Excellent resistive switching in nitrogen-doped Ge₂Sb ₂Te₅ devices for field-programmable gate array configurations

The nitrogen-doped Ge₂Sb₂Te₅ (GST) programmable metallization cell is investigated to address the low switching voltage and need for a high resistance ratio, which are critical issues for the filed-programmable gate array (FPGA) configuration. Nitrogen doping of GST yields Ge-N covalent bonds, as confirmed by x-ray photoelectron spectroscopy and Raman spectroscopy; this increases the resistivity of GST. Consequently, an excellent resistance ratio (∼10⁷) with appropriate operating voltage and stable retention properties more than for 10⁴s at 85 °C are achieved. The results indicate that the film is a suitable alternative candidate for the logic switch in static-random-access-memory-based FPGA technology.