[109466] in Cypherpunks
Re: About Alpha radiation...
daemon@ATHENA.MIT.EDU (Tim Griffiths)
Thu Mar 25 03:16:58 1999
Date: Thu, 25 Mar 1999 09:55:03 +0200
From: Tim Griffiths <griffith@wis.weizmann.ac.il>
To: cypherpunks@toad.com
Reply-To: Tim Griffiths <griffith@wis.weizmann.ac.il>
> Jean-Francois Avon wrote:
>
> Alpha from other sources might be another story, but still, the
> slightest material is enough to shield from alphas...
Alpha's from radiative decay, yes. Alpha's from space can have energies
at least two orders of magnitude higher. Don't forget as well that an
Alpha doesn't need to penetrate to the conducting layer (2DEG) in a
FET transistor to cause damage - charging effect by the secondary
electrons are enough to stop it working.
On the other hand, I agree with you that for a chip in a case, in a box,
under a desk, in a room then it should be safe.
Tim May wrote:
> Alpha particles are a known problem with silicon chips. And I ought
> to know.
So should I, but I don't..:) Do you have any more details, i.e. Alpha's
from what source/of what energy, under what conditions?
Tim G
--
Tim Griffiths griffith@wis.weizmann.ac.il
Center for Submicron Research http://tim01.ex.ac.uk
Weizmann Institute of Science (972)-8-934-2736
Rehovot 76100 Israel
'Do not attempt to oppose the Way of the Universe.
But first make sure you know the Way of the Universe'.
- Musashi
