JPH09289149A - X-ray mask and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an X-ray mask to be less deteriorated in positional accuracy when a film is formed or removed by a method wherein a reference mark and a absorbing body are formed of different materials. SOLUTION: In an X-ray mask, a reference mark 3 and absorbing bodies 4 are formed of different materials, whereby a selective etching can be carried out. Therefore, in a process where the absorbing bodies 4 are patterned, the reference mark 3 formed of material different from that of the absorbing bodies 4 can be used as a reference, whereby a positional variation caused by the stress in the patterning process of the absorbing body 4 can be corrected, and the absorbing bodies 4 are improved in accuracy. Therefore, the reference mark 3 and the absorbing bodies 4 are formed of different materials, whereby the position of an absorbing body film or an etching mask film can be measured before and after the film is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray mask and a method for manufacturing the same, and more particularly, to reduce the influence of stress of a thin film material when manufacturing an X-ray mask and improve the positional accuracy and alignment accuracy. The present invention relates to an X-ray mask and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, with the miniaturization of semiconductor devices, X-ray exposure using X-rays as light having a shorter wavelength has been developed instead of UV exposure, and X-ray masks used for such X-ray exposure have been developed. A heavy metal film such as Ta or W is used as the absorber.

A reference mark and an alignment mark (mask mark) are formed by utilizing a part of the absorber film such as Ta or W.
When the absorber film is patterned using an electron beam exposure apparatus, correction is performed by referring to this reference mark at the time of exposure in order to prevent position variation due to temperature changes of the sample and the apparatus.

In the device process, heterodyne alignment is used in order to improve the alignment accuracy between the X-ray mask and the semiconductor wafer, and the mask mark and the wafer mark provided on the semiconductor wafer have different wavelengths. The alignment is performed by irradiating slightly different alignment light from different directions and detecting the phase difference of each primary light from the edge of the mask mark as a beat signal.

Since there are roughly three types of conventional X-ray mask manufacturing steps, these three manufacturing steps will be described with reference to FIG. See FIG. 6 (a). FIG. 6 (a) is a so-called back-etching subsequent type, in which a membrane such as SiC is formed on a silicon substrate, and then an absorber such as a Ta film is formed. Next, resist coating and exposure / development are performed, and then the absorber is patterned. Then, the central part of the silicon substrate is back-etched from the back surface to expose the membrane to form a support frame, and finally, a SiC ring or the like. Glue the frame to the support frame.

However, in the case of the post-back-etching type, in addition to the placement accuracy by drawing, the stress of the membrane balanced with the silicon substrate collapses in the back-etching step, and the absorber already patterned. There is a problem in that the pattern varies in position, or the absorber pattern is thermally distorted in the frame bonding step, so that high-precision position accuracy cannot be obtained.

See FIG. 6B. FIG. 6B is a so-called back etching preceding type, in which an absorber is formed on a silicon substrate and the frame is adhered to the back surface of the silicon substrate, and then the back etching is performed. The absorber is patterned after etching, then resist coating, and exposure / development.

FIG. 6C is also referred to as a so-called back etching precedent type. FIG. 6C also shows that a frame is adhered to the back surface of the silicon substrate on the back surface of the silicon substrate and back etching is performed.
The absorber is formed into a film, followed by resist coating and exposure /
After development, the absorber is patterned.

In these steps (b) and (c), the absorber is patterned after the frame adhering step and after the back etching step, so that the stress of the membrane and the distortion due to the adhering of the frame have an effect. Is eliminated and the position accuracy is improved.

However, even in this case, since the stress of the absorber itself and the stress of the resist exist, the stress of the absorber is determined by the film forming conditions of the sputtering apparatus used for forming the film of the absorber. Control, or
The stress was reduced by performing annealing or ion implantation after the film formation.

[0011]

However, the above-mentioned (b)
In the case of the above step, even if the stress control is performed after the film formation of the absorber, there is a problem that the residual stress of the absorber changes in the heat process and the back etching process accompanying the adhesion of the frame.

Further, in the case of the step (c), the method of measuring the stress by the height change accompanying the film formation or the film removal, which is usually used for measuring the stress, should measure the stress. There is a problem that the measurement becomes difficult because the absorber is present on the thin film membrane.

