By now, the capacity of RAM chips has reached impressive values, but more and more memory is needed for analytics and AI tasks. The usual planar arrangement of DRAM cells cannot save the situation – the process technology does not keep pace with the increasing requirements for capacity. The way out could be vertical arrangement of DRAM cells similar to 3D NAND.
It is claimed that flipping cells are being developed by individual RAM manufacturers. True, none of them answered the question of the source about the work on such technology. At the same time, the widespread adoption of 3D NAND allows us to hope that manufacturers have dived deep enough into the technology of multilayer fabrication of memory chips to transfer experience to the production of multilayer monolithic DRAM.
Of course, the release of multilayer NAND and multilayer DRAM are two different things. The RAM cell stores data (charge) in a relatively large capacitor controlled by a single transistor. The finer the process technology, the longer the capacitor. If the DRAM cells are laid on their side (placed vertically), then the capacitors will go far to the side. The benefit from such an arrangement will only be in the case of making multiple layers.
Now DRAM manufacturers are still continuing to increase the density of memory cells by reducing technological production standards. Planar technology will hold out for some time, including due to the transition to EUV scanners, but this resource will be quickly exhausted, and the need for memory will not. Therefore, it is reasonable to expect an increase in DRAM volumes due to the vertical arrangement of cells.