Nonvolatile Memory Effect in Indium Gallium Arsenide-Based Metal-Oxide-Semiconductor Devices Using II-VI Tunnel Insulators

This paper reports the successful use of ZnSe/ZnS/ZnMgS/ZnS/ZnSe as a gate insulator stack for an InGaAs-based metal-oxide-semiconductor (MOS) device, and demonstrates the threshold voltage shift required in nonvolatile memory devices using a floating gate quantum dot layer. An InGaAs-based nonvolatile memory MOS device was fabricated using a high-kappa II-VI tunnel insulator stack and self-assembled GeO (x) -cladded Ge quantum dots as the charge storage units. A Si3N4 layer was used as the control gate insulator. Capacitance-voltage data showed that, after applying a positive voltage to the gate of a MOS device, charges were being stored in the quantum dots. This was shown by the shift in the flat-band/threshold voltage, simulating the write process of a nonvolatile memory device.