The solution of over-erase problem controlling poly-Si grain size-modified scaling principles for flash memory

Clear evidence is presented that the floating gate poly-Si grain size dominates flash memory erase characteristics. Smaller grain size shows a narrower erase distribution. Thus conventional scaling theories should be modified to include that grain size must be shrunk proportional to the cell size. A process technology breakthrough will have to be achieved to form smaller size grains because 16 M will be the maximum capacity using current process technology with this new theory. It is also shown how 64 M flash memories can be achieved without such a technology breakthrough.<>