Cycle number manipulating effect on crystallization temperature of superlattice-like [Ge/Ge8Sb92]n phase-change films

Abstract

Superlattice-like(SLL) phase-change films have attracted increasing attention because they can provide more controllable degree of freedoms besides composition. At present the cycle number manipulating effect on crystallization temperature of SLL phase-change films is discussed less and the analysis method should be further improved. Here, four new SLL samples, [Ge(1 nm)/Ge8Sb92(9 nm)]n (n = 1,2,3,4), are prepared. Cycle number manipulating effect on crystallization temperature of the four SLL films is investigated by coherent phonon spectroscopy (CPS) and the sheet resistance measurement. Both kinds of measurements prove the effect of cycle number on Tc and show that Tc decreases with the increasing n of the SLL films, following an exponential law. Based on the combination of alloying effect and equivalent interfacial effect, the cycle number manipulation effect on Tc of SLL films is explained. Our work further improves the analysis method of cycle number manipulating effect on crystallization temperature of SLL films.