JPS6355777B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of exposing a fine pattern on a dry plate made of glass or the like to electron beams in order to create a mask.

In an electron beam exposure method in which a fine area on a material to be exposed such as a wafer is irradiated with an electron beam to expose a circuit pattern, etc. on the fine area, the stage on which the material to be exposed is placed or the material to be exposed is exposed. The position of the fine area may move and rotate by a small amount due to thermal expansion/contraction or distortion, or the irradiation position of the electron beam may be affected by contamination along the electron beam path. It becomes impossible to irradiate the area with the electron beam as planned. In order to avoid such troubles, marks are formed on the material to be exposed, and the mark positions are detected by scanning the marks with an electron beam at predetermined intervals during the exposure time. Relative movement and rotation are measured and feedback is provided to the electron beam deflection system and/or stage movement system so as to correct any of the electron beam irradiation positions due to these movements and rotations.

However, when exposing a dry plate to create a mask, the substrate of the dry plate is usually made of glass, so it may be impossible, if not impossible, to form marks by engraving or otherwise on the dry plate to be exposed. , is extremely troublesome.

Therefore, conventionally, as shown in FIG. 1, marks M1, M2, M3 are made of the same material as the substrate of dry plate 1,
A reference member 2 is prepared, the reference member 2 is attached to the dry plate 1, and the movement and rotation of the dry plate 1 and the thermal expansion and contraction of the dry plate itself are detected by detecting the marks on the reference member 2. I have to. In FIG. 1, H is a dry plate holder.

However, in such conventional technology, the magnitude of thermal expansion and contraction of the substrate itself is determined based on the detection of the amount of thermal expansion and contraction of the reference member 2, so the reference member 2 must always be formed of the same material as the substrate. . Therefore, each time the material of the substrate is changed between different types of glass, a new reference member must be manufactured from the same material as the substrate and attached to the dry plate 1, which is troublesome.

Furthermore, the thermal time constant for the temperature of the dry plate substrate itself to be conducted to the reference member is so large that it cannot be ignored, making it impossible to accurately know changes in thermal expansion and contraction of the substrate itself.
Furthermore, since there is inevitably a temperature gradient between the substrate itself and the reference member, it is not possible to accurately know the amount or change of thermal expansion and contraction.

The present invention has been made to solve these conventional drawbacks, and one embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a perspective view of a part of the apparatus for implementing the present invention, and 3 in the figure is a stage. Although not shown, the stage 3 is placed on the bottom of the exposure chamber via a ball, and is movable over the bottom. The stage 3 is provided with a recess 4, into which a dry plate holder 5 is inserted. Furthermore, upper surface regulating plates 6a, 6b, 6c, and 6d are attached to the four corners of the stage 3 via screws or the like, respectively. Similar upper surface regulation plate 7
a, 7b, 7c, and 7d are also attached to the four corners of the dry plate holder 5, respectively. 8 is a dry plate, and the dry plate 8 is inserted into the dry plate holder 5 in the direction of arrow K. When the dry plate 8 is inserted into the dry plate holder 5, the eccentric camshaft 9 rotates and the plate springs 10a, 10b press the dry plate 8 against the upper surface regulating plates 7a, 7b, 7c, 7d. Mark attachment devices 11a and 11b are attached to the dry plate 8 at a distance from each other before the dry plate 8 is inserted into the exposure chamber. The mark attaching device will be explained based on FIG. 3a showing an enlarged sectional view thereof, and FIG. 3b showing a view of FIG. 3a viewed from the direction of arrow S. The mark holder has two plates 13, 14 which are rotatable about an axis 12. A portion of the upper plate is cut out to provide an opening 15. A mark plate 16 is adhered to the plate 14. The mark plate 16 is made of a material with low thermal expansion, such as glass, and has marks M1, M1, etc., on the mark plate 16, for example.
M2, M3, etc. are engraved. The plates 13 and 14 are also made of a material with a low coefficient of thermal expansion, such as molybdenum tungsten or non-magnetic invar.
The plates 13 and 14 are always connected to the plates 13 and 14 by springs 17.
A force is applied in a direction to close the tip T of 14. The mark attachment devices 11a and 11b are operated by the operator from the board 1.
3 and 14 to open the ends of the plates 13 and 14, and then move the dry plate 8 to the plates 13 and 1 as shown in FIG. 3a.
It is attached to the dry plate 8 so as to be sandwiched between the plates 4 and 4. Returning to FIG. 2, the dry plate holder 5 has a dry plate 8.
Notches 17 for receiving the mark attachment devices 11a, 11b when inserting the dry plate 8 into the dry plate holder 5 with the mark attachment devices 11a, 11b attached to the
a, 17b are provided. The stage 3 is also provided with cutouts 18a and 18b for receiving the mark attachment devices 11a and 11b. 19a,1
9b, 19c, 19d are holes, and the holes 19a,
19b, 19c, and 19d, when the dry plate holder 5 is inserted into the recess 4, the holder 5 is connected to the upper surface regulating plate 6.
This is for guiding a presser bar (not shown) for pressing on the parts a, 6b, 6c, and 6d. Also 20,
Reference numeral 21 denotes a laser beam reflecting mirror bonded to the stage 3.

