JPH06120204A - Back etching equipment - Google Patents

Abstract

PURPOSE:To prevent etching of a part not requiring corrosion even when etching solution leaks, and enable stable back etching, by installing liquid-stopping packings double on the inside and the outside, and installing a vacuum trap linked with the space between the packings and a vacuum pump. CONSTITUTION:Material part constituting the other surface side of a substratum 8a on which a thin film is formed is etched and eliminated, and a membrane retained by the substratum 8a is formed. In this back etching equipment, packings 7 which are interposed at least at the part where the surface to be etched of the substratum 8a is fixed to a penetrating aperture part 5 of an etching liquid reservoir 1 are installed double on the inside and the outside. A space constituted of the part between the packings 7 and a pressure reducing groove 6 arranged around the aperture part 5 is formed. A vacuum trap 3 for leak etching liquid and a vacuum pump 4 are installed which trap is linked with the space. For example, the substratum 8a is an X-ray mask intermediate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an X-ray exposure mask X
The present invention relates to an etching device for producing a thin film, that is, a membrane used for a window for transmitting a line or a window for holding electromagnetic waves and transmitting electromagnetic waves.

[0002]

2. Description of the Related Art A back etching process according to the present invention is carried out when a membrane of an X-ray exposure mask (hereinafter referred to as an X-ray mask) is manufactured as a typical example. Therefore, regarding the manufacturing process of the conventional X-ray mask,
This will be described with reference to (FIG. 2) to (FIG. 4). An X-ray transmission window 13 and an X-ray absorption layer are formed on the surface of the silicon base material 12,
The X-ray absorbing layer is patterned to form the X-ray absorber pattern 14 to form the X-ray mask intermediate 8 (see FIGS. 2 to 3). Since the silicon base material 12 does not transmit X-rays, a mask is provided on the back surface of the silicon base material 12 with the etching resistant material 11, the silicon base material 12 is brought into contact with an etching solution, and back etching is performed to perform X-ray irradiation on the silicon base material 12. A transmission window 15 is provided (see FIG. 4).

FIG. 4 shows a cross-sectional view of a conventional back etching apparatus for an X-ray mask. In the conventional apparatus, the etching solution reservoir 1 is provided with an opening 5 penetrating the bottom portion thereof, and the X-ray mask intermediate 8b is pressure-bonded to the lateral position of the opening 5 through the packing 7 to form the opening 5 of the etching liquid reservoir 1. To bring the etching liquid 2 into contact with a predetermined region of the X-ray mask intermediate 8b,
Using the etching resistant material as a mask, the silicon base material is back-etched and removed to produce an X-ray transmission window.

By the way, in the X-ray mask manufacturing process,
Like the conventional back etching device for X-ray masks, X
If the line mask intermediate is placed horizontally on the bottom of the etching solution reservoir, the etching solution may leak from the packing for liquid stopper. When the etching solution leaks from the packing portion, the etching solution spreads along the X-ray mask intermediate body. At this time, when the X-ray absorber pattern is already formed on the surface, the etching solution is formed. May destroy the pattern. Further, even before the surface is formed with the X-ray absorber pattern, the surface is corroded by the etching solution, which causes a problem that the surface cannot be patterned well in the subsequent steps.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to prevent the etching liquid from leaking even if the etching liquid leaks from the liquid-stop packing part. By making it possible to carry out a stable back-etching process by making it possible to carry out a stable back-etching process by passing along the substrate, and by preventing the etching from reaching the places where corrosion damage is unnecessary or where corrosion is not required, the membrane can be easily and reliably produced. It is about being able to do it.

[0006]

Means for solving the above-mentioned problems are provided by the present invention. That is, the material portion forming the multi-sided surface of the base material on which the thin film is formed is removed by etching, In a back etching apparatus for producing a membrane supported by a base material, at least a packing for interposing the surface to be etched of the substrate at a portion where the etching surface of the etching liquid reservoir penetrates is provided in double inside and outside. Having a space formed between the double packings and a pressure reducing groove provided around the opening.
A back etching apparatus having a vacuum trap for a leak etching solution and a vacuum pump connected to the space is provided.

FIG. 1 is a sectional view showing an embodiment of an X-ray mask back etching apparatus of the present invention. The X-ray mask intermediate body 8a is pressure-bonded to the opening 5 of the etching solution reservoir 1 via the double packing 7. In addition, the gap between the packings and the pressure reducing groove 6 which are doubly applied are connected to each other through a vacuum trap 3 for a leak etching solution.
Is constantly reduced to a constant pressure. The surface of the X-ray mask intermediate may be in the state before the patterning of the X-ray absorber or in the state before the patterning.

