Abstract
We study the effects of nitrogen (N)-doping on the electrical memory reliability of GeSbTe phase-change materials based on GeTe prototype models. We find that the loss of secondary bonding (e.g., resonant interlayer bonding) determines the feasibility of various types of N-doping that can be easily adopted by the GeSbTe system. We give a more generalized explanation beyond compliance with the formation of local Ge<sub>3</sub>N<sub>4</sub> motifs. The nitrogen-induced change in local order produces crystalline GeTe with shallow states near the valence band edge. These states are localized on the nearest-neighbor Ge sites, thus reducing the conductivity in the crystalline phase. This trend carries over to c-GeTe with Ge vacancy. The N-doped amorphous GeTe models exhibit enhanced degrees of band tail overlap, which pins the Fermi energy in the mid-gap and thus gives rise to even higher resistivities in the amorphous phases. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
| Original language | English |
|---|---|
| Pages (from-to) | 431-441 |
| Journal | Physica Status Solidi (B) Basic Research |
| Volume | 252 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 1 Feb 2015 |
Bibliographical note
Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to [email protected].Research Keywords
- Band overlapping
- Loss of secondary bonding
- N-doping
- Phase change memory materials
- Shallow states