Non-volatile floating gate memory cell with floating gates formed in cavities, and array thereof, and method of formation

摘要

A non-volatile memory cell has a single crystalline semiconductive material, such as single crystalline silicon, of a first conductivity type. A first and a second region each of a second conductivity type, different from the first conductivity type, spaced apart from one another is formed in the semiconductive material. A channel region, having a first portion, and a second portion, connects the first and second regions for the conduction of charges. A dielectric is on the channel region. A floating gate, which can be conductive or non-conductive, is on the dielectric, spaced apart from the first portion of the channel region. The first portion of the channel region is adjacent to the first region, with the first floating gate having generally a triangular shape. The floating gate is formed in a cavity. A gate electrode is capacitively coupled to the first floating gate, and is spaced apart from the second portion of the channel region. The second portion of the channel region is between the first portion and the second region. A bi-directional non-volatile memory cell has two floating gates each formed in a cavity. A method of making the non-volatile memory cell and the array are also disclosed.