Abstract

In deep ultraviolet lithographic tools, precise measurement of excimer laser pulse energy is essential. However, system noise of the energy sensor, which is used to monitor the laser pulse during exposure dose control, complicate pulse energy measurement. To improve measurement precision, a specific finite impulse response filter is proposed for signal denoising. Particularly, the convolution kernel of the specific finite impulse response filter is derived from the nonlinear fitting of the energy sensor output. Experimental results show that the measurement precision of the energy sensor improves 2–3 times with the specific finite impulse response filter. To verify the effectiveness of the energy sensor, it is used for transmittance measurement; the measurement result of a Corning 7980 witness sample is consistent with that measured by a commercial ultraviolet spectrophotometer and the measurement accuracy is 0.11% (k=2).

© 2017 Optical Society of America

PDF Article

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription