Multi-resistance states in the electrical switching behavior of amorphous Si15Te75Ge10 thin films: Possibility of multi-bit storage

• Multiple resistance levels are achieved using a single chalcogenide phase change material.
• Current ramp rate influences the SET resistance level of thin film devices.
• Multi-stage crystallization is seen to be effecting multiple resistance levels.
• The material is tested for the SET–RESET capability for possible application in PCM.

Electrical switching studies on amorphous Si15Te75Ge10 thin film devices reveal the existence of two distinct, stable low-resistance, SET states, achieved by varying the electrical input to the device. The multiple resistance levels can be attributed to multi-stage crystallization, as observed from temperature dependant resistance studies. The devices are tested for their ability to be RESET with minimal resistance degradation; further, they exhibit a minimal drift in the SET resistance value even after several months of switching.