60 u00e5 thereafter though not shown in the drawings an anti reflecting film not shown consisting of sio x n y or si 3 n 4 is formed on the silicide layer 115 the anti reflecting film the silicide layer 115 the third polysilicon layer 114 and the dielectric film 113 are then patterned by means of the etch process using the control gate mask thus forming a control gate 116 consisting of the third polysilicon layer 114 and the silicide layer 115 next the first polysilicon layer 112 is patterned by means of the self aligned etch process using the patterned anti reflecting film thus forming the floating gate consisting of the first polysilicon layer 112 thereby the flash memory cell is manufactured as described above the method of manufacturing the flash memory cell according to the present invention can have the following advantages first only one isolation mask for defining an isolation region is used in the process of forming the isolation layer accordingly the degree of difficulty in the process can be lowered and the process cost could be reduced second the top corner of the trench is formed to have a tilt angle of a low angle it is thus possible to prevent the tunnel oxide film or the gate oxide film form being thinly form in a subsequent process and prohibit generation of a moat third the.