Study of resist outgassing by F2 laser irradiation

Yasuo Itakura; Youichi Kawasa; Akira Sumitani; Seiichi Ishikawa; Shigeo Irie; Toshiro Itani

doi:10.1117/12.485087

12 June 2003 Study of resist outgassing by F₂ laser irradiation

Yasuo Itakura, Youichi Kawasa, Akira Sumitani, Seiichi Ishikawa, Shigeo Irie, Toshiro Itani

Proceedings Volume 5039, Advances in Resist Technology and Processing XX; (2003) https://doi.org/10.1117/12.485087
Event: Microlithography 2003, 2003, Santa Clara, California, United States

Abstract

F₂ laser lithography at 157nm is the most promising candidate of post-ArF excimer laser lithography. A major concern, however, is the deterioration of 157nm optics due to contamination under F₂ laser irradiation. An evaluation of outgassed products of 157nm resist and their effect on optical materials and is therefore indispensable for F₂ laser lithography. Semiconductor Leading Edge Technologies Inc. (Selete) and Komatsu Ltd. designed and constructed a resist outgassing evaluation system in order to develop exposure tools and resists for 157nm lithography. The system determines the negative effects of outgassing resist contaminants on the transmittance of optical materials under F₂ laser irradiation. The system has two units. One unit collects resist outgas and analyzes sampled gas in a gas chromatograph mass spectrometer (GC-MS). The other unit is a resist outgassing adhesion unit, which measures the transmittance change of optical materials due to contamination adhesion in real-time. Our analysis showed that most outgassed products were from the resist protecting groups and photo acid generators (PAG) including small hydrocarbons like isobutene, benzene derivatives and dimethoxymethane. After irradiating a 157nm lithography resist with a total dose of 30J/cm² the transmittance of a calcium fluoride (CaF₂) substrate decreased from initially 90% to 85%. This was due to adhesion contamination as x-ray photoelectron spectroscopy (XPS) analysis showed an organic contamination deposition of over 5nm thickness on the CaF₂ substrate.

Citation Download Citation

Yasuo Itakura, Youichi Kawasa, Akira Sumitani, Seiichi Ishikawa, Shigeo Irie, and Toshiro Itani "Study of resist outgassing by F₂ laser irradiation", Proc. SPIE 5039, Advances in Resist Technology and Processing XX, (12 June 2003); https://doi.org/10.1117/12.485087

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