Accordingly, the present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a transfer mask container in which a transfer mask is stored in a mask holder with high positional accuracy, a manufacturing method thereof, and It is an object of the present invention to provide a transfer mask that can perform positioning with high accuracy by a simple operation when the transfer mask is accommodated in a mask holder, and a manufacturing method thereof.

In order to solve the above problems, the present invention has the following configuration.
(Configuration 1)
A transfer mask container comprising a mask holder and a transfer mask housed in the mask holder, wherein the mask holder has a housing portion for housing the transfer mask, and the transfer mask has an opening pattern. The transfer mask in the mask holder having a formed thin film and a support frame made of silicon for supporting the thin film, and etched at the end of the thin film simultaneously with the formation of the opening pattern A guide surface that restricts movement of the transfer mask is formed, and the guide surface of the transfer mask is accommodated in the mask holder so as to face an internal surface formed in the accommodating portion of the mask holder. Mask container.

(Configuration 2)
2. The transfer mask container according to Configuration 1, wherein at least a part of the guide surface is in contact with an inner surface of the mask holder.

(Configuration 3)
In the method of manufacturing a transfer mask container, which includes a mask holder and a transfer mask housed in the mask holder, the mask holder has a housing part for housing the transfer mask, and the transfer mask has an opening. The mask holder includes a thin film on which a pattern is formed and a support frame made of silicon that supports the thin film, and is etched at the end of the thin film simultaneously with the formation of the opening pattern. A guide surface for restricting the movement of the transfer mask is formed, and the transfer mask is accommodated in the mask holder with the guide surface of the transfer mask facing an inner surface formed in the accommodating portion of the mask holder. A process for producing a transfer mask container, comprising a step.

(Configuration 4)
4. The method for manufacturing a transfer mask container according to Configuration 3, wherein at least a part of the guide surface is brought into contact with an inner surface of the mask holder.

(Configuration 5)
A transfer mask used for electron beam exposure in a state accommodated in a mask holder, comprising a thin film having an opening pattern for transfer formed thereon, and a support frame made of silicon for supporting the thin film, the thin film The transfer mask is characterized in that a guide surface that is etched simultaneously with the formation of the opening pattern and that can be brought into contact with the mask holder is formed at an end of the transfer mask.

(Configuration 6)
6. The transfer mask according to Configuration 5, wherein the thin film has a thickness of 5 μm to 200 μm.

(Configuration 7)
A method of manufacturing a transfer mask used for electron beam exposure in a state of being accommodated in a mask holder, wherein a SiO ₂ layer and a silicon thin film are formed on a silicon substrate, and a first etching mask layer is further laminated thereon. A step of preparing an SOI substrate, a step of patterning the first etching mask layer by a photolithography process using a resist, and etching using the patterned first etching mask layer as a mask to form the silicon thin film. Forming a transfer opening pattern; forming a second etching mask layer on an outer surface including front and back surfaces of an SOI substrate having the transfer opening pattern formed on the silicon thin film; and the second etching mask layer. By a photolithographic process using a resist. And a step of processing the shape of the support frame on the silicon substrate using the patterned second etching mask layer as a mask. An end portion of the thin film is defined by etching to form a guide surface that regulates movement of the transfer mask in the mask holder when the transfer mask is accommodated in the mask holder. Production method.

(Configuration 8)
The method for manufacturing a transfer mask according to Configuration 7, wherein the step of forming the opening pattern includes a dry etching step.
(Configuration 9)
Forming a groove for separating the transfer mask from the back side of the SOI substrate by wet etching when separating the transfer mask formed in a plurality on the single SOI substrate from the SOI substrate; and And a step of separating the transfer mask from the substrate. 9. A method of manufacturing a transfer mask according to Configuration 7 or 8, comprising:

  According to the present invention, the mask holder has a concave accommodating portion for accommodating a transfer mask, the inner surface is formed in the concave accommodating portion, and the transfer mask includes a support frame made of silicon, and the support frame. And a thin film made of silicon having an opening pattern, and a guide surface that restricts the movement of the transfer mask for positioning is formed on the outer peripheral end of the thin film so as to face the inner surface. When the transfer mask is accommodated in the mask holder, the movement in the horizontal direction is regulated by positioning the transfer mask in the horizontal direction by making the guide surface and the inner surface of the concave accommodating portion face each other. Therefore, the transfer mask container in which the transfer mask is accommodated in the mask holder with high positional accuracy can be provided by processing the opposing surfaces with the necessary accuracy.

