JPH11297595A - X-ray alignment method, x-ray aligner and x-ray mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray alignment method, X-ray aligner and X-ray mask that is capable of preventing X-ray mask damages or transfer pattern defects. SOLUTION: A laser beam 4 is transmitted from a laser light source 2, in parallel with a wafer 7 suction-attached on to a wafer stage 8 and an X-ray mask 6 placed with a certain gap above the upper surface of the wafer 7. A transmitted light 5 that transmits between the wafer 7 and the X-ray mask 6 is received at the laser receiving unit 3. The quantity of light is measured, and foreign matters are detected by checking the decrease in the quantity of light. After the distance between the laser beam 4 and the wafer 7 is adjusted to a certain distance by a location detector 10, the wafer stage 8 is moved horizontally in a direction normal to the paper while keeping a certain distance and the quantity of light is measured at the laser receiving unit 3 to detect foreign matters 9 over the entire wafer 7. If any foreign matter 9 is detected on a wafer 7, the foreign matter 9 is removed and the wafer is further cleaned. Alternatively, the wafer is not exposed. Similar process is applied to the X-ray mask.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray exposure method and an X-ray exposure apparatus for preventing a mask from being damaged, and an X-ray mask used for the X-ray exposure.

[0002]

2. Description of the Related Art FIG. 14 is a block diagram of a conventional X-ray exposure apparatus, which is disclosed in NTT R & D Vol. 43 No. 6 1
994. In the figure, 26
Is a wafer cassette, 28 is a wafer stage, 29 is a vertical XY for moving the wafer stage 28 in the horizontal and vertical directions.
Stage, 25 is a mask stage, 30 is a take-out window,
31 is an X-ray.

Next, an X-ray exposure method using this X-ray exposure apparatus will be described. The wafer 7 in the wafer cassette 26 set in the X-ray exposure apparatus is carried to the wafer stage 28 by a wafer transfer device (not shown). Wafer 7
The wafer stage 28 that has absorbed the
The XY stage 29 is held by a vertical XY stage 29 whose position can be changed so as to be opposed to and movable in the horizontal and vertical directions. Next, the X-ray mask mounted on the mask stage 25 and the wafer 7 are
Position adjustment is performed at a predetermined minute interval (gap between mask and wafer) between μm and 40 μm. The wafer stage 28 can adjust the position of the wafer 7 in the gap direction and the rotation direction,
The mask stage 25 can control the position of the X-ray mask. Further, precise alignment can be performed by detecting the relative position between the X-ray mask and the wafer 7 using an alignment optical unit (not shown). When the position adjustment between the X-ray mask and the wafer 7 is completed, the X-ray 31 is irradiated onto the X-ray mask, and the X-ray mask pattern is transferred to the wafer 7. In this X-ray exposure apparatus, the X-ray mask pattern can be transferred over the entire surface of the wafer by repeating position adjustment and X-ray exposure after moving the wafer 7 using the vertical XY stage 29.

[0004]

SUMMARY OF THE INVENTION The conventional X as described above
The X-ray exposure apparatus adjusts the mask-wafer gap without detecting foreign matter even if foreign matter is present on the wafer surface facing the X-ray mask or foreign matter is present on the X-ray mask. If the size of the X-ray mask is larger than the gap between the mask and the wafer, there is a problem that the X-ray mask comes into contact with foreign matter and is damaged.

[0005] Further, if there is a foreign substance between the wafer and the wafer stage, the wafer locally rises,
The X-ray mask has a problem that it is broken by contact with the wafer.

Further, even if the X-ray mask is not damaged, there is a problem that the area where the foreign matter exists becomes a transfer pattern defect.

Further, even if foreign matter is found, the foreign matter cannot be removed by the X-ray exposure apparatus. Therefore, after the wafer is carried out from the X-ray exposure apparatus and the foreign matter is removed, it must be set again in the X-ray exposure apparatus. There is a problem that the number of processes increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an X-ray exposure apparatus capable of detecting or removing foreign matter. X-ray exposure method capable of preventing the occurrence of transfer pattern defects
It is an object to provide a line exposure apparatus and an X-ray mask.

[0009]

According to a first X-ray exposure method of the present invention, a mask is arranged at a predetermined mask-wafer interval on a surface on which a resist is formed on the upper surface of a wafer, and the X-ray exposure method is performed.
An X-ray exposure method for transferring a pattern of the mask to the resist by irradiating a line, wherein the mask is on a surface facing a wafer, or an upper surface or a lower surface of the wafer after resist application, or the wafer For detecting foreign matter on the upper surface or the lower surface of the uncoated resist.

In a second X-ray exposure method according to the present invention, in the first X-ray exposure method, when the distance between the mask and the wafer is d, it is determined whether or not the size of the foreign matter is d / 2 or more. It is to judge.

In a third X-ray exposure method according to the present invention, in the first X-ray exposure method, foreign matter detection is performed at any timing before, during, or after exposure.

In a fourth X-ray exposure method according to the present invention, a mask is arranged at a predetermined mask-wafer interval on a surface on which a resist is formed on the upper surface of a wafer, and the mask is irradiated with X-rays. An X-ray exposure method for transferring a mask pattern onto the resist, wherein the exposure is performed while measuring the number of floating foreign particles in the X-ray exposure apparatus.

According to a fifth X-ray exposure method of the present invention, in the above-mentioned fourth X-ray exposure method, when a floating foreign substance is detected, a mask is formed on the surface of the mask facing the wafer or on the wafer. The step of detecting foreign matter on the upper or lower surface after resist application or on the upper or lower surface of the wafer without resist application is performed.

In a sixth X-ray exposure method according to the present invention, in the first or fourth X-ray exposure method, when a foreign substance is detected, the mask is replaced.

In a seventh X-ray exposure method according to the present invention, in the first or fourth X-ray exposure method, when foreign matter is detected, no exposure is performed.

In an eighth X-ray exposure method according to the present invention, when a foreign substance is detected in the first X-ray exposure method, the exposure is performed after removing the foreign substance.

In a ninth X-ray exposure method according to the present invention, when foreign matter is detected in the first X-ray exposure method, exposure is performed while avoiding the foreign matter.

In a tenth X-ray exposure method according to the present invention, in the first X-ray exposure method, when a foreign substance is detected, the foreign substance is removed, and then the substrate is further washed and exposed. is there.

An eleventh X-ray exposure method according to the present invention is the same as the first X-ray exposure method, wherein the height of the foreign matter is detected.

A twelfth X-ray exposure method according to the present invention, in the first X-ray exposure method, detects the length of foreign matter.

According to a thirteenth X-ray exposure method according to the present invention, in the first X-ray exposure method, the length of the foreign matter is detected,
Next, the height of the foreign matter is detected.

According to a fourteenth X-ray exposure method according to the present invention, in the first X-ray exposure method, foreign matter is detected using scattered light from the foreign matter illuminated with reference light.

In a fifteenth X-ray exposure method according to the present invention, in the tenth X-ray exposure method, the reference light is a laser beam.

In a sixteenth X-ray exposure method according to the present invention, in the tenth X-ray exposure method, the reference light is visible light.

In a seventeenth X-ray exposure method according to the present invention, in the tenth X-ray exposure method, the reference light is white light.

According to an eighteenth X-ray exposure method according to the present invention, in the first X-ray exposure method, foreign matter is detected by arranging a laser light source and a laser receiving unit to face each other and transmitting the foreign matter. This is performed by measuring the laser beam intensity.

According to a nineteenth X-ray exposure method according to the present invention, in the first X-ray exposure method, the foreign matter is detected by arranging the laser light source and the laser receiving unit so as to face each other and transmitting the foreign matter. This is for measuring the phase of the laser light.

In a twentieth X-ray exposure method according to the present invention, in the first X-ray exposure method, the foreign substance is detected by arranging a laser light source and a laser receiver on a plane parallel to the wafer surface.
This is for measuring the intensity of the laser beam after being scattered by the foreign matter.

In a twenty-first X-ray exposure method according to the present invention, in the first X-ray exposure method, the foreign substance is detected by arranging a laser light source and a laser receiving unit on a plane parallel to the wafer surface.
This is to measure the phase of the laser light after being scattered by the foreign matter.

According to a twenty-second X-ray exposure method according to the present invention, in any one of the eighteenth to twenty-first X-ray exposure methods, a laser beam having a diameter of several μm or less is used.

According to a twenty-third X-ray exposure method according to the present invention, in any one of the eighteenth to twenty-first X-ray exposure methods, a laser beam having a diameter of several μm or more is used.

A twenty-fourth X-ray exposure method according to the present invention uses the fan-shaped spread laser beam in any of the eighteenth to twenty-first X-ray exposure methods.

