Recent advances in doped Ge2Sb2Te5 thin film based phase change memories

Abstract

Nowadays, chalcogenide-based phase change materials (PCMs) are proving themselves superior in the category of memory devices due to a combination of their unique set of properties. PCMs have the capability of reversible switching, which makes them unique among all other existing data storage devices. Among various existing PCMs, stoichiometric composition Ge₂Sb₂Te₅ (GST) is considered as one of the best compositions on the pseudo-binary tie line of GeTe–Sb₂Te₃. They can exhibit fast read and write speeds, high scalability, and better data retention. Despite these commendable advantages, some key challenges need to be addressed, such as the limited cyclability, high RESET current, and weak thermal stability. A probable approach to deal with these challenges effectively can be either by varying GST composition or doping a suitable element in the host lattice. Over the past few years, several types of dopants have been added to make GST composition applicable for fast processing memory and high-speed switching devices. The present review briefly summarizes the effect of various dopants on the various properties of GST thin films. The comprehension of doping-induced properties of GST materials helps to recognize their technological applicability for desired applications and opens up a window in the context of new applications.