Resistive random access memory
View Patent ↗A resistive random access memory may include a memory array and a periphery around the memory array. Decoders in the periphery may be coupled to address lines in the array by forming a metallization in the periphery and the array at the same time using the same metal deposition. The metallization may form row lines in the array.
1. A memory comprising:
a memory array including transverse row lines and bitlines, said row lines having an upper surface;
a memory periphery associated with the memory array, said periphery including decoders electrically coupled to said transverse row lines and bitlines;
a first dielectric over the memory array and the memory periphery;
a second dielectric over the first dielectric, wherein the second dielectric is different from the first dielectric;
a third dielectric over the second dielectric;
a fourth dielectric over the third dielectric
a first opening over the memory array through third and fourth dielectrics but not through the first and second dielectrics;
a second opening over the memory periphery through the first, second, third, and fourth dielectrics;
a metallization in the first and second openings and having an upper surface, wherein the upper surface of said metallization in the periphery being substantially co-planar with the upper surface of the metallization in the memory array, wherein said metallization having a first thickness in the first opening and further having a second thickness in the second opening, the second thickness greater than the first thickness;
a first contact in the memory array, wherein the first contact extends from the first opening, through the first and second dielectrics and contacts two adjacent metal plugs below the first dielectric; and
a second contact in the memory periphery, wherein the second contact extends from the second opening to a gate of a transistor.
2. The memory of claim 1 wherein the metallization is a first metallization, and the memory further comprises a second metallization in the periphery above the first metallization, said decoders are formed in said periphery in said second metallization.
3. The memory of claim 1 including said bitlines extending below said row lines.
4. The memory of claim 3 , said bitlines being, coupled to column decoders by a pair of vertically spaced sets of parallel metallizations, one metallization for each bitline.
5. The memory of claim 4 wherein said vertically spaced sets of metallizations extend generally parallel to said bitlines and said sets are vertically separated by vertically extending vias, the lowermost of said metallizations being formed directly on said bitlines.
6. The memory of claim 3 , said row lines being coupled to said decoders by a first set of parallel metallizations extending generally parallel to said row lines.
7. The memory of claim 6 , said first set coupled to said row lines by vertically extending vias.
8. The memory of claim 7 , said row lines being coupled to said decoders through said first set of metallizations via additional metallizations coupled to said first set of metallizations by a vertically extending via.
9. The memory of claim 1 , further comprising:
a third contact formed over the memory periphery, wherein the third contact includes a portion exposed by a third opening through the first, second, third, and fourth dielectrics in the memory periphery.