Halbleiterspeichereinrichtung mit nichtflüchtigen Speicherzellen, Anreicherungsladetransistoren und peripheren Schaltkreisen mit Anreicherungstransistoren

A semiconductor memory device comprises a non-volatile memory cell array (70) having a plurality of memory cells (71), enhancement type load transistors (73, 73') having a threshold voltage, and at least one peripheral circuit, such as level shifters (74), column decoders (76), etc., including enhancement type transistors having a threshold voltage. For increasing the writing speed of the memory cells (71), the threshold voltage of the enhancement type load transistors (73, 73') is set so that it is different from that of the enhancement type transistors of the peripheral circuit. For example, the threshold voltage of the enhancement type load transistors (73, 73') is lower than that of the enhancement type transistors of the peripheral circuit.