According to the present invention, the guide surface for restricting the movement of the transfer mask in the mask holder is formed at the outer peripheral end portion of the thin film in the transfer mask by the same photolithography process as the opening pattern of the thin film. be able to.
According to the method of the present invention, the aperture pattern and the guide surface are processed into the thin film by the same photolithography, thereby eliminating the need for processing in separate steps, mediating the alignment work that is a cause of accuracy degradation. Processing with high relative positional accuracy between the pattern and the guide surface is possible. Furthermore, the processing of the guide surface is not performed by combining wet etching with a thick film (such as exceeding several hundred microns), but by performing dry etching, processing with high accuracy becomes possible.

  For the above reasons, when the transfer mask is accommodated in the mask holder, the guide surface formed on the outer periphery of the thin film end and the inner surface of the concave accommodating portion are opposed to each other, so High positioning accuracy can be obtained, and positioning with high accuracy can be performed with a simple operation.

It is sectional drawing which shows one Embodiment of the manufacturing method of the transfer mask which concerns on this invention to process order. The transfer mask accommodating body of this invention is shown, (a) is the longitudinal cross-sectional view, (b) is the top view. (A) And (B) is a top view which shows the other example of the transfer mask which concerns on this invention, respectively. It is sectional drawing which shows the other example of the transfer mask which concerns on this invention.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a sectional view showing an embodiment of a method for manufacturing a transfer mask according to the present invention in the order of steps. FIG. 2 shows a transfer mask container of the present invention, in which (a) is a longitudinal sectional view thereof and (b) is a plan view thereof.

  The transfer mask container according to the present invention comprises a mask holder and a transfer mask accommodated in the mask holder as in Configuration 1, wherein the transfer mask is accommodated in the mask holder. The transfer mask has a thin film on which an opening pattern is formed, and a support frame made of silicon that supports the thin film, and the opening pattern is formed at an end of the thin film. A guide surface is formed that is etched simultaneously with the formation of the mask to restrict the movement of the transfer mask in the mask holder, and the guide surface of the transfer mask is opposed to the inner surface formed in the accommodating portion of the mask holder. And it is accommodated in the said mask holder, It is characterized by the above-mentioned.

One embodiment of the transfer mask container according to the present invention will be described with reference to FIG. 1 (j) or 2. The transfer mask 20 is supported by the support frame 1 made of silicon and the support frame 1. And a thin film 2 made of silicon having an opening pattern 3 and an SiO ₂ layer 4 formed between the support frame 1 and the thin film 2. In addition, a particularly characteristic configuration of the transfer mask 20 according to the present invention is that a guide surface is formed at the outer peripheral end of the thin film 2 so as to face the inner surface for use in positioning. In the example shown in FIG. 1 (j), the protrusion width of the guide surface from the support frame 1 of the thin film 2 protruding outward from the outer periphery of the support frame 1 is α.

  On the other hand, the mask holder 30 for accommodating the transfer mask 20 includes a mask holder main body portion 31 having a concave accommodating portion 33 for accommodating the transfer mask 20, and the surface of the thin film 2 of the transfer mask 20 accommodated in the concave accommodating portion 33. And a mask holder lid portion 32 formed with a convex portion for fixing the transfer mask 20 from the upper surface at a position where it can be pressed and pressed. When the transfer mask 20 is received, the concave receiving portion 33 is formed with an inner surface 34 and a bottom surface 35 that oppose the guide surface of the transfer mask.

