Non-volatile memory cells based on ZnxCd1−xS ferroelectric Schottky diodes

Ferroelectric Schottky diodes were fabricated with n-type Zn0.4Cd0.6S. These devices show promising nonvolatile memory properties and the integration into complementary metal-oxide-semiconductor (CMOS) circuits seems feasible. So far, we have demonstrated on-resistances down to 100 Ω, on/off ratios up to 107, switching voltages below 100 mV, operating temperatures up to 180 °C, and switching times below 50 ns. The devices can be deposited at low temperatures (200 °C) by conventional rf-sputtering and survive the 30-min anneal at 400 °C in forming gas, which is mandatory in CMOS processing.