Ge quantum dot memory realized with vertical Si/SiGe resonant tunneling structure

A modified memory cell using self-assembled Ge quantum dots as float gate is proposed for DRAM application. The vertical structure is strained SiGe channel/n-Si/i-SiGe/n-Si/Ge dots/SiO₂/poly-Si gate. The inside n-Si/i-SiGe/n-Si double barrier acts as tunneling barrier for hole instead of conventional tunneling silicon oxide layer. The function and advantages of the device were analyzed primarily. This novel structure can also be developed to realize non-volatile memory operating at low voltage, if hetero-structure materials system with appropriate band alignment is found.