That is, when a thin film is deposited on a substrate, the displacement accompanying the deposition increases as the substrate becomes thinner, but when the thickness of the substrate becomes thinner than a certain amount, the displacement becomes smaller, and therefore the membrane becomes smaller. This is because it is impossible to measure the stress of the formed thin film even if the thin film is formed on the thin film.

The position variation due to the stress of the resist used in the absorber patterning step depends on the resist component (molecular weight) and the prebaking temperature, but if the resist film thickness and stress are constant, the stress of the resist is constant. Since the amount of position variation due to the same is the same, the relative position coordinates of the plurality of X-ray masks match each other.

However, in the actual exposure, X-ray exposure is used in the patterning process of the gate pattern and the contact layer pattern, but electron beam exposure and ultraviolet exposure are used in the exposure of other parts.
In hybrid exposure using such different exposure apparatuses in combination, the relative position coordinates of each mask are different.

In other words, if the exposure apparatus is different, the resist used for patterning will inevitably be different. Therefore, the stress also changes due to the difference in the resist composition, resulting in a positional shift between the masks.

Further, the film thickness of the resist required in the mask process is preferably as thin as possible in order to reduce the blur due to backscattering. However, in the device process, the thickness of the resist applied on the silicon wafer is Depending on the purpose, for example, the resist pattern as an ion implantation mask is required to be thicker than a normal pattern. Therefore, even if the same resist is used, the mask process and the device process have the same resist film thickness. It is hard to think that it will happen, and therefore, a relative positional change occurs between the two.

Therefore, in order to solve such a problem,
Direct drawing, i.e., patterning is performed by performing drawing while detecting the reference mark to form an ideal grid, but if the reference mark coordinates are not on the ideal grid, it will be drawn according to the distorted shape, Actually, since the reference mark is also patterned by using the resist, the position of the reference mark itself is changed by the stress of the resist.

In addition, in direct drawing when manufacturing a device,
Even if the reference mark coordinates are distorted by the stress of the resist, the underlying pattern is distorted to the same extent, so that the alignment accuracy does not deteriorate.

Further, in the X-ray lithography process, when pattern transfer is performed, heterodyne alignment is performed in order to perform highly accurate alignment. In this case, the alignment light transmitted through the mask mark is X-ray. Since multiple interference occurs between the line mask and the silicon wafer, and alignment accuracy is deteriorated, a light shielding film is provided so that the alignment mark does not transmit the alignment light.

Therefore, in this case, if SiC is used as the membrane and chlorine-based gas is used at the time of etching the absorber, since the membrane made of SiC is hardly etched, the mask mark detection signal indicates that the mask mark material and the light-shielding film are complex. A sufficient S / N ratio was not obtained, which was determined by the diffraction efficiency due to the difference in refractive index.

On the other hand, when a fluorine-based gas is used as the etching gas or SiN is used as the membrane, the membrane is etched to some extent, and the thickness of the membrane at the position where the mask mark exists and the thickness of the membrane at other positions. There is a difference in height, and the diffraction efficiency can be improved by the phase difference of the alignment light based on this difference.

However, due to the so-called microloading effect in which the etching time varies depending on the pattern size, the etching amount of the membrane varies depending on the pattern shape and location, and there is the problem that the diffraction efficiency is not constant.
There is a problem that the position of the absorber pattern changes due to the stress of the membrane accompanying the etching of the membrane.

Therefore, it is an object of the present invention to reduce the deterioration of the positional accuracy that occurs when a film is formed or removed.

[0025]

FIG. 1 is an explanatory view of the principle configuration of the present invention, and means for solving the problems in the present invention will be described with reference to FIG. In the figure, reference numerals 1 and 5 are a support frame and a frame, respectively. See FIG. 1 (1) The present invention is characterized in that the reference mark 3 and the absorber 4 are made of different materials in the X-ray mask.

As described above, by forming the reference mark 3 and the absorber 4 with different materials, selective etching becomes possible. Therefore, in the step of patterning the absorber 4,
By using the reference mark 3 formed of different material in advance as a reference, it is possible to correct the positional variation due to the stress in the patterning process of the absorber 4, and the accuracy is improved.

