Single Event Effect Induced Multiple-Cell Upsets in a Commercial 90 nm CMOS Digital Technology

Heavy ion and proton single event upset (SEU) testing has been conducted on static random access memories (SRAM) from two commercial 90 nm technology nodes custom manufactured on epitaxial substrates. The SRAMs were from the same manufacturer; however, the SRAMs utilized two different 90 nm technology process nodes. One 90 nm node was for low power and the other was for performance. Both heavy ion and proton test results indicated multiple-cell upsets. Latchup was not observed in this low voltage epitaxial substrate sample testing. Heavy ion SEU data indicated that above a linear energy transfer of 7 (MeV-cm²)/mg the multiple-cell upsets outnumber the single-cell upsets. Charge sharing is considered the mechanism for multiple-cell upsets.