Line roughness formation during plasma etch: mechanism and reduction

Lingkuan Meng; Xiaobin He; Chunlong Li; Junfeng Li; Chao Zhao; Jiang Yan

doi:10.1117/12.2046327

28 March 2014 Line roughness formation during plasma etch: mechanism and reduction

Lingkuan Meng, Xiaobin He, Chunlong Li, Junfeng Li, Chao Zhao, Jiang Yan

Proceedings Volume 9054, Advanced Etch Technology for Nanopatterning III; 90540D (2014) https://doi.org/10.1117/12.2046327
Event: SPIE Advanced Lithography, 2014, San Jose, California, United States

Abstract

In this work, we have investigated the evolution of line roughness from e-beam lithography to final gate patterning based on conventional SiO₂/Si₃N₄/SiO₂ (ONO) hard mask using a Capacitively Coupled Plasma (CCP) etcher. A severe roughness was observed on gate patterning line when PR patterns were directly transferred into ONO hard mask even if a high etch selectivity of ONO hard mask to PR was used by CF₄/CH₂F₂/Ar plasma. The formation mechanisms of line roughness were presented by a) effect of decomposed oxygen radical from bulk SiO₂ by ion bombardment, b) rough surface morphology of poly-silicon accelerates etch of both hard mask and PR sidewalls by reflected ion. It is found that a combination of a capping layer and α-Si gate can reduce strong dependence on PR mask and eliminate ion reflection effect from rough surface morphology. Our results show that gate pattern indicates a smooth line without deformation and final gate length of 29nm with Line Width Roughness of 3.5nm is achieved.

Citation Download Citation

Lingkuan Meng, Xiaobin He, Chunlong Li, Junfeng Li, Chao Zhao, and Jiang Yan "Line roughness formation during plasma etch: mechanism and reduction", Proc. SPIE 9054, Advanced Etch Technology for Nanopatterning III, 90540D (28 March 2014); https://doi.org/10.1117/12.2046327

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