(2) Further, in the present invention according to the above (1), the reference mark 3 is set to Cr, Co, Ru, Mo, W, A.
u, Al ₂ O ₃ , SiO ₂ , In ₂ O ₃ , or Ta
The absorber 4 is made of any one of N, and the absorber 4 is made of any one of Ta, Ta ₂ O ₅ , and Ta ₄ B.

As described above, the reference mark 3 is made of Cr, Co, Ru, Mo, W, Au, which has a large resistance to chlorine gas.
By using Al ₂ O ₃ , SiO ₂ , In ₂ O ₃ , or TaN, and by forming the absorber 4 with Ta, Ta ₂ O ₅ , or Ta ₄ B, which can be etched with a chlorine-based gas. , RIE (reactive ion etching) using a chlorine-based gas enables selective etching.

(3) Further, in the present invention according to the above (1), the reference mark 3 is composed of Au or Al, and the absorber 4 is W, W-Ti, Ta, Ta ₂ O ₅ , Ta
It is characterized in that it is composed of any one of N and Ta ₄ B.

As described above, the reference mark 3 is composed of Au or Al having a high resistance to the fluorine-based gas, and the absorber 4 is W, W which can be etched with the fluorine-based gas.
_{-Ti, Ta, Ta 2 O 5} , TaN, or, Ta ₄ B
With this structure, selective etching can be performed by RIE using a fluorine-based gas.

(4) Further, according to the present invention, in the method for manufacturing an X-ray mask, the absorber 4 is formed after forming the reference mark 3, and then the absorber 4 on the reference mark 3 is selectively removed. After that, the arrangement of the reference marks 3 is measured before applying the resist, and the measurement result is input to the alignment mark coordinate values as an offset value to pattern the absorber 4.

As described above, the stress of the resist of the absorber pattern is measured by measuring the arrangement of the reference mark 3 immediately before applying the resist and exposing the resist in consideration of the deviation of the measured value from the ideal value. It is possible to compensate for the position variation due to, and it becomes important to correct the shift of the relative position coordinates in hybrid exposure in particular.

(5) Further, according to the present invention, in the method of manufacturing an X-ray mask, when the reference mark 3 is formed, the alignment mark is simultaneously formed and the membrane 2 is made of SiC.
The chlorine-based gas is used as an etching gas in the patterning process of the absorber 4, and the fluorine-based gas is used as an etching gas in the patterning process of the reference mark 3 and the alignment mark. It is characterized in that the membrane 2 is etched by 100 to 800 nm in the patterning step.

Although SiC is hardly etched by chlorine-based gas, it is etched by fluorine-based gas. Therefore, the membrane 2 made of SiC is simultaneously etched by using fluorine-based gas in the patterning process of the reference mark 3 and the alignment mark. It is possible to improve the diffraction efficiency of the alignment light and improve the mask alignment accuracy.

(6) In the method of manufacturing an X-ray mask according to the present invention, the position coordinates of the reference mark 3 are detected twice before and after the absorber 4 is formed, and based on the difference between them. It is characterized in that the positional change due to the stress of the absorber 4 is measured.

In this way, the stress of the absorber 4 formed on the thin membrane 2 is measured by detecting the position of the reference mark 3 twice before and after the absorber 4 is formed. Will be possible.

(7) Further, in the present invention, in the above (6), the stress of the absorber 4 is measured from the position variation, and the pattern data of the transfer pattern is provided so as to compensate the position variation expected from the stress value. It is characterized in that the absorber 4 is corrected and patterned.

As described above, by correcting the pattern data of the transfer pattern so as to compensate for the expected positional fluctuation from the measured stress value of the absorber 4, the absorber due to the influence of the stress of the absorber 4 itself. It is possible to reduce the positional variation of the pattern.

[0039]

FIG. 2 shows a first embodiment of the present invention.
This will be described with reference to FIG. See FIG. 2 (a). First, a thickness of 1.0 to 2.5 μm, which becomes a membrane of an X-ray mask, is formed on the surface of a silicon substrate 11 having a thickness of 525 μm by a low pressure chemical vapor deposition method (LPCVD method).
A SiC film 12 having a thickness of 2 μm is formed, and then the surface of the SiC film 12 deposited on one surface of the silicon substrate 11 is flattened by a polishing method and the S film deposited on the other surface is polished.
After removing the iC film 12, a W film 13 having a thickness of 30 to 650 nm, for example, 500 nm, is formed by a sputtering method.
Deposit.

