A MOSFET with Si-implanted gate-SiO/sub 2/ insulator for nonvolatile memory applications

A MOSFET with Si-implanted gate-SiO/sub 2/ insulator (MEmory-Insulator Transistor, MEIT) is fabricated and investigated, especially with emphasis on its feasibility for nonvolatile memory applications for the first time. A high-dose Si/sup +/ implantation to thermal SiO/sub 2/ introduces excess-Si sites acting as traps responsible for a memory effect. As a result, a large V/sub T/ window of approximately 10 V is achieved by applying small electric fields of 3-5 MV/cm to the MEIT insulator for write/erase programming. By taking advantage of the memory effect, it is found that MEIT achieves sufficient programming characteristics as a flash E/sup 2/PROM as well as simplicity of the single poly-Si-gate process. Most of all, the V/sub T/ window is scarcely degraded, at least, up to 10/sup 7/ write/erase cycles. Although further investigation is needed, MEIT is promising for nonvolatile memory applications.<>