The invention discloses an SONOS memory. The SONOS memory is constructed in such a way that a P trap is internally provided with a source region and a drain region, a channel region of the memory is arranged between the source region and the drain region, an ONO dielectric layer is arranged at a silicon surface of the channel area, and a polysilicon grid is disposed on the ONO dielectric layer; side walls of the polysilicon grid are arranged on the ONO dielectric layer at the two sides of the polysilicon grid; the side walls are of double-layer structures, an internal layer close to the polysilicon grid is a silicon nitride side wall, and an external layer is a silicon oxide side wall; and the two ends at the grid length of the bottom of the polysilicon grid are provided with spaces recessed into the polysilicon grid, the spaces are filled up with silicon oxide, and the total thickness of the dielectric layer at the two ends of the channel of the polysilicon grid is enabled to be greater than that of the dielectric layer above the channel region. The invention further discloses a technical method of the SONOS memory.