Using the apparatus configured as described above, the operator attaches the mark attachers 11a and 11b to the dry plate 8 while separating them from each other, as described above, before inserting the dry plate 8 into the exposure chamber and exposing it. After that, the dry plate 8 is inserted into the dry plate holder 5, and the dry plate holder 5 is further inserted into the recess of the stage 3 arranged in the exposure chamber. Therefore, the dry plate 8 is arranged in the exposure chamber so that the upper surface of the mark plate 16 and the upper surface of the dry plate 8 are flush with each other, as shown in FIG. In this way, while measuring the position of the stage 3 by applying light from the laser length measurement system to the reflecting mirrors 20 and 21, the stage 3 is moved intermittently to change the exposure area on the dry plate 8 and exposure is performed. . Between these exposures, the stage 3 is moved and the mark M2 of the mark attacher 11a and the mark attacher 1 are connected to each other.
The mark M2 of 1b is scanned with an electron beam, and the position coordinates of these marks are determined. If the obtained position coordinates move parallel to the planned coordinate position, or if there is a deviation such that the entire body rotates, the deflection amount of the electron beam deflection system is adjusted to correct this deviation. Alternatively, exposure is performed by correcting the amount of movement of the stage movement system.

In the present invention described above, the mark attachment device 11
The marks on the mark holder are designed to fit these mounts in order to minimize the intervention of any member that may cause mechanical or thermal misalignment between the marks formed on a and 11b and the substrate of the dry plate. The containers 11a and 11b are moved in exactly the same manner as the marks engraved on the portions of the dry plate 8 to which they are attached. Therefore, if the positions of these marks are determined by applying an electron beam to the marks formed on the mark holders 11a and 11b, the dry plate 8
It is possible to directly measure the total amount of movement and total amount of rotation based on the parallel movement, rotation, thermal expansion and contraction of the stage etc. that holds the dry plate 8, and the thermal expansion and contraction of the dry plate 8 itself. Therefore, according to the present invention, it is not necessary to manufacture the mark plate 16 etc. from the same material as the substrate, and therefore the same mark attachment device can be used regardless of the material of the substrate.

Note that the embodiment described above is only one embodiment of the present invention, and other embodiments may be used. For example, in the above-described embodiment, two mark attachment devices are attached to the dry plate, but three or more mark attachment devices may be attached as long as they are attached at a distance from each other.

Further, as the mark attachment device, one having a configuration as shown in FIG. 5 may be used. However, in FIG. 5, the same components as in FIG. 3 are given the same numbers. In this embodiment, unlike the previous embodiment, the mark plate 16 is pressed against the upper plate 14 by springs 22 and 23 instead of being glued to the upper plate 14, and the dry plate 8 inserted by the spring 24 be forced to.

In such an embodiment, even if the thermal expansion and contraction of the upper plate 14 is so large that it cannot be ignored, the movement of the mark can be made the same as the movement of the part of the dry plate on which the mark attachment device is attached.

[Brief explanation of drawings]

Figure 1 is a diagram for explaining the conventional method, Figure 2 is a diagram for explaining the conventional method.
The figure shows an example of an apparatus for carrying out the present invention, FIG. 3 shows an enlarged view of the mark mounter, and FIG. 4 shows a dry plate in an exposure chamber and marks attached to the dry plate. A diagram to explain the attachment device,
FIG. 5 is a diagram showing still another embodiment. 3: stage, 5: dry plate holder, 8: dry plate,
11a, 11b: Mark holder, 16: Mark plate, M1, M2, M3: Mark, 20, 21: Reflector, 22, 23, 24: Spring.

Claims (1)

[Claims] 1 Place the mask substrate on the stage and
A method in which a reflecting mirror is attached to an end of the stage, and the stage is moved while the position of the reflecting mirror is measured by a laser length measurement system to expose the mask substrate to an electron beam. Attach multiple members with marks formed on them at a distance,
By detecting the marks on each member with an electron beam, the positional shift and rotation amount of the mask substrate and the thermal expansion and contraction of the substrate itself are detected, and based on the detection, the deflection amount of the electron beam and/or the movement amount of the stage is determined. An electron beam exposure method characterized by performing exposure after correction.