According to a twenty-fifth X-ray exposure method according to the present invention, in the first X-ray exposure method, the detection of foreign matter is performed by image processing by taking the application state of a resist applied on a wafer as an image signal. Things.

According to a twenty-sixth X-ray exposure method according to the present invention, in the first X-ray exposure method, the detection of foreign matter is performed by using a wire stretched on a straight line in a vertical direction to about half the mask-wafer distance. This is performed by scanning the wafer, the mask, or the wire while maintaining the following distance.

In a twenty-seventh X-ray exposure method according to the present invention, a mask is arranged at a predetermined mask-wafer interval on a surface on which a resist is formed on the upper surface of a wafer, and the mask is irradiated with X-rays. An X-ray exposure method for transferring a mask pattern onto the resist, wherein the mask is on a surface facing the wafer, or the upper or lower surface of the wafer after resist application, or the upper surface of the wafer without resist application. Alternatively, the method includes a step of removing foreign matter on the lower surface.

The twenty-eighth X-ray exposure method according to the present invention is the same as the twenty-seventh X-ray exposure method, but further comprising a washing step after the step of removing foreign matter.

According to a twenty-ninth X-ray exposure method according to the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure methods, the foreign matter is removed by blowing gas onto the foreign matter.

According to a thirtieth X-ray exposure method of the present invention, in the above-mentioned twenty-ninth X-ray exposure method, foreign matter is sucked together with the blown gas.

According to a thirty-first X-ray exposure method according to the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, the foreign substance is removed by charging the foreign substance and adsorbing the foreign substance in the opposite sign. This is done by adsorbing on the body.

According to a thirty-second X-ray exposure method according to the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, foreign matter is removed by vibrating a wafer or a mask.

According to a thirty-third X-ray exposure method according to the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, a foreign substance is removed by providing a flat plate with a mask parallel to the flat plate.
This is performed by scanning a wafer or an X-ray mask held at a distance of about half or less of the inter-wafer interval.

According to a thirty-fourth X-ray exposure method of the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, the foreign matter is removed by irradiating the foreign matter with a laser.

According to a thirty-fifth X-ray exposure method according to the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, foreign matter is removed by providing a flat plate facing a wafer or a mask, and removing the flat plate. This is performed by generating a discharge between the wafer and the mask.

According to a thirty-sixth X-ray exposure method according to the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure methods, foreign matter is removed using a brush.

According to a thirty-seventh X-ray exposure method of the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure methods, the foreign matter is removed using an ice scrubber.

According to a thirty-eighth X-ray exposure method according to the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, the foreign matter is removed by spraying a liquid.

According to a thirty-ninth X-ray exposure method according to the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, foreign matter is removed by spraying dry ice.

[0048] A fortieth X-ray exposure method according to the present invention is the same as the thirty-ninth X-ray exposure method, except that an inert element is used as dry ice.

A forty-first X-ray exposure method according to the present invention is the same as the above-mentioned thirty-ninth X-ray exposure method, except that CO ₂ is used as dry ice.

According to a forty-second X-ray exposure method of the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, foreign matter is removed by spraying both gas and liquid. .

According to a forty-third X-ray exposure method according to the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure method, the foreign matter is removed by masking in a vertical direction from a straight wire. This is performed by scanning a wafer, a mask, or a wire while maintaining the distance between wafers at about half or less.

In a forty-fourth X-ray exposure method according to the present invention, a mask is arranged at a predetermined mask-wafer distance on a surface on which a resist is formed on the upper surface of a wafer, and the mask is irradiated with X-rays. An X-ray exposure method for transferring a pattern of a mask onto the resist, wherein a protruding portion is provided around the mask so as to protrude from the mask surface by a length equal to or more than half the distance between the mask and the wafer.

In a forty-fifth X-ray exposure method according to the present invention, in the forty-fourth X-ray exposure method, a predetermined distance between the mask and the wafer is set in advance between the wafer and the mask outside the mask. The wafer is moved under the mask while maintaining the mask-wafer interval.

In the first X-ray exposure apparatus according to the present invention, a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist is applied and formed, and the mask is irradiated with X-rays. X-ray exposure means for transferring the pattern of the resist onto the resist, and on the surface of the mask facing the wafer, or on the upper or lower surface of the wafer after resist coating, or on the upper or lower surface of the wafer without resist coating. Foreign matter detecting means for detecting foreign matter.

A second X-ray exposure apparatus according to the present invention is the same as the first X-ray exposure apparatus, except that the second X-ray exposure apparatus has a removing means for removing the detected foreign matter.

The third X-ray exposure apparatus according to the present invention is the same as the first X-ray exposure apparatus, except that it has a cleaning means for cleaning a mask, a wafer after resist application or a wafer not coated with resist. .

In a fourth X-ray exposure apparatus according to the present invention, a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist is applied and formed, and the mask is irradiated with X-rays. X-ray exposure means for transferring the pattern of the resist onto the resist, and on the surface of the mask facing the wafer, or on the upper or lower surface of the wafer after resist coating, or on the upper or lower surface of the wafer without resist coating. Foreign matter removing means for removing foreign matter.

A fifth X-ray exposure apparatus according to the present invention is the same as the above-described fourth X-ray exposure apparatus, except that a cleaning means for cleaning a mask, a wafer after resist application or a wafer not coated with resist is provided. .

In the sixth X-ray exposure apparatus according to the present invention, a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist is applied and formed, and the mask is irradiated with X-rays. X-ray exposure means for transferring the pattern described above to the resist, and foreign matter count measuring means for measuring the number of floating foreign matters in the X-ray exposure apparatus main body.

The seventh X-ray exposure apparatus according to the present invention is the same as the first, fourth or sixth X-ray exposure apparatus, except that the mask pattern design is the same in the X-ray exposure apparatus body. Are always two or more.

In the first X-ray mask according to the present invention, a mask is arranged on a surface on which a resist is formed on the upper surface of a wafer at a predetermined mask-wafer distance, and the mask is irradiated with X-rays. An X-ray mask used in an X-ray exposure method for transferring the pattern to the resist, wherein the mask has a protruding portion protruding from the mask surface by a length equal to or more than half of the mask-wafer distance from the mask surface. .

[0062] A second X-ray mask according to the present invention is the same as the first X-ray mask, wherein a protruding portion can be mounted.

A third X-ray mask according to the present invention is the same as the first X-ray mask, except that the projection is formed integrally with the mask.

[0064]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a schematic diagram for explaining a foreign matter detection method in the X-ray exposure apparatus according to the first embodiment.
In FIG. 1, 1 is an X-ray exposure apparatus, 2 is a laser light source, 3
Is a laser receiving unit, 4 is a laser beam, 5 is a transmitted beam, 6 is an X-ray mask, 7 is a wafer, 8 is a wafer stage, 9 is a foreign substance,
Reference numeral 10 denotes a position detector, and 11 denotes a detection circuit. A resist film is applied to the upper surface of the wafer 7 adsorbed on the wafer stage 8. At the time of exposure, the upper surface of the wafer 7 and X
The position of the line mask 6 is adjusted to a predetermined minute interval d (gap between the mask and the wafer) between 10 μm and 40 μm,
X-rays are irradiated from above the X-ray mask 6 to transfer the mask pattern of the X-ray mask 6 to the resist on the upper surface of the wafer 7.

The laser light source 2 installed in the X-ray exposure apparatus 1 emits a laser beam 4 in parallel with the upper surface of the wafer 7 adsorbed on the wafer stage 8, and the laser beam is transmitted through the wafer by the laser receiver 3. The transmitted light 5 is received. After the distance between the laser beam 4 and the wafer 7 is adjusted to be constant by the position detector 10, only the stage is horizontally moved in the direction perpendicular to the plane of the drawing while maintaining the distance. At this time, the laser light source 2
Since the laser receiver 3 does not move, the laser beam 4 moves on the entire surface of the wafer 7.

When the laser beam 4 irradiates the foreign substance 9, a part thereof is scattered or absorbed and the light amount of the laser receiving section 3 is reduced. Therefore, the presence or absence of the foreign substance can be easily detected by using the detection circuit 11. Further, by bringing the mask 6 close to the laser beam instead of the wafer 7, foreign substances on the mask 6 can also be detected. At this time, by adjusting the distance between the laser beam 4 and the wafer 7 or the mask 6 to half the distance between the mask and the wafer, the size (maximum length or height) of at least half the distance between the mask and the wafer is adjusted. Foreign matter can be detected. Further, the laser light source 2 is moved without moving the wafer 7 and the mask 6.
By moving both the laser receiving unit 3 and the laser receiving unit 3 in parallel with the wafer surface or the mask surface, foreign substances on the wafer 7 or the mask 6 can be detected.