  The mask holder lid 32 is opened at least in the region of the accommodated transfer mask 20 where the opening pattern 3 of the thin film 2 is formed, and the mask holder main body 31 is accommodated in the accommodated transfer mask 20. Are opened at least in the opening region 6 on the rear surface of the support frame. Therefore, when the transfer mask 20 is accommodated in the concave accommodating portion 33 of the mask holder main body portion 31 and the mask holder lid portion 32 is closed from above, the mask holder lid portion 32 has at least the opening pattern 3 in the thin film 2 of the transfer mask 20. The bottom surface 35 of the concave housing portion 33 of the mask holder main body 31 is in contact with at least the back surface (bottom surface) of the support frame 1 excluding the opening 6 on the back surface side of the support frame 1 of the transfer mask 20. It has become.

  As described above, the mask holder main body 31 is formed with the concave accommodating portion 33 for accommodating the transfer mask 20, and the inner surface 34 of the concave accommodating portion 33 is the outer periphery of the thin film 2 of the accommodated transfer mask 20. By facing the guide surface formed at the end portion 5, it functions as a positioning guide on the mask holder side for determining the position in the horizontal direction. Further, the bottom surface 35 of the concave accommodating portion 33 can be used as a positioning guide for determining the vertical position by bringing the back surface of the supporting frame 1 of the accommodated transfer mask 20 into contact. The material for forming the mask holder 30 is, for example, silver, copper, silver-copper alloy, palladium, nonmagnetic stainless steel, tantalum, tungsten, molybdenum, zirconium, etc. from the viewpoint of thermal conductivity, electrical conductivity, machinability, and the like. When these metal materials are used, each positioning guide portion (of the concave accommodating portion 33) which is processed with an accuracy of 1/1000 mm by machining and is provided on the mask holder 30 side. The inner surface 34 and the bottom surface 35) are also machined with similar machining accuracy.

When the transfer mask 20 is accommodated in the mask holder 30, the guide surface formed on the outer peripheral end 5 of the thin film 2 in the transfer mask 20 and the concave accommodation that serves as a horizontal positioning reference in the mask holder main body 31. By facing the inner surface 34 of the portion 33, the transfer mask is positioned in the horizontal direction.
For example, in the case of a rectangular transfer mask, positioning is achieved by facing at least the guide surface constituting one side of the outer peripheral end 5 and the inner surface 34. In this case, the position in the rotation direction in the horizontal direction is suitably determined. Moreover, the opposing part of a guide surface and an internal surface can contact | abut. In the case of a mode in which two adjacent sides are opposed to each other in a rectangular transfer mask, the position in the biaxial direction orthogonal to the horizontal direction is suitably determined in addition to the rotation direction. Also in this case, the facing portion can abut.

  Further, the range in which the transfer mask accommodated in the concave accommodating portion 33 can move in the horizontal direction within the concave accommodating portion 33 can be limited within the range of positional deviation that can be allowed when the transfer mask is accommodated in the holder. The distance between the inner surface 34 and the guide surface can be set. Specifically, the facing position of the inner surface 34 can be set within a range in which the shift of the transfer mask can be allowed with reference to the guide surface of the transfer mask.

  For example, when a rectangular transfer mask is accommodated in the rectangular concave accommodating portion 33, the facing distance between the inner surface 34 of the concave accommodating portion 33 and the guide surface of the transfer mask is set as follows. It can be in the range of 5 μm to 150 μm. Furthermore, it is desirable to set it as the range of 25 micrometers-80 micrometers. These opposing distances are a range of distances when the transfer mask is arranged in the holder so that the respective opposing places have the same distance. At the time of actual accommodation, the transfer mask moves within the movable range in the accommodation portion, and thus the distance between the guide surface and the inner surface 34 may not fall within this numerical range. In this way, the distance between the inner surface 34 and the guide surface of the concave accommodating portion 33 facing each other is set so as to limit the range in which the transfer mask can move in the horizontal direction, thereby maintaining the required alignment accuracy. The operation of accommodating the transfer mask in the holder is facilitated, and even after the transfer mask is accommodated, the movement range of the transfer mask is limited within the range where the guide surface abuts on the inner surface 34, so that the transfer mask is set. It is possible to prevent a problem that the position is shifted beyond the range.

