Dynamic behavior of helium bubbles at high temperature in Si studied by in situ TEM, STEM-EELS, and TDS
Dynamic behavior of helium bubbles at high temperature in Si studied by in situ TEM, STEM-EELS, and TDS
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DOI：
10.1063/1.5118684
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发表时间：
2019-10-07
影响因子：
3.2
通讯作者：
Yatomi, A.
中科院分区：
文献类型：
--
作者：
Ono, K.;Miyamoto, M.;Yatomi, A.
我们利用原位透射电子显微镜（TEM）证明了高温下氦离子照射FZ (011)Si样品所形成的氦气泡的随机运动。对随机运动的分析得到了气泡的扩散系数，它取决于气泡的大小和退火温度。利用扫描透射电子显微镜-电子能量损失能谱测量，单个气泡中的氦密度高达70 +/- 14 He/nm(3)。它与辐照温度、束流通量和退火温度有关，但与气泡尺寸无关。气泡在800 K左右保持了高密度的氦原子，但在970 K以上退火后，单个气泡内的氦密度显著降低。用热解吸光谱测量了样品中氦的热解吸，温度在650 K到1100 K之间，中心在890 K左右。透射电镜显示了相应的显微组织。在这些结果的基础上，讨论了热解吸剖面，即低温下氦的释放是由迁移和聚结的过压气泡和迁移到试样表面的气泡释放的，高温下氦的释放是由静止的大气泡释放的。由AIP出版社授权出版。
We demonstrated, using in situ transmission electron microscopy (TEM), the random motion of helium bubbles formed by irradiation with helium ions in an FZ (011)Si specimen at high temperatures. Analysis of the random motion yielded the bubble diffusivity, which was dependent on the bubble size and the annealing temperature. The helium density in individual bubbles, measured using scanning transmission electron microscopy-electron energy loss spectroscopy, was as high as 70 +/- 14 He/nm(3). It was dependent on the irradiation temperature, beam flux, and annealing temperature but was independent of the bubble size. The bubbles retained a high density of helium atoms at around 800 K, but a significant reduction of the helium density within individual bubbles took place after annealing above about 970 K. Thermal desorption of helium from the specimen, measured using thermal desorption spectroscopy, occurred at temperatures between 650 K and 1100 K, centering at around 890 K. TEM revealed the corresponding microstructure. On the basis of these results, the thermal desorption profile was discussed in terms of the release of helium at lower temperatures from migrating and coalescing overpressurized bubbles and bubbles migrating to the specimen surface, and at higher temperatures from stationary large bubbles. Published under license by AIP Publishing.