JP2001217186A - Electron beam lithography system, semiconductor device, and mask as well as manufacturing method for them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of measurement by preventing the switching of gain during measurement of current quantity in an electron beam lithography system equipped with a Faraday cup which measures current quantity of electron beams by using a several kinds of gains which switch stepwise according to current quantity. SOLUTION: A stage 2 is provided with two Faraday cups 5, 6 the switching patterns of gains used by the respective Faraday cups are made different from each other to selectively use either cup 5, 6 according to current quantity, thereby preventing the current quantity from coming close to a switching point of gains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam drawing apparatus provided with a Faraday cup for measuring a current amount of an electron beam, a semiconductor device and a mask formed by using the electron beam drawing apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 7, an electron beam writing apparatus mounts a substrate 1 such as a mask substrate or a semiconductor substrate having a resist film formed on a surface thereof on a stage 2, and An electron beam 3 condensed by an electromagnetic lens or the like is scanned on 1 to selectively expose. Thereafter, the resist film is patterned by a development process. The stage 2 of such an electron beam writing apparatus is provided with a Faraday cup (not shown) used for adjusting the origin when performing electron beam exposure. The Faraday cup is formed of metal or the like, and is configured such that when the electron beam 3 is incident on the Faraday cup, the energy amount is converted into a current amount and measured. Actual work substrate 1
Prior to performing the selective exposure on the electron beam, the current amount of the electron beam 3 is set. At this time, the current amount is measured using a Faraday cup, and adjustment is performed so that the desired current amount is obtained. Further, even after the start of the actual selective exposure, the current amount is measured using a Faraday cup, for example, at intervals of several minutes. If the current amount is out of a preset standard, the pattern accuracy deteriorates, and the exposure process is stopped.

In a conventional electron beam lithography apparatus, the current amount measurement using the Faraday cup as described above is performed by using the same current measuring device as shown in FIG. Several types of gains that are switched according to the amount are used. Such a gain is automatically selected by switching in a stepwise manner according to the current amount, and the current amount of the electron beam incident on the Faraday cup is measured by using only one selected gain. For example, the current amount of i1 is measured using the gain of g1, and the current amount of i7 is measured using the gain of g4.

[0004]

However, in the case where the current amount near the switching point of the gain such as i2 and i4 in FIG. 8 is measured, if the current amount varies at the time of the measurement, the measurement is accurately performed by switching the gain. However, there is a problem that the current amount of the electron beam cannot be set, or the exposure processing is stopped at that point in the middle of the actual selective exposure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and measures the current amount of an electron beam incident on a Faraday cup by using several kinds of gains switched according to the current amount. The purpose of the present invention is to provide an electron beam drawing apparatus that can quickly perform stable current amount measurement by preventing gain switching during measurement, and further form a pattern using this electron beam drawing apparatus. It is another object of the present invention to obtain a semiconductor device and a mask having high pattern accuracy and improved reliability.

[0006]

Means for Solving the Problems Claim 1 according to the present invention.
The described electron beam lithography apparatus includes a Faraday cup for measuring the amount of current of an incident electron beam using only one of the gains, wherein several types of gains are switched in a stepwise manner according to the amount of current. The selective exposure is performed by scanning the electron beam on the processing substrate, and has two types of the Faraday cups having different gain switching patterns, and one of the Faraday cups is selectively used.

According to a second aspect of the present invention, there is provided an electron beam writing apparatus according to the first aspect, wherein a current amount designating means for designating a set current amount and one of two types of Faraday cups according to the set current amount. A Faraday cup selecting means for selecting the Faraday cup, and a stage moving means for moving the stage for holding the substrate to be processed until the selected Faraday cup comes to the electron beam incident position. The current amount is measured.

According to a third aspect of the present invention, in the electron beam writing apparatus, several kinds of gains are switched stepwise in accordance with the amount of current, and only one of the selected gains is used for the electron beam. A Faraday cup for measuring the amount of current, for performing selective exposure by scanning the electron beam on the substrate to be processed, wherein the Faraday cup has different gain switching patterns from each other.
It has various kinds of gain parameters, and one of them is selectively used.

