Inline metrology of high aspect ratio hole tilt using small-angle x-ray scattering

Peter Gin; Matthew Wormington; Alexander Brady; Kevin Matney; Jin Zhang; Osman Sorkhabi

doi:10.1117/12.2614312

26 May 2022 Inline metrology of high aspect ratio hole tilt using small-angle x-ray scattering

Peter Gin, Matthew Wormington, Alexander Brady, Kevin Matney, Jin Zhang, Osman Sorkhabi

Proceedings Volume 12053, Metrology, Inspection, and Process Control XXXVI; 1205312 (2022) https://doi.org/10.1117/12.2614312
Event: SPIE Advanced Lithography + Patterning, 2022, San Jose, California, United States

Abstract

High aspect ratio (HAR) structures found in 3D NAND memory structures have unique process control challenges. The etch used to fabricate channel holes several microns deep with aspect ratios beyond 50:1 is a particularly challenging process that requires exquisitely accurate and precise control. It is critical to carefully analyze multiple aspects of the etch process, such as hole profile, tilt, uniformity, and quality both during development and production. X-ray critical dimension (XCD) metrology, which is also known as critical dimension small-angle X-ray scattering (CD-SAXS), is a powerful technique that can provide valuable insights on the arrangement, shape, and size of periodic arrays of HAR features. XCD is capable of fast, non-destructive measurements in the cell-area of production wafers, making XCD ideal for in-line metrology. Through several case studies, we will show that XCD can be used to accurately and precisely determine key properties of holes etched into hard mask and multilayer oxide / nitride (ON) film stacks. We show that the measurement of hole tilt can be achieved without the aid of a structural model using a fast tilt methodology that provides sub-nanometer precision. Measurements were performed across several production wafers to determine the etch uniformity and quality. Particular attention was given at the edge of the wafers to account for large variation observed.

Conference Presentation

Citation Download Citation

Peter Gin, Matthew Wormington, Alexander Brady, Kevin Matney, Jin Zhang, and Osman Sorkhabi "Inline metrology of high aspect ratio hole tilt using small-angle x-ray scattering", Proc. SPIE 12053, Metrology, Inspection, and Process Control XXXVI, 1205312 (26 May 2022); https://doi.org/10.1117/12.2614312

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