Nitrogen-Doping Effect on Ge₂Sb₂Te₅ Chalcogenide Alloy Films during Annealing

Abstract

The microstructural and electrical-property changes of undoped and 5.4% nitrogen-doped Ge 2 Sb 2 Te 5 were investigated. The transition temperature of sheet resistance increased owing to nitrogen doping, which corresponded well with the observed phase-change states. The lattice parameters of the undoped and nitrogen-doped Ge 2 Sb 2 Te 5 exhibited the same tendency of decrease with increasing annealing temperature. Considering the increase in the Ge 2 Sb 2 Te 5 energy state owing to the presence of interstitial nitrogen, the increase in the crystallization temperature is contrary to the thermodynamic viewpoint. Nitrogen atoms and N 2 gas can be located at the interstitial site without distorting the crystal structure. #

Effect of nitrogen doping on the thermal conductivity of GeTe thin films

“…1. This effect is found to be more marked in GeTe than in ternary Ge–Sb–Te compounds 14, and could be related to a preferential orientation of N‐doped GeTe crystals.…”

Crystallization of Ge2Sb2Te5 and nitrogren-doped Ge2Sb2Te5 phase-change-materials thin films studied by in situ combined X-ray scattering techniques

“…It has already been shown that nitrogen incorporation into GST and phase-change materials significantly affects the PCM amorphous phase structure and stability (Raty et al, 2013). Nitrogen doping of PCM is known to induce a large increase of the crystallization temperature (Kojima et al, 1998;Seo et al, 2000;Kim et al, 2010;Yang et al, 2010) and a significant change in the crystallization mechanism of PCM. The crystallization temperature of PCM is substantially raised as the nitrogen content level is increased, even for small nitrogen content variations (Kojima et al, 1998;Seo et al, 2000;Jeong et al, 2000;Kim et al, 2010;Cheng et al, 2013).…”

“…Nitrogen doping of PCM is known to induce a large increase of the crystallization temperature (Kojima et al, 1998;Seo et al, 2000;Kim et al, 2010;Yang et al, 2010) and a significant change in the crystallization mechanism of PCM. The crystallization temperature of PCM is substantially raised as the nitrogen content level is increased, even for small nitrogen content variations (Kojima et al, 1998;Seo et al, 2000;Jeong et al, 2000;Kim et al, 2010;Cheng et al, 2013). When the nitrogen content is increased in GST, it is mainly observed to inhibit crystallization, through a more gradual and less abrupt drop of sheet resistance upon crystallization (Kim et al, 2010;Cheng et al, 2013), through thermodynamic enthalpy variations (Seo et al, 2000;Jeong et al, 2000) and through grain refinement (Jeong et al, 2000;Kim et al, 2010;Cheng et al, 2013).…”

“…The crystallization temperature of PCM is substantially raised as the nitrogen content level is increased, even for small nitrogen content variations (Kojima et al, 1998;Seo et al, 2000;Jeong et al, 2000;Kim et al, 2010;Cheng et al, 2013). When the nitrogen content is increased in GST, it is mainly observed to inhibit crystallization, through a more gradual and less abrupt drop of sheet resistance upon crystallization (Kim et al, 2010;Cheng et al, 2013), through thermodynamic enthalpy variations (Seo et al, 2000;Jeong et al, 2000) and through grain refinement (Jeong et al, 2000;Kim et al, 2010;Cheng et al, 2013). From a structural point of view, the crystalline volume fraction of GST thin films is reduced by nitrogen incorporation, and its incorporation leads to an increase of the lattice parameter of the GST crystalline phase (Jeong et al, 2000;Kim et al, 2010).…”

“…When the nitrogen content is increased in GST, it is mainly observed to inhibit crystallization, through a more gradual and less abrupt drop of sheet resistance upon crystallization (Kim et al, 2010;Cheng et al, 2013), through thermodynamic enthalpy variations (Seo et al, 2000;Jeong et al, 2000) and through grain refinement (Jeong et al, 2000;Kim et al, 2010;Cheng et al, 2013). From a structural point of view, the crystalline volume fraction of GST thin films is reduced by nitrogen incorporation, and its incorporation leads to an increase of the lattice parameter of the GST crystalline phase (Jeong et al, 2000;Kim et al, 2010). By using such a crystallization inhibition effect, the phase change kinetics can be tuned by doping (Cho et al, 2015).…”