60nm half pitch contact layer printing: exploring the limits at 1.35NA lithography

Joost Bekaert; Eric Hendrickx; Geert Vandenberghe

doi:10.1117/12.772596

7 March 2008 60nm half pitch contact layer printing: exploring the limits at 1.35NA lithography

Joost Bekaert, Eric Hendrickx, Geert Vandenberghe

Proceedings Volume 6924, Optical Microlithography XXI; 69243A (2008) https://doi.org/10.1117/12.772596
Event: SPIE Advanced Lithography, 2008, San Jose, California, United States

Abstract

The ever increasing NA to meet the stringent requirements on pitch and litho target does not come without a price. In particular for the printing of contact layers, the toll is taken in terms of decreased process latitudes and CD uniformity. Depending on the specific contact layer design, it has become increasingly important to choose the most adequate resolution enhancement technique. At the ultimate NA of 1.35, depth of focus through pitch has become a key factor, and values in the order of 100-120nm are the painful truth imposed by physics. In this paper, the attention goes to through-pitch contact imaging, with the attempt to achieve half pitches around 60nm. Thereby, the main focus lies on the relation between source shape and minimum achievable k₁. In addition, the pro's and con's of two options for throughpitch process latitude enhancement are considered. These options are firstly the effect of assist feature placement in combination with off-axis illumination, and secondly the application of the Focus Drilling technique. Finally, the different contributions to contact hole CD non-uniformity are addressed.

Citation Download Citation

Joost Bekaert, Eric Hendrickx, and Geert Vandenberghe "60nm half pitch contact layer printing: exploring the limits at 1.35NA lithography", Proc. SPIE 6924, Optical Microlithography XXI, 69243A (7 March 2008); https://doi.org/10.1117/12.772596

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