According to a fourth aspect of the present invention, there is provided an electron beam writing apparatus according to the third aspect, wherein a current amount designating means for designating a set current amount and one of two gain parameters according to the set current amount. Gain parameter selection and setting means for selecting the Faraday cup and setting the Faraday cup, and stage moving means for moving the stage for holding the substrate to be processed until the Faraday cup comes to the electron beam incident position. This is for measuring the current amount of the electron beam.

According to a fifth aspect of the present invention, there is provided an electron beam writing apparatus according to any one of the first to fourth aspects, wherein a discontinuity point at which the gain is switched in one of the gain switching patterns is the same as that of the other pattern. This is almost the center of the continuous area.

According to a sixth aspect of the present invention, there is provided a semiconductor device having a fine pattern drawn on a semiconductor substrate by an electron beam drawing technique, wherein the fine pattern is any one of the first to fifth aspects. The image was drawn by using the described electron beam drawing apparatus.

According to a seventh aspect of the present invention, there is provided a mask having a shielding film pattern drawn on a glass substrate by an electron beam lithography technique, wherein the shielding film pattern is any one of the first to fifth aspects. Are drawn using the electron beam drawing apparatus described in (1).

According to a second aspect of the present invention, in the method of manufacturing a semiconductor device, a film to be processed is formed on a semiconductor substrate.
A step of forming a resist film on the entire surface thereof, and drawing and exposing the resist film using the electron beam drawing apparatus according to any one of claims 1 to 5, and then performing a developing process to form a resist pattern. And forming a fine pattern of the processed film by etching the underlying processed film using the resist pattern.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a mask, comprising: forming a shielding film on a glass substrate, forming a resist film on the entire surface thereof; After drawing and exposing using the electron beam drawing apparatus according to any one of 1 to 5, performing a developing process to form a resist pattern, and etching the underlying shielding film using the resist pattern. Forming a shielding film pattern by using the above method.

According to a tenth aspect of the present invention, in the method of manufacturing a semiconductor device, a film to be processed is formed on a semiconductor substrate, and a photoresist film is formed on the entire surface of the film.
8. A step of transferring a pattern on the photoresist film by a lithography technique using a mask according to claim 7 and then performing a development process to form a resist pattern; And forming a pattern by etching the processed film.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram schematically showing a configuration of an electron beam writing apparatus according to Embodiment 1 of the present invention. In the drawing, reference numeral 2 denotes a stage on which a substrate 1 (not shown) is mounted, 4 denotes an apparatus main body, and 5 and 6 denote a first Faraday cup and a second Faraday provided on the stage 2 and made of metal or the like. When an electron beam is incident on the Faraday cups 5 and 6 using a cup, the amount of energy is converted into the amount of current and measurement is performed. 7 is a current amount designating unit for designating a set current amount of the electron beam, 8 is a Faraday cup selecting unit for selecting one of the first and second Faraday cups 5 and 6, 9 is a selected Faraday cup 5,
Stage moving means 10 for moving stage 2 until electron beam 6 comes to the electron beam incident position, Faraday cups 5, 6
Current amount display means for displaying the amount of current of the electron beam incident on the device.

As described in the prior art, in the electron beam lithography apparatus, a substrate 1 on which a resist film is formed is placed on a stage 2 and collected on the substrate 1 by an electromagnetic lens or the like. The irradiated electron beam 3 is scanned and selectively exposed (see FIG. 7), thereby forming a resist pattern on the substrate 1 to be processed. Prior to the actual selective exposure of the substrate 1 to be processed, the current amount setting of the electron beam is performed. At this time, the current amount is set by selecting and using one of the appropriate Faraday cups 5 and 6. Is measured and adjusted so as to be stabilized at a desired current amount. Also, even after the start of the actual selective exposure, the current amount is measured using the selected Faraday cups 5 and 6 at intervals of several minutes, for example. Stop the exposure processing.

