KR20010037947A - Repair method for photomask - Google Patents

Abstract

PURPOSE: A method for repairing a photomask is provided to improve capacity of a semiconductor chip, by reducing a repair fail and manufacturing the photomask where defects are decreased. CONSTITUTION: A repair monitoring pattern is formed in a photomask region not used in a process for manufacturing a semiconductor device to eliminate an align error of laser beam used in a repair process of a photomask. Shift, size and intensity of the laser beam are measure by using the repair monitoring pattern to inspect the align error or a deposition state of a photomask repair apparatus.

Description

Repair method for photomask

The present invention relates to a repair method of a photomask, and more particularly, to a method of checking and correcting an alignment state of a laser beam in a repair apparatus when easily repairing a fail of a photomask.

The problem of the photomask repair process is that there are many repair errors due to the laser beam used for the repair. There are various kinds of defects in the manufacture of photomasks, and in order to repair such defects, the laser beam of the repair equipment must be able to be transformed into various shapes, and the vertical direction of the laser beam is precisely aligned in the required direction.入射) should be.

It is difficult to repair a desired pattern if it becomes oblique incident or the shape of the beam is deformed.

In the photomask process, a laser beam is shifted differently from a desired direction, or a beam size is reduced or enlarged, and thus a problem occurs while cutting a pattern into a desired shape, which is a major cause of decreasing manufacturing yield.

As described above, the repair method of the photomask according to the prior art reduces the yield of the semiconductor device by reducing the yield of the repair process because the direction of the laser beam used in the repair process of the photomask is shifted or the beam size is changed. Therefore, there is a problem in that high integration of the semiconductor device is difficult.

The present invention, in order to solve the above problems of the prior art, by checking and correcting the alignment state of the laser beam of the repair equipment in advance to repair the alignment state of the laser beam to compensate for the laser beam size or inclination in a desired direction in advance It is an object of the present invention to provide a method for repairing a photomask that can be repaired by repairing and improving the yield of a semiconductor device.

1 is a plan view showing a repair method of a photomask according to a first embodiment of the present invention.

2 is a plan view illustrating a repair method of a photomask according to a second embodiment of the present invention;

3 is a plan view illustrating a repair method of a photomask according to a third embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

11: quartz substrate 13: chrome pattern

15: shape of the laser beam

In order to achieve the above object, the repair method of the photomask according to the present invention,

Forming a repair monitoring pattern in the photomask area which is not used in the manufacturing process of the semiconductor device, in order to solve the alignment error of the laser beam used in the repair process of the photomask;

And checking the alignment error or deposition state of the photomask repair apparatus based on the laser beam by measuring the shift, size, and intensity of the laser beam using the repair monitoring pattern.

Here, the process of forming the repair monitoring pattern may be replaced by a process using a repair monitoring photomask provided with a pattern for monitoring the laser beam during the repair process.

On the other hand, the principle of the present invention for achieving the above object,

Alignment of the beam before repairing by inserting a repair monitoring box for measuring the alignment of the laser beam used in the repair process into a chrome pattern, an area not used by the photomask user, that is, a non-exposed area not used in the semiconductor exposure process. This is a method for confirming and easily performing a repair process of the photomask.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Failing in the repair process is likely to lead to rejection even if the previous process proceeds without error.

In particular, it is extremely difficult to manufacture a photomask having a good critical dimension and registration as the circuit line width is reduced. When the circuit line width is small, the yield of the photomask is extremely deteriorated.

Therefore, the failing of the repair process is the biggest cause of rejection in the back-end process of the photomask manufacturing process.

There may be a variety of methods for configuring the repair monitoring pattern introduced into the non-exposure area in order to solve the alignment error of the laser beam, and can be modified in the shape desired by the user. It can be modified in any form as long as the pattern can confirm the beam size (magnification), beam offset or beam shift, and beam rotation.

1A to 1F are plan views illustrating a repair method of a photomask according to a first embodiment of the present invention, in which an unused portion of a semiconductor device is used or another photomask having a pattern prepared in advance The following shows the monitoring patterns available for free use.

The pattern (a) of FIG. 1 can be used to find the shift, size, intensity, etc. of the laser beam.

The dotted line part (b) of FIG. 1 shows the laser beam of the same size as the pattern to repair in order to remove the pattern of (a).

(C)-(f) of FIG. 1 have shown the shape of the pattern which remains after removing the pattern of (a) using the laser beam of said (b).

If the shape of (c) remains, it can be seen that the beam is shifted in the x-axis direction.