FIG. 2 shows a state in which foreign matter 9 is sandwiched between wafer 7 and mask stage 8. Since the wafer 7 is attracted to the mask stage 8, it rises in accordance with the size of the foreign matter 9. Since the laser beam 4 scatters on the raised portion, the amount of foreign matter 9 sandwiched between the wafer 7 and the
Can be detected, and the size of the foreign matter can be determined based on the result of measuring the relationship between the decrease in the amount of light and the size of the foreign matter in advance. Therefore, in the foreign matter detection method of this embodiment, the foreign matter 9 attached to the back surface of the wafer 7 and the foreign matter 9 on the stage 8 can also be detected, and the size thereof can be determined. Further, scattered light may be used for detecting the foreign matter 9. In this case, there is usually a mask stage, an alignment optical system, and the like in a direction perpendicular to the wafer, and it is difficult to install a detector. Therefore, both the light source and the detector are preferably installed in a direction parallel to the wafer surface.

The present embodiment relates to a foreign matter detecting method, but can be used as a foreign matter removing method by increasing the intensity of laser light.

Embodiment 2 FIG. 3 is a schematic diagram for explaining a method of detecting foreign matter in the X-ray exposure apparatus according to the second embodiment, and is a bird's-eye view viewed from above the wafer. 3, reference numeral 15 denotes scattered light; 25, an X-ray mask stage;
Reference numeral 0 denotes a laser beam expander.

The laser light 4 emitted from the laser light source 2 set in the X-ray exposure apparatus 1 is enlarged in a fan shape over the entire surface of the X-ray mask 6 by a laser light expander 50,
The laser beam passes between the line mask 6 and the wafer 7 and reaches the laser receiver 3. The laser beam 4 is adjusted by the position detector 10 so as to be parallel to the X-ray mask 6 fixed on the X-ray mask stage 25 in advance and to have a distance from the X-ray mask 6 which is about half the distance between the mask and the wafer. I have. In order to perform exposure, the wafer 7 is aligned with the X-ray mask 6. At this time, when the laser beam 4 irradiates the foreign substance 9, a part thereof is scattered or absorbed, and the light amount of the laser receiving unit 3 is reduced. Therefore, the presence or absence of the foreign substance can be easily detected by using the detection circuit 11.

In this embodiment, since the laser beam 4 is expanded in a fan shape by the laser beam expander 50, the region where the intensity of the laser beam is reduced by the foreign material 9 is larger than the size of the foreign material 9. In addition, there is no need to prepare the laser receiver 3 having a high resolution in order to detect the presence or absence of the foreign matter 9, so that the apparatus can be configured at low cost.

Further, during exposure, irrespective of before and after exposure, X
Since the presence or absence of foreign matter can be detected in real time over the entire line mask, the mask can be more reliably prevented from being damaged due to contact with foreign matter 9.

When the diameter of the laser beam before entering the laser beam expander 50 is set to several μm or less, the distance between the mask and the wafer is sufficiently narrower. 6 and the like, the ratio of laser light scattered from other than foreign matter is reduced, so that noise entering the laser receiving unit 3 can be reduced, and foreign matter detection accuracy can be improved.

When the diameter of the laser beam is set to several μm or more, the laser light source 2 does not need to have high processing accuracy, so that the apparatus can be constructed at low cost.

When the laser receiving section 3 is placed on a plane parallel to the wafer surface and at a position where the laser light 4 does not directly enter, and receives only scattered light from a foreign substance, the laser receiving section 3 is affected by the laser light 4. Therefore, the presence / absence of a foreign substance can be more reliably detected.

In the present embodiment, the laser beam magnifier 5
Although the laser light is expanded over the entire surface of the X-ray mask by 0, foreign substance detection can be performed without using the laser light expander 50 if a wider laser light is used.

Further, in this embodiment, the laser beam intensity is measured by the laser receiving section 3. However, when the phase of the laser beam is measured, a nearly transparent foreign substance such as an organic substance can be detected.

Also, one or more C
Foreign matter may be detected by image processing using a CD camera.

Further, the laser receiving section 3 may be configured as an aggregate of smaller laser receiving sections.

Embodiment 3 FIG. 4 is a schematic diagram for explaining a method for detecting foreign matter in an X-ray exposure apparatus according to the third embodiment. In FIG. 4, reference numeral 12 denotes a CCD camera, 1
3 is a light source, 14 is reference light, 15 is scattered light, and 16 is reflected light.

The wafer 7 is irradiated with the reference light 14 from the light source 13. The reference light 14 is reflected by the wafer 7 and its reflection angle is substantially equal to the incident angle on the wafer 7. If there is a foreign substance 9 on the wafer 7, the reference light 14 is scattered by the foreign substance 9 and scattered at an angle different from that of the reflected light 16. The scattered light 15 scattered at an angle different from that of the reflected light 16 is converted into an electric signal by the CCD camera 12, and the foreign matter 9 can be detected by passing through the detection circuit 11. Further, the size of the foreign matter 9 can be determined based on the result of measuring the relationship between the intensity of the scattered light and the size of the foreign matter in advance.

Although there is a wafer 7 on which a circuit pattern is formed, the position of the CCD camera 12 and the position of the light source 13 are adjusted to distinguish the scattered light from the circuit pattern from the foreign matter 9. The scattered light 15 can be detected.

If white light is used as the reference light 14, the device can be constructed at low cost. Also, instead of white light, visible light,
Laser light or infrared light may be used.

Further, since the position of the foreign matter 9 on the entire surface of the wafer 7 can be specified by using the CCD camera 12, the exposure can be performed while avoiding the foreign matter 9 and there is an advantage that the wafer 7 is not wasted.

Further, in the present embodiment, the case of the wafer 7 has been described, but the foreign matter 9 can be detected with respect to the X-ray mask 6 in the same manner as in the case of the wafer 7.

Embodiment 4 FIG. 5 is a schematic diagram for explaining a foreign matter detection method and a foreign matter removal method in the X-ray exposure apparatus according to the fourth embodiment. In FIG. 5, 28
Is a wafer stage, 56 is a wire, and 57 is a wire attachment part.

Hereinafter, a method for detecting and removing foreign matter using a wire will be described. The wire 56 is attached to the wafer stage 28 holding the wafer 7 through the wire attaching portion 57.
Are attached with a constant tension so as to be parallel to the wafer stage 28 and pass outside the wafer 7. Further, the state of the wire 56 is monitored using the detection circuit 11. Before exposing the wafer 7, the wire 56 is set at a distance of about half the mask-wafer distance from the mask surface, and then the entire mask is scanned from outside the X-ray mask 6 in parallel with the X-ray mask surface. Since the wire 56 is provided in front of the wafer 7 with respect to the scanning direction, the wafer 7 does not come into contact with the foreign matter 9 before the wire 56. The foreign matter 9 on the X-ray mask 6 in contact with the wire 56 is removed by the wire 56, so that the foreign matter 9 does not damage the X-ray mask 6.

In this embodiment, since the state of the wire 56 is monitored by the detection circuit 11 by, for example, measuring the tension generated in the wire, the presence or absence of foreign matter can be confirmed for each mask. Furthermore, the adhesion of foreign matter is strong,
If there is a possibility that the X-ray mask 6 may be damaged at the time of foreign matter removal, measures such as stopping scanning of the wire may be performed to prevent the mask from being damaged.

In the above embodiment, the wire is scanned with respect to the mask.
Foreign matter can also be detected and removed.

Further, a flat plate may be provided in place of the wire, and a wafer or an X-ray mask held at a distance of about half or less of the mask-wafer interval may be scanned in parallel with the flat plate.

Embodiment 5 FIG. 6 is a schematic diagram for explaining a foreign matter removing method in the X-ray exposure apparatus according to the fifth embodiment. In FIG. 6, 17 is a gas outlet, 18 is a gas inlet, and 19 is a gas.

A clean gas 19 that has passed through a filter is blown toward the wafer 7 from the outlet 17. When the gas 19 collides with the foreign material 9 with a force higher than the adhesive force of the foreign material 9,
The foreign matter 9 is separated from the wafer 7, scattered with the gas 19, and can be removed from the wafer 7. At this time, the foreign matter 9 can be removed from the entire surface of the wafer 7 by moving the stage 8 and spraying while changing the location of the gas 19 hitting the wafer 7.

Further, by sucking the foreign matter 9 together with the gas 19 from the suction port 18, it is possible to prevent the foreign matter 9 from re-adhering to the wafer 7.

As the gas 19, air or He was used according to the exposure atmosphere. However, a clean gas which does not affect the exposure may be used.

Further, instead of gas, liquid, drus ice, ice, or a mixture of gas and liquid may be used. When an inert gas such as Ar (argon gas) is used as dry ice, foreign substances can be removed without causing a chemical change to the substrate. Also dry ice, as C
When O ₂ is used, the device can be configured at low cost.

