JPH01152625A - Apparatus for and method of manufacturing x-ray exposure mask - Google Patents

Abstract

PURPOSE:To keep the faltness of an X-ray exposure mask without locally concentrating force and in particular improve the flatness of an X-ray absorptive side by holding said mask keeping in succession the flatness from the inside to the outside of said mask. CONSTITUTION:A planar reference structure 2 has a through-hole 3 through the center thereof, which hole surrounds an X-ray absorptive pattern region 5 included by an X-ray exposure mask 4. A planar part 1 makes contact with an annular region 6 surrounding the X-ray absorptive pattern region 5. A plurality of the same annular grooves 7 are formed along the periphery of the through-hole 3 in the vicinity of the planar part 1 located in close vicinity of the through-hole 3. Each annular groove 7 is communicated with one end of an air hole 8, the other end of which hole is opened to the side of the planar reference structure 2 and connected to a vacuum unit. Hereby, the annular region 6 of the X-ray exposure mask 4 in contact with the annular groove 7 is attracted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus and method for manufacturing an X-ray exposure mask for transferring fine patterns with high precision.

[Conventional technology]

The X-ray exposure method is known as an exposure method that overcomes the limitations of pattern miniaturization caused by exposure diffraction when an exposure pattern is transferred onto a semiconductor substrate or the like.

In order to perform X-ray exposure, an L1 X-ray exposure mask with sufficiently thick X-ray transmittance is required, and the substrate of the X-ray exposure mask is made of a material with excellent X-ray transparency. An X-ray absorbing pattern made of a thin film of X-ray absorbing material is formed on this substrate. When the X-ray absorptive pattern of the X-ray exposure mask formed in this way is transferred to, for example, a semiconductor substrate, the X-rays used generally have a wavelength of 4 to several 1O2.
Angstrom soft X-rays.

The above-mentioned X-ray exposure methods can be roughly divided into three methods: a batch transfer method and a step-and-repeat method. - Since the batch transfer method transfers a large area at once, the transfer accuracy decreases when a pattern with a width of 1 μm or less is transferred. For this reason, a step-and-repeat method is mainly used for pattern transfer with a width of 1 μm or less.

In the case of the step-and-repeat method, the gap between the X-ray exposure mask and the 81 substrate coated with X-ray resist on the side to be exposed is several lO to minimize the "blurring" of the transfer.
It can be suppressed to μm. For this reason, considering the positional accuracy of the X-ray absorbing pattern, the flatness of the X-ray exposure mask is 5 to 5.
It should be kept in the range of 10 μm. As a conventional technique for improving the flatness, there is an X-ray transfer mask disclosed in Japanese Patent Application Laid-open No. 75770/1983. This technology uses a reinforcing frame made of borosilicate glass or other material that is difficult to deform to support the X-ray exposure mask while maintaining the flatness of the mask surface by vacuum suctioning the mask surface at once. It is attached to a frame. This reinforcement ensures that the flatness of the mask surface is maintained even after vacuum suction is removed from the mask surface.

[Problem that the invention seeks to solve]

However, in the conventional method described above that attempts to maintain uniform flatness of the X-ray exposure mask, the X-ray exposure mask is vacuum-suctioned all at once, so force is concentrated locally, causing distortion of the X-ray exposure mask. occurs.

For this reason, there is a problem in the uniformity of the flatness of the X-ray exposure mask.

The present invention maintains flatness without locally concentrating force by holding an X-ray exposure mask sequentially from the inside to the outside. It is an object of the present invention to provide an improved manufacturing apparatus and manufacturing method for an X-ray exposure mask.

[Means for solving problems]

In order to achieve the above object, a first aspect of the present invention includes an X-ray absorbing pattern area on one side of an X-ray transparent thin film formed on a substrate, and an annular area around the X-ray absorbing pattern area. In an apparatus for manufacturing an X-ray exposure mask, which has a support frame for supporting the X-ray transparent thin film corresponding to the annular area on the other side of the X-ray transparent thin film, the annular area formed on one side is The present invention is directed to an apparatus for manufacturing an X-ray exposure mask, which includes a flat part that comes into contact with the flat part, a plurality of annular grooves formed in the flat part, and air holes that communicate with the outside from each of the annular grooves.

