Solid memory

Abstract

In one embodiment of the present invention, 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 crystalline state and an amorphous state of a chalcogen compound including Te which serves as a recording material. Since, however, a recording thin film is formed of a polycrystal 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 is solved by preparing a solid memory having a superlattice structure with a thin film containing Sb and a thin film containing Te. The solid memory can realize the number of times of repeated recording and erasing of 10 15 .

1 . A Solid Memory,
 electric characteristics thereof changing due to phase-separation of a substance constituting the solid memory,   the substance serving as a material for recording and reproducing data, the material including a laminated structure of artificial superlattices whose electric characteristics change due to the phase-separation.   
     
     
         2 . The solid memory as set forth in  claim 1 , wherein:
 the laminated structure is made of alloy thin films including stibium (Sb) atoms and alloy thin films including tellurium (Te) atoms.   
     
     
         3 . The solid memory as set forth in  claim 1 , wherein:
 a thickness of each of the alloy thin films including stibium (Sb) atoms and the alloy thin films including tellurium (Te) atoms ranges from 0.3 to 2 nm.   
     
     
         4 . The solid memory as set forth in  claim 2 , wherein:
 data is recorded by causing interfaces between the alloy thin films including stibium (Sb) atoms and the alloy thin films including tellurium (Te) atoms to be in a one-dimensionally anisotropically separated state.   
     
     
         5 . The solid memory as set forth in  claim 2 , wherein:
 data is erased by causing interfaces between the alloy thin films including stibium (Sb) atoms and the alloy thin films including tellurium (Te) atoms, having been in a one-dimensionally anisotropically separated state, to be in a recombined state.   
     
     
         6 . The solid memory as set forth in  claim 2 , wherein:
 a thickness of each of the alloy thin films including stibium (Sb) atoms and the alloy thin films including tellurium (Te) atoms ranges from 0.3 to 2 nm.