| PCM (Phase-change memory) storage technology based on the reversible switch properties of phase-change materials is promising. In 1968, S. R. Ovshinsky first found Te48As30Si12Ge10 compound could be switched fast, repeatedly and stably between amorphous and crystalline, and the optical and electrical properties between these two phases were different greatly. The materials as Te48As30Si12Ge10 compound with these special characteristic can be used in such as phase-change optical disk or phase-change random access memory storage technology.Ge2Sb2Te5 is one of the most successful phase-change storage materials which is widely used in rewritable optical disk. Magnetron sputtering is the main method of preparing PCM films. The qualities of films depend both on the preparation process and the purity, composition, structure, mass density of the sputtering targets, which are the original materials of films. In this area, most researchers of our country focused on the modification of PCM materials and device structure. Relatively, there is few reports of making sputtering targets of PCM materials, researchers and films producters always import expensive targets from aboard. The patents of preparation technology is monopolized in same developed countries. To avoid enslaving by them, it is imperative to study the preparation technology of PCM targets.This research focused on the targets preparation and films properties of Ge2Sb2Te5 in Ge-Sb-Te system. There were two steps in preparing targets. First, using high-purity Ge, Sb and Te ignot weighed by stoichiometry as the raw materials, smelting in vacuum atmosphere for alloying. Second, we shattered the alloy to powder and prepared targets with hot-press sintering. We studied the pressure, temperature, holding time of hot-press sintering which affect the mass density or structure of the targets. Pure phase and high density Ge2Sb2Te5 sputtering targets were obtained at 570℃,40Mpa,4h by hot-pressed sintering, with main phase Ge2Sb2Te5 content 95% and relative density 98%, which can be considered as promising targets for film deposition. We deposited thin films by RF magnetron sputtering. The phase structure, composition, morphology and other properties of the films before and after heat-treating in different temperatures proved that the targets can be used to prepare high quality thin films of phase-change memory. Based on the study on preparation of the Ge2Sb2Te5 targets and films as PCM (Phase Change Memory) materials,5.6 at% Sn-and Bi-was doped respectively in the target for improving the optical and electrical properties. The results show that Sn-doped thin film's reflection difference arises to 36.6% at 500 nm wavelength, which increases 14.4% as to the un-doped materials. That means this material has better potential property as optical memory. The resistivity difference between amorphous and hexagon state of the Sn-and Bi-doped thin films increases as the Ge2Sb2Te5 film's. First principle calculation based on density function theory was used to calculate the energy band structure and electronic state density of the materials. Under this result, we explain the reason of resistivity's change after Sn-and Bi-doped.In this research, The hot-press sintering and film deposition process of Ge2Sb2Te5 PCM target were established.5.6 at% Sn-and Bi-was doped respectively in Ge2Sb2Te5 to improve the reflection and resistivity difference. The test results prove that target can be used to prepare high quality thin films of PCM.
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