[109493] in Cypherpunks
Re: About Alpha radiation...
daemon@ATHENA.MIT.EDU (Marty Levy)
Fri Mar 26 02:59:15 1999
Date: Fri, 26 Mar 1999 07:31:52 +0000
From: "Marty Levy" <rwww60@email.sps.mot.com>
To: gw-terisa <gw@terisa.com>, Jean-Francois Avon <jf_avon@citenet.net>,
Cypherpunks <cypherpunks@toad.com>
Reply-To: "Marty Levy" <rwww60@email.sps.mot.com>
Alpha particles are a major source of bit disturb errors in terrestrial-usage
semiconductors. The primary source is the packaging used to encapsulate the
chip. Low alpha mold compounds can reduce this in plastic encapsulated
devices, but cannot eliminate it. The presence of alpha generators in ceramic
packages is even more difficult to control. Trench-style DRAM cells are less
susceptible to alpha upsets due to the protection afforded by the silicon
substrate. Multiple levels of interconnect also improve the situation, but of
course shrinking device geometries make it worse.
There is a great deal of literature on this subject for anyone who really wants
to know. I would start with IEDM, IRPS (International Reliability Physics
Symposium) and various IEEE societies dealing with solid-state devices.
