System for constant field erasure in a flash EPROM

摘要

A FLASH EPROM cell in accordance with the present invention is disclosed in which the erasure is accomplished under a constant electric field. The FLASH EPROM cell includes a semiconductor device including a source, a drain and a gate and a constant current circuit coupled to the source. The constant current circuit ensures that a constant field is applied to the tunneling oxide of the FLASH EPROM cell during erasure thereof. In so doing, the FLASH EPROM cell can be erased with a minimum of stress to the device. In addition, the FLASH EPROM cell of the present invention can be used with various power supplies without affecting the characteristics thereof. Finally, through the FLASH EPROM cell of the present invention, the short channel effect associated with smaller device sizes can be substantially reduced.