March 4, 2011 — Gigaphoton released the latest developments in its EUV source program at this week’s SPIE Advanced Lithography conference. The company reported achieving a conversion efficiency (CE) of 3.3% with tin droplets <20µm in diameter (see figure) with its plasma-based laser produced plasma (LPP).

Click to Enlarge

Figure. Conversion efficiency vs. droplet size for tin plasma-based LPP EUV source. SOURCE: Gigaphoton

Click to EnlargeIn a podcast interview at the conference, Kenji Takahisa, manager in Gigaphoton’s management planning department, explained the physics behind the performance. Listen to the interview: Download (iPhone/iPod users) or Play Now

The key is the use of a short wavelength pre-pulse to irradiate the tin droplet. The small focus size of the pre-pulse laser penetrates the tin droplets, creating optimal conditions (i.e., an ideal "fine mist"). When the main laser irradiates the target droplet, a "perfect mist" is distributed in the focal plane of the CO2 main laser; the mist is transformed into vapor and is ionized. Any remaining debris, which is also ionized, can then be guided by a magnetic mitigation system to a tin "catcher" away from the collector mirror. Such mitigation ensures a longer life of the collector mirror. Takahisa also explains the experimental data shown in the figure in the interview.

More from SPIE Advanced Lithography 2011:

Subscribe to Solid State Technology/Advanced Packaging.

Follow Solid State Technology on via editors Pete Singer, and Debra Vogler,

Or join our Facebook group


Easily post a comment below using your Linkedin, Twitter, Google or Facebook account. Comments won't automatically be posted to your social media accounts unless you select to share.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>



Automated thickness measurement system speeds production
09/20/2017ACU-THIK is an automated thickness measurement tool incorporating dual contact probes for high accuracy inspection of semiconductor wafers....
3D-Micromac launches the second generation of its high-performance microcell OTF laser systems
04/17/2017The high-performance production solution for Laser Contact Opening (LCO) of PERC solar cells achieves a th...
ULVAC launches NA-1500 dry etching system for 600mm advanced packaging systems
03/24/2017ULVAC, Inc. is pleased to announce the NA-1500 dry etching system for 600mm advanced packaging substrates, providing for u...