Impact of EUVL mask surface roughness on an actinic blank inspection image and a wafer image

Takeshi Yamane; Tsuneo Terasawa

doi:10.1117/12.964965

8 November 2012 Impact of EUVL mask surface roughness on an actinic blank inspection image and a wafer image

Takeshi Yamane, Tsuneo Terasawa

Proceedings Volume 8522, Photomask Technology 2012; 85220H (2012) https://doi.org/10.1117/12.964965
Event: SPIE Photomask Technology, 2012, Monterey, California, United States

Abstract

An impact of EUVL mask surface roughness on actinic inspection was studied. The background level (BGL) of an actinic inspection image is caused by the light scattered from the mask blank surface roughness. The BGL is found to be proportional to the square of the mask surface roughness measured by AFM. By using this proportionality coefficient, a global distribution of the surface roughness can be obtained at the same time while inspection a mask. On the other hand, any local variation of BGL indicates variation of the mask surface roughness at each pixel. Assuming that the roughness at a center pixel is 0.15 nm rms (SEMI standard specification) and those at the surrounding pixels are 0.1 nm rms, the signal intensity at the center pixel is found to be approximately the same as that of a 1.2 nm-high and 40 nm-wide programmed defect. In that case, CD error on a wafer image due to the reflectivity loss by the roughness is found to be not critical. This means that the local roughness should be less than 0.15 nm rms, and that the inspection system can detect such a local variation of the roughness with 100 % probability.

Citation Download Citation

Takeshi Yamane and Tsuneo Terasawa "Impact of EUVL mask surface roughness on an actinic blank inspection image and a wafer image", Proc. SPIE 8522, Photomask Technology 2012, 85220H (8 November 2012); https://doi.org/10.1117/12.964965

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