JPH0667407A - Comparative inspection method for foreign matter on reticule mask - Google Patents

Abstract

(57) [Abstract] [Purpose] Regarding the improvement of the reticle / mask surface inspection method, the reticle / mask surface foreign material comparison inspection capable of finding an appropriate cleaning method based on the inspection result of the reticle / mask surface foreign material. The purpose is to provide a method. [Structure] A step of storing the position of the foreign matter of the first inspection result of the foreign matter on the reticle / mask surface, and a position of the foreign matter of the second inspection result of the foreign matter on the reticle / mask surface after rewashing. It is configured to include a step and a step of comparing the position of the first foreign matter with the position of the second foreign matter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for inspecting the surface of a reticle mask. With the recent miniaturization of reticle / mask patterns, it is necessary to completely eliminate the presence of minute foreign particles when inspecting the surface of a reticle / mask. In some cases, foreign substances were still found in the reinspection of the surface after the recleaning treatment, and in some cases, foreign substances were still found in the reinspection of the surface after the recleaning treatment was performed a plurality of times.

Under the above circumstances, a comparative inspection of the foreign matter on the surface of the reticle / mask can be performed by comparing the positions of the foreign matter found during the surface inspection of the reticle / mask to find a suitable cleaning method. A method is required.

[0003]

2. Description of the Related Art In the conventional method for inspecting foreign matter on the surface of a reticle, the presence or absence of defects and the presence of foreign matter are judged at the time of inspection by comparing an object to be inspected, for example, a reticle with inspection data.

After the first cleaning, an inspection is performed to determine the presence or absence of foreign matter adhesion. If no foreign matter adhesion is found, the inspection is completed and the reticle is passed to the next step. After the first washing, an inspection is performed to determine the presence / absence of foreign matter adhesion. When foreign matter adhesion is recognized, a second washing is performed and then a second inspection is performed to determine the presence / absence of foreign matter adhesion. If no foreign matter is admitted, the inspection is completed and the reticle is flown to the next process.

In the unlikely event that foreign matter is still found in the second inspection, a third washing is performed and then a third inspection is performed to determine the presence or absence of foreign matter.
If no foreign matter is admitted, the inspection is completed and the reticle is flown to the next process.

However, since foreign substances that could not be removed by these washings adhered, there were cases in which the foreign substances could not be removed no matter how many washings were performed.

[0007]

In the conventional method for inspecting foreign matter on the surface of the reticle mask described above, foreign matter is found in the surface inspection of the reticle mask, and even in the reinspection of the surface after the recleaning process. There is a problem that foreign matter may be found, and the foreign matter may still be found in the re-inspection of the surface after a plurality of recleaning treatments.

In view of the above circumstances, the present invention has an object of providing a comparative inspection method for foreign matter on the surface of a reticle / mask, which allows a suitable cleaning method to be found from the result of the inspection of foreign matter on the surface of the reticle / mask. It is a thing.

[0009]

A comparative inspection method for foreign matter on the surface of a reticle / mask according to the present invention comprises a step of storing the position of the foreign matter as a result of the first inspection of the foreign matter on the surface of the reticle / mask and after recleaning. The step of storing the position of the foreign matter as a result of the second inspection of the foreign matter on the reticle / mask surface of
It is configured to include a step of comparing the position of the foreign material for the second time and the position of the foreign material for the second time.

[0010]

In other words, in the present invention, the position of the foreign matter of the first inspection result of the foreign matter on the reticle / mask surface is stored, and the foreign matter of the second inspection result of the foreign matter on the reticle / mask surface after rewashing is stored. The position is memorized, the position of the first foreign matter is compared with the position of the second foreign matter, and when a common foreign matter position is found, the cleaning method is reviewed to make this common. Since the foreign matter can be removed, it is possible to wash the reticle mask in which the common foreign matter remains on the surface many times and prevent waste of repeated inspection.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIG. FIG. 1 is a diagram showing an object to be inspected according to an embodiment of the present invention.

FIG. 1A is a view showing a reticle to be inspected for the first time. The reticle 1 to be inspected has a common foreign matter 1a and a foreign matter 1b.
Shows a state in which the reticle 1 is in contact with the reticle 1 to be inspected.
With the left end of the origin as the origin, the position of the common foreign matter 1a is displayed as coordinates (a, b), and the position of the foreign matter 1b is displayed as coordinates (c,
d)

FIG. 1 (b) is a diagram showing the second reticle to be inspected, showing a state in which the common foreign matter 2a is attached to the reticle 2 to be inspected, and the left end of the reticle 2 to be inspected is the origin. , When the position of the common foreign matter 2a is displayed in coordinates (e, f)
Becomes

In such a case, these coordinates are read by the inspection device and stored in the storage device of the computer, and if the coordinates (a, b) and (e, f) are the same, the common foreign matter 1a is common. It is possible to determine that the foreign matter 2a is the same foreign matter, and it can be seen that the foreign matter 1b having the coordinates (c, d) has been removed by the second cleaning.

In the above embodiment, the coordinates of the foreign matter were read in the second inspection and compared with the coordinates of the first foreign matter, but the coordinates of the foreign matter were read in the first inspection in the second inspection. It is also possible to inspect the presence or absence of the foreign matter at the position of the coordinate, and to inspect whether the foreign matter has been removed or remains after the second cleaning.

[0016]

As is apparent from the above description, according to the present invention, it is possible to find an optimum cleaning method for removing foreign matters on the surface of a reticle / mask by improving the inspection method which is extremely simple. There are advantages, significant economic and
It is possible to provide a comparative inspection method for foreign matter on the surface of a reticle mask, which can be expected to improve reliability.

[Brief description of drawings]

FIG. 1 is a diagram showing an inspection object according to an embodiment of the present invention,

[Explanation of symbols]

 1 is a reticle to be inspected, 1a is a common foreign substance, 1b is a foreign substance, 2 is a reticle to be inspected, 2a is a common foreign substance,

Claims (1)

[Claims] 1. A step of storing the position of the foreign matter of the first inspection result of the foreign matter on the reticle / mask surface, and the step of storing the position of the foreign matter of the second inspection result of the foreign matter on the reticle / mask surface after recleaning. And a step of comparing the position of the first foreign matter with the position of the second foreign matter, the method for inspecting foreign matter on the surface of a reticle / mask.