SOLID MEMORY

Recording and erasing of data in PRAM have hitherto been performed based on a change in physical characteristics caused by primary phase transformation of a crystallized state and an amorphous state of a recording material which is a Te-containing chalcogen compound. Since, however, a recording thin film is formed of a polycrystalline but not a single crystal, a variation in resistance values occurs and a change in volume caused upon phase transition has placed a limit on the number of times of readout of the record. The above problem has been solved by a solid memory comprising a Ge-containing thin film having a superlattice structure and an Sb-containing thin film having a superlattice structure. The solid memory can realize a number of times of repeated recording and erasing of 10.