Validation of the Variable Depth Bragg Peak Method for Single-Event Latchup Testing Using Ion Beam Characterization

The Variable Depth Bragg Peak method has been investigated for single event latchup testing by comparing latchup cross sections for heavy ions at low and high energies and by pulse height analysis. Results show that, unlike for an SOI device previously tested, where the charge collection depth is very small (70 nm), the comparison is not straightforward for latchup because of the large charge collection volumes involved. The variation in LET with depth for lower-energy ions greatly affects the comparison, but, if a charge collection depth of 50 μm is assumed and the LET is averaged over that distance, the comparison improves significantly.