HK-2/HK-1 stacked dielectric was proposed as the gate dielectric for sub-20 nm FinFET technology. Compared to single HK-1 dielectric, the stacked gate dielectric exhibits superior performance in terms of improved drive current by 20~22% and increased transconductance by ~22%. The main reason accounting for the better performance, besides the higher gate capacitance by 4%, is the enhanced carrier mobility by ~33% resulting from less remote scattering due to smaller amount of charged oxygen vacancies which was physically confirmed by EELS and XPS. Owing to the reduced oxygen vacancies, from bias temperature instability and lifetime test, the stacked gate dielectric demonstrates augmented reliability as well. Most importantly, HK-1 and HK-2 are common dielectrics completely compatible with typical processes, rendering the stacked dielectric a promising one for next-generation FinFETs technology.

A stacked oxide semiconductor of n-type ZnO/p-type NiO with diode behavior was proposed as the novel charge-trapping layer to enable low-voltage flash memory for green electronics. The memory performance outperforms that of other devices with high κ and a nanocrystal-based charge-trapping layer in terms of a large hysteresis memory window of 2.02 V with ±3 V program/erase voltage, a high operation speed of 1.88 V threshold voltage shift by erasing at -4 V for 1 ms, negligible memory window degradation up to 10(5) operation cycles, and 16.2% charge loss after 10 years of operation at 85 °C. The promising electrical characteristics can be explained by the negative conduction band offset with respect to Si of ZnO that is beneficial to electron injection and storage, the large number of trapping sites of NiO that act as other good storage media, and most importantly the built-in electric field between n-type ZnO and p-type NiO that provides a favorable electric field for program and erase operation. The process of diode-based flash memory is fully compatible with incumbent VLSI technology, and utilization of the built-in electric field ushers in a new avenue of accomplishing green flash memory.

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