Since the W film 13 is used as the reference mark 14, when the position is detected using the electron beam, in order to obtain a sufficient S / N ratio of the reflected electron signal, the electron beam is accelerated. Although depending on the voltage and the beam current, the thickness of the W film 13 may be 30 nm or more.

Further, BCl ₃ / C is used as an etching gas.
In RIE (reactive ion etching) using l ₂ , the etching selection ratio between W and Ta that serves as an absorber film is about 4 times, so that a W film thickness of 500 nm is sufficient.

Next, referring to FIG. 2B, a resist (not shown) having a thickness of 0.4 μm is applied, and then exposed and developed to form reference marks 14 at four corners around the chip area. At the same time as forming the pattern, a pattern for forming a heterodyne mark is formed at a predetermined position, and this resist pattern (not shown) is used as a mask to remove W by using CF ₄ gas.
The film 13 is etched to form fiducial marks 14 and heterodyne marks (not shown).

In this etching step, the underlying SiC film 12 is simultaneously etched by 100 to 800 nm, for example 320 nm, to enhance the diffraction efficiency of the alignment light.

That is, the etching depth is about 1/2 of the wavelength of the alignment light, that is, λ / 2, and it depends on the wavelength of the alignment light, but it need not be strictly λ / 2 and is necessary. It may be set appropriately according to the S / N ratio to be set. If too much etching is performed, position fluctuation due to stress fluctuation of the membrane becomes a problem.
00 nm is suitable.

Then, as shown in FIG. 2C, a thickness of 30 is formed on the entire surface by sputtering.
0 to 800 nm, for example, T which becomes an absorber of 600 nm
a film 15 is deposited.

At this time, the residual stress of the Ta film affects the reading of the reference mark 14 to be referred to and the position margin of the Ta film removing pattern on the reference mark 14 in the subsequent pattern drawing process. It is desirable to control the stress of the Ta film 15 to be substantially zero by performing the annealing process.

Next, as shown in FIG. 3D, a resist is newly applied, exposed and developed to form a resist pattern (not shown) for forming the mark region opening 16, and then this resist pattern is used as a mask. As a result, the Ta film 15 is etched by RIE using BCl ₃ / Cl ₂ as an etching gas to form the mark region opening 16.

Since the thickness of the absorber is as thick as about 300 to 800 nm after the Ta film 15 as the absorber is formed, the reflected electrons from the reference mark 14 can be directly detected. Impossible and fiducial mark 1
This is because the step on the surface of the absorber due to the step of No. 4 is also smoothed, so that it becomes necessary to form the mark area opening 16 for detecting the position of the reference mark 14.
Since 4 and the absorber are made of different materials, selective etching is possible.

The size of the mark region opening 16 is, for example, 100 μm □ including the mechanical alignment margin of the exposure apparatus when the size of the reference mark 14 is 20 μm. The Ta film 15 on the mark is not removed.

Next, referring to FIG. 3E, a frame 17 made of a SiC ring is adhered to the back surface of the silicon substrate 11, and wet etching using hydrofluoric / nitric acid is performed using the frame 17 as a mask to remove the silicon substrate 11. Back etching is performed to expose the SiC film 12 serving as a membrane, and the remaining silicon substrate 11 is used as the support frame 18.

3E, the position of the reference mark 14 is measured by an electron beam exposure apparatus, and the difference between the measured position of the reference mark 14 and the ideal lattice is added to the alignment coordinate, for example, measured 4. The coordinates of the reference mark 14 at the corner are (10000, 1
0000), (-10000, 10000), (-10
000, -10000), (10000, -1000)
0) to (10000.4,10000.4),
(-10000.3, 10000.4), (-1000
0.3, -10000.4), (10000.4, -1
0000.4), the above values are input to the alignment mark coordinates for direct drawing.