  As will be described later, since the outer peripheral end 5 of the thin film 2 formed on the outer periphery of the support frame 1 in the transfer mask 20 is formed by a photolithography process, high processing accuracy can be obtained. By using the surface, the outer peripheral end portion 5 of the thin film 2 and the inner surface 34 of the concave accommodating portion 33 are opposed to each other, so that high positioning accuracy between the transfer mask 20 and the mask holder 30 can be obtained, and the above-described simple Can be positioned with high accuracy. Note that this photolithographic process can be controlled to have a manageable line width variation (processing accuracy) of about 1/1000 μm or less according to a combination of reduction drawing with a reticle or direct drawing with an electron beam drawing machine and a dry etching process. It is possible.

  That is, according to the present invention, it is possible to obtain a transfer mask container in which the transfer mask is accommodated at a predetermined position of the mask holder with high positional accuracy. For example, the transfer mask is accommodated in the mask holder attached to the exposure apparatus. When exchanging the transfer mask together with the mask holder, it is possible to save the trouble of adjusting the alignment of the transfer mask.

For fixing the mask holder main body 31 and the mask holder lid 32 in the mask holder 30, for example, after the transfer mask 20 is positioned and accommodated, the mask holder lid 32 is fixed with bolts or screws. The mask holder body 31 can be fixed by means. Further, the mask holder body 31 and the mask holder lid 32 are provided with a screw structure so that the female screw and the male screw are in a relationship, respectively, and the mask holder lid is screwed into the mask holder. 32 may be fixed to the mask holder main body 31.
Further, according to the present invention, there is no need to fix the transfer mask by using a conventional low melting point metal that can be melted and solidified, for example, and the low melting point metal used at that time protrudes or becomes a foreign object. Unnecessary contamination like this does not occur.

  Further, the overall shape (in plan view) of the transfer mask 20 is not limited to a rectangular shape, and may be a shape as shown in FIGS. 3A and 3B, for example. As shown in FIG. 3 (A), corners are chamfered or concave portions are provided on each side as shown in FIG. 3 (B), so that a holding portion for holding by a transfer mask handling means such as tweezers is provided. It can be provided. At least one pair of the holding portions is formed at a position symmetrical to the approximate center of the pattern surface of the transfer mask, excluding the outer peripheral end portion of the thin film and the portion facing the inner surface for positioning. It is desirable. This makes it easy to use as a guide surface for positioning without damaging the outer peripheral edge of the thin film, and when holding the transfer mask, it does not interfere with tweezers when housed in the holder. Can be accommodated.

  Further, the film thickness of the thin film 2 in the transfer mask 20 is not particularly limited, but a predetermined thickness is necessary, and for example, it is preferably in the range of 5 μm to 200 μm. If the film thickness of the thin film 2 is less than 5 μm, the strength as a guide of the outer peripheral end portion 5 portion of the thin film 2 which is brought into contact with the inner surface 34 of the concave accommodating portion 33 and positioned is insufficient. On the other hand, if the thickness of the thin film 2 is larger than 200 μm, the charged particle beam passing through the opening pattern of the thin film may be affected by the side wall of the opening pattern and may not be accurately transferred.

