JPS6323541B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to black defects that occur during the manufacturing process of semiconductor manufacturing masks such as photomasks and reticles used in semiconductor manufacturing processes, and white defects that occur during the same process. This is a mask defect repair completion detection method for detecting the completion of repair of remaining defects in an apparatus for repairing black defects caused by incomplete repair by film deposition using an ion beam.

[Conventional technology]

Conventionally, in the sputtering removal of the above-mentioned black defects using an ion beam, it has not been considered to monitor the completion of defect removal, and it has not been considered to monitor the completion of the removal of the defects. By determining the value of and knowing the ion beam irradiation time with a constant current value or the cumulative current value during ion beam irradiation, it is compared with the value of the ion beam irradiation amount and it is determined that defect removal is completed.

[Problem that the invention seeks to solve]

In the above conventional method, the ion beam is irradiated more than necessary, resulting in unnecessary irradiation time and a decrease in throughput. Furthermore, unnecessary ion beam irradiation causes sputtering and scratches on the substrate portion of the mask. This flaw is critical for photomasks. The border of the flawed area reflects light diffusely, which can have an adverse effect depending on the depth of the flaw.

The present invention is a method for solving the above-mentioned problems in repairing black defects using an ion beam defect repairing device for semiconductor manufacturing masks.

[Means for solving problems]

Secondary ions from the pattern-forming material emitted by ion beam irradiation to the black defect part of the mask and secondary ions from the substrate material with a different pattern are simultaneously monitored, and the detected amount of both secondary ions is measured. The ratio of the above is determined by a separate experiment so that the light or X-rays passing through the mask can be sufficiently transmitted,
Furthermore, the period from when secondary ions from the substrate material begin to be detected until secondary ions from the pattern forming material are no longer detected is a certain appropriate value at which damage to the substrate material by the ion beam is minimal. This is a means for detecting the end of mask defect correction at a certain point in time.

[Effect]

Secondary ions emitted from the pattern forming material as a residual defect by ion beam irradiation to the black defect part of the mask are detected by a detector dedicated to the secondary ions, and when the defect correction is near the end. The detected amount of secondary ions begins to decrease. At the same time, secondary ions emitted from the substrate material of the pattern begin to be detected by a detector dedicated to the secondary ions, and the detected amount begins to increase. When the ratio of the detected amounts of both secondary ions reaches a predetermined value that is preferable as the end of defect repair, the end of defect repair is detected.

〔Example〕

FIG. 1 shows a method for completing mask defect correction using the method according to the present invention.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a focused ion beam, which is scanned by a deflector (not shown) over black defects on a semiconductor manufacturing mask 2 to remove spatter. The secondary ions 3 emitted by the spatter are separated in mass by a sector magnet 4. Two different 2 emitted from the mass-separated pattern forming material and the substrate material of the pattern
The secondary ions 5 and 7 are detected by a first ion detector 6 and a second ion detector 8, respectively. The signals from both detectors are processed by the secondary ion detection signal processing circuit 9, where the ratio of the detected amounts of both secondary ions is calculated and compared with a preset ratio. When the same value is reached, the blanking electrode power supply and A signal is sent to the controller 10, which drives the power supply, applies a voltage to the blanking electrode 11, and increases the ion beam current 1.
is blocked by the slit 12, and the defect correction is completed.

〔Effect of the invention〕

As explained above, by using the method according to the present invention, unnecessary ion beam irradiation can be avoided and throughput can be improved. Furthermore, scratches on the substrate of the mask can be minimized, and in particular, adverse effects on the photomask can be minimized.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment using the mask defect correction completion method of the present invention. 1... Ion beam, 2... Mask for semiconductor manufacturing, 3... Secondary ions, 4... Sector magnet, 5... Secondary ions, 6... First ion detector, 7... Secondary ions, 8...Second ion detector, 9...Secondary ion detection signal processing circuit, 10...
...Blanking electrode power supply and control device, 11...
...Blanking electrode, 12...Slit.

Claims (1)

[Claims] 1. A method for repairing a black defect in a semiconductor manufacturing mask using an ion beam, in which secondary ions emitted by ion beam irradiation for the purpose of repairing the black defect are observed. A method for detecting completion of mask defect correction, comprising: confirming completion of black defect correction. 2. As the secondary ions, the completion of the black defect is confirmed by measuring the detected amount of secondary ions emitted from the pattern forming material on the mask and secondary ions emitted from the substrate material of the pattern. A method for detecting completion of mask defect correction according to claim 1. 3. The detection of the secondary ions involves simultaneously mass-separating two or more ion products using a sector magnet, and simultaneously separating and detecting the two or more ion products. Detection method.