Single-event testing using heavy ion irradiation through thick layers of material

Upset results for backside irradiated PowerPC750s (thin epi) and SDRAMs (deep charge collection from diffusion) illustrate the validity of single event test data when irradiating through a layer of silicon substrate. However, heavy-ion LET assignments require accurate material and thickness determination. Taking irradiating through materials further, the Texas A&M cyclotron uses adjustable degraders to offer a continuous range of heavy ion LETs as well as an optional in-air test fixture.