Memory cell having closed curve structure

摘要

A memory cell including a drain, a channel, and a floating gate. The channel surrounds the drain and includes a first rounded closed curve structure around the drain. The floating gate is situated over the channel and includes a second rounded closed curve structure over the channel.

主权项

1. An EPROM memory cell suitable for an EEPROM array, the EPROM memory cell comprising:
a drain including a top and a bottom, wherein the drain is formed of an N+ doped region; a channel that surround the drain and includes a first rounded closed curve structure around an entire surface area of the drain including a surface area of the bottom of the drain, wherein the channel is formed of a P doped region, wherein the first rounded closed curve structure increases uniformity of the length of the channel throughout the width of the channel relative to a rectangular channel; a control gate situated over the channel; and a floating gate capacitively coupled to the control gate, wherein the floating gate is situated over the channel and includes a second rounded closed curve structure over the channel to form the EPROM memory cell.