DIG HSG

This marks the successful development of fully integrated 512 Mb DRAMs, integrating hemispherical grain (HSG) merged Al2O3/HfO2 (AHO) cylinder capacitors for the first time. The implementation of the highly manufacturable reverse HSG one cylinder storage node (RHOCS) technique and AHO capacitor process has been achieved. Notably, the cell capacitance of the HSG-merged-AHO capacitor demonstrated a significant improvement of up to 24% compared to the ALO capacitor, without any capacitor-related leakage current failure. These advancements in capacitor technology within the 512 Mb DRAMs resulted in enhanced retention characteristics and exceptional test yield, primarily attributed to the improved cell capacitance.