Although the method of spraying gas, liquid, ice or the like has been described above, foreign matter can be removed very easily by using a brush.

Embodiment 6 FIG. FIG. 7 is a schematic diagram for explaining a foreign matter removing method in the X-ray exposure apparatus according to the fourth embodiment. In FIG. 7, reference numeral 20 denotes a charged body, 21 denotes an adsorbent, and 22 denotes a voltage power supply.

The wafer 7 attracted to the stage 8 and the charging member 20 are arranged to face each other. The charging member 20 is integrated with the adsorbing member 21 on the lower surface. A voltage is applied between the charging body 20 and the stage 8 using a voltage power supply 22 to charge the adsorption body 21 and the wafer 7. At this time, the foreign matter 9 on the wafer 7 is charged with the opposite sign to the charged body 20 and is pulled by the charged body 20 by the electrostatic force. When the applied voltage is increased and the electrostatic force becomes stronger than the adhesive force of the foreign matter 9, the foreign matter 9 separates from the wafer 7 and is attracted to the attracting body 21 on the lower surface of the charging body 20.

Further, since the foreign matter 9 once adsorbed does not leave the adsorbent 21, reattachment can be prevented.

In the above embodiment, the charging member is provided facing the wafer, and the foreign material is charged to attract the foreign material to the attraction member by electrostatic force. However, a flat plate facing the wafer or the mask is provided. Alternatively, a foreign substance may be removed by applying a voltage between the flat plate and the mask stage or the wafer stage using a voltage power supply and generating a discharge between the flat plate and the wafer or the mask.

Embodiment 7 FIG. FIG. 8 is a schematic diagram for explaining a foreign matter removing method in the X-ray exposure apparatus according to the seventh embodiment. In FIG. 8, 23 is a vibration generator, 24
Denotes a vibrator, and 25 denotes an X-ray mask stage.

The vibrator 24 is brought into contact with the X-ray mask 6 while holding the X-ray mask 6 on the X-ray mask stage 25, and the vibration from the vibration generator 23 is transmitted to the X-ray mask 6 through the vibrator 24 to vibrate. The X-ray mask 6 has a 2 μm-thick membrane such as a SiN film and an absorber of 0.5 μm Ta or the like formed on a 2 mm-thick Si, and its exposure region needs to transmit X-rays. , And is formed of a thin film composed of a membrane and an absorber after removing Si. If the vibrator 24 is brought into direct contact with the thin film, the X-ray mask 6 may be damaged. However, the X-ray mask 6 can be vibrated without being damaged by bringing the vibrator 24 out of the exposure area of the X-ray mask 6. .
When the X-ray mask 6 is vibrated with a force larger than the adhesive force of the foreign matter 9, the foreign matter 9 peels off from the X-ray mask 6 and can be removed. At this time, since the adhesive force of the foreign matter 9 differs depending on its size and type, the foreign matter 9 can be effectively removed by appropriately selecting the frequency and amplitude of the vibration.

In the case of the wafer 7 held on the stage 8, the vibrating body 24 is brought into contact with the wafer edge to vibrate. Although the resist is applied to the wafer 7 before the exposure, the resist is removed at the wafer edge portion. Therefore, even if the vibrator 24 is brought into contact with the resist, the resist does not adhere and the vibrator 24 is not contaminated. . If the vibrating body 24 is contaminated, foreign matter will be attached to the wafer 7 from the vibrating body 24. Therefore, it is important to prevent the vibrating body 24 from being contaminated.

Embodiment 8 FIG. FIG. 9 is a schematic diagram for explaining the X-ray exposure method according to the eighth embodiment. 9, 1 is an X-ray exposure apparatus, 6 is an X-ray mask, 7 is a wafer, 9 is a foreign substance, 31 is an X-ray, 32 is a resist coating apparatus, 33 is a resist, 34 is a signal line, and 35 is a foreign substance detecting apparatus. And 36 are foreign matter removing devices, and 37 is a cleaning device.

The X-ray mask 6 moves to the foreign matter detector 35, and the foreign matter detector 35 detects the presence or absence and the position of the foreign matter 9 on the X-ray mask 6, and determines the size of the foreign matter 9 (maximum length or height). ). When the size of the foreign matter 9 is d / 2 or more, where d is the distance between the mask and the wafer, X
The line mask 6 moves to the foreign matter removing device 36, and the foreign matter removing device 36 removes the foreign matter 9 based on the positional information on the X-ray mask 6 of the foreign matter 9 sent from the foreign matter detecting device 35 via the signal line 34. Perform Also, as a more reliable method,
When the foreign matter 9 is detected, all of the foreign matter 9 is moved to the foreign matter removing device 36, and the foreign matter 9 is removed. Further, in order to more reliably remove the foreign matter, the X-ray mask 6 moves to the cleaning device 37 for cleaning, and thereafter returns to the foreign matter detection device 35. The X-ray mask 6, for which the foreign matter detection device 35 has confirmed that no foreign matter has adhered, moves to the X-ray exposure apparatus 1, where the X-ray mask 6 is installed.
Wait until is brought.

A resist 33, which is a photosensitive polymer, is applied on the wafer 7 formed in the previous step by the resist coating device 32. The wafer 7 coated with the resist 33 moves to the foreign matter detection device 35, and the foreign matter detection device 35 detects the presence or absence and position of the foreign matter on the wafer, and obtains the size (maximum length or height) of the foreign matter 9. . If the size of the foreign material 9 is d / 2 or more, where d is the mask-wafer distance, the wafer 7 moves to the foreign material removing device 36 and is sent from the foreign material detecting device 35 via the signal line 34. Foreign material 9
Foreign matter detecting device 35 based on the
Performs the removal of the foreign matter 9. As a more reliable method, when the foreign matter 9 is detected, all the foreign matter 9 is moved to the foreign matter removing device 36 and the foreign matter 9 is removed. In order to further reliably remove foreign matter, the wafer 7 is moved to the cleaning device 37 and cleaned, and then returns to the resist coating device 32 again. The wafer 7, which has been confirmed by the foreign matter detector 35 to be free of foreign matter, moves to the X-ray exposure apparatus 1,
Position adjustment is performed so that a gap between the line mask 6 and a predetermined mask-wafer gap is obtained. At this time, since it has already been confirmed that there is no foreign matter on the wafer 7 and the X-ray mask 6, damage to the X-ray mask due to contact with the foreign matter cannot occur. When the position adjustment is completed, the X-ray mask 6 is irradiated with X-rays 31 to transfer the X-ray mask pattern to the wafer 7.

In the present embodiment, the foreign matter is removed after the foreign matter is detected, and then the exposure is performed. However, in order to more reliably prevent the damage of the X-ray mask, the size of the foreign matter 9 is set between the mask and the wafer. When the distance is d, if it is d / 2 or more, the wafer 7 or the X-ray mask 6 where the foreign matter is detected may not be exposed. Further, if the wafer 7 or the X-ray mask 6 in which the foreign matter is detected is not exposed, the damage of the X-ray mask can be more reliably prevented.

Even if the foreign matter on the wafer 7 is not removed, the X-ray exposure apparatus 1 can send the signal from the foreign matter detecting device 35 to the signal line 34.
Based on the size, height, and positional information on the wafer 7 of the foreign matter sent through the, the exposure can be performed while avoiding the foreign matter.

Further, the wafer 7 or the X-ray mask 6 does not move to the cleaning device 37 after the foreign matter is removed,
5 and the foreign substance inspection may be performed again.

Further, the wafer 7 or the X-ray mask 6 may be exposed after removing foreign matter on the entire surface without detecting foreign matter, or after further removing foreign matter, the cleaning device 3 may be used.
7 and then may be exposed.

If the foreign matter is removed from the wafer 7 even before the resist is applied, the foreign matter can be more reliably removed.

Further, when the foreign substance detection and foreign substance removal of the wafer 7 or the X-ray mask 6 are performed in combination with a plurality of detection methods and a plurality of removal methods, the foreign substance can be more reliably detected and removed.

Further, in the present embodiment, the foreign object detecting device 35
Are separated from the X-ray exposure apparatus 1 but may be integrated for in-line operation, or may include a foreign matter detection mechanism and a foreign matter removal mechanism inside the X-ray exposure apparatus 1.

Embodiment 9 FIG. FIG. 10 shows Embodiment 9
FIG. 2 is a schematic diagram for explaining an X-ray exposure method in
FIG. 11 is a schematic diagram showing a resist film formation state after resist film formation in the case where a foreign substance is present on a wafer according to the ninth embodiment, as viewed from right above the wafer. In FIG. 10, reference numeral 38 denotes a foreign matter height measuring device.