  Further, when the transfer mask is accommodated in the mask holder, the outer peripheral end 5 and the inner surface 34 are preferably formed perpendicular to the main plane (horizontal plane) of the transfer mask. When the transfer mask is accommodated in the holder, the guide surface shape does not hinder the operation in the accommodating direction, and further, a surface for positioning in the horizontal plane direction is provided perpendicular to the horizontal plane. It becomes possible to carry out positioning with high accuracy. For example, the outer peripheral end 5 and the inner surface 34 are preferably in the range of 80 ° to 100 ° with respect to the main plane of the transfer mask when the transfer mask is accommodated in the mask holder. Furthermore, it is desirable to be within the range of 88 ° to 92 °. In addition, by setting this angle range, the outer peripheral end portion forms a taper and does not become a knife edge, which is advantageous in terms of strength. In order to form the outer peripheral end 5 in such a vertical manner by using photolithography, it is desirable to process the outer peripheral end using anisotropic etching such as dry etching. At this time, by processing the opening portion and the outer peripheral end portion of the transfer mask at the same time by the same photography process, the relative positional accuracy of the opening portion and the outer peripheral end portion 5 can be kept high. Furthermore, since it is not necessary to form the opening and the outer peripheral end 5 separately, there is a merit that the number of processes can be reduced.

  The protrusion width of the guide surface formed on the outer peripheral end 5 of the thin film 2 in the transfer mask 20 from the support frame 1 is, for example, in consideration of the strength of silicon used as the material of the support frame. When the film thickness of 2 is 5 μm to 50 μm, it is preferably 5 times or less. In FIG. 4, the protrusion width from the support frame 1 of the guide surface of the thin film 2 protruding outward from the outer periphery of the support frame 1 is β (β> α) wider than α in FIG. An example is given. Further, the processing accuracy of the protruding width is determined by the balance between the processing accuracy of the support frame and the processing accuracy of the thin film. Therefore, if the design value of the protrusion width of the guide surface of the thin film 2 from the support frame 1 is small, the required protrusion width may not be ensured when the variation in processing accuracy due to wet etching of the support frame is large. The minimum value of the protrusion width is preferably 10 μm regardless of the thickness of the thin film. Furthermore, it is more desirable that the minimum value be 20 μm.

Next, a description will be given of a method for manufacturing a transfer mask according to the present invention that is used while being accommodated in a mask holder.
FIG. 1 is a sectional view showing an embodiment of a method for manufacturing a transfer mask according to the present invention in the order of steps.
The transfer mask manufacturing method according to the present invention relates to a transfer mask manufacturing method manufactured using the above-described SOI (Silicon on Insulator) substrate. This SOI substrate has a structure in which _two silicon plates are bonded together via a SiO ₂ layer.

In the present embodiment, as shown in FIG. 1A, an SOI having a three-layer structure of Si layer 12 (thickness 20 μm) / SiO ₂ layer 13 (thickness 2 μm) / Si layer 14 (thickness 500 μm). Using a substrate, a dry etching mask layer for forming an opening pattern on the substrate surface side (Si layer 12 side) on the Si layer 12 of the substrate and simultaneously processing the outer peripheral edge of the thin film of the transfer mask 11 was prepared by forming a 1 μm thick SiO ₂ layer. As the dry etching mask layer 11, in addition to the oxide layer such as the SiO ₂ layer, a metal such as titanium, chromium, tungsten, zirconium, nickel, an alloy containing these metals, or these metals or alloys and A metal compound with oxygen, nitrogen, carbon or the like can also be used.

Next, the dry etching mask layer 11 is patterned by a photolithography process using a resist to form a predetermined opening formation pattern and a thin film outer peripheral end portion processing pattern.
That is, a resist layer 15 (for example, a photosensitive silicon resin layer having a thickness of 2 μm) is formed on the dry etching mask layer 11 (see FIG. 1B), and a predetermined pattern is drawn on the resist layer 15. After performing drawing and developing, a predetermined resist pattern 15a for opening formation and a resist pattern 15b for processing the outer peripheral edge of the thin film were formed (see FIG. 1C).

