JPS58178520A - Inspecting and correcting device of photomask - Google Patents

Abstract

PURPOSE:To eliminate the causes of errors due to erroneous optical axis to improve throughput in a series of processes by a method wherein the inspecting and correcting processes are constituted so that they may be performed within the same system. CONSTITUTION:An inspecting and correcting photomask 2 is placed on a sample plate 1 for alignment to scan a region divided from the mask 2 by means of the laser beams oscillated by a laser oscillator 3. Then the scanning signals corresponding to any inspected patterns are detected by the detectors 5-7. The scanning signals detected by the detectors 5-7 are respectively transmitted to a judging circuit 8 to be compared with the scanning signals based on the design data transmitted from a design data processing circuit 9 and discriminated if said signals are related to any defective pattern. Any position coordinates discriminated to be a defective pattern are memorized by a correcting coordinate memory circuit 10. Next, when the inspection of the mask 2 is finished, a correcting coordinate is read out of the memory circuit 10 to locate the sample plate 1 on the corrected position focusing the laser beams on the corrected position to correct the defective pattern.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] [The present invention relates to a method for detecting defective patterns existing in photomasks used in the production of semiconductor integrated circuits and for correcting defective patterns. Regarding the revision IEIII 4th place.

[Conventional i-technique and its problems]

Conventionally, when inspecting the pattern formed on the photomask and correcting the defective pattern portion existing on the photomask, the design data used when forming the pattern on the photomask during the photomask inspection fW & direct. The first scanning signal generated based on the design data is compared with the second scanning f signal obtained from the pattern to be inspected 7 formed based on the design data, and the position where the defective pattern exists is detected. After performing all mask inspections, the obtained defect location mmm is recorded on a recording medium, and during photomask correction W&, the defect location lt1! is recorded from the recording medium output from the inspection device. Inspect and repair the photomask by inputting i+s, moving the photomask to the IIA# position, aligning the focused light point of the laser beam to the defective pattern area, and removing the defective pattern area by focusing the laser beam. I was doing it.

However, when inspecting and repairing photomasks in such a process, there are errors caused by the difference in coordinate systems between the inspection equipment that inspects the photomask and the repair equipment that corrects the defective patterns of the photomask, and the differences between both systems. There are various error factors, such as errors caused by different light sources used for inspection and correction, and errors caused by different optical axes, and the fact that the photo Problems such as new defects caused by dirt and dust adhering to the mask, and the need for re-inspection as a backup after repairing defects in the photomask.As a result of one or more of the following problems, the time from photomask inspection to repair is shortened. [Objective of the Invention] In order to eliminate the above-mentioned problems, the present invention detects the eclipse (turn) of the photomask using a laser beam and compares it with design data. Provided is a photomask inspection and repair device having a pattern detection section that detects defective patterns and a pattern correction section that focuses a laser beam and irradiates the defective pattern to remove the defect and pattern. The purpose is to

[GG of the Invention] The present invention as described above is characterized in that the first scanning signal generated based on the design data used at the time of photomask production and the pattern to be inspected on the photomask formed based on the design data are transmitted with a laser beam. 20th run 11F obtained by scanning with!
The system stores the coordinates of the defect position to be detected by comparing and matching the numbers, and after the inspection is completed, the laser beam used for calibration is focused on the turn part of the photomask placed on the sample stage. [Effects of the Invention] According to the present invention, the process of irradiating and correcting most of the turn portions is performed on one 7 stem. Compared to the above process, there is no error in the coordinate system because the f-detection device and the correction device are performed within the same system. Since the same laser beam is used in the inspection process and repair process, there is no deviation of the optical axis. This has the effect of improving the throughput of a series of processes from inspection to correction. [Embodiments of the Invention] The present invention will be described in detail below with reference to the drawings.

The drawing is a system configuration diagram showing an embodiment of a photomask inspection and repair apparatus according to the present invention.

Place the mask 2 to be inspected and corrected on the sample stage 1, perform θ alignment of the photomask 2 with high accuracy, register the inspection area, and align the sample stage with the inspection start position of the photomask 2. The laser beam oscillated from the laser oscillation! 113 is driven by the laser scanning 4! 114 to scan the l value range (hereinafter referred to as F cell) divided into the X and Y matrix of the photomask 2 to form the pattern to be inspected. The corresponding scanning signal is sent to the first signal detection unit 5.51!2
Signal output section 6. $3 Obtained by the signal detection section 7. Here, the second signal detecting section 6 and the signal detecting section 7 detect whether the turn signal is formed of chromium (turn signal or dirt or dust attached to the photomask 2). The nine scanning signals obtained from the signal output section, which is a signal detection section for the
1.42, s3 scanning signal and the scanning signal generated based on the design data sent from the design data generation circuit 9 are compared to determine whether it is a defective pattern portion, and the defective pattern portion is determined. It is determined that the 9th position Ili coordinate is stored in the correction IE coordinate cycle i@10, and when the inspection for the l cell is #% completed, it is moved to the next cell. The interferometer 13 and the Y laser interferometer 14 measure the length, and the vS table is moved cell by cell for inspection. Then, when one photomask has been inspected for 4Srt, the corrected coordinates are drawn from the corrected coordinate memory l1i810, the sample stage is precisely aligned to that position, and the laser focusing system #1115 is used. The laser focusing mechanism 16 was driven to focus the laser beam on the repair position of the photomask 2, and the defect pattern of the photomask 2 could be repaired by focusing the laser beam.

It should be noted that the present invention is not limited to the above-mentioned actual m arrays, and can be implemented with various modifications without departing from the gist thereof.

[Brief explanation of the drawing]

The drawing is a diagram showing an example of the overall configuration of a photomask inspection and repair apparatus according to the present invention. 1...ttyN units 2...photomask, 3...
Laser oscillation device, 4 Laser scanning device, 5... No. 1111 detection section, 6... 42 signal detection section, 7-i
43 @ detection unit, 8- Defect 4'll constant 1! ! J
m. 9...Design data generation circuit, 10...Shu IE Zajiroki circuit, 11...X stage drive circuit, 12...Y stage drive circuit, 13...X laser interference needle,
14... Y laser interferometer, 15... Laser focusing circuit, 16... Laser Kento Organization, 17... Computer, 18... Magnetic tape storage, 19... Magnetic disk device , Add...Display with keyboard or buri/tar.

Claims (1)

[Scope of Claims] A signal detection unit that scans a pattern to be inspected formed on a photomask used for manufacturing semiconductor integrated circuits with a laser beam to obtain a scanning signal. I! obtained from design data used when forming a pattern on a photomask. a defect determination unit that compares and collates the scanning signal corresponding to the TI scanning area and the scanning signal obtained from the signal detection unit to obtain the coordinates where the defect exists, and holds the defect position obtained in the above as the corrected coordinates. Move the correction seat [marker section] and the correction coordinates beyond the correction seat keyaki memory section, align the sample stage with the photomask to that position with high precision, and move it to the defective pattern section of the photomask. The focused light spot of the laser beam is collected and the laser beam is irradiated.
7 Inspection and correction of a photomask 1 & installation characterized by having a pattern correction section for correcting a defective pattern portion of the photomask.