| 摘要 |
<p>A method for manufacturing a multi-bit flash memory cell is provided to improve the degree of integration by forming an improved channel region capable of storing two or more bits of data using an ion implantation mask for exposing partially a channel region. An ion implantation mask(230) is formed on a semiconductor substrate(100). The ion implantation mask is used for opening a first region of a channel region(110). An ion implantation is performed on the resultant structure by using the ion implantation mask, so that the channel region is divided into a first threshold voltage region and a second threshold voltage region. A tunnel dielectric film is formed on the channel region. A floating gate and a control gate are formed on the tunnel dielectric film.</p> |