Next, the dry etching mask layer 11 (SiO ₂ layer) is patterned by dry etching using a fluorine-based gas using the resist pattern 15a for opening formation and the resist pattern 15b for processing the outer periphery of the thin film as a mask. A predetermined opening forming pattern and a thin film outer peripheral end portion processing pattern were formed (see FIG. 1D). Here, the remaining resist patterns 15a and 15b were removed (see FIG. 1E).
Although not shown, a mode in which a plurality of transfer masks are arranged on a single substrate with a predetermined interval between the transfer masks was adopted.

Subsequently, the Si layer 12 is dry-etched by reactive ion etching (RIE) using the predetermined opening forming pattern and the thin film outer peripheral edge processing pattern formed in the dry etching mask layer 11 as a mask. A pattern 12a and a thin film outer peripheral end 12b were formed (FIG. 1 (f)).
At this time, the depth of the opening pattern 12a is 20 μm corresponding to the thickness of the Si layer 12, and etching was performed until the SiO ₂ layer 13 as an etching stopper layer was reached.

  In this way, the outer peripheral edge of the thin film is processed simultaneously when the thin film opening pattern is formed by the photolithography process, so that the relative positional accuracy with the thin film opening pattern can be improved. It can be determined using it. That is, for positioning the transfer mask with respect to the mask holder, a guide surface is formed on the outer peripheral edge of the thin film by a photolithography process for forming an opening pattern of the thin film. High relative position accuracy can be obtained. In particular, as in this embodiment, it is preferable that the photolithography process in this case includes an anisotropic etching process using dry etching.

  Next, a resist layer 16 (for example, having a thickness of 2 μm) is formed as a wet etching mask layer on the entire substrate for the purpose of protecting the substrate surface side and processing the back surface side (forming the opening for the support frame and the groove for separating the transfer mask) A photosensitive silicon resin layer), the resist layer 16 on the back side of the substrate is patterned by a photolithography process, and a resist pattern 16a for forming an opening of the support frame and a resist pattern 16b for forming a separation groove for separating a transfer mask are formed. It formed (refer FIG.1 (g)).

Subsequently, the Si layer 14 on the back side of the substrate is wet-etched using the resist pattern 16a for forming the opening of the support frame and the resist pattern 16b for forming the separation groove for separating the transfer mask as a mask. 17 and a separation groove 18 for separating the transfer mask were formed (see FIG. 1H).
As an etchant, a mixed solution composed of ethylenediamine, pyrocatechol and water was used, and wet etching was performed until the exposed Si layer 14 on the back side of the substrate reached the SiO ₂ layer 13 as an etching stopper layer.

Next, the remaining resist layer 16 and the resist patterns 16a and 16b and the portion remaining in the opening of the SiO ₂ layer 13 as an etching stopper layer were removed by a cleaning process including a buffered hydrofluoric acid treatment ( (Refer FIG.1 (i)).

In this cleaning step, the individual transfer masks are separated, and thus the transfer mask 20 of the present invention is completed (see FIG. 1 (j)). The details of the configuration of the completed transfer mask 20 are as described above. The support frame 1 of the transfer mask 20 is formed between the Si layer 14 and the thin film 2 is formed between the Si layer 12 and the support frame 1 and the thin film 2. The SiO ₂ layer 4 is formed by the SiO ₂ layer 13 as the etching stopper layer.

  As described above, the transfer mask manufacturing method of the present invention includes a step of forming, by a photolithography process, the guide surface formed on the outer peripheral end of the thin film protruding outward from the outer periphery of the support frame in the transfer mask. It is characterized by this. In particular, when separating a plurality of individual transfer masks formed on a single substrate from the substrate, a groove for separating the transfer mask from the back side of the substrate is formed by wet etching, and by subsequent cleaning, The present invention can be more suitably implemented by combining with the step of separating the individual transfer masks from the substrate.

  Further, in the transfer mask manufacturing method of the present invention, the photolithography process for forming the outer peripheral edge of the thin film in the transfer mask is a photolithography process for forming the opening pattern of the thin film, and in particular, in this case, the photolithography Since the process includes an anisotropic etching process using dry etching, the processing accuracy of the outer peripheral edge of the thin film and the relative positional accuracy between the outer peripheral edge of the thin film and the opening pattern are improved. Is more preferably exhibited.

