JPH0493837A - Foreign matter detector and manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To reduce integrated inspection times for foreign matter depending on its hard detection rate to be reduced in setting said times by enabling the repeating inspection times to be set optionally in accordance with the faces to be inspected. CONSTITUTION:The integrated inspection times of the foreign matter on a photomask and a pellicle can be optionally set from the viewpoint of the relation between the integrated inspection times and the detection rate. Any of the integrated inspection times of the face to be inspected, such as a photomask, pellicle, or a combination of both, can be optionally programmed, thus need for setting the integrated inspection times high for foreign matter hard to detect can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the inspection of foreign substances on the surfaces of photomasks and pellicles.

[Prior Art] In the conventional technology, a laser beam is irradiated from an oblique direction onto a surface to be inspected of a sample, and the surface to be inspected is scanned. A photomultiplier tube detects the incident light scattered by foreign matter adhering to the surface to be inspected, and the size of the foreign matter is determined from the intensity of the scattered light.

However, if the foreign object is minute, the intensity of the scattered light may not be sufficient to detect the foreign object. Therefore, foreign objects are detected with a high detection rate by repeatedly inspecting and integrating the data.

[Problems and Purposes to be Solved by the Invention The particle sizes of problematic foreign substances are different on the photomask and on the pellicle. This is because the Cr pattern surface of the photomask and the pellicle surface are separated by several millimeters due to the pellicle frame.
This is because foreign matter on the pellicle is difficult to transfer when it is on the r-plane. For this reason, the size of foreign particles that cause dazzling is 1 micron or more on a photomask, whereas it is several tens of microns on a pellicle.

However, in the conventional technology, since the number of integrations cannot be arbitrarily set for the inspection surface, the number of integrations must be set in accordance with the foreign matter on the photomask, where minute foreign matter is a problem.

For this reason, the pellicle surface is also inspected with the same integrated number of times, resulting in wasted inspections and at the same time increasing the inspection time.

Furthermore, the flow of the product must be stopped before the foreign matter inspection of the photomask and pellicle is completed, and the operating rate of the exposure apparatus also decreases.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and its purpose is to provide a foreign matter inspection apparatus that can appropriately set the number of integrations under inspection conditions for photomask and pellicle surfaces.

[Means for Solving the Problems] (1) The foreign matter inspection device of the present invention performs repeated inspection in order to increase the detection rate of foreign matter when inspecting foreign matter on the surface of a photomask and a pellicle attached to the photomask. The foreign matter inspection apparatus has a function of performing the above-mentioned tests and integrating the data, and is characterized in that the number of repeated inspections can be arbitrarily set for the inspection surface.

(2) A method for manufacturing a semiconductor device according to the present invention is characterized in that the foreign matter inspection apparatus according to claim 1 is used when inspecting foreign matter on the surface of a photomask and a pellicle attached to the photomask.

[Example 2] In the present invention, when inspecting for foreign objects, a laser beam is irradiated obliquely onto the surface of the sample to be inspected, and the surface to be inspected is scanned. The size of the foreign object is determined by the intensity of the scattered light detected by a multiplier tube, and the method of distinguishing between the foreign object and the Cr pattern on the photomask is based on the reflected wave from the Cr pattern when irradiated with a polarized laser beam. Since the vibration plane (electric field vector) is rotated by 90 degrees, the reflected waves rotated by 90 degrees are removed by a filter, and the foreign object detection rate is improved in a foreign object inspection device that receives and identifies only the reflected waves from foreign objects. When performing repeated inspections and integrating data in order to increase the number of foreign particles, it is important to check the relationship between the detection rate and the number of accumulations of foreign particles on the photomask and foreign particles on the pellicle shown in Figure 2. In order to be able to set the number of times arbitrarily, regardless of whether the inspection surface is selected as a photomask surface, a pellicle surface, or a combination of a photomask and a pellicle surface, The program allows you to arbitrarily set the number of integrations on the pellicle surface.

As described above, by changing the program, it is possible to set an appropriate number of integrations for the photomask and pellicle surface, and the inspection time can be reduced by 12 minutes compared to the conventional technology, as shown in Figure 1. Ta.

This time, the present invention was explained using one embodiment, but when focusing on the combination of the inspection surface and foreign matter, it is possible to inspect not only the foreign matter of the photomask and the pellicle attached to the photomask, but also the inspection of the pellicle attached to the photomask. It can also be fully applied to foreign matter inspection on the Cr patterned surface and glass surface of a photomask.

Furthermore, the present invention has sufficient effects on devices other than semiconductor devices as long as it inspects photomasks and pellicles attached to photomasks for foreign substances.

[Effects of the Invention] As described above, according to the present invention, (1) When inspecting foreign matter on the surface of a photomask and a pellicle attached to the photomask, in order to increase the detection rate of foreign matter, repeated inspections are performed and data are collected. In a foreign substance inspection device having a function of integrating the number of times, the number of repeated inspections can be arbitrarily set for the inspection surface.

The product flows smoothly even during the optical process.

(2) The foreign matter inspection apparatus according to claim 1 is used when inspecting foreign matter on the surface of a photomask and a pellicle attached to the photomask.

This makes it possible to appropriately set the inspection conditions for the inspection surface, so it is no longer necessary to set the number of integrations to a high value in accordance with foreign substances with a low detection rate.

Therefore, unnecessary repetition of inspections is avoided, which has the effect of shortening inspection time and improving throughput.

In addition, by shortening the inspection time, the next exposure can be

[Brief explanation of drawings]

FIG. 1 is a diagram showing the inspection time in the present invention and the conventional technology. Figure 2 shows the number of integrations and the detection rate for foreign particles on the photomask surface and the pellicle surface. that's all

Claims (2)

[Claims] (1) When inspecting foreign particles on the surface of a photomask and a pellicle attached to the photomask, a foreign particle inspection device has a function of repeatedly inspecting and accumulating data in order to increase the detection rate of the foreign particles. A foreign matter inspection device characterized in that the number of times of the repeated inspection can be arbitrarily set for the inspection surface. (2) A method for manufacturing a semiconductor device, characterized in that the foreign matter inspection apparatus according to claim 1 is used when inspecting foreign matter on the surface of a photomask and a pellicle attached to the photomask.