In each Faraday cup 5, 6,
Several kinds of gains that are switched stepwise according to the amount of current are used, and the amount of current of the electron beam 3 is measured using only one automatically selected gain. FIG. 2A shows gain parameters used by the first Faraday cup 5, and FIG. 2B shows gain parameters used by the second Faraday cup 6. These two types of Faraday cups are shown. The gain parameters used by the cups 5 and 6 have different switching patterns. The two types of switching patterns are set such that the discontinuity point at which the gain of one Faraday cup 5 (6) is switched is located at the center of the continuous area of the same gain in the other Faraday cup 6 (5). ing. For example, a current amount of 200 nA
On the other hand, while the gain used in the first Faraday cup 5 is the switching point between g1 and g2, the gain used in the second Faraday cup 6 is at the center of the current amount range corresponding to G2. Since the gain switching patterns used by the two types of Faraday cups 5 and 6 are set as described above, one of the appropriate Faraday cups 5 and 6 is used so that the current amount does not become near the gain switching point. 6 can be selected.

Next, the operation of measuring the current amount of the electron beam using the Faraday cups 5 and 6 will be described below with reference to FIG. First, a desired set current amount of the electron beam 3 is designated by the current amount designation means 7 (S1), and the Faraday cup selection means 8 selects the first and second Faraday cups 5 and 6 according to the set current amount. Choose one. The selection criterion is determined in advance so that the Faraday cups 5 and 6 that use the gain parameter whose specified current amount is farther from the current amount at which the gain is switched are selected. For example, if 100 nA is specified in S1, the second Faraday cup 6 is selected in S2 (S2). Next, when the first Faraday cup 5 is selected in S2 using the stage moving means 9, the stage 2 is moved until the first Faraday cup 5 comes to the electron beam incident position (S3a), When the second Faraday cup 6 is selected in step (3), the stage 2 is moved until the second Faraday cup 6 comes to the electron beam incident position (S3b). After this, the electron beam 3
Is measured, the current amount of the electron beam 3 incident on the Faraday cups 5 and 6 set at the incident positions is measured, and is displayed by the current amount display means 10 (S4).

In this embodiment, two types of Faraday cups 5 and 6 having different gain switching patterns are provided.
Is provided to select one of the Faraday cups 5 and 6 according to the specified set current amount, so that the current amount can be prevented from being near the gain switching point. Accordingly, it is possible to prevent the gain from being switched at the time of measuring the current amount, to improve the reliability of the current amount measurement and adjustment, and to quickly and reliably set the current amount of the electron beam.

In this embodiment, two types of gain switching patterns correspond to one Faraday cup 5.
In the other Faraday cup 6 (5), the discontinuous point at which the gain is switched in (6) is set at the center of the continuous area of the same gain, but this is not restrictive.
When the gain switching points are set to be different, one of the Faraday cups 5 and 6 can be selected so that the current amount does not become near the gain switching point.

Embodiment 2 FIG. In the first embodiment, two types of Faraday cups 5 and 6 having different gain switching patterns are provided. However, one Faraday cup has two types of gain parameters having different gain switching patterns. Alternatively, any appropriate gain parameter may be selected and used according to the amount of current. FIG. 4 is a schematic configuration diagram schematically showing a configuration of an electron beam writing apparatus according to Embodiment 2 of the present invention.
In the figure, 2, 4, 7, and 10 are the same as those in the first embodiment.
11 is a Faraday cup provided on the stage 2, and 12 is a gain parameter selection and setting means for selecting one of the two types of gain parameters of the Faraday cup 11 and setting the gain parameter for the Faraday cup 11. , 13 are stage moving means for moving the stage 2 until the Faraday cup 11 comes to the electron beam incident position. FIGS. 5A and 5B show the Faraday cup 1
Either one is selected and used for 2
This is a kind of gain parameter, and has different gain switching patterns. The gain switching pattern of these two types of gain parameters is set such that the discontinuity point at which one of the gains is switched is located at the center of the continuous area of the same gain on the other.

