Performance Evaluation of Field-Enhanced P-Channel Split-Gate Flash Memory

A p-channel split-gate Flash memory cell, employing a field-enhanced structure, is investigated in this letter. A cell with a sharp poly-tip structure is utilized to enhance the electric field, while using Fowler–Nordheim tunneling through the interpoly oxide. The cell demonstrated an erase voltage as low as 12 V. In cell programming, both channel-hot-hole impact ionization induced channel-hot-electrons (CHE) and band-to-band tunneling induced hot electrons (BBHE) are evaluated. BBHE shows an injection efficiency of 2 orders in magnitude higher than that of CHE. The cell also demonstrated an acceptable program disturb window, which is of high concern in a p-channel stacked-gate cell. Both programming approaches can pass 300 k program/erase cycles.