What is the concern with an alpha particle?
Todays smaller semiconductor design geometries and charge sensitive circuitry can be adversely effected by energetic alpha particles. An alpha particle can cause what is known as a “Single Event Upset” or “Soft Error Upset” or “SEU”. A 5.3 MeV Po210 alpha particle (a daughter in the Uranium decay family of lead) will travel approximately 4 centimeters (1.57 inches) in air at sea level (see Range of Alpha Particles in Air). High energy alpha particles can penetrate silicon devices to a depth of approximately 25 microns. Along the track of the alpha particle, electrons are dislodged from the crystal lattice sites. If the abundance of electrons are collected by the empty storage well, then the cell can flip from 1 to a 0 logic state generating a soft error in the device. While usually no permanent damage occurs, the error can never be reproduced by random test pattern generation, potentially causing unecessary design changes, where a change in material components might be more in line. On