1 the support frame 2 thin film 3 aperture pattern 4 of the SiO ₂ layer 5 thin outer peripheral edge portion 6 supporting frame of the back surface of the opening 11 the dry etching mask layer 12 Si layer 13 SiO ₂ layer 14 Si layers 15 and 16 resist layer 17 supporting frame Opening 18 Separation groove 20 Transfer mask 30 Mask holder 31 Mask holder main body 32 Mask holder lid 33 Concave housing part 34 Internal surface 35 of concave housing part Bottom surface of concave housing part

Claims (9)

In a transfer mask container comprising a mask holder and a transfer mask housed in the mask holder,
The mask holder has an accommodating portion for accommodating the transfer mask,
The transfer mask has a thin film in which an opening pattern is formed, and a support frame made of silicon that supports the thin film, and an end portion of the thin film was etched simultaneously with the formation of the opening pattern. A guide surface that regulates movement of the transfer mask in the mask holder is formed,
A transfer mask container, wherein a guide surface of the transfer mask is accommodated in the mask holder so as to face an internal surface formed in an accommodating part of the mask holder.   The transfer mask container according to claim 1, wherein at least a part of the guide surface is in contact with an inner surface of the mask holder. In a method for manufacturing a transfer mask container, comprising a mask holder and a transfer mask housed in the mask holder,
The mask holder has an accommodating portion for accommodating the transfer mask,
The transfer mask includes a thin film having an opening pattern formed thereon and a support frame made of silicon that supports the thin film, and an end portion of the thin film is etched at the same time as the opening pattern is formed. In addition, a guide surface that regulates movement of the transfer mask in the mask holder is formed,
A method for producing a transfer mask container, comprising the step of accommodating the transfer mask in the mask holder with the guide surface of the transfer mask facing an internal surface formed in the accommodating part of the mask holder .   The method for manufacturing a transfer mask container according to claim 3, wherein at least a part of the guide surface is brought into contact with an inner surface of the mask holder. A transfer mask used for electron beam exposure in a state accommodated in a mask holder,
A thin film on which an opening pattern for transfer is formed, and a support frame made of silicon that supports the thin film;
A transfer mask, characterized in that a guide surface that is etched simultaneously with the formation of the opening pattern and that can come into contact with the mask holder is formed at an end of the thin film.   The transfer mask according to claim 5, wherein the thin film has a thickness of 5 μm to 200 μm. A method for manufacturing a transfer mask used for electron beam exposure in a state of being accommodated in a mask holder,
Preparing an SOI substrate in which a SiO ₂ layer and a silicon thin film are formed on a silicon substrate, and a first etching mask layer is further laminated thereon;
Patterning the first etching mask layer by a photolithography process using a resist;
Forming a transfer opening pattern in the silicon thin film by etching using the patterned first etching mask layer as a mask;
Forming a second etching mask layer on the outer surface including the front and back surfaces of the SOI substrate having a transfer opening pattern formed on the silicon thin film;
Patterning the second etching mask layer by a photolithography process using a resist;
Using the patterned second etching mask layer as a mask, and processing the shape of a support frame on the silicon substrate,
In the step of forming the opening pattern, an end portion of the thin film is defined by etching, thereby forming a guide surface that regulates movement of the transfer mask in the mask holder when the transfer mask is accommodated in the mask holder. A method for producing a transfer mask, comprising:   The method for manufacturing a transfer mask according to claim 7, wherein the step of forming the opening pattern includes a dry etching step. When separating a plurality of the transfer masks formed on a single SOI substrate from the SOI substrate,
9. The method according to claim 7, comprising a step of forming a groove for separating the transfer mask from the back side of the SOI substrate by wet etching, and a step of separating the transfer mask from the substrate. Manufacturing method of the transfer mask.

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