Highly Sb-Rich Ge-Sb-Te Engineering in 4Kb Phase-Change Memory for High Speed and High Material Stability Under Cycling

Carbon ion implantation as healing strategy for improved reliability in phase-change memory arrays

“…Data extracted from XRR analyses (Fig. 5) highlight: a) a lowering of the density of the implanted layers (less than 5 g/cm 3 ) with respect to standard GST (equal to about 6 g/cm 3 ), correlated to a structural relaxation of the material featuring a higher number of defects due to the high dose exposure; b) an increasing thickness of the impacted region when increasing the dose (from 10 15 to 10 16 at/cm 2 ). This is in accordance with a reduction of the internal stress of the amorhous Ge2Sb2Te5 layer [10], with significant benefits in terms of relaxation of the contraints for the following of the BEOL of the integration.…”

“…Good thermal stability, high SET speed and large reading window enabling almost analog resistance levels (i.e. Multi-Level Cell) make PCM enough versatile to meet the requirements of automotive applications [2], Storage Class Memory [3] and neuromorphic computing [4]. However, some challenges remain to be achieved for next PCM products generation, like the lowering of programming current, the reduction of the resistance drift, and extremely low bit error rate (i.e.…”

A Self-referenced and regulated sensing solution for PCM with OTS selector

“…Beyond the well-known feature of PCM cells already demonstrated in the literature, i.e. a large resistance ratio of 10 3 , a low variability thanks to a bulk phase change (crystalline and amorphous state), a mature process, and a large endurance 10 9 [4][5][6][7], the performances of memory with OTS as selector is mainly driven by the OTS selectivity. Regarding the OTS selectivity feature, numerous papers have reported very different performances [9][13] [14], with selectivity ranging from 10 3 to 10 7 .…”

“…and dataintensive treatment, exacerbates the requirement in terms of performances and memory capacity on edge devices, such as the high-end Micro Controller Unit (MCU). In this context, highdensity memory based on emerging concept could replace actual solutions such as 1.5T NOR Flash memory or 1T1R Phase Change Memory (PCM) [1][2][3][4][5][6][7]. In this context, to decrease drastically the bit cell footprint, a back-end selector solution could be adopted.…”

TiTe/Ge2Sb2Te5Bi-layer-based Phase-Change Memory Targeting Storage Class Memory

“…Material engineering in PCM is the key method to improve speed and endurance performances to target SCM requirements. For example, Sb-rich GST has been recognized as a suitable phase-change material for SCM thanks to its ns range programming time [5] and a record endurance of 2 × 10 12 [6]. However, these materials require a very good control of the stoichiometry, which otherwise could induce devices variability.…”