Memory characterization of SiGe quantum dot flash memories with HfO2 and SiO2 tunneling dielectrics

In this study, we have developed a SiGe dot floating-gate flash memory with high-K dielectric (HfO₂) tunneling oxide. Using SiGe dots and HfO₂ tunneling oxide, a low program/erase voltage can be achieved, along with good endurance and charge retention characteristics as compared to the SiGe dots with a SiO₂ tunneling oxide. We have also examined the impact of Ge concentration in the SiGe dots on charge retention time. This demonstrates that the SiGe dots with HfO₂ tunneling oxide can be used as the floating gate to replace SiGe dots with SiO₂ tunneling oxide and have a high potential for further scaling of floating gate memory devices.