Patent ID: 7632456

Claim:
A non-volatile phase change memory cell comprising a phase change memory material comprising a base material and at least one non-metallic light element added to the base material, wherein the base material has a composition which, when expressed in terms of atomic fractions of constituent atoms, corresponds to either that of congruent melting with a minimum melting point or that of eutectic melting within the range of ±0.15 atomic fraction for each constituent element and wherein the memory material is expressed by the following composition consisting of: A x M y (Sb a Te 1-a ) z wherein, A is at least one non-metallic element selected from the group consisting of boron, carbon, nitrogen and oxygen; M is Ge; and x, y, z and a are mole fractions satisfying x+y+z=1, 0<x<0.2, 0<y<0.15, and 0.6≦a≦0.85, respectively.