On Carbon doping to improve GeTe-based Phase-Change Memory data retention at high temperature

摘要

This paper investigates material and electrical properties of a new chalcogenide alloy for Phase-Change Memories (PCM): Carbon-doped GeTe (named GeTeC). First, several physico-chemical, optical and electrical analyses have been performed on full-sheet chalcogenide depositions in order to understand the intrinsic GeTeC phase-change behavior, and to characterize structure and composition of amorphous and crystalline states. Then, GeTeC with two different Carbon doping (4% and 10%) has been integrated in pillar-type analytical PCM cells. Physico-chemical and electrical data indicate that GeTeC is characterized by a much more stable amorphous phase compared to undoped GeTe. Thus, GeTeC offers a slower programming speed versus GeTe, but an improved data retention at high temperature. Finally, we argue that GeTeC alloy is a promising candidate for future developments of PCM technologies for embedded applications.