Thermal stability and electronic structures of N-doped SiSb films for high temperature applications of phase-change memory

摘要

Undoped and N-doped Si_(10.5)Sb_(89.5) films were deposited by magnetron sputtering. The X-ray diffraction spectra indicated that all of the films crystallized into crystalline Sb with a rhombohedral structure after annealing at 280℃for 3 min. X-ray photoelectron spectroscopy analysis indicated that the incorporated nitrogen combined with Si to form silicon nitride in the SiSb films. The changes in electrical resistance and thermal stability of the undoped and N-doped Si_(10.5)Sb_(89.5_ films were investigated. The crystallization temperature increased from ～225℃ to ～250℃ when 13 at.% nitrogen was added into the Si_(10.5)Sb_(89.5) film and increased further with increasing nitrogen content. The thermal stability of the amorphous film was enhanced by nitrogen doping. The maximum temperature for 10-year retention of amorphous state of a pure Si_(10.5)Sb_(89.5) film is ～140℃ and the temperature of N-doped Si_(10.5)Sb_(89.5) films is even higher, which may be helpful to improve the data retention and performance of phase-change memory in high temperature applications.