High-voltage complementary BEOL-FETs on Cu interconnects using N-type IGZO and P-type SnO dual oxide semiconductor channels

摘要

A BEOL-process-compatible, high-voltage complementary MISFET inverter formed on Si-LSI Cu-interconnects (hereafter we call BEOL-CMOS, Fig. 1), is presented for the first time. High Ion/Ioff ratio N-type IGZO and P-type SnO dual oxide semiconductor channels are integrated to form BEOL-CMOS logic with just two mask addition to the state-of-the-art BEOL process (Figs. 2 and 3). BEOL-CMOS flow is developed from the NFET [1–3] and PFET [4] unipolar technologies, resolving several integration issues. The high-VDD inverters enable low-Vin/high-Vout and high-Vin/low-Vout interactive operation (Vin: up to 20V, Vout: 0.9∼5V, Figs. 5 and 7). This BEOL-CMOS technology is a strong candidate to realize low-power voltage-bridging I/Os, which gives standard LSIs a special add-on function for smart society applications.