The second aspect of the present invention has an X-ray absorbing pattern area on one side of an X-ray transparent thin film formed on a substrate, and an annular area around the X-ray absorbing pattern area, and In a method for manufacturing an X-ray exposure mask having a support frame supporting an X-ray transparent thin film corresponding to an annular region on the other side of the transparent thin film, while sequentially applying an external force from the inside to the outside of the annular region, The method includes the steps of holding the X-ray absorbing pattern area in a plane, and then fixing a reinforcing frame along the end surface of the support frame while holding the X-ray absorbing pattern area and the annular area in a plane. The content includes a method for manufacturing an X-ray exposure mask.

[For production]

As described above, when using the X-ray exposure mask manufacturing apparatus of the first aspect of the present invention, the flat part of the manufacturing apparatus is brought into contact with the annular area around the X-ray absorbing pattern area. After this, the inner annular groove among the plurality of annular grooves formed in the plane part is vacuum-suctioned through the air hole. Next, while maintaining the flatness of the X-ray absorbing pattern area, the annular grooves outside the above-mentioned annular grooves are vacuum-suctioned through the air holes. In this way, the flatness of the X-ray absorbing pattern area is maintained.

The second method of manufacturing an X-ray exposure mask of the present invention includes:
The flatness of the X-ray absorbing pattern area is maintained while applying an external force from the inside to the outside of the annular area.

Then, the reinforcing frame is fixed to the end face of the support frame while keeping the X-ray absorbing pattern area and the annular area flat.

〔Example〕

EMBODIMENT OF THE INVENTION Below, the manufacturing apparatus of the X-ray exposure mask and the manufacturing method of the X-ray exposure mask of this invention are demonstrated based on drawing. First, as a first invention, an embodiment of an apparatus for manufacturing an X-ray exposure mask will be described. This manufacturing apparatus is a flat reference body 2 having a flat portion 1 as shown in FIGS. 1 and 2. The central part of the flat reference body 2 is a through hole 3, and this through hole 3 surrounds an X-ray absorbing pattern region 5 of the X-ray exposure mask 4, as will be described in detail later. Plane part 1
is in contact with an annular region 6 around the X-ray absorbing pattern region 5 that the X-ray exposure mask 4 similarly has. A plurality of annular grooves 7 are formed along the periphery of the through hole 3 in the vicinity of the flat portion 1 close to the periphery of the through hole 3 . This annular groove 7 is formed concentrically. Each annular groove 7 communicates with one of separate air holes 8, and the other air hole 8 opens at the side of the flat reference body 2. The opening of the air hole 8 is connected to a vacuum device (not shown), so that the annular region 6 of the X-ray exposure mask 4 in contact with the annular groove 7 is sucked.

Next, we will explain the process of fixing the reinforcing frame to the support frame of the X-ray exposure mask 4 using the planar reference body 2 having the structure described above. Explain.

FIG. 3 is a sectional view of the X-ray exposure mask 4.

A silicon substrate (hereinafter referred to as S1 substrate) 9 used in this X-ray exposure mask 4 is mirror-polished to a thickness of 0.3 to 4.0 mm. There are CVs on both sides of the Si substrate 9.
By using apparatus D, a SIN film 10 - having a thickness of 3 μm and serving as an X-ray transparent thin film is formed. 31
A photoresist pattern is formed on the SIN film 10 on the lower surface side of the substrate 9, and by performing an etching process using this photoresist pattern as a mask, an X-ray transmitting window 11 is formed in the center of the lower surface of the substrate 9. . The part of the S1 substrate 9 surrounding this X-ray transmission window 11 becomes a support frame 12,
The SIN film 10 left on the support frame 12 becomes a protective film 13. A 1 μm thick X-ray absorbing material layer made of tungsten W or tantalum Ta is formed on the upper surface of the SiN film 11 by sputtering. Furthermore, a resist pattern is formed on this X-ray absorbing material layer by, for example, a normal electron beam lithography method, and by performing a dry etching process using this resist pattern as a mask, the X-ray absorbing pattern area 5 is formed. An X-ray absorbing pattern 14 is formed. The circumference of this X-ray absorbing pattern 14 becomes an annular region 6.

Next, a first step for fixing the reinforcing frame 15 to the support frame 12 of the X-ray exposure mask 4 having the above structure will be described. First, as shown in FIG.
is brought into contact with the annular region 6 of the X-ray exposure mask 4. That is, the through hole 3 of the flat reference body 2 is located in the X-ray absorbing pattern area 5.
to the state where it is stored. In this state, the air hole 8 communicating with the annular groove 7 near the through hole 3 is sucked from atmospheric pressure to 60 Torr by a vacuum device (not shown). Due to this vacuum suction, the annular region 6 near the through hole 3 is attracted to the flat part 1 of the flat reference body 2. Next, using a Fieso interferometer,
While measuring the flatness of the SIN film 11 in the line-absorbing pattern area 5, air holes 8 communicating with the annular groove 7 on the outside of the annular groove 7 in the suction state are sucked from atmospheric pressure to 60 Torr. By this vacuum suction, the annular region 6 outside the annular region 6 in the above-described suction state is attracted to the flat part 1. By performing the first step in this way, the flatness of the SIN film 11 in the X-ray absorbing pattern area 5 is 2.
．． What used to be 5 μm became 0.5 μm.

