
EUV Lithography's Prospects Are Brightening - jcr
http://spectrum.ieee.org/tech-talk/semiconductors/devices/euv-lithography-is-brightening-up
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Pietertje
This is a difficult one, I'm really excited about lithography and want to
share my knowledge but since I'm working at one of those firms (dislcaimer
here) I can share little...

So, let's stay safe and share some public knowledge:

1) The article mentions source power being a major factor and a huge
improvement has been the addition of the prepulse (pancake). Here a great
video showing how this concept works:
[https://www.youtube.com/watch?v=bRbHDtPbHe0](https://www.youtube.com/watch?v=bRbHDtPbHe0)

2) Short, beginners level, introduction how the EUV source works (note: this
movie is made before ASML tookover Cymer, so some history here):
[https://www.cymer.com/euv-lithography/how-an-euv-light-
sourc...](https://www.cymer.com/euv-lithography/how-an-euv-light-source-works)

3) Chris Mack's coverage of the last SPIE conferences give a nice summary of
the field:
[http://www.lithoguru.com/scientist/conferences.html](http://www.lithoguru.com/scientist/conferences.html)
Note that Mack is an EUV-sceptic, his views on EUV are not commonly shared.

------
ars
I wonder how they intend to expose wafers to this. As far as I know there are
no materials that are transparent to EUV.

Even air is opaque, so you have to work in a vacuum.

So I'm wondering how they will vaporize bits of tin and not have the tin
contaminate the wafers.

~~~
djmdjm
There are a few EUV transparent materials for light source windows, including
silicon and zirconium. See [http://www.luxel.com/wp-
content/uploads/2010/04/EUVL-Paper.p...](http://www.luxel.com/wp-
content/uploads/2010/04/EUVL-Paper.pdf)

There are other concerns wrt contamination though, e.g. masks degrading in the
EUV radiation and emitting contaminants that end up on the wafer. This is more
likely to happen at higher power levels.

These and other concerns are discussed at Chris Mack's website
[http://life.lithoguru.com/](http://life.lithoguru.com/) (he is quoted in the
linked article). His series of posts on the SPIE Advanced Lithography
Symposium 2016 is particularly interesting and seems to be the basis of most
of the more-popular press articles on EUV in the last week.

~~~
ars
Very interesting link. I at first wondered how such a thin film would be
strong enough, then realized they intend to have both sides of the window in
vacuum so there is no pressure differential, and no need for strength. (Which
should have been obvious since air is opaque.)

