Effects of nitrogen doping on the properties of Ge15Sb85 phase-change thin film

✍ Scribed by Yin Zhang; Jie Feng; Bingchu Cai

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 849 KB
• Volume: 256
• Category: Article
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2009.09.077

✦ Synopsis

The effects of nitrogen doping on the chemical bonding state, microstructure, electrical property and thermal stability of Ge 15 Sb 85 film were investigated in detail. The doped N atoms tend to bond with Ge to form Ge 3 N 4 , as proved by X-ray photoelectron spectroscopy analyses. X-ray diffraction patterns showed that both undoped and N-doped Ge 15 Sb 85 films crystallize into a hexagonal phase very similar to Sb. The thickness reduction upon crystallization for undoped and N-doped Ge 15 Sb 85 films is less than 5%. The crystalline resistivity, crystallization temperature, and thermal stability of amorphous state all increase after nitrogen doping, while the grain size decreases. By adding 7.0 at.% N into the Ge 15 Sb 85 film, the crystalline resistivity increases twelve times and the crystallization temperature increases about 50 8C. The maximum temperature for 10-year retention of amorphous Ge 15 Sb 85 film is estimated to be 147 8C and that of N-doped films is even higher, which will promise better data retention of phase-change random access memory especially in the high-temperature application.