SIMULATION OF THE PROGRAM OPERATIONS OF THE FLOTOX EEPROM

A model for the simulation of the programming operations of a FLOTOX E EPROM cell is proposed. The model takes into account the following phe nomena occurring during the erase operation: (I)depletion layers in th e tunnel (thin) oxide area, the channel area, the poly-drain overlap a rea and the source diffusion area; (2) band to band tunnelling in the tunnel area; (3) impact ionization of the tunnelling electrons; and (4 ) channel depletion. Results for the write operation are also presente d as a comparison. The computer model serves as a tool for theoretical understanding of the programming operation of the FLOTOX EEPROM, and a model for future CAD tools. Results of the simulation show the appea rance of an anomalous tunnel current peak that compares well with the experimental results presented by other authors.