Subthreshold Source-Side Injection (S3I): A Promising Programming Mechanism for Scaled-Down, Low-Power Flash Memories

Flash memory has recently become the fastest growing segment in the semiconductor memory market. This is due to its high scalability which has already reduced cost/Megabit below that of dRAM´s. However, Flash cells based on tunnelling require relatively high voltages to be generated on chip, while the channel-hot-electron (drain) injection (CHEI) alternative consumes a high current for programming, which inhibits supply voltage scaling. In this paper a novel Subthreshold Source-Side Injection (S³I) mechanism for future generation Flash programming is presented, which could well overcome these drawbacks. S³I is shown to be a very promising mechanism for future low-power Flash memories.