Performance and reliability evaluations of p-channel flash memories with different programming schemes

In this paper, a complete study of the cell reliability based on a unique oxide damage characterization for two different programming schemes of p-channel flash cell are presented. These two programming schemes are Channel Hot Electron (CHE) injection or Band-to-Band (BTB) tunneling induced hot electron injection. Degradation of memory cells after P/E cycles due to the above oxide damages has been identified. It was found that both N/sub it/ and Q/sub ox/ will dominate the device degradation during programming. Although p-flash cell has high speed performance compared with n-flash cell, extra efforts are needed for designing reliable p-channel flash cell by appropriate drain engineering or related device optimization.