Impact of Technology Scaling on SRAM Soft Error Rates

Soft error rates for triple-well and dual-well SRAM circuits over the past few technology generations have shown an apparently inconsistent behavior. This work compares the heavy-ion induced upset cross-section in 28, 40, and 65 nm dual- and triple-well SRAMs over a wide range of particle LETs. Similar experiments on identical layouts for all these technologies along with 3-D TCAD simulations are used to identify the dominant mechanisms for single-event upsets. Results demonstrate that the well-engineering strongly influence the single-event response of SRAMs. Layout also plays an important role and the combined effects of well-engineering and layout determine the soft-error sensitivity of SRAMs fabricated in advanced technology nodes.