GeSbTebased

GeSbTe based materials, often abbreviated as GST, represent a class of phase-change materials with unique properties that make them highly suitable for non-volatile memory applications. These compounds are typically alloys of germanium (Ge), antimony (Sb), and tellurium (Te), with specific stoichiometric ratios that dictate their performance. The key characteristic of GST materials is their ability to reversibly switch between two distinct structural and electrical states: an amorphous state and a crystalline state.

The amorphous state of GST is characterized by a disordered atomic arrangement and a high electrical resistance. Conversely, the crystalline state, which can be either hexagonal or cubic depending on the specific composition and processing, exhibits a more ordered structure and significantly lower electrical resistance. This transition between states is induced by applying electrical pulses. A short, high-amplitude pulse heats the material above its crystallization temperature, causing it to transform into the crystalline state. A longer, lower-amplitude pulse, or a higher temperature pulse followed by rapid quenching, can revert it back to the amorphous state.

This reversible amorphous-to-crystalline phase change is the foundation of phase-change random-access memory (PCRAM) or PRAM. The difference in resistance between the two states can be read as binary data (0 or 1). GST's rapid switching speeds, high endurance, and relatively simple fabrication process have made it a leading candidate for next-generation memory technologies that offer non-volatility, similar to flash memory, but with the speed and endurance closer to dynamic random-access memory (DRAM). Research continues to optimize GST compositions and device structures for improved performance and scalability.