Calibration and matching of floating gate devices

We measure the matching characteristics of floating gate MOSFET devices. Arrays of ten FG PFET devices were fabricated on two different runs of the same process. Matching characteristics were measured: (1) direct from the foundry, (2) after Fowler-Nordheim tunneling, (3) after self-limiting PFET hot-electron injection, and (4) after UV exposure. We also found significant threshold voltage drift in long-term memory tests.