| 摘要 |
<p>Charge retaining properties of nonvolatile memory, particularly MONOS-type nonvolatile memory, are improved. The nonvolatile memory cell comprises a semiconductor substrate. A tunnel silicon oxide film (107), a silicon nitride film (104) that serves as a charge accumulation film, a silicon oxide film (105), and a gate electrode (108) are provided in that order on the semiconductor substrate. The tunnel silicon oxide film (107) has a laminated structure comprising a silicon oxynitride film (102) and a silicon oxide film (103). In this case, a construction is adopted wherein the density of a nitrogen atom contained in the silicon oxynitride film (102) decreases from the interface of the semiconductor substrate and the silicon oxynitride film (102) in the thickness direction of the silicon oxynitride film (102).</p> |
