The influence of oxygen and nitrogen doping on GeSbTe phase-change optical recording media properties

Abstract

Nitrogen and oxygen doped and co-doped GeSbTe (GST) films for phase-change optical recording are investigated. It is found that the crystallization temperature increased as well as the crystalline microstructure refined by doping. The carrier-to-noise ratio (CNR) and erasability of phase-change optical disks are improved being up to 52 and 35 dB, respectively, by using an appropriate nitrogen doping or co-doping concentration in the recording layer. Optical disks with co-doped recording layer are found to be superior in the recording characteristics then the single doped recording layer disks.

Effect of indium doping on the properties of GeSb phase‐change alloy

“…The high electrical contrast of four orders of magnitude between the amorphous and crystalline states of the film and the fast transition in the resistivity could be utilized for high-speed memory devices. It should be noted here that the T c of In 0.3 Ge 15 Sb 85 alloy reported in this work (430 K) is slightly higher than that of Ge 15 Sb 85 alloy reported recently by the same group [18] (420 K). However, the T c of Ge 15 Sb 85 alloy has been reported to exhibits a higher T c value of about 500 K by another group [19].…”

“…It should be noted here that the T c of In 0.3 Ge 15 Sb 85 alloy reported in this work (430 K) is slightly higher than that of Ge 15 Sb 85 alloy reported recently by the same group [18] (420 K). However, the T c of Ge 15 Sb 85 alloy has been reported to exhibits a higher T c value of about 500 K by another group [19]. The dissimilarity between these results could be attributed to several factors such as the method of deposition, sample stoichiometry, surface oxidization, and the heating rate.…”

“…Recently, Te-free Ge-Sb binary alloys have emerged as a new class of PCMs that has relatively high crystallization temperature leading to a long data retention time. The emerged PCM, namely Ge 15 Sb 85 , could be a suitable candidate, where it is reported that Ge 15 Sb 85 requires a lower electric field for threshold switching than other tellurium-based PCMs [12]. Those results offer the possibility to tailor the threshold voltage for downscaled devices by material selection and incorporating additional defects [12].…”

“…Extensive efforts have been devoted recently on the incorporation of different additives to the PCMs and their effects on the switching properties [13][14][15][16]. In many cases the dopants have led to an improvement in the data retention and reduction in the rest current in solid-state memory devices.…”

“…In many cases the dopants have led to an improvement in the data retention and reduction in the rest current in solid-state memory devices. Therefore, this work is focused to investigate the crystallization characteristics, electrical, and optical properties of indium-modified Ge 15 15 Sb 85 film was confirmed by X-ray diffraction (XRD) using a Philips PW/1840 XRD with Ni filter and Cu-Ka radiation (l ¼ 1.542 Å). The composition of the sample was investigated by energy-dispersive X-ray analysis (EDX).…”