Improved Operation Characteristics for Nonvolatile Charge-Trapping Memory Capacitors with High-κ Dielectrics and SiGe Epitaxial Substrates.

A novel high-κ Al2O3/HfO2/Al2O3 nanolaminate charge trapping memory capacitor structure based on SiGe substrates with low interface densities is successfully fabricated and investigated. The memory capacitor exhibits excellent program-erasable characteristics. A large memory window of ∼4 V, a small leakage current density of ∼2 × 10−6 Acm−2 at a gate voltage of 7 V, a high charge trapping density of 1.42 × 1013 cm−2 at a working voltage of ±10 V and good retention characteristics are observed. Furthermore, the programming (at 10 V for 10 μs) and erasing speeds (at −10 V for 10 μs) of the fabricated capacitor based on SiGe substrates are significantly improved as compared with counterparts reported earlier. It is concluded that the high-κ Al2O3/HfO2/Al2O3 nanolaminate charge trapping capacitor structure based on SiGe substrates is a promising candidate for future nano-scaled nonvolatile flash memory applications. [ABSTRACT FROM AUTHOR]