In this paper, the dynamic random access memory (DRAM) cell technology
is introduced and the important technological breakthroughs are reviewed.
The criteria of DRAM memory cell design is discussed and the key fabrication
technologies of 6F2 memory cell and stack capacitor DRAM
cell are summarized. The technological evolution of array access transistor
is also reviewed. The transistors with U-shaped transistor or FinFET
and the fabrication process flow of 6F2 DRAM chip were
discussed. Based upon the technical requirements for DRAM cell, the
possible device technologies for the next generation DRAM cell was
summarized. It is predicted that (1) U-shape channel transistor will
be the mainstream technology for the future DRAM cell beyond 20 nm;
(2) low
国家自然科学基金资助项目(61322404)
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