EEPROM CELL STRUCTURE AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide an EEPROM cell structure having a non-uniform thickness of a channel dielectric film, and also to provide a manufacturing method thereof. SOLUTION: This EEPROM cell structure comprises: a semiconductor substrate 201; a memory transistor (MTR) 240 and a selecting transistor (STR) 242 mounted on the semiconductor substrate 201; a floating bonding 244 which is formed in a part of the substrate 201 lain between the transistors, and further by being extended partially into the region below the MTR240; and a gate dielectric film lain in the MTR240 along a transverse direction which consists of a tunnel region that has a thickness of Ttunneland is lain on the fixed portion of the floating bonding 244, a near channel region that has a thickness of Tnearthicker than Ttunneland is lain one side of the tunnel region positioned at the opposite side of the STR, and a far channel region that has a thickness of Tfarthinner than Tnearand is lain on one side of the near channel region positioned at the opposite side of the tunnel region. COPYRIGHT: (C)2005,JPO&NCIPI