See FIG. 3F. Next, a resist (not shown), for example, ZEP-52.
0 (product name manufactured by Zeon Corporation) is applied to 0.2 μm, and 200
After performing pre-baking at 5 ° C. for 5 minutes, while detecting the reference mark, a pattern for forming a device pattern by direct drawing is exposed based on the input alignment mark coordinates described above, and then a resist formed by developing is exposed. BC using a pattern (not shown) as a mask
The Ta film 15 is etched by RIE using l ₃ / Cl ₂ as an etching gas to form a device pattern including the Ta pattern 19, that is, a pattern for forming a device.

According to the first embodiment of the present invention, the magnification error caused by the resist stress is 40 ppm (0.4 /
10000) can be corrected.

That is, even if the position coordinate of the reference mark is measured after coating the resist as in the conventional case, the position displaced due to the stress of the resist is detected, and the displaced reference mark is used as an ideal reference. When exposure is performed, when all the resist is finally removed, the pattern formed by being released from the stress of the resist causes a positional change and a deviation from an ideal reference occurs.

However, as in the present invention, the position coordinates of the reference mark are measured before the resist is applied, and when the device pattern is drawn using the electron beam exposure apparatus after the resist is applied, the resist is applied. Even if the position of the reference mark changes, the changed position is the coordinate of the measured reference mark and direct drawing is performed in accordance with it, so even if the resist is removed and there is a change due to stress,
The positional relationship between the device pattern and the reference mark after the change does not change, and the device pattern can be formed at an almost ideal position regardless of the stress of the resist.

In the first embodiment, the absorber and the reference mark are made of different materials, but the same material may be used if it is merely to reduce the effect of resist stress. For example, a Ta film may be used. In that case, after depositing the SiC film and the Ta film on the silicon substrate, the frame is bonded and back-etched, and then BCl ₃ / Cl _{2 is used.} The Ta film is etched by RIE using as an etching gas to form a reference mark and a heterodyne mark. Then, CF ₄ or BCl ₃ gas is used to remove the underlying SiC film.
The etching may be performed for 0 to 800 nm, and thereafter, the position of the reference mark may be measured in the same manner as the process of the first embodiment, and the position may be corrected to form the absorber pattern.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the above-mentioned first embodiment, the effect of the stress of the resist is avoided, but in reality, the stress of the absorber becomes a problem.
This embodiment avoids the influence of the stress of the absorber.

Referring to FIG. 4A, the second embodiment corresponds to the conventional step (c). First, the silicon substrate 2 having a thickness of 525 μm is used.
The thickness of the X-ray mask membrane on the surface of No. 1 is 1.0 to 2.5 by the low pressure chemical vapor deposition method (LPCVD method).
A SiC film 22 having a thickness of, for example, 2 μm is formed, and then the surface of the SiC film 22 deposited on one surface of the silicon substrate 21 is planarized by a polishing method, and the SiC film 22 deposited on the other surface is removed. Remove.

Then, SiC is formed on the back surface of the silicon substrate 21.
After the frame 23 made of a ring is adhered, the silicon substrate 21 is back-etched by performing wet etching using hydrofluoric nitric acid using the frame 23 as a mask to expose the SiC film 22 to be the membrane and to leave it. Supporting frame 24 for silicon substrate 21
And

Next, as shown in FIG. 4B, a thickness of 30 to 650 n is obtained by a sputtering method.
m, for example, a 500 nm W film 25 is deposited. Also in this case, since the W film 25 is used as the reference mark 26, when the position is also detected using the electron beam, the etching rate is taken into consideration in order to obtain a sufficient S / N ratio of the reflected electron signal. 30 nm to 500 nm is sufficient.

Next, referring to FIG. 4C, a resist (not shown) having a thickness of 0.4 μm is applied, and then exposed and developed to form reference marks 26 at four corners around the chip area. At the same time as forming the pattern, a pattern for forming a heterodyne mark is formed at a predetermined position, and this resist pattern (not shown) is used as a mask to remove W by using CF ₄ gas.
The film 25 is etched to form fiducial marks 26 and heterodyne marks (not shown).

After removing the resist pattern, the first position measurement of the reference mark 26 is performed using the electron beam exposure apparatus.

Next, as shown in FIG. 5D, a thickness of 30 is formed on the entire surface by sputtering.
0 to 650 nm, for example, T which becomes an absorber of 600 nm
a film 27 is deposited. Also in this case, it is desirable to control the stress of the Ta film 27 to be substantially zero by performing the annealing process.

