Design of electrical probe memory with TiN capping layer

The concept of electrical probe memory using phase-change media has recently received considerable attention due to its promising potential for next-generation data storage device. However, the physical performances of the conventional electrical probe memory are strongly limited by its diamond-like carbon capping layer ascribed to its large contact resistance and sharp difference between the theoretically optimized properties values and the experimentally measured values. Therefore, the diamond-like carbon capping layer is replaced by a titanium nitride layer here, and the modified device architecture is re-optimized by a newly developed three-dimensional model, resulting in a media stack consisting of a 2-nm Ge₂Sb₂Te₅ layer sandwiched by 2-nm titanium nitride layer with an electrical conductivity of 2 × 10⁵ Ω⁻¹ m⁻¹ and a thermal conductivity of 12 W m⁻¹ K⁻¹, and a 40-nm titanium nitride bottom layer with an electrical conductivity of 2 × 10⁶ Ω⁻¹ m⁻¹ and a thermal conductivity of 12 W m⁻¹ K⁻¹. The advantageous features of such a device on the writing of both crystalline and amorphous bits are also demonstrated according to the developed model.