Incident angle change caused by different off-axis illumination in extreme ultraviolet lithography

Eun-Jin Kim; Jee-Hye You; Seong-Sue Kim; Han-Ku Cho; Ilsin An; Hye-Keun Oh

doi:10.1117/12.814031

18 March 2009 Incident angle change caused by different off-axis illumination in extreme ultraviolet lithography

Eun-Jin Kim, Jee-Hye You, Seong-Sue Kim, Han-Ku Cho, Ilsin An, Hye-Keun Oh

Proceedings Volume 7271, Alternative Lithographic Technologies; 727143 (2009) https://doi.org/10.1117/12.814031
Event: SPIE Advanced Lithography, 2009, San Jose, California, United States

Abstract

Extreme ultraviolet lithography (EUVL) is believed to be possible patterning technology which can make 22 nm and below. EUV uses a reflective mask so that the mask is shined with the oblique incident light. Thus, the study of incident angle effect is very important. Currently, 6 degree oblique incidence is main stream, but 5 degree incident angle is also studied for 0.25 NA. Incident angles larger than 6 degree are also considered for larger NA. This incident angle will affect many things, eventually to the line width. Shadow effect also strongly depends on the incident angle. This shadow effect in the EUVL mask is an important factor that decreases the contrast of the aerial image and causes a directional problem, thus it will make line width variation. The off-axis illumination (OAI) will be used with conventional on-axis illumination to make much smaller patterns. This OAI will split the main beam and change the incident angle. We found that if the incident angle increased with higher degree of coherence, the aerial image went worse. The CD difference between the horizontal and the vertical pattern is also dependent on the degree of coherence even though it is small.

Citation Download Citation

Eun-Jin Kim, Jee-Hye You, Seong-Sue Kim, Han-Ku Cho, Ilsin An, and Hye-Keun Oh "Incident angle change caused by different off-axis illumination in extreme ultraviolet lithography", Proc. SPIE 7271, Alternative Lithographic Technologies, 727143 (18 March 2009); https://doi.org/10.1117/12.814031

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