JPH10207044A - Transmission mask for charge beam exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission mask for charge beam exposure which facilitates data input and facilitates the formation of discrete information marks for identifying individual masks. SOLUTION: A bonding silicon substrate 4 formed by bonding single crystal silicon wafers 1, 2 having face bearings of (100) with a silicon oxidized film 2 is used. Transmission hole patterns 6 and the four points symmetrical type discrete information marks 7, 8 are formed the one surface of the single crystal silicon wafers and therefore, protective films 9 are formed on both surfaces of the bonding silicon substrate. Protective film patterns 9a are formed on the single crystal silicon wafer 3. With the protective film patterns 9a as a mask, the single crystal silicon wafer 3 is subjected to anisotropic wet etching by a hot alkaline soln. to form apertures 11 and 12. The protective films 9 and protective film patterns 9a are subjected to a peeling treatment and conductive films are formed on the front surface of the mask and the flanks of the transmission hole patterns, by which the transmission mask 13 for charge beam exposure is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an LSI, a VLSI
Regarding the exposure of charged beams (electron beam or charged particle beam) used for drawing fine patterns such as the manufacture of semiconductor integrated circuits, etc., and for modifying materials, etc. And a transmission mask for charged beam exposure.

[0002]

2. Description of the Related Art Conventionally, on a stepper, when identifying a reticle in a reticle cassette, a numerical value is represented by a band-shaped pattern (bar code) having a different thickness, and an identification number unique to the reticle is recognized. When inputting a unique identification number even in a transmission mask for charged beam exposure, it is sufficiently conceivable to use a conventional barcode method. Actually, when a barcode pattern is created in a transmission mask for charged beam exposure using through holes, the size of the pattern is mixed, and in the case of a narrow pattern, the mechanical strength of the transmission mask tends to be unstable. there were.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is a charged beam capable of easily inputting data and easily forming individual information marks for identifying individual masks. An object is to provide a transmission mask for exposure.

[0004]

According to the present invention, in order to achieve the above object, in a first aspect of the present invention, in a transmission mask used in a charged beam exposure method, a mask identification number unique to the transmission mask. A transmission mask for charged beam exposure, wherein a four-point symmetric individual information mark is used as the medium.

According to a second aspect of the present invention, in the transmission mask for charged beam exposure, the four-point symmetric individual information mark is provided as a through hole outside a pattern exposure area of the transmission mask. It is.

The transmission mask for charged beam exposure according to the present invention comprises:
As a medium for the mask-specific number identification information, a four-point symmetric individual information mark (registered trademark: Karla code,
-132093).
The basic principle of the four-point symmetric individual information mark is as follows, as shown in FIG. 3, 1 (= 2 ⁰ ), 2 (=
2 ¹ ), 4 (2 ² ), and 8 (= 2 ³ ) are written, the four cells are painted, and the total number of the painted cells is 16 as shown in FIG. Data). The code can be displayed with such a simple combination of patterns.

[0007]

Embodiments of the present invention will be described below. 1A is a plan view of a transmission mask for charged beam exposure according to the present invention, and FIG. 1B is a cross-sectional view taken along line YY of the transmission mask for charged beam exposure according to the present invention. (A)-(f) is sectional drawing which shows the manufacturing process of the transmission mask for charged beam exposure which concerns on this invention.

The transmission mask for charged beam exposure according to the present invention comprises:
As shown in FIG. 1A, four-point symmetric individual information marks 7 and 8 are provided outside the exposure area of the transmission mask 6.
Light or an electron beam is incident on the four-point symmetric individual information mark, the light receiving element reads the code pattern of the four-point symmetric individual information mark, and recognizes it as binary data. Further, the pattern size of the four-point symmetric individual information mark is not particularly limited, but it is preferable that the pattern size is as small as possible and can be accommodated in the transmission mask for charged beam exposure, for example, about 10 μm □ to 50 μm □. Further, the four-point symmetric individual information mark can be processed in the same process as that of the portion of the transmission mask that becomes the charged hole transmission hole pattern by means of ordinary photolithography or electron beam lithography.

First, a bonded silicon substrate 4 is prepared by bonding a single crystal silicon wafer 1 having a plane orientation of (100) and a single crystal silicon wafer 3 with a silicon oxide film 2.
A photosensitive layer is formed on the surface of the single crystal silicon wafer 1 and patterned to form a resist pattern 5 for producing a transmission hole pattern and a four-point symmetric individual information mark (see FIG. 2A).

Next, using the resist pattern 5 as a mask, the single-crystal silicon wafer 1 is etched to a depth reaching the silicon oxide film 2 by dry etching such as reactive ion etching or the like, and the transmission hole pattern 6 and four-point symmetry are obtained. Formula individual information marks 7 and 8 are formed (see FIG. 2B).

Next, a protective film 9 for wet etching is formed on both surfaces of the bonded silicon substrate 4 on which the transmission hole pattern 6 of the charged beam and the four-point symmetric individual information marks 7 and 8 are formed. A resist pattern 10 is formed on the protective film 9 on the substrate 3 (see FIG. 2C).

Next, using the resist pattern 10 as a mask, the protective film 9 on the single-crystal silicon wafer 3 is dry-etched to form a through-hole pattern and an opening for the four-point symmetric individual information mark. A film pattern 9a is formed (see FIG. 2D).