Next, the operation of measuring the current amount of the electron beam using the Faraday cup 11 will be described below with reference to FIG. First, a desired set current amount of the electron beam 3 is specified by the current amount specifying means 7 (T1), and according to the set current amount, the gain parameter selection setting means 12 selects one of two types of gain parameters. (T2) The selected gain parameter is set for the Faraday cup 11 (T3a, T3b). At T2, a selection criterion is determined in advance so that a gain switching pattern (gain parameter) in which the specified current amount is farther away from the current amount serving as a gain switching point is selected. Next, the stage 2 is moved using the stage moving means 13 until the Faraday cup 11 comes to the electron beam incident position.
Is moved (T4), and thereafter, the electron beam 3 is emitted by the electron gun, the current amount of the electron beam 3 incident on the Faraday cups 5, 6 set at the incident position is measured, and the current amount display means 10 (T5).

In this embodiment, similarly to the first embodiment, the current amount can be prevented from being near the gain switching point, and the gain can be prevented from being switched at the time of the current amount measurement. In addition, the reliability of the adjustment is improved, and the current amount setting of the electron beam can be performed quickly and with high reliability.

In this embodiment, since the number of the Faraday cup 11 is one, the stage movement at T4 is performed at T2.
May be performed prior to the selection of the gain parameter in. Further, the two types of gain switching patterns (gain parameters) are configured such that the discontinuous point at which one of the gains is switched is located at the center of the continuous area having the same gain, as in the first embodiment. However, the present invention is not limited to this. By setting the gain switching point to be different,
It is possible to select a gain parameter that does not cause the amount of current to be near the gain switching point.

Embodiment 3 FIG. An example of manufacturing a semiconductor device or a mask by actually writing a pattern on a semiconductor substrate or a mask substrate using the electron beam writing apparatus described in the first and second embodiments will be described below. An example in which a fine gate electrode pattern is formed on a semiconductor substrate will be described. First, a gate oxide film and a gate electrode film as a film to be processed are sequentially formed on the semiconductor substrate from which the elements have been separated. A resist film is formed on the entire surface of the gate electrode film, and the electron beam 3 is scanned over the semiconductor substrate using the electron beam drawing apparatus described in Embodiment 1 or 2 to selectively draw and expose the resist film. (See FIG. 7). Subsequently, a developing process is performed to form a resist pattern, and then the underlying gate electrode film is etched using the resist pattern as a mask to obtain a fine pattern of the gate electrode film. As described above, since writing is performed using the electron beam writing apparatus described in Embodiment 1 or 2, the current amount of the electron beam can be set quickly and with high reliability, and the reliability of pattern writing is improved. The reliability in the device and its manufacture is improved.

In this embodiment, the fine pattern of the gate electrode film is formed, but fine patterns of other films to be processed can be similarly formed.

A mask pattern can also be formed in the same manner. In this case, a shielding film such as a chromium film is formed on the entire surface of a glass substrate as a mask substrate, and a resist film is formed thereon. Then, electron beam writing is performed on the resist film. Subsequently, development processing is performed to form a resist pattern, and thereafter, the underlying shielding film is etched using the resist pattern to obtain a shielding film pattern. Also in this case, since writing is performed using the electron beam writing apparatus described in the first or second embodiment, the current amount of the electron beam can be set quickly and reliably, and the reliability of pattern writing is improved. And the reliability in the production thereof is improved.

Further, a pattern can be formed on a semiconductor substrate by using the mask thus manufactured.
A film to be processed is formed on a semiconductor substrate, a photoresist film is formed thereon, and a resist pattern is formed on the photoresist film using a known lithography technique. At this time,
Using the mask patterned using the electron beam lithography apparatus described in the first or second embodiment, for example, reduction projection exposure using KrF excimer laser light as exposure light is performed, and the photoresist film on the semiconductor substrate is exposed. The resist pattern is formed by transferring the pattern, and then performing a developing process. Thereafter, the underlying film to be processed is etched using this resist pattern to form a pattern of the film to be processed. Thus, Embodiment 1 or 2
The pattern is formed on a semiconductor substrate by lithography using a highly reliable mask formed by patterning using the electron beam lithography apparatus shown in FIG. Reliability is improved.

