The study of NiCr/GeTe ohmic contacts in the GeTe film based directly heated phase change switch

NiCr can be used as a heating electrode to effectively reduce the insertion loss and switching power of the phase change switch. Therefore, the specific contact resistivity (rho(c)) between NiCr and GeTe was obtained, which is 7.45 x 10(-7) (CTLM) or 3.66 x 10(- 7) (TLM). EDS shows that annealing at 300 degrees C induces NiCr diffusion to the GeTe films surface, which reduces the number of dangling bonds and facilitates the reduction of rho(c)(GeTe/NiCr). oS indicates that the GeTe films surface treated with NH4OH solution is enriched in Ge2+ leading to a decrease in rho(c)(GeTe/NiCr). In contrast, the GeTe films surface treated with HCl solution is enriched in Te-0, and the removal of oxides is obvious, while the rho(c)(NiCr/GeTe) increases. Finally, a direct heating phase change switch base on GeTe films was realized using NiCr film as the heating electrode with resistance window of over 10(5).

Automated summary

NiCr can effectively reduce the insertion loss and switching power of the phase change switch when used as a heating electrode. The specific contact resistivity between NiCr and GeTe was obtained, and the effects of different treatments on the resistivity were analyzed. A direct heating phase change switch based on GeTe films was successfully realized using NiCr film as the heating electrode.