Memory cell of charge-trapping non-volatile memory

Abstract

A memory cell of a charge-trapping non-volatile memory is provided. The memory cell is formed on a well region of a semiconductor substrate. The memory cell includes a storage transistor. A gate structure of the storage transistor includes a first tunneling layer, a second tunneling layer, a trapping layer, a blocking layer and a gate layer. The first tunneling layer is contacted with a surface of the well region. The second tunneling layer covers the first tunneling layer. The trapping layer covers the second tunneling layer. The blocking layer covers the trapping layer. The gate layer covers the blocking layer. The second tunneling layer has gradient nitrogen distribution. A first nitrogen concentration of a first region of the second tunneling layer close to the first tunneling layer is lower than a second nitrogen concentration of a second region of the second tunneling layer close to the trapping layer.