[0030]

As described above, in the electron beam writing apparatus according to the first aspect of the present invention, several types of gains are switched stepwise according to the amount of current, and light is incident using only one selected gain. A Faraday cup for measuring a current amount of the obtained electron beam, and performing selective exposure by scanning the electron beam on a substrate to be processed, wherein the two types of Faraday cups having different gain switching patterns are different from each other. It is possible to prevent the gain from being switched at the time of measuring the current amount, since either of them is selectively used,
The reliability of the current amount measurement and adjustment is improved, and the current amount setting of the electron beam can be quickly and reliably performed.

According to a second aspect of the present invention, there is provided an electron beam writing apparatus according to the first aspect, wherein a current amount specifying means for specifying a set current amount and one of two types of Faraday cups according to the set current amount. Faraday cup selecting means for selecting the whiteness, and stage moving means for moving the stage for holding the substrate to be processed until the selected Faraday cup comes to the electron beam incident position, wherein the electrons incident on the Faraday cup are provided. Since the beam current amount is measured, a highly reliable current amount measurement can be stably and reliably performed.

In the electron beam writing apparatus according to a third aspect of the present invention, several kinds of gains are switched stepwise in accordance with the amount of current, and only one of the selected gains is used for the electron beam. A Faraday cup for measuring the amount of current, for performing selective exposure by scanning the electron beam on the substrate to be processed, wherein the Faraday cup has different gain switching patterns from each other.
Since there are various gain parameters and either one is selectively used, it is possible to prevent the gain from being switched at the time of the current amount measurement, and the reliability of the current amount measurement and adjustment is improved.
The current amount setting of the electron beam can be quickly and reliably performed.

According to a fourth aspect of the present invention, there is provided an electron beam writing apparatus according to the third aspect, wherein one of a current amount designating means for designating a set current amount and one of two gain parameters according to the set current amount. Gain parameter selection and setting means for selecting the Faraday cup and setting the Faraday cup, and stage moving means for moving the stage for holding the substrate to be processed until the Faraday cup comes to the electron beam incident position. Since the electron beam current amount measurement is performed, a highly reliable current amount measurement can be stably and reliably performed.

According to a fifth aspect of the present invention, there is provided an electron beam writing apparatus according to any one of the first to fourth aspects, wherein a discontinuity point at which the gain is switched in one of the gain switching patterns is the same as that of the other. Since the electron beam hits substantially the center of the continuous region, by selecting one of them, the current amount of the electron beam can be effectively prevented from being near the gain switching point.

According to a sixth aspect of the present invention, there is provided a semiconductor device having a fine pattern drawn on a semiconductor substrate by an electron beam drawing technique, wherein the fine pattern is any one of the first to fifth aspects. Since drawing is performed using the electron beam drawing apparatus described above, the reliability of the semiconductor device can be improved.

According to a seventh aspect of the present invention, there is provided a mask having a shielding film pattern drawn on a glass substrate by an electron beam lithography technique, wherein the shielding film pattern is any one of the first to fifth aspects. Since the image is drawn by using the electron beam drawing apparatus described in (1), the reliability of the mask can be improved.

According to a method of manufacturing a semiconductor device according to the present invention, a film to be processed is formed on a semiconductor substrate.
A step of forming a resist film on the entire surface thereof, and drawing and exposing the resist film using the electron beam drawing apparatus according to any one of claims 1 to 5, and then performing a developing process to form a resist pattern. And forming a fine pattern of the film to be processed by etching the underlying film to be processed using the resist pattern, thereby improving the reliability of pattern formation.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a mask, comprising: forming a shielding film on a glass substrate; forming a resist film on the entire surface thereof; After drawing and exposing using the electron beam drawing apparatus according to any one of 1 to 5, performing a developing process to form a resist pattern, and etching the underlying shielding film using the resist pattern. And forming a shielding film pattern, thereby improving the reliability of mask pattern formation.

According to a tenth aspect of the present invention, in the method of manufacturing a semiconductor device, a film to be processed is formed on a semiconductor substrate, and a photoresist film is formed on the entire surface of the film.
8. A step of transferring a pattern on the photoresist film by a lithography technique using a mask according to claim 7 and then performing a development process to form a resist pattern; To form a pattern by etching the processed film,
Pattern formation with improved reliability can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electron beam writing apparatus according to Embodiment 1 of the present invention.

