Interferometer for phase measurements in phase-shift masks

Derek B. Dove; T. C. Chieu; Amalkumar P. Ghosh

doi:10.1117/12.142132

26 March 1993 Interferometer for phase measurements in phase-shift masks

Derek B. Dove, T. C. Chieu, Amalkumar P. Ghosh

Proceedings Volume 1809, 12th Annual BACUS Symposium on Photomask Technology and Management; (1993) https://doi.org/10.1117/12.142132
Event: Photomask Technology, 1992, Sunnyville, CA, United States

Abstract

The etch depth of phase shift masks is typically measured by means of profilometry and the expected phase shift is calculated from a knowledge of the refractive index at the lithographic wavelength of interest. In the case of masks utilizing deposited films the index may differ from values for bulk materials and commonly varies to some degree with method of deposition. The interferometer offers a method for the measurement of phase directly and, hence, for a means to obtain refractive index values for phase shift films on quartz blank substrates. Arrangements are described for direct phase measurements using visible, 632.8 nm, and UV, 257 nm, radiation.

Citation Download Citation

Derek B. Dove, T. C. Chieu, and Amalkumar P. Ghosh "Interferometer for phase measurements in phase-shift masks", Proc. SPIE 1809, 12th Annual BACUS Symposium on Photomask Technology and Management, (26 March 1993); https://doi.org/10.1117/12.142132

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available