Next, a resist is newly applied, exposed and developed to form a resist pattern (not shown) for forming the mark area opening 28, and then this resist pattern is used as a mask. As a result, the Ta film 27 is etched by RIE using BCl ₃ / Cl ₂ as an etching gas to form a mark region opening 28.

Also in this case, the size of the mark region opening 16 is 100 μm □ including the margin of the mechanical alignment of the exposure apparatus when the size of the reference mark 14 is 20 μm, for example. The Ta film 15 on the heterodyne mark is not removed.

After removing the resist pattern, the position of the second reference mark 26 is measured by using the electron beam exposure apparatus, and the Ta film is formed with a difference in position between the first and second times. Therefore, the position data corrected is input based on the result of the position change.

Next, referring to FIG. 5F, a resist (not shown), for example, ZEP-52 is used.
0 (product name manufactured by Zeon Corporation) is applied to 0.2 μm, and 200
After performing pre-baking at 5 ° C. for 5 minutes, while detecting the reference mark 26, a pattern for device pattern formation is exposed by direct drawing based on the corrected and input position data, and then developed to form a resist. Using a pattern (not shown) as a mask, BCl ₃ /
By RIE using Cl ₂ as an etching gas, T
The a film 27 is etched to form a device pattern including the Ta pattern 29.

It should be noted here that the resist is finally completely removed, while the absorber remains according to the device pattern. Therefore, a negative resist is used in the electron beam exposure apparatus. When the drawing rate of is extremely low, most of the absorber is removed, so the reference mark 2
Since 6 returns almost to the position before the film formation of the absorber, the coordinates measured in the first time are used as the absolute coordinates.

Further, when the drawing rate in the electron beam exposure apparatus using a positive type resist is extremely low, most of the absorber remains, so that the reference mark 26 remains almost at the position after film formation of the absorber. Therefore, the coordinates measured the second time are used as absolute coordinates.

When applied to an actual device pattern, since the position of the reference mark 26 after patterning varies depending on the drawing rate and the pattern arrangement, the position data of the first time and the position data of the second time are changed. The position accuracy can be improved by converting the data difference and adding it to the second measurement result.

As described above, in the second embodiment,
Not only the influence of the stress of the resist but also the influence of the stress of the absorber can be avoided, so that the positional accuracy can be further improved.

In the above description of the second embodiment, the reference mark 26 is formed after back etching, but it may be formed before the back etching step.

As described above, the first embodiment and the second embodiment of the present invention
However, in the present invention, since the Ta film on the heterodyne mark is not removed, the absorber made of the Ta film functions as a light shielding film in the heterodyne alignment process, so that the light shielding film is separately provided. The step of forming is unnecessary.

Further, in the description of each of the above-mentioned embodiments, the electron beam exposure apparatus is used to detect the reference mark, but a position inspection apparatus such as a light wave 5I (Nikon product name) may be used. It is a thing.

Further, in the above description of each embodiment, only the resist is used as an etching mask when etching the absorber, but the influence of the micro loading effect and the proximity effect due to electron beam drawing is reduced. Therefore, a SiO ₂ film or an Al ₂ O ₃ film may be used as an etching mask.

In this case, although the position changes due to the stress of the etching mask itself, when the etching mask is finally removed entirely, the position of the reference mark should be measured before the film formation of the etching mask like the resist. Just go.

That is, specifically, the reference mark and the mask mark are formed, the absorber is formed, the absorber on the reference mark is removed, the first reference mark position is measured, the etching mask is formed, and The second step of measuring the position of the reference mark and drawing the device pattern may be sequentially performed.

Further, when the etching mask is not removed, it is equivalent to that the etching mask and the absorber have a stress as a unit, so that the absorber and the etching mask are formed after the first position measurement. You can do a film.

In this case, the difference between the measurement results of the first surface and the second surface is In-Plane-Disto due to the film stress when the absorber or the etching mask is formed on the membrane.
It means that it represents a region (in-plane strain).

That is, the position variation due to film formation, stress control by annealing or ion implantation can be inferred from the position variation before and after each process, and by feeding back the result, the position associated with the patterning process can be estimated. Fluctuations can be compensated.

Further, by arranging a plurality of marks on the membrane in a matrix form at a pitch of 3 mm within, for example, 21 mm □, it is possible to measure the in-plane distribution of the stress of the film formed in that region. .

Further, in the above embodiment, the Ta film is used as the absorber film, but Ta is used instead of Ta film.
Similarly, Ta ₂ O ₅ or Ta ₄ B that can be etched with chlorine gas may be used. In that case,
C, which has a high resistance to chlorine-based gas as a reference mark
r, Co, Ru, Mo, Au, Al ₂ O ₃ , SiO ₂ ,
In ₂ O ₃ or TaN may be used, and Cr, C
o, Ru, Mo, Au, Al ₂ O ₃ , SiO ₂ , In ₂
The resistance of O ₃ and TaN to BCl ₃ / Cl ₂ is 10 times or more that of Ta.

Further, as the absorber, W, W-Ti, Ta, Ta ₂ O ₅ and T which can be etched with a fluorine-based gas are used.
Alternatively, aN or Ta ₄ B may be used. In that case, Au or Al having a high resistance to the fluorine-based gas may be used as the reference mark.

[0084]

According to the present invention, since the pattern is directly drawn by using the position coordinates of the reference mark measured before applying the resist, it is possible to avoid the influence of the stress of the resist.
Further, by configuring the reference mark and the absorber with different materials, it becomes possible to measure the positions of the absorber film or the etching mask before and after the film formation, respectively, and use the results of the position measurement to measure the absorber film or the etching film. Since the influence of mask stress can be avoided, X with high accuracy
A line mask can be manufactured, which is particularly useful in a manufacturing process of a semiconductor device that employs hybrid exposure.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a principle configuration of the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process partway through the first embodiment of the present invention.

FIG. 3 is an explanatory view of a manufacturing process of the first embodiment of the present invention after FIG. 2;

FIG. 4 is an explanatory diagram of a manufacturing process partway through a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a manufacturing process after FIG. 4 according to the second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a conventional X-ray mask manufacturing process.

[Explanation of symbols]

 1 Support Frame 2 Membrane 3 Reference Mark 4 Absorber 5 Frame 11 Silicon Substrate 12 SiC Film 13 W Film 14 Reference Mark 15 Ta Film 16 Mark Area Opening 17 Frame 18 Support Frame 19 Ta Pattern 21 Silicon Substrate 22 SiC Film 23 Frame 24 Support Frame 25 W film 26 Reference mark 27 Ta film 28 Mark area opening 29 Ta pattern

Claims (7)

[Claims] 1. An X-ray mask, wherein the reference mark and the absorber are made of different materials. 2. The reference mark is made of Cr, Co, Ru, M.
o, W, Au, Al _TwoO_Three, SiO_Two, In_TwoO_ThreeOr some
Ia consists of any one of TaN, and
The absorber is Ta, Ta_TwoO_Five, Or Ta_FourB No
It is constituted by any one of
The X-ray mask described in 1. 3. The reference mark is made of Au or Al, and the absorber is W, W-Ti, Ta, T.
The X-ray mask according to claim 1, wherein the X-ray mask is made of any one of a ₂ O ₅ , TaN, and Ta ₄ B. 4. After the reference mark is formed, an absorber is formed into a film, and then the absorber on the reference mark is selectively removed, and then the arrangement of the reference mark is measured before applying a resist. A method for manufacturing an X-ray mask, characterized in that the measurement result is input to an alignment mark coordinate value as an offset value to pattern the absorber. 5. The patterning of the reference mark and the alignment mark, wherein the alignment mark is formed at the same time when the reference mark is formed, the membrane is made of SiC, and chlorine-based gas is used as an etching gas in the absorber patterning step. A method of manufacturing an X-ray mask, wherein a fluorine-based gas is used as an etching gas in the step, and the membrane is etched by 100 to 800 nm in the step of patterning the reference mark and the alignment mark. 6. The position coordinate of the reference mark is detected twice before and after film formation of the absorber, and the position variation due to the stress of the absorber is measured based on the difference.
Manufacturing method of line mask. 7. The absorber is patterned by measuring the stress of the absorber from the position change and correcting the pattern data of the transfer pattern so as to compensate the position change expected from the stress value. 7. The method for manufacturing an X-ray mask according to claim 6, wherein.