Density changes upon crystallization of Ge2Sb2.04Te4.74 films
Density changes upon crystallization of Ge2Sb2.04Te4.74 films
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DOI：
10.1116/1.1430249
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发表时间：
2002-01-01
期刊：
影响因子：
--
通讯作者：
Wuttig, M
中科院分区：
文献类型：
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作者：
Njoroge, WK;Wöltgens, HW;Wuttig, M
通过x射线反射精确测定了退火后溅射Ge2Sb2.04Te4.74薄膜的密度，并与x射线衍射（XRD）数据进行了比较。在退火至400度时，膜密度在130度和280度左右分两步增加。XRD分析表明，这些增加分别是由非晶型向NaCl型和NaCl型向六方结构转变的结果。非晶相、nacl型相和六方相的平均密度分别为5.87+/-0.02、6.27+/-0.02和6.39+/-0.02 g/cm(3)。这对应于nacl型相和六方相在结晶时的密度变化，分别为6.8+/-0.2%和8.8+/-0.2%。同时测定了薄膜厚度减少6.5+/-0.2%和8.2+/-0.2%，这与密度变化非常吻合。nacl型相和六方相的XRD值分别为6.43 ~ 6.48和6.48 g/cm(3)。这表明形成了几乎无空洞的薄膜。(C) 2002年美国真空学会。
The density of sputtered Ge2Sb2.04Te4.74 thin films upon annealing has been precisely determined by x-ray reflection and compared to the values determined from x-ray diffraction (XRD) data. The film density increases in two steps around 130 and 280 degreesC upon annealing up to 400 degreesC. These increases are consequences of phase transitions from amorphous to NaCl type and from NaCl type to hexagonal structure, respectively, as revealed by XRD. Average density values of 5.87+/-0.02, 6.27+/-0.02, and 6.39+/-0.02 g/cm(3) were measured for the amorphous, NaCl-type, and hexagonal phases, respectively. This corresponds to density changes upon crystallization of 6.8+/-0.2% and 8.8+/-0.2% for NaCl-type and hexagonal phases, respectively. The accompanying film thickness reductions were determined to be 6.5+/-0.2% and 8.2+/-0.2%, which compares very well with the density changes. The corresponding XRD values are determined to be 6.43-6.48 and 6.48 g/cm(3) for NaCl-type and the hexagonal phases, respectively. This shows that nearly void-free films are formed. (C) 2002 American Vacuum Society.