The resist coating device 32 performs spin coating while discharging a resist 33 made of a photosensitive polymer onto the wafer 7 formed in the previous step from just above the center of the wafer 7. After the completion of the spin coating, a resist 33 having a predetermined thickness is formed on the wafer 7. Resist thickness is usually 1μ
If the foreign matter 9 having a height of several μm or more adheres to the wafer 7 before applying the resist, the resist 33 collides with the foreign matter 9 during the spin coating and scatters, and as shown in FIG. This causes a change in the resist film formation state (striation 33a). Striation 33a
Reaches a size of several mm or more even when the size of the foreign matter 9 is about several μm in diameter. Therefore, the foreign matter detection device 35 captures the image of the resist film formation state, performs image processing, and determines the presence or absence of the foreign matter by identifying the presence or absence of the striation 33a. In addition, striation 3
Since 3a spreads on the radiation starting from the foreign substance from the center of the wafer, the coordinates of the foreign substance on the wafer 7 can be determined by obtaining the starting point of the striation 33a. Next, the wafer 7 having foreign matter is sent to a foreign matter height measuring device, and the height of each foreign matter is measured based on the position information of the foreign matter sent from the foreign matter detection device 35 through the signal line 34. The height of a foreign substance having a size of about several μm can be easily measured by measuring reflected light from a laser beam applied to the foreign substance. The wafer 7 for which no foreign matter has been adhered by the foreign matter detection device 35 is the X-ray exposure device 1
And the position is adjusted so that the gap between the X-ray mask 6 and a predetermined mask-wafer gap is established. At this time, since it has already been confirmed that there is no foreign matter on the wafer 7, damage to the X-ray mask due to contact with the foreign matter cannot occur. When the position adjustment is completed, the X-ray mask 6 is irradiated with X-rays 31 to transfer the X-ray mask pattern to the wafer 7.

In this embodiment, the presence / absence of fine foreign matter is detected in an enlarged manner through the striation 33a. Therefore, a high-accuracy foreign matter detecting device is not required and the device can be constructed at low cost.

The striation 3 on the entire surface of the wafer 7
The presence / absence of 3a and the height measurement of the foreign matter can be determined within one minute, and the foreign matter detection and the height measurement of the foreign matter are completed during the processing time of another wafer, so that the resist coating device 32 and the foreign matter can be measured without lowering the throughput. The detection device 35, the foreign matter height measuring device 38, and the X-ray exposure device 1 can be processed in-line.

Further, the X-ray exposure apparatus 1 is
Based on the size, height, and positional information on the wafer 7 of the foreign matter sent from the signal line 5 via the signal line 34, exposure can be performed while avoiding the foreign matter.

If the height of the foreign matter is less than half the gap between the mask and the wafer, exposure may be performed even in the area where the foreign matter is present in order to adjust the etching area. Since the etching rate changes depending on the etching area and causes dimensional fluctuation, it is important to make the etching areas the same in order to secure dimensional controllability.

Embodiment 10 FIG. FIG. 12 is a schematic cross-sectional view for explaining a method of setting a gap between an X-ray mask and a wafer in an X-ray exposure apparatus according to the tenth embodiment. In FIG. 12, reference numeral 39 denotes a mask guard, and reference numeral 40 denotes a reference plane of an X-ray mask-wafer gap.

The X-ray mask 6 in which the mask guard 39 having a height of about half or more of the gap between the X-ray mask and the wafer is mounted on the surface of the X-ray mask 6 is installed in the X-ray exposure apparatus 1. The position of the X-ray mask 6 is adjusted with respect to the reference plane 40 of the gap between the X-ray mask and the wafer outside the wafer 7 so that a predetermined gap between the X-ray mask and the wafer is formed. Next, the position of the wafer 7 sucked on the stage 8 is adjusted so as to be the same height as the reference plane 40 of the gap between the X-ray mask and the wafer. Position adjustment is performed by phase difference detection using laser light. Next, the X-ray exposure is started after the stage 8 is moved to the target exposure field on the wafer 7 while keeping the X-ray mask 6 and the wafer 7 at the relative position of the gap between the X-ray mask and the wafer with respect to the reference plane 40. I do. After the exposure is completed, move to the next field while maintaining the gap between the X-ray mask and the wafer,
Exposure is performed sequentially. At this time, the foreign matter 9 that has come into contact with the mask guard 39 attached to the X-ray mask 6 is scraped off or repelled by the mask guard 39, so that the foreign matter does not come into contact with the X-ray mask surface. The damage of the X-ray mask can be prevented.

In the present embodiment, the X-ray mask will not be damaged even if foreign matter 9 having a height greater than the gap between the X-ray mask and the wafer exists on the wafer.

When the mask guard 39 is contaminated by contact with foreign matter, it can be removed and replaced.

Further, it is possible to select a mask guard 39 having a thickness suitable for a predetermined X-ray mask-wafer gap.

Further, when the mask guard is integrally formed at the time of manufacturing the X-ray mask, the positional distortion accompanying the mounting of the mask guard 39 can be minimized.

Embodiment 11 FIG. FIG. 13 is a schematic diagram for explaining an X-ray exposure method in the X-ray exposure apparatus according to the eleventh embodiment. In FIG. 13, reference numeral 51 denotes a foreign matter counting device, 52 denotes an exposure atmosphere supply port, 53 denotes an exposure atmosphere intake port, 54 denotes an X-ray mask holder, and 55 denotes an airflow of the exposure atmosphere.

In the X-ray exposure apparatus 1, an exposure atmosphere whose quality is controlled by a temperature adjustment, a particle removal filter, and a chemical filter is always supplied from an exposure atmosphere supply port 52 and is taken into an exposure atmosphere intake port 53.
The foreign matter counting device 51 installed in the middle of the gas flow 55 of the exposure atmosphere always measures the number and size of the floating foreign matter in the exposure atmosphere, and when a floating foreign matter of a predetermined size or more is detected. When the number of foreign substances increases, it is possible to notify the user of the X-ray exposure apparatus of the stop of exposure or a caution signal. Therefore, before the foreign matter adheres to the X-ray mask 6, appropriate measures such as maintenance of the apparatus can be performed, and breakage of the X-ray mask can be prevented. Further, the X-ray exposure apparatus 1
Inside the X-ray mask holder 54, two or more X-ray masks 6 having the same mask design pattern are installed. If the foreign matter counting device 51 detects foreign matter during exposure using one of the X-ray masks 6, it is necessary to carry out an inspection because foreign matter may be attached on the used X-ray mask 6. There is. At this time, by immediately exchanging the X-ray mask 6 with another X-ray mask 6, exposure can be continuously performed even when the X-ray mask 6 to which foreign matter may be attached is inspected. Can be minimized.

In the present embodiment, the foreign matter counting device 51 is installed immediately after the exposure atmosphere supply port 52 and the exposure atmosphere intake port, but may be at a position close to the X-ray mask 6 or at a plurality of locations. A foreign matter counting device 51 may be provided.

[0129]

According to the first X-ray exposure method of the present invention, a mask is arranged at a predetermined mask-wafer interval on a surface on which a resist is formed on the upper surface of a wafer, and the X-ray is exposed. X to irradiate and transfer the mask pattern to the resist
A line exposure method, comprising the step of detecting foreign matter on the surface of the mask facing the wafer, or on the upper or lower surface of the wafer after resist application, or on the upper or lower surface of the wafer without resist application. Therefore, when foreign matter is attached, measures such as not performing exposure can be performed, and thus damage to the X-ray mask due to contact with the foreign matter can be prevented. In addition, since foreign matter detection is performed inside the X-ray exposure apparatus, foreign matter attached outside the X-ray exposure apparatus and foreign matter attached inside the X-ray exposure apparatus can be detected, and damage to the X-ray mask can be more reliably prevented. it can. Further, since the X-ray mask does not need to be re-produced due to the damage of the X-ray mask, the transfer cost can be reduced. In addition, if it is expected that a transfer pattern defect will occur due to foreign matter detection, exposure can be omitted, and the occurrence of a transfer pattern defect can be prevented.

According to the second X-ray exposure method of the present invention, when the distance between the mask and the wafer is d, it is determined whether or not the size of the foreign matter is not less than d / 2, whereby the foreign matter can be removed. The necessity, the necessity of cleaning, and the necessity of exposure can be determined.

In the third X-ray exposure method according to the present invention, in the first X-ray exposure method, foreign matter is detected at any timing before, during, or after exposure.
Since the presence or absence of foreign matter can be detected in real time, it is possible to more reliably prevent mask damage due to contact with foreign matter.

In the fourth X-ray exposure method according to the present invention, a mask is arranged at a predetermined mask-wafer interval on a surface on which a resist is formed on the upper surface of a wafer, and the mask is irradiated with X-rays. An X-ray exposure method for transferring a pattern of a mask onto the resist, wherein the exposure is performed while measuring the number of floating foreign substances in the X-ray exposure apparatus. , And prevent damage to the X-ray mask.

