Semi-floating gate memory and preparation method thereof

The invention discloses a semi-floating gate memory and a preparation method thereof. The semi-floating gate memory includes: a semiconductor substrate having a first doping type; a semi-floating gatewell region which has a second doping type and is positioned in the upper layer region of the semiconductor substrate; a U-shaped groove which penetrates through the semi-floating gate well region, and the bottom of the U-shaped groove is located at the lower boundary of the semi-floating gate well region; a first gate dielectric layer which covers the surface of the U-shaped groove; the floatinggate covers the first gate dielectric layer and forms a convex shape with a high middle part and two low sides; a tunneling transistor channel layer which covers the upper surface of the middle bulgeof the floating gate; second gate dielectric layers which are formed on the two sides of the tunneling transistor channel layer and extend to cover the surface of the floating gate, and the control gate covers the second gate dielectric layers and the upper surface of the tunneling transistor channel layer; gate side walls which are positioned on the two sides of the first gate stack and the second gate stack; and a source electrode and a drain electrode which are formed in the semi-floating gate well region and are positioned on the two sides of the first gate stack layer and the second gatestack layer.