Ta-doped Ge5Sb95 phase change thin films for high speed and low power application

Abstract

In the field of phase change memory (PCM), the contradiction between operation speed and thermal stability is one of the critical factors restricting its development, including realizing the framework of storage class memory. Ta-doped Ge5Sb95 has been proposed as a potential material, which displays better thermal stability and higher phase transition speed than classic Ge2Sb2Te5. Ta incorporation can improve the crystallization temperature and data retention ability, while increasing the electrical resistance, which reveals a significant enhancement in amorphous thermal stability and a reduction in programming power consumption, with almost no sacrifice in phase transition speed. For the PCM cells based on the optimized composition Ta0.16(Ge5Sb95)0.84, reversible phase transitions are successfully realized by using 20 ns electric pulse and RESET power consumption is as low as picojoule level with a resistance ratio up to 10000 times, showing high thermal stability, fast speed, and low power consumption application potential in PCM.