Ellipsometric critical dimension metrology employing mid-infrared wavelengths for high-aspect-ratio channel hole module etch processes

G. Andrew Antonelli; Nick Keller; Troy Ribaudo; Franklin J. Wong; Wenmei Ming; Hepeng Ding; Zhuo Chen; Ross Grynko; Ahmad Fumani; Zhuan Liu; Sadao Takabayashi; John Hauck; Joshua Frederick; Dan Engelhard; Bo Hui Ng; Biow Hiem Ong; Luey Chwan Liong

doi:10.1117/12.2583786

22 February 2021 Ellipsometric critical dimension metrology employing mid-infrared wavelengths for high-aspect-ratio channel hole module etch processes

G. Andrew Antonelli, Nick Keller, Troy Ribaudo, Franklin J. Wong, Wenmei Ming, Hepeng Ding, Zhuo Chen, Ross Grynko, Ahmad Fumani, Zhuan Liu, Sadao Takabayashi, John Hauck, Joshua Frederick, Dan Engelhard, Bo Hui Ng, Biow Hiem Ong, Luey Chwan Liong

Author Affiliations +

Proceedings Volume 11611, Metrology, Inspection, and Process Control for Semiconductor Manufacturing XXXV; 116111O (2021) https://doi.org/10.1117/12.2583786
Event: SPIE Advanced Lithography, 2021, Online Only

Abstract

A novel mid-infrared critical dimension (IRCD) metrology has been developed on a platform suitable for fab production. Compared to traditional optical critical dimension (OCD) technology based on ultraviolet, visible, and near-IR light, the IRCD system exploits unique optical properties of common semiconductor fab materials in the mid-infrared to enable accurate measurements of high-aspect-ratio etched features. In this paper, we will show two examples of critical dry etch steps in 3D NAND channel formation module of an advanced node that require nondestructive process control: (1) channel hole active area etch and (2) amorphous carbon hardmask etch. In the first example, we take advantage of the absorption bands of silicon dioxide and silicon nitride to get accurate CD measurements at different depths, resulting in high-fidelity z-profile metrology of the channel – key to guiding process development and accelerated learning for 3D NAND device manufacturing. In the second example, the most common amorphous carbon hardmask materials for advanced 3D NAND nodes are opaque in the traditional OCD wavelength range; however, in the mid-infrared, there is light penetration and hence spectral sensitivity to dimensional parameters including sub-surface features. We show successful detection of intentional process skews and as well accurate bottom CD measurements of the hardmask.

Conference Presentation

Citation Download Citation

G. Andrew Antonelli, Nick Keller, Troy Ribaudo, Franklin J. Wong, Wenmei Ming, Hepeng Ding, Zhuo Chen, Ross Grynko, Ahmad Fumani, Zhuan Liu, Sadao Takabayashi, John Hauck, Joshua Frederick, Dan Engelhard, Bo Hui Ng, Biow Hiem Ong, and Luey Chwan Liong "Ellipsometric critical dimension metrology employing mid-infrared wavelengths for high-aspect-ratio channel hole module etch processes", Proc. SPIE 11611, Metrology, Inspection, and Process Control for Semiconductor Manufacturing XXXV, 116111O (22 February 2021); https://doi.org/10.1117/12.2583786

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