Patent ID: 7233054

Claim:
A non-volatile phase change memory cell comprising a compound having the following formula: (Ge A Sb B Te c ) 1-x (R a S b Te c ) x wherein, Ge is germanium; Sb is antimony; Te is tellurium; R is an element selected from the elements belonging to the IVB group in the periodic table; S is an element selected from the elements belonging to the VB group in the periodic table; A, B, C, and a, b and c are atomic mole ratios satisfying the condition that the R—S—Te alloy part is stoichiometrically equivalent to the Ge—Sb—Te alloy part; x is a mole fraction in the range of 0 to 1; R a S b Te c has the same crystal structure as Ge A Sb B Te C ; and at least one element of R and S has a higher atomic number and a smaller diatomic bond strength than that of the corresponding element in the GeSb portion of Ge—Sb—Te.