There is no problem as the material for the etching solution reservoir 1 as long as it is resistant to the etching solution 2. Synthetic resin such as vinyl chloride and fluororesin, stainless steel or metal is used as the etching solution resistant metal. Metallic materials such as plated ones can be used. The etching liquid reservoir 1 may have any shape as long as the mounting surface of the X-ray mask intermediate 8a is flat, and the overall shape is not limited, but a circular shape matching the shape of the silicon base material used is easy to handle. That is preferable. As the packing material,
There is no problem as long as the resistance to the etching solution is high. For example, a fluorine-based material is preferable because it has high resistance and is easily available.

[0009]

In the X-ray mask etching apparatus of the present invention, 2
Since the space between the heavy packings and the pressure reducing groove is constantly depressurized to a constant pressure, the adhesion between the etching solution reservoir and the packing and between the X-ray mask intermediate and the packing is maintained. Improves and prevents liquid leakage.
Even if the packing that comes into contact with the etching solution leaks due to deterioration of the packing, the vacuum pump operates to maintain a constant pressure, and the leaking etching solution is discharged through the pressure reducing groove. Since it is discharged to the leak etching solution vacuum trap, the back etching can be favorably performed without spreading on the X-ray mask intermediate.

[0010]

EXAMPLE An example of the present invention will be described below with reference to FIG. A circular opening 5 having a diameter of 60 mm was provided at the bottom of the fluororesin cylindrical etching solution reservoir 1 and back etching was performed on the X-ray mask intermediate 8a having a diameter of 3 inches. Between the X-ray mask intermediate 8a and the etching liquid reservoir 1, packings 7 having a diameter of 3.1 mm were installed on both sides of the pressure reducing groove 6 having a width of 3.1 mm for stopping the etching liquid. The pressure between the packings and the pressure-reducing groove 6 was constantly maintained at 100 Pa (0.75 Torr) by the rotary pump 4 connected via the leak etching liquid vacuum trap 3.

The X-ray mask intermediate 8a was made of a silicon base material having a thickness of 1 mm, and was used after being patterned on the X-ray transparent support film. As the etching liquid 2, a 30 wt% potassium hydroxide aqueous solution was used. The back-etching was performed for 4 hours by heating the etching solution 2 to 90 ° C. with a heater (not shown) provided in the etching-solution reservoir 1, and the back-etching was successfully completed without causing liquid leakage. The line transmission window is completed.

[0012]

According to the back etching apparatus of the present invention, the etchant is unlikely to leak, and even if the leak occurs due to deterioration of the packing in contact with the etchant, the etchant does not leak. After entering the space for vacuum, it is discharged to a vacuum trap for a leak etching solution, and therefore back etching can be performed without being transmitted along the substrate and causing corrosion on the side surface or the front surface of the substrate. The pattern on the surface of the X-ray mask intermediate is not destroyed. As a result, a stable back etching process can be performed, and a membrane can be easily and surely manufactured.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a schematic cross-sectional view of one embodiment (for an X-ray mask) of a back etching apparatus according to the present invention.

FIG. 2 is an explanatory view showing an example of an X-ray mask intermediate before back etching, with a schematic cross-sectional view. (Common to both the present invention and conventional)

FIG. 3 is an explanatory diagram showing, in a schematic sectional view, an example of an X-ray mask having an X-ray transmission window formed by back etching.

FIG. 4 is an explanatory view schematically showing an example (for an X-ray mask) of a conventional back etching apparatus in a schematic sectional view.

[Explanation of symbols]

 1 ... Etching solution reservoir 2 ... Etching solution 3 ... Leakage etching solution vacuum trap 4 ... Vacuum pump 5 ... Opening part 6 ... Decompression groove 7 ... Packing 8, 8a , 8b ... X-ray mask intermediate body 9 ... Cushion 10 ... Surface plate 11 ... Etching resistant material 12 ... Silicon base material 13 ... X-ray transparent support film 14 ... X-ray Absorber pattern 15 ... Window for X-ray transmission

Claims (1)

[Claims] 1. A back-etching apparatus for producing a membrane supported on a base material by etching a material portion of the base material on which a thin film is formed, the material constituting the multi-sided surface of the base material being etched to penetrate at least an etching solution reservoir. The packing to intervene in the portion where the surface to be etched of the substrate is attached to the opening is provided in double, inside and outside, and between the double packing and the pressure reducing groove provided around the opening. And a vacuum pump for a leak etching solution connected to the space, and a vacuum pump.