This topic explores a BEOL-compatible complementary gain cell (GC) memory by integrating oxide semiconductor nFETs and 2D material pFETs in a monolithic 3D architecture. The complementary design enables stable read/write operation with improved noise margin, while the BEOL stacking approach significantly increases memory density without impacting underlying CMOS logic. This approach provides a scalable pathway toward high-density embedded cache with efficient operation and seamless integration into advanced logic technologies.