According to a fifth X-ray exposure method of the present invention, in the above-mentioned fourth X-ray exposure method, when a floating foreign substance is detected, the mask is placed on the surface of the mask facing the wafer or on the wafer. Since the step of detecting foreign matter on the upper surface or lower surface after resist application or the upper surface or lower surface of the wafer not coated with resist is performed, foreign object detection can be performed at appropriate timing.

In the sixth X-ray exposure method according to the present invention, in the above-described first or fourth X-ray exposure method, when a foreign substance is detected, the mask is replaced. Exposure can be continuously performed even when inspecting an X-ray mask that may be present, so that a decrease in throughput can be minimized.

In the seventh X-ray exposure method according to the present invention, in the first or fourth X-ray exposure method, when foreign matter is detected, the exposure is not performed. Damage can be prevented.

In the eighth X-ray exposure method according to the present invention, in the first X-ray exposure method, when a foreign matter is detected, the foreign matter is removed and the exposure is performed. Occurrence can be prevented.

In the ninth X-ray exposure method according to the present invention, in the first X-ray exposure method, when a foreign substance is detected, there is a foreign substance that cannot be removed because the exposure is performed while avoiding the detected foreign substance. However, it is possible to transfer to a region where there is no foreign matter, and the yield can be improved.

According to the tenth X-ray exposure method of the present invention, when foreign matter is detected in the first X-ray exposure method, after the foreign matter is removed, further cleaning is performed before exposure. Therefore, the foreign matter can be more reliably removed.

According to the eleventh X-ray exposure method of the present invention, in the first X-ray exposure method, since the height of the foreign matter is detected, it can be determined whether or not the foreign matter comes into contact with the X-ray mask. . In addition, if the X-ray mask is not contacted, exposure can be performed, and the etching area during etching can be made the same.

According to the twelfth X-ray exposure method according to the present invention, in the first X-ray exposure method, the length of the foreign matter is detected. Can be determined.

According to the thirteenth X-ray exposure method of the present invention, in the first X-ray exposure method, the length of the foreign matter is detected, and then the height of the foreign matter is detected. It is possible to obtain both detection and detailed foreign matter information.

According to the fourteenth X-ray exposure method of the present invention, in the first X-ray exposure method, the detection of foreign matter
By using the scattered light from the foreign matter illuminated by the reference light, the foreign matter can be detected separately from the pattern formed on the wafer.

According to the fifteenth X-ray exposure method according to the present invention, in the fourteenth X-ray exposure method, the position of the foreign matter can be determined by scanning the wafer surface using laser light as reference light. Exposure can be avoided.

According to the sixteenth X-ray exposure method of the present invention, in the fourteenth X-ray exposure method, the presence or absence of foreign matter can be easily confirmed visually by using visible light as reference light. .

According to the seventeenth X-ray exposure method according to the present invention, in the fourteenth X-ray exposure method, the detection device can be equipped at low cost by using white light as the reference light.

According to the eighteenth X-ray exposure method according to the present invention, in the first X-ray exposure method, the detection of foreign matter
Since the laser light source and the laser receiving unit are arranged facing each other and the laser light intensity after transmitting the foreign matter is measured, the laser light source and the laser receiving unit can be arranged in parallel with the wafer or the X-ray mask. In addition, the arrangement of the detection device becomes easy.

According to the nineteenth X-ray exposure method according to the present invention, in the first X-ray exposure method, detection of foreign matter
Since the laser light source and the laser receiving unit are arranged to face each other and the phase of the laser light after transmitting the foreign matter is measured, a nearly transparent foreign matter such as an organic matter can be detected.

According to the twentieth X-ray exposure method of the present invention, in the first X-ray exposure method, the detection of foreign matter is
The laser light source and the laser receiver are placed on a plane parallel to the wafer surface, and the measurement is performed by measuring the intensity of the laser light after being scattered by the foreign matter. Can be detected.

According to the twenty-first X-ray exposure method according to the present invention, in the first X-ray exposure method, the detection of foreign matter
Since the laser light source and the laser receiving unit are arranged on a plane parallel to the wafer surface and the phase of the laser light after being scattered by the foreign matter is measured, a nearly transparent foreign matter such as an organic matter can be detected.

According to the twenty-second X-ray exposure method of the present invention, in any one of the eighteenth to twenty-first X-ray exposure methods, a laser beam having a diameter of several μm or less is used. Since the ratio of the laser light scattered by the laser beam is reduced, noise entering the laser receiving unit can be reduced, and the accuracy of foreign matter detection can be improved.

According to the twenty-third X-ray exposure method of the present invention, in any one of the eighteenth to twenty-first X-ray exposure methods, since a laser beam having a diameter of several μm or more is used, a high processing power can be used for the laser light source. Since there is no need to require accuracy, the apparatus can be configured at low cost.

According to the twenty-fourth X-ray exposure method according to the present invention, in any one of the eighteenth to twenty-first X-ray exposure methods, since the laser beam spread in a fan shape is used, the intensity of the laser beam is reduced by foreign matter. The area to be enlarged is larger than the size of the foreign matter, so that it is not necessary to prepare a laser receiver having a high resolution to detect the presence or absence of the foreign matter, and the apparatus can be constructed at low cost.

According to the twenty-fifth X-ray exposure method according to the present invention, in the first X-ray exposure method, detection of foreign matter
Since the application state of the resist applied on the wafer is taken as an image signal and is performed by image processing, it is possible to detect fine foreign substances by enlarging them through striation and comparing the resist application states, which is high. Since detection accuracy is not required, the detection device can be configured at low cost, and high-speed foreign object detection can be realized.

According to the twenty-sixth X-ray exposure method according to the present invention, in the first X-ray exposure method, the detection of foreign matter
Since the scanning is performed by scanning the wafer or the mask or the wire while maintaining the distance from the wire stretched on a straight line to a distance of about half or less of the mask-wafer interval in the vertical direction, the apparatus can be configured at low cost.

According to the twenty-seventh X-ray exposure method of the present invention, since the foreign matter is removed in advance, the foreign matter detecting step can be omitted.

According to the twenty-eighth X-ray exposure method according to the present invention, in the twenty-seventh X-ray exposure method, a cleaning step is provided after the step of removing the foreign matter, so that the foreign matter can be more reliably removed. can do.

According to the twenty-ninth X-ray exposure method of the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, the foreign matter is removed by blowing gas onto the foreign matter. And foreign matter can be removed without damaging the X-ray mask.

According to the thirtieth X-ray exposure method of the present invention, in the above-described twenty-ninth X-ray exposure method, foreign matter is sucked together with the blown gas, so that the removed foreign matter does not adhere again.

According to the thirty-first X-ray exposure method of the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, the foreign matter is removed by charging the foreign matter and changing the sign of the foreign matter to the opposite sign. The foreign matter can be removed at a high speed by a simple method of adsorbing to the charged adsorbent.

According to the thirty-second X-ray exposure method according to the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, foreign matter removal is performed by adjusting the frequency or amplitude at which the wafer or mask is vibrated. By doing so, foreign substances can be removed more reliably. In addition, since the vibration is transmitted to a place distant from the vibrating body and has an effect of removing foreign substances, it is easy to dispose the vibrating body in the X-ray exposure apparatus.

According to the thirty-third X-ray exposure method of the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, a flat plate is provided for removing foreign matter, and a mask is provided in parallel with the flat plate. Since the scanning is performed by scanning the wafer or the X-ray mask held at a distance of about half or less of the distance between the wafers, it is possible to reliably remove foreign substances having a height of half or more of the gap between the mask and the wafer.

According to the thirty-fourth X-ray exposure method of the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure methods, the foreign matter is removed by irradiating the foreign matter with a laser. Only foreign matter can be selectively removed without damaging the wafer and other parts of the mask.

According to the thirty-fifth X-ray exposure method of the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, foreign matter is removed by providing a flat plate facing a wafer or a mask. Since discharge is generated by generating a discharge between the flat plate and the wafer or the mask, the discharge occurs between the projections on the wafer or the mask. Can be removed.

According to the thirty-sixth X-ray exposure method according to the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure methods, the foreign matter is removed by a mechanical force using a brush. Even strongly adhered foreign matter can be removed.

According to the thirty-seventh X-ray exposure method according to the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure methods, damage to the wafer is suppressed by removing foreign matter with an ice scrubber. be able to.

According to the thirty-eighth X-ray exposure method according to the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure methods, since the liquid is removed, damage to the wafer can be further reduced. .

According to the thirty-ninth X-ray exposure method according to the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure methods, since removal is performed with dry ice, even a foreign substance having a strong adhesive force can be more reliably obtained. Can be removed.