Next, using the protective film pattern 9a as a mask, the single-crystal silicon wafer 3 is back-etched to a depth of the silicon oxide film 2 with a heated alkali solution of potassium hydroxide to form the through-hole pattern openings 11 and 4 The single-crystal silicon frame 3a in which the point-symmetric individual information mark openings 12 are formed is manufactured (see FIG. 2E).

Next, the protection film 9 on the single crystal silicon wafer 1a and the protection film pattern 9a on the single crystal silicon frame 3a
Is removed, and a conductive film is formed on the mask surface and the side surface of the transmission hole pattern to obtain the transmission mask 13 for charged beam exposure of the present invention (see FIG. 2 (f)).

[0015]

The present invention will be described in detail with reference to the following examples.
A bonded silicon substrate 4 is prepared by bonding a single-crystal silicon wafer 1 and a single-crystal silicon wafer 3 having a 3-inch diameter of 500 μm and a plane orientation (100) with a silicon oxide film 2, and a positive EB resist EBR-900 (Toray) Was spin-coated to form a photosensitive layer having a thickness of 1 μm. Subsequently, the transmission hole pattern and the four-point symmetric individual information mark are drawn by an electron beam drawing apparatus (HL-700 manufactured by Hitachi, Ltd.), and the resist pattern 5 is subjected to predetermined development and post-bake processing.
Was formed (see FIG. 2A).

Next, using the resist pattern 5 as a mask, the single crystal silicon wafer 1 is etched to a depth reaching the silicon oxide film 2 by an ECR (Electron Cyclotron Resonance) ion etching apparatus, and the resist pattern is stripped by O ₂ plasma. Through the processing, a transmission hole pattern 6 and four-point symmetric individual information marks 7 and 8 were formed (see FIG. 2B). Here, the etching gas is Cl ₂
Use those of SF ₆ was added 10%, microwave power was 200 W.

Next, the bonded silicon substrate on which the transmission hole pattern 6 and the four-point symmetric individual information marks 7 and 8 are formed is put into a low pressure CVD apparatus, and C ₂ H ₂ and SiH ₂ Cl ₂
And a protective film 9 made of a 100 nm thick SiCx film was formed on both surfaces of the bonded silicon substrate. Further, a photosensitive layer was formed on the protective film 9 on the single-crystal silicon wafer 3 side, and a patterning process was performed by ordinary photolithography to form a resist pattern 10 (see FIG. 2C).

Next, the protective film 9 was etched by RIE (reactive ion etching) using the resist pattern 10 as a mask to form a protective film pattern 9a for forming an opening (see FIG. 2D).

Next, using the protective film pattern 9a as a mask, the single crystal silicon wafer 3 is treated at a liquid temperature of 90.degree.
Back etching with a KOH aqueous solution was used to produce a single-crystal silicon frame 3a in which a transmission hole pattern opening 11 and a four-point symmetric individual information mark opening 12 were formed (see FIG. 2E).

Next, the protection film 9 on the single crystal silicon wafer 1a and the protection film pattern 9a on the single crystal silicon frame 3a
Was removed, and a conductive film was formed on the mask surface and the side surface of the transmission hole pattern, whereby a transmission mask 13 for charged beam exposure of the present invention was obtained (see FIG. 2 (f)).

[0021]

As described above, by using a four-point symmetric individual information mark as a medium for number identification information unique to a mask, an individual information mark for identifying each mask can be formed in a simple pattern. In addition, it can be installed in a relatively small area, and does not impair the mechanical strength of the transmission mask for charged beam exposure. Further, the exposure area of the transmission mask for charged beam exposure can be effectively used.

[Brief description of the drawings]

FIG. 1A is a plan view showing a transmission mask for charged beam exposure according to an embodiment of the present invention. FIG. 2B is a cross-sectional view taken along the line YY of the configuration of the transmission mask for charged beam exposure according to one embodiment of the present invention.

FIGS. 2A to 2F are cross-sectional views showing the steps of manufacturing a transmission mask for charged beam exposure according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing the principle of digitizing four-point symmetric individual information marks used in the present invention.

FIG. 4 is an explanatory diagram showing a basic code expression of a four-point symmetric individual information mark used in the present invention.

[Explanation of symbols]

1, 3 single crystal silicon wafer 1a single crystal silicon wafer on which transmission hole pattern and four-point symmetric individual information mark are formed 2 silicon oxide film 2a transmission hole pattern and four-point symmetric individual information Silicon oxide film on which marks are formed 3a Single crystal silicon frame on which openings of transmission hole patterns and four-point symmetrical individual information mark openings are formed 4 Bonded silicon substrate 5 Resist pattern 6 Transmission Hole pattern 7, 8: Four-point symmetric individual information mark 9: Protective film 9a: Protective film pattern 10: Resist pattern 11: Transmission hole pattern opening 12: Four-point symmetric individual information mark opening 13 ... Transmission mask for charged beam exposure

Claims (2)

[Claims] 1. A transmission mask for use in a charged beam exposure method, wherein a four-point symmetric individual information mark is used as a medium for number identification information unique to the mask of the transmission mask. mask. 2. The transmission mask for charged beam exposure according to claim 1, wherein said four-point symmetric individual information mark is provided as a through hole outside a pattern exposure area of said transmission mask.