Comparison and uncertainties of standards for critical dimension atomic force microscope tip width calibration

Ronald Dixson; Ndubuisi G. Orji

doi:10.1117/12.714032

5 April 2007 Comparison and uncertainties of standards for critical dimension atomic force microscope tip width calibration

Ronald Dixson, Ndubuisi G. Orji

Author Affiliations +

Proceedings Volume 6518, Metrology, Inspection, and Process Control for Microlithography XXI; 651816 (2007) https://doi.org/10.1117/12.714032
Event: SPIE Advanced Lithography, 2007, San Jose, California, United States

Abstract

Since the advent of critical-dimension atomic force microscopes (CD-AFMs) in the 90s, these tools have enjoyed growing acceptance in semiconductor manufacturing both for process development and to support in-line critical dimension (CD) metrology. The most common application of CD-AFMs has been to support critical-dimension scanning electron microscope (CD-SEM) and scatterometer metrology as a reference for tool matching or as a nondestructive alternative to transmission electron microscopy (TEM) and scanning electron microscopy (SEM) cross sections. For many years, CD-AFM users typically developed in-house reference standards for tip width calibration - often based on SEM or TEM cross sections. But the uncertainty of such standards was often large or unknown. Tip characterizer samples - which used a sharp ridge to calibrate the tip width - are commercially available. However, scanning such samples can result in tip damage, and the uncertainty of tip calibrations based on this method is at least 5 nm. In 2004, NIST, SEMATECH, and VLSI Standards collaborated on the development and release of single crystal critical dimension reference materials (SCCDRMs) to SEMATECH member companies. These specimens, which are fabricated using a lattice-plane-selective etch on (110) silicon, exhibit near vertical sidewalls and high uniformity and can be used to calibrate CD-AFM tip width to approximately 1 nm standard uncertainty (k = 1). Also in 2004, commercial critical dimension standards (CCDS) were introduced. Using CD-AFM instruments at both NIST and SEMATECH, we have performed a comparison of nominal 45 nm and 70 nm CCDS specimens with the SCCDRM calibration. Our observations show that these two independently performed calibrations are in agreement.

Citation Download Citation

Ronald Dixson and Ndubuisi G. Orji "Comparison and uncertainties of standards for critical dimension atomic force microscope tip width calibration", Proc. SPIE 6518, Metrology, Inspection, and Process Control for Microlithography XXI, 651816 (5 April 2007); https://doi.org/10.1117/12.714032

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