According to the fortieth X-ray exposure method according to the present invention, in the thirty-ninth X-ray exposure method, since an inert gas is used as dry ice, no chemical reaction occurs with the wafer.

According to the 41 X-ray exposure method according to [0169] the present invention, in the first 39 X-ray exposure method, it can be inexpensively because it uses CO ₂ as dry ice.

According to the forty-second X-ray exposure method of the present invention, in the above-described eighth, tenth, or twenty-seventh X-ray exposure method, the force acting on the foreign matter by using both gas and liquid is reduced. More optimal control can be performed.

According to the forty-third X-ray exposure method of the present invention, in the eighth, tenth, or twenty-seventh X-ray exposure method, the foreign matter can be removed in a vertical direction from a straight wire. Since the scanning is performed by scanning the wafer, the mask, or the wire while maintaining the distance between the mask and the wafer at about half or less, the apparatus can be configured at low cost.

According to the forty-fourth X-ray exposure method of the present invention, the intrusion of foreign matter can be prevented by providing a protrusion protruding from the mask surface by at least half the distance between the mask and the wafer around the mask. Can be prevented and contact with the X-ray mask can be avoided.

According to the forty-fourth X-ray exposure method according to the present invention, in the forty-fourth X-ray exposure method, a predetermined mask-wafer distance is set between the wafer and the mask outside the mask. Since the wafer is moved under the mask, it is possible to reliably avoid contact with the X-ray mask even if foreign matter is present on the wafer.

According to the first X-ray exposure apparatus of the present invention, a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist is applied and formed into a film, and the mask is irradiated with X-rays. X for transferring the pattern of the mask to the resist
Line exposure means, and foreign matter detection means for detecting foreign matter on the surface of the mask facing the wafer, or the upper or lower surface of the wafer after resist coating, or the upper or lower surface of the wafer without resist coating. Since the device is provided, measures such as not performing exposure when foreign matter is attached can be performed, and thus, damage to the mask due to contact with the foreign matter can be prevented. Further, since foreign matter detection is performed inside the X-ray exposure apparatus, foreign matter adhered outside the X-ray exposure apparatus and foreign matter adhered inside the X-ray exposure apparatus can be detected, and the mask can be more reliably prevented from being damaged.

According to the second X-ray exposure apparatus of the present invention, the first X-ray exposure apparatus is provided with the removing means for removing the detected foreign matter. Can be prevented.

According to the third X-ray exposure apparatus of the present invention, the above-mentioned first X-ray exposure apparatus is provided with cleaning means for cleaning a mask, a wafer after resist application or a wafer not coated with resist. Therefore, the foreign matter can be more reliably removed by washing.

According to the fourth X-ray exposure apparatus of the present invention, a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist is applied and formed, and is irradiated with X-rays. X for transferring the pattern of the mask to the resist
Line exposure means, and foreign matter removing means for removing foreign matter on the surface of the mask facing the wafer, or on the upper or lower surface of the wafer after resist coating, or on the upper or lower surface of the wafer without resist coating. Since foreign substances are removed in advance, foreign substance detection can be omitted.

According to the fifth X-ray exposure apparatus of the present invention, the above-mentioned fourth X-ray exposure apparatus is provided with cleaning means for cleaning a mask, a wafer after resist application or a wafer not coated with resist. Therefore, the foreign matter can be more reliably removed by washing.

According to the sixth X-ray exposure apparatus of the present invention, a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist is applied and formed, and the X-ray is irradiated. X for transferring the pattern of the mask to the resist
X-ray exposure means and a foreign matter count measuring means for measuring the number of floating foreign matters in the X-ray exposure apparatus main body, so that appropriate measures such as apparatus maintenance can be performed before the foreign matters adhere to the X-ray mask, The damage of the X-ray mask can be prevented.

According to the seventh X-ray exposure apparatus of the present invention, in the above-mentioned first, fourth or sixth X-ray exposure apparatus, the X-ray exposure apparatus having the same mask pattern design in the X-ray exposure apparatus main body. Since two or more line masks are always provided, exposure can be continuously performed even when inspecting an X-ray mask to which foreign matter may be attached, thereby minimizing a decrease in throughput. be able to.

According to the first X-ray mask according to the present invention,
Foreign matter can be prevented from entering. Further, the mask provided with the protruding portion and the wafer are set at a predetermined mask-wafer distance, and then the wafer is moved while maintaining the predetermined mask-wafer distance, so that the wafer is placed on the wafer. Even if foreign matter is present, contact with the X-ray mask can be avoided.

According to the second X-ray mask of the present invention,
Since the projection can be mounted, even if the projection is contaminated, only the projection needs to be replaced, and the cost can be reduced.

The third X-ray mask according to the present invention has the same structure as that of the first X-ray mask, except that the projection is formed integrally with the mask. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a foreign matter detection method in an X-ray exposure apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a schematic diagram showing a foreign matter detection method according to Embodiment 1 of the present invention and a state in which foreign matter is sandwiched between a wafer and a stage.

FIG. 3 is a schematic diagram of a foreign matter detection method in an X-ray exposure apparatus according to Embodiment 2 of the present invention.

FIG. 4 is a schematic diagram of a foreign matter detection method in an X-ray exposure apparatus according to Embodiment 3 of the present invention.

FIG. 5 is a schematic diagram of a foreign matter detection / removal method in an X-ray exposure apparatus according to Embodiment 4 of the present invention.

FIG. 6 is a schematic diagram of a foreign matter removing method in an X-ray exposure apparatus according to Embodiment 5 of the present invention.

FIG. 7 is a schematic diagram of a foreign matter removing method in an X-ray exposure apparatus according to Embodiment 6 of the present invention.

FIG. 8 is a schematic diagram of a method for removing foreign matter in an X-ray exposure apparatus according to Embodiment 7 of the present invention.

FIG. 9 is a schematic diagram for explaining an X-ray exposure method according to an eighth embodiment of the present invention.

FIG. 10 is a schematic diagram for explaining an X-ray exposure method according to Embodiment 9 of the present invention.

FIG. 11 is a schematic diagram showing a resist film formation state after resist film formation in the case where a foreign substance is present on a wafer according to Embodiment 9 of the present invention.

FIG. 12 is a schematic diagram for explaining an X-ray exposure method according to Embodiment 10 of the present invention.

FIG. 13 is a schematic diagram for explaining an X-ray exposure method according to Embodiment 11 of the present invention.

FIG. 14 is a configuration diagram of a conventional X-ray exposure apparatus.

[Explanation of symbols]

1 X-ray exposure apparatus, 2 laser light source, 3 laser receiving section, 4 laser light, 5 transmitted light, 6 X-ray mask, 7
Wafer, 8 stage, 9 foreign matter, 10 position detector,
11 detection circuit, 12 CCD camera, 13 light source, 1
4 Reference light, 15 scattered light, 16 reflected light, 17 outlet, 18 inlet, 19 gas, 20 charged body, 21
Adsorbent, 22 voltage power supply, 23 vibration generator, 24 vibrator, 25 X-ray mask stage, 26 wafer cassette, 28 wafer stage, 29 vertical XY stage, 3
0 extraction window, 31 X-ray, 32 resist coating device, 33 resist, 34 signal line, 35 foreign matter detecting device, 36 foreign matter removing device, 37 cleaning device, 38 foreign matter height measuring instrument, 39 mask guard, 40 X-ray mask-
Reference plane of gap between wafers, 50 laser beam magnifier, 5
1 Foreign particle counter, 52 Exposure atmosphere supply port, 53 Exposure atmosphere intake port, 54 X-ray mask holder, 55
Exposure atmosphere gas flow, 56 wires, 57 wire attachments.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/30 531A 531M (72) Inventor Muneyoshi Suita 2-3-2 Marunouchi 2-chome, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72 ) Inventor Kenji Marumoto 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Takashi 123 2-3 Inside 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. 72) Inventor Jun Aya 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation

Claims (55)

