US Patent 7795665 Flash memory

A flash memory comprising a substrate, a stacked structure over the substrate, a source, a drain and a source-side spacer is provided. The stacked structure includes a tunneling oxide layer, a floating gate on the tunneling oxide layer, an inter-gate dielectric layer on the floating gate and a control gate on the inter-gate dielectric layer. The source and the drain are disposed in the substrate on the sides of the floating gate, respectively. The source-side spacer is disposed on a sidewall of the stacked structure near the source, thereby preventing the tunneling oxide layer and the inter-gate dielectric layer near the source from being re-oxidized, resulting in an increased thickness.