A proposed image intensity expressing local irradiance

Shuji Nakao; Itaru Kanai; Shinroku Maejima; Mitsuru Okuno; Naohisa Tamada; Junjiro Sakai; Akira Imai; Tetsuro Hanawa; Kazuyuki Suko

doi:10.1117/12.812203

16 March 2009 A proposed image intensity expressing local irradiance

Shuji Nakao, Itaru Kanai, Shinroku Maejima, Mitsuru Okuno, Naohisa Tamada, Junjiro Sakai, Akira Imai, Tetsuro Hanawa, Kazuyuki Suko

Author Affiliations +

Proceedings Volume 7274, Optical Microlithography XXII; 72742Z (2009) https://doi.org/10.1117/12.812203
Event: SPIE Advanced Lithography, 2009, San Jose, California, United States

Abstract

Authors would like to raise a discussion about image intensity for surface exposure, off course, including optical lithography. As a springboard for the discussion, a novel definition of image "intensity", which expresses local irradiance associating with optical image, is proposed. An experimental result, which strongly supports the proposed "intensity", is also obtained. To describe exposure dose, energy input for unit area with unit of J/m2, is applied as a measure of this amount. A phrase of "dose-to-clear" is frequently used to show sensitivity of a resist film. In contrast, conventional image intensity of optical image is defined as a value, which is proportional to volume energy density associating with image. The value is described with unit of J/m3. In some papers, it is mentioned that number of photochemical reactions in resist film is proportional to the volume energy density of electromagnetic filed, that is, conventional image intensity. It seems unclear what physical value is proper measure of surface exposure. We considered that, in optical lithography, energy flux is proper value to indicate degree of resist exposure from experience and some former reports. Then, a novel image "intensity", which expresses local irradiance associating with optical image, is proposed. The proposed image "intensity" is proportional to surface normal component of Poynting vector.

Citation Download Citation

Shuji Nakao, Itaru Kanai, Shinroku Maejima, Mitsuru Okuno, Naohisa Tamada, Junjiro Sakai, Akira Imai, Tetsuro Hanawa, and Kazuyuki Suko "A proposed image intensity expressing local irradiance", Proc. SPIE 7274, Optical Microlithography XXII, 72742Z (16 March 2009); https://doi.org/10.1117/12.812203

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

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
10 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Polarization

Photomasks

Electromagnetism

Diffraction

Image filtering

Optical lithography

Magnetism

Show All Keywords

Keywords/Phrases

Search In:

Publication Years