Next, the second step will be explained. A reinforcing frame 15 made of borosilicate glass material is pasted onto the protective film 13 of the support frame 12 using an epoxy adhesive 15a while keeping the X-ray absorbing pattern area 5 and the annular area 6 flat. The X-ray exposure mask 4 with the reinforcing frame 15 bonded to the support frame 12 in this manner is heated in an oven maintained at a temperature of 90° C. for one hour. The epoxy adhesive 15a is cured by heating, and as shown in FIG. 5, the X-ray exposure mask 4 is removed from the flat reference body 2, and the second step is completed. SIN film 10 of completed X-ray exposure mask 4
Since the flatness of the X-ray absorbing pattern region 5 is maintained at 0.5 μm as described above, the flatness of the X-ray absorbing pattern region 5 is good.

〔Effect of the invention〕

From the above, the X-ray exposure mask manufacturing apparatus of the first invention forms a plurality of annular grooves in the plane portion that abuts the annular area around the X-ray absorbing pattern area, and each of the annular grooves Vacuum can be drawn from the communicating air holes to each annular groove, which eliminates the problem of distortion caused by local concentration of force on the X-ray exposure mask, and allows for high-quality X-ray exposure masks. Masks can be manufactured. Further, in the method for manufacturing an X-ray exposure mask of the second invention, the annular region of the X-ray exposure mask is sequentially vacuumed from the inner annular region near the X-ray absorbing pattern region to the outer annular region. The flatness of the X-ray absorbing pattern area is maintained while suctioning, and since the reinforcing frame is fixed to the support frame of the X-ray exposure mask, better flatness is maintained compared to conventional vacuum suctioning methods. can. For this reason, the gap between the X-ray exposure mask and the semiconductor substrate coated with the X-ray resist to be exposed can be set to several tens of micrometers or less. Therefore, even if continuous exposure is performed, the above-mentioned gap accuracy is maintained, the exposure quality is improved, and the efficiency of the exposure work is improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an apparatus for manufacturing an X-ray exposure mask according to the first invention, FIG. 2 is a sectional view shown by arrow A-A in FIG. 1, and FIG. 3 is a diagram showing the X-ray exposure mask. A cross-sectional view, FIG. 4 is a cross-sectional view showing the middle of the process of an X-ray exposure mask manufactured by the method for manufacturing an XAG light mask of the second invention, and FIG.
The figure is a sectional view showing a manufactured X-ray exposure mask. 1... Flat part, 4... X-ray exposure mask, 5...
X-ray absorptive pattern region, 6... annular region, 7...
Annular groove, 8... air hole, 9... substrate (31 substrates),
10...X-ray transparent thin film (SIN film), 12...
Support frame, 15... Reinforcement frame. Applicant's agent Sato - 1 stallion and 3 calvings

Claims (1)

[Scope of Claims] 1. An X-ray absorbing pattern area is provided on one surface side of an X-ray transparent thin film formed on a substrate, and an annular area around this X-ray absorbing pattern area is provided. In an apparatus for manufacturing an X-ray exposure mask, which has a support frame for supporting the X-ray transparent thin film corresponding to the annular region on the other surface side of the transparent thin film, the annular region formed on the one surface side 1. A manufacturing apparatus for an X-ray exposure mask, comprising: a flat part that comes into contact with the flat part; a plurality of annular grooves formed in the flat part; and air holes that communicate with the outside from each of the annular grooves. 2. The X-ray transparent thin film formed on the substrate has an X-ray absorbing pattern area on one side and an annular area around the X-ray absorbing pattern area, and the other side of the X-ray transparent thin film. A method for manufacturing an X-ray exposure mask having a support frame supporting the X-ray transparent thin film corresponding to the annular region on the side thereof,
a step of holding the X-ray absorbing pattern area in a plane while sequentially applying an external force from the inside to the outside of the annular area, and then making the X-ray absorbing pattern area and the annular area flat. A method for manufacturing an X-ray exposure mask, comprising the step of fixing a reinforcing frame along an end surface of the support frame while holding the support frame.