FIG. 2 shows gain parameters used by two types of Faraday cups according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of measuring an amount of current by the electron beam writing apparatus according to the first embodiment of the present invention;

FIG. 4 is a schematic configuration diagram of an electron beam writing apparatus according to Embodiment 2 of the present invention.

FIG. 5 shows two types of gain parameters according to the second embodiment of the present invention.

FIG. 6 is a flowchart showing an operation of measuring a current amount according to the second embodiment of the present invention;

FIG. 7 is a perspective view showing exposure by an electron beam drawing apparatus.

FIG. 8 shows gain parameters used by a Faraday cup of a conventional electron beam writing apparatus.

[Explanation of symbols]

1 substrate to be processed, 2 stages, 3 electron beams, 4
Electron beam writing apparatus main body, 5 first Faraday cup, 6 second Faraday cup, 7 setting current amount designating means, 8 Faraday cup selecting means, 9 stage moving means, 11 Faraday cup, 12 gain parameter selection setting means , 13 Stage moving means.

Claims (10)

[Claims] An Faraday cup for measuring the amount of current of an incident electron beam using only one of the above-mentioned gains is switched in a stepwise manner according to the amount of current. An electron beam writing apparatus for performing selective exposure by scanning the electron beam, comprising two types of Faraday cups having mutually different gain switching patterns, wherein one of the Faraday cups is selectively used. Drawing device. 2. A current amount specifying means for specifying a set current amount; a Faraday cup selecting means for selecting one of two types of Faraday cups according to the set current amount; 2. The electron beam writing method according to claim 1, further comprising a stage moving means for moving the stage for holding the substrate to be processed until the substrate reaches the incident position, wherein the current amount of the electron beam incident on the Faraday cup is measured. apparatus. 3. A Faraday cup, wherein several kinds of gains are switched stepwise according to the amount of current, and a Faraday cup for measuring the amount of current of an incident electron beam using only one of the gains is provided. In the electron beam writing apparatus for performing selective exposure by scanning the electron beam, the Faraday cup has two kinds of gain parameters in which the gain switching patterns are different from each other, and one of them is selectively used. Electron beam writing apparatus. 4. A current amount specifying means for specifying a set current amount, a gain parameter selection and setting means for selecting one of two types of gain parameters according to the set current amount and setting the gain parameter in a Faraday cup, 4. The apparatus according to claim 3, further comprising: stage moving means for moving the stage for holding the substrate to be processed until the electron beam reaches the electron beam incident position, wherein the current amount of the electron beam incident on the Faraday cup is measured. Electron beam drawing equipment. 5. The electron beam according to claim 1, wherein a discontinuity point at which the gain is switched in one of the gain switching patterns substantially corresponds to a center of a continuous area having the same gain. Drawing device. 6. A fine pattern drawn on a semiconductor substrate by an electron beam drawing technique, wherein the fine pattern is
A semiconductor device which has been drawn by using the electron beam drawing device according to claim 1. 7. A shielding film pattern drawn by an electron beam drawing technique on a glass substrate, wherein the shielding film pattern is drawn by using the electron beam drawing apparatus according to any one of claims 1 to 5. A mask characterized in that: 8. An electron beam writing apparatus according to claim 1, wherein a film to be processed is formed on a semiconductor substrate, and a resist film is formed on the entire surface of the film. Forming a resist pattern by performing development processing after drawing and exposing using a process, and forming a fine pattern of the process target film by etching the underlying process target film using the resist pattern And a method of manufacturing a semiconductor device. 9. A step of forming a shielding film on a glass substrate and forming a resist film on the entire surface thereof, and applying the resist film to the electron beam writing apparatus according to any one of claims 1 to 5. And forming a resist pattern by performing development processing after drawing and exposing using a resist pattern, and forming a shielding film pattern by etching the underlying shielding film using the resist pattern. Manufacturing method of a mask. 10. A step of forming a film to be processed on a semiconductor substrate and forming a photoresist film on the entire surface thereof, and forming the photoresist film on the mask by a lithography technique using the mask according to claim 7. After transferring the pattern,
Performing a development process to form a resist pattern;
Etching the underlying film to be processed using the resist pattern to form a pattern.