[Claims] A mask is arranged on a surface on which a resist is formed on an upper surface of a wafer at a predetermined mask-wafer distance,
An X-ray exposure method for irradiating X-rays to transfer the pattern of the mask onto the resist, wherein the mask is on a surface facing the wafer, or the upper or lower surface of the wafer after resist application, or An X-ray exposure method comprising a step of detecting foreign matter on an upper surface or a lower surface of a wafer on which a resist is not applied. 2. When the distance between the mask and the wafer is d,
2. The X-ray exposure method according to claim 1, wherein it is determined whether or not the size of the foreign matter is d / 2 or more. 3. The X-ray exposure method according to claim 1, wherein foreign matter detection is performed at any timing before, during, or after the exposure. 4. A mask is arranged at a predetermined mask-wafer interval on a surface on which a resist is formed on the upper surface of the wafer,
An X-ray exposure method for irradiating X-rays to transfer the pattern of the mask onto the resist, wherein the exposure is performed while measuring the number of floating foreign particles in the X-ray exposure apparatus. 5. When a floating foreign substance is detected, the foreign substance on the surface of the mask facing the wafer, the upper or lower surface of the wafer after resist coating, or the upper or lower surface of the wafer without resist coating. 5. The X-ray exposure method according to claim 4, further comprising the step of detecting the X-ray. 6. The X-ray exposure method according to claim 1, wherein a mask is replaced when foreign matter is detected. 7. The X-ray exposure method according to claim 1, wherein no exposure is performed when a foreign substance is detected. 8. The method according to claim 1, wherein when a foreign substance is detected, the exposure is performed after removing the foreign substance.
Line exposure method. 9. The X-ray exposure method according to claim 1, wherein when foreign matter is detected, the exposure is performed while avoiding the foreign matter. 10. The X-ray exposure method according to claim 1, wherein when a foreign substance is detected, the foreign substance is removed, and then the substrate is further cleaned and exposed. 11. The X-ray exposure method according to claim 1, wherein the height of the foreign matter is detected. 12. The X-ray exposure method according to claim 1, wherein the length of the foreign matter is detected. 13. The X-ray exposure method according to claim 1, wherein the length of the foreign matter is detected, and then the height of the foreign matter is detected. 14. The X-ray exposure method according to claim 1, wherein the foreign matter is detected using scattered light from the foreign matter illuminated with reference light. 15. The X-ray exposure method according to claim 14, wherein the reference light is a laser light. 16. The X-ray exposure method according to claim 14, wherein the reference light is visible light. 17. The X-ray exposure method according to claim 14, wherein the reference light is white light. 18. The method according to claim 1, wherein the detection of the foreign matter is performed by arranging a laser light source and a laser receiving unit so as to face each other, and measuring the intensity of the laser beam after passing through the foreign matter.
The X-ray exposure method according to the above. 19. The method according to claim 1, wherein the detection of the foreign matter is performed by arranging a laser light source and a laser receiving unit so as to face each other, and measuring a phase of the laser light transmitted through the foreign matter. Line exposure method. 20. The method according to claim 1, wherein the detection of the foreign matter is performed by arranging the laser light source and the laser receiving portion on a plane parallel to the wafer surface and measuring the intensity of the laser light scattered by the foreign matter. 2. The X-ray exposure method according to 1. 21. A method for detecting foreign matter, comprising: arranging a laser light source and a laser receiving part on a plane parallel to a wafer surface and measuring a phase of laser light scattered by the foreign matter. Item 7. The X-ray exposure method according to Item 1. 22. The X-ray exposure method according to claim 18, wherein a laser beam having a diameter of several μm or less is used. 23. The X-ray exposure method according to claim 18, wherein a laser beam having a diameter of several μm or more is used. 24. The X-ray exposure method according to claim 18, wherein a laser beam spread in a fan shape is used. 25. The X-ray exposure method according to claim 1, wherein the detection of the foreign matter is performed by image processing by taking the application state of the resist applied on the wafer as an image signal. 26. A method for detecting foreign matter by scanning a wafer, a mask, or a wire while keeping a distance from a wire stretched on a straight line to a distance of about half or less of a mask-wafer interval in a vertical direction. The X-ray exposure method according to claim 1, wherein: 27. An X-ray in which a mask is arranged at a predetermined mask-wafer interval on a surface on which a resist is formed on the upper surface of a wafer, and the pattern of the mask is transferred to the resist by irradiating the mask with X-rays. An exposure method, comprising a step of removing foreign matter on the surface of the mask facing the wafer, or on the upper or lower surface of the wafer after resist application, or on the upper or lower surface of the wafer without resist application. An X-ray exposure method comprising: 28. The method according to claim 27, further comprising a washing step after the step of removing foreign matter.
Line exposure method. 29. The X-ray exposure method according to claim 8, wherein the foreign matter is removed by blowing a gas to the foreign matter. 30. The X-ray exposure method according to claim 29, wherein the foreign matter is sucked together with the blown gas. 31. The X-ray according to claim 8, wherein the foreign matter is removed by charging the foreign matter and adsorbing the foreign matter on an adsorbent charged with the opposite sign to the foreign matter. Exposure method. 32. The method according to claim 8, wherein the foreign matter is removed by vibrating the wafer or the mask.
28. The X-ray exposure method according to any one of 10 and 27. 33. The method according to claim 8, wherein the foreign matter is removed by scanning a wafer or an X-ray mask which is provided with a flat plate and held at a distance of about half or less of the mask-wafer distance in parallel with the flat plate. 28. The X-ray exposure method according to any one of the above items, 10 or 27. 34. The X-ray exposure method according to claim 8, wherein the foreign matter is removed by irradiating the foreign matter with a laser. 35. The method according to claim 8, wherein the foreign matter is removed by providing a flat plate facing the wafer or the mask and generating a discharge between the flat plate and the wafer or the mask. The X-ray exposure method according to any one of the above. 36. The X-ray exposure method according to claim 8, wherein the foreign matter is removed using a brush. 37. The X-ray exposure method according to claim 8, wherein the foreign matter is removed using an ice scrubber. 38. The method according to claim 8, wherein the foreign matter is removed by spraying a liquid.
The X-ray exposure method according to any one of the above. 39. The X-ray exposure method according to claim 8, wherein the foreign matter is removed by spraying dry ice. 40. The X-ray exposure method according to claim 39, wherein an inert element is used as dry ice. 41. The X-ray exposure method according to claim 39, wherein CO ₂ is used as dry ice. 42. The method according to claim 8, wherein the foreign matter is removed by blowing both gas and liquid.
28. The X-ray exposure method according to any one of 0 and 27. 43. A method for removing foreign matter by scanning a wafer, a mask, or a wire while maintaining a vertical distance from a wire stretched on a straight line at a distance of about half or less of a mask-wafer distance. The X-ray exposure method according to any one of claims 8, 10, and 27. 44. An X-ray for arranging a mask on a surface on which a resist is formed on the upper surface of a wafer at a predetermined mask-wafer interval, and irradiating X-rays to transfer the pattern of the mask to the resist. An X-ray exposure method, comprising: providing a protruding portion protruding from the mask surface by a length equal to or more than half of the mask-wafer distance from the mask surface around the mask. 45. A method in which a predetermined distance between the wafer and the mask is set in advance outside the mask at a predetermined mask-wafer distance, and then the wafer is moved under the mask while maintaining the mask-wafer distance. The X-ray exposure method according to claim 44, wherein: 46. An X-ray exposure method in which a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist has been applied and formed into a film, and the pattern of the mask is transferred to the resist by irradiating X-rays. Means for detecting foreign matter on the surface of the mask facing the wafer, or on the upper or lower surface of the wafer after resist coating, or on the upper or lower surface of the wafer without resist coating. An X-ray exposure apparatus comprising: 47. The X-ray exposure apparatus according to claim 46, further comprising a removing means for removing the detected foreign matter. 48. The X-ray exposure apparatus according to claim 46, further comprising cleaning means for cleaning a mask, a wafer after resist application or a wafer not coated with resist. 49. An X-ray exposure method in which a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist has been applied and formed into a film, and the pattern of the mask is transferred to the resist by irradiating X-rays. Means for removing foreign matter on the surface of the mask facing the wafer, or on the upper or lower surface of the wafer after resist coating, or on the upper or lower surface of the wafer without resist coating. An X-ray exposure apparatus comprising: 50. The X-ray exposure apparatus according to claim 49, further comprising cleaning means for cleaning a mask, a wafer after resist application or a wafer not coated with resist. 51. An X-ray exposure method in which a mask is arranged at a predetermined mask-wafer interval on the upper surface of a wafer on which a resist is applied and formed into a film, and the mask pattern is transferred to the resist by irradiating X-rays. An X-ray exposure apparatus comprising: means for counting the number of foreign particles in the main body of the X-ray exposure apparatus. 52. The X-ray exposure apparatus according to claim 46, wherein the X-ray exposure apparatus body always has two or more X-ray masks having the same mask pattern design. apparatus. 53. An X-ray in which a mask is arranged on a surface on which a resist is formed on an upper surface of a wafer at a predetermined mask-wafer interval, and the pattern of the mask is transferred to the resist by irradiating the mask with X-rays. What is claimed is: 1. An X-ray mask for use in an exposure method, comprising: a protruding portion protruding from a mask surface by a length equal to or more than half of a mask-wafer interval from the mask surface. 54. The X-ray mask according to claim 53, wherein the projecting portion can be mounted. 55. The X-ray mask according to claim 53, wherein the projection is formed integrally with the mask.