And, if the shape of (d) is left, we know that the beam has a magnification component, and if the shape of (e) is left, the rotation of the beam is (f). The strength is uneven and you can see that it is crushed at the edges.

In the case of (c) of FIG. 1, the repair may be performed by shifting the laser beam in the x-axis direction by the remaining portion during repair.

In the case of (d) of FIG. 1, the size component of the beam must be obtained to compensate for the beam size larger or smaller. If the beam size is 1 μm and the remaining pattern size in (d) is 0.1 μm, the beam has a size of about 10%. In this case, 10% must be compensated and repaired using a beam size of 1.1 μm.

In the case of (e) and (f) of FIG. 1, the compensation can be made in the actual process, but the abnormal state of the equipment should be checked in advance to correct the beam state at right angles. In particular, in the case of (f), the beam intensity is likely to be small.

In the above example, the case where both the pattern size and the size of a laser beam are the same is given. However, by modifying the pattern size and beam size in various ways, correction can be made in the same manner as the above examples.

2A to 2D are plan views illustrating a repair method of a photomask according to a second embodiment of the present invention.

2 (a) can calculate a precise beam shift in one direction and a laser beam intensity in one direction. In the repair process of the photomask, it is very important that the laser beam is accurately incident on the pattern edge portion to be repaired.

If you try to make a chrome line by removing the part by injecting a beam having a dotted line of (b) in the pattern of (a), the shape of (c) after removing the desired pattern without the size component of the beam If left, it is possible to know whether the beam is shifted and the degree of shift in a specific direction, so that correction can be made as described in the first embodiment.

Also, as in the case of (d), there is no shift of the beam, but it can be seen that the strength of the beam is small when the pattern is removed as the uneven pattern after repair. In this case, correction can be made by slightly adjusting the intensity of the beam.

The first and second embodiments of the present invention described above were mainly a pattern design for knowing the state of the laser beam and a scheme for removing such elements.

3 (a) and 3 (b) are plan views illustrating a repair method of a photomask according to a third embodiment of the present invention, and illustrate patterns used in a deposition process during a repair process of a photomask. However, such a pattern may be used to repair the phase non-inverting portion of the phase inversion mask into the phase inversion region.

(A) and (b) of FIG. 3 can be used in the case of inspecting unformity by depositing in a repair process.

The process of forming a desired pattern by adding a non-transparent material on a photomask is called deposition. Such deposition is very important for the deposition uniformity of the non-transparent material in the process of manufacturing the photomask.

This is because, if the uniformity is not good, the non-permeable material may be removed in a subsequent cleaning process. If the deposition material drops even once, it is a reason for rejection.

Therefore, deposition uniformity must be monitored from time to time, depending on the circumstances of the equipment.

3 (a) and 3 (b) show a pattern for confirming deposition uniformity before repair in a non-transmissive region as a method for removing such repair fail.

3 (b) can be used to confirm the deposition uniformity at the pattern edge similarly to that described in the second embodiment.

In addition, these patterns are used to accurately etch the thickness of the quartz substrate, that is, in the case of the phase inversion mask of the type formed by etching the quartz substrate, using the pattern prepared in advance according to the size or shape of the defect The quartz substrate should be etched accordingly. In this case, it can be usefully used as a repair monitoring pattern that can check the condition of the equipment in advance.

As in some of the examples above, checking the alignment error or deposition status of the photomask repair device is a very important repair technique. In addition, it is indispensable in the photomask manufacturing process to check the fail in advance and proceed with the process.

As described above, the repair method of the photomask according to the present invention is used to manufacture a photomask among materials used in a wafer exposure process, and is used in a repair process, which is a bottleneck point of the photomask, thereby reducing the repair failure and producing a mask. It is possible to manufacture a photomask with reduced defects and to improve semiconductor chip performance. In addition, the present invention can be utilized to monitor various types of defects existing in the deposition state or the non-shielding region, which is efficient.

Claims (2)

Forming a repair monitoring pattern in the photomask area which is not used in the manufacturing process of the semiconductor device, in order to solve the alignment error of the laser beam used in the repair process of the photomask; The repair method of the photomask comprising the step of checking the alignment error or deposition state of the photomask repair apparatus based on the laser beam by measuring the shift, size and intensity of the laser beam using the repair monitoring pattern. The method of claim 1, Instead of forming the repair monitoring pattern, the repair method of the photomask, characterized in that for using a repair monitoring photomask provided with a pattern for monitoring the laser beam during the repair process.