OCD enhanced: implementation and validation of spectral interferometry for nanosheet inner spacer indentation

D. Schmidt; C. Durfee; S. Pancharatnam; M. Medikonda; A. Greene; J. Frougier; A. Cepler; G. Belkin; D. Shafir; R. Koret; R. Shtainman; I. Turovets; S. Wolfling

doi:10.1117/12.2582364

5 March 2021 OCD enhanced: implementation and validation of spectral interferometry for nanosheet inner spacer indentation

D. Schmidt, C. Durfee, S. Pancharatnam, M. Medikonda, A. Greene, J. Frougier, A. Cepler, G. Belkin, D. Shafir, R. Koret, R. Shtainman, I. Turovets, S. Wolfling

Author Affiliations +

Proceedings Volume 11611, Metrology, Inspection, and Process Control for Semiconductor Manufacturing XXXV; 116111U (2021) https://doi.org/10.1117/12.2582364
Event: SPIE Advanced Lithography, 2021, Online Only

Abstract

In this work, the novel enhancement to multichannel scatterometry data collection, Spectral Interferometry, is introduced and discussed. The Spectral Interferometry technology adds unique spectroscopic data by providing absolute phase information. This enhances metrology performance by improving sensitivity to weak target parameters and reducing parameter correlations. Spectral Interferometry enhanced OCD capabilities were demonstrated for one of the most critical and challenging applications of gate-all-around nanosheet device manufacturing: lateral etching of SiGe nanosheet layers to form inner spacer indentations. The inner spacer protects the channel from the source/drain regions during channel release and defines the gate length of the device. Additionally, a methodology is presented, which enables reliable and reproducible manufacturing of reference samples with engineered sheet-specific indent variations at nominal etch processing. Such samples are ideal candidates for evaluating metrology solutions with minimal destructive reference metrology costs. Two strategies, single parameter and sheet-specific indent monitoring are discussed, and it was found that the addition of spectroscopic information acquired by Spectral Interferometry improved both optical metrology solutions. In addition to improving the match to references for single parameter indent monitoring, excellent sheet-specific indent results can be delivered

Conference Presentation

Citation Download Citation

D. Schmidt, C. Durfee, S. Pancharatnam, M. Medikonda, A. Greene, J. Frougier, A. Cepler, G. Belkin, D. Shafir, R. Koret, R. Shtainman, I. Turovets, and S. Wolfling "OCD enhanced: implementation and validation of spectral interferometry for nanosheet inner spacer indentation", Proc. SPIE 11611, Metrology, Inspection, and Process Control for Semiconductor Manufacturing XXXV, 116111U (5 March 2021); https://doi.org/10.1117/12.2582364

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