Electron paramagnetic resonance study of silicon-28 single crystal for realization of the kilogram
Electron paramagnetic resonance study of silicon-28 single crystal for realization of the kilogram
复制标题
硅28单晶电子顺磁共振研究实现千克
DOI：
10.1088/1681-7575/ac5584
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发表时间：
2022
期刊：
影响因子：
2.4
通讯作者：
Umeda Takahide
中科院分区：
文献类型：
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作者：
Mizushima Shigeki;Umeda Takahide
为了使用X射线晶体密度方法实现高精度的千克，需要对硅-28晶体中的空位缺陷数量进行质量亏损校正。在本文中，我们提出的电子顺磁共振（EPR）光谱实验的结果进行了硅-28晶体。从Si 28 - 23 Pr 11晶体梨晶的径向中心附近切割晶体，其中在通过浮区法生长的梨晶内预期相对高的空位缺陷浓度。我们得到了同相和异相EPR谱，分别集中在快自旋和慢自旋弛豫中心。根据在黑暗和光照下的EPR测量，发现具有未成对电子的磷杂质的浓度在1.6× 10 12 cm− 3和3.4× 10 12 cm− 3之间。相反，在硅-28晶体中，EPR活性空位缺陷在当前测量的检测灵敏度（约1× 10 12 cm− 3）下未检测到，尽管在Si/SiO 2界面处，检测到面密度在0.4× 10 12 cm− 2和1.7× 10 12 cm− 2之间的悬挂键缺陷（Pb 0中心）。在光照下大量磷供体的实验检测表明存在补偿中心（电子能级充当受体），其浓度至多为1.6× 10 12 cm− 3。我们确定，这样的浓度主要是由硼受体补偿的，并且几乎没有电活性空位缺陷的贡献，0.0（6）× 10 12 cm− 3。这个值比以前报道的1× 10 14 cm− 3到4× 10 14 cm− 3的正电子湮没光谱测定的空位缺陷浓度小得多。
To realize the kilogram with high accuracy using the x-ray crystal density method, mass deficit correction to account for the number of vacancy defects in silicon-28 crystals is necessary. In this paper, we present the results of electron paramagnetic resonance (EPR) spectroscopy experiments performed on a silicon-28 crystal. The crystal was cut from near the radial center of the Si28–23Pr11 crystal boule where a relatively high vacancy defect concentration was expected within the boule, which was grown by the floating zone method. We obtained both the in-phase and out-of-phase EPR spectra, which focused on the fast-and slow-spin relaxation centers, respectively. Based on EPR measurements both in the dark and under illumination, the concentrations of phosphorus impurities with unpaired electrons were found to be between 1.6× 10 12 cm− 3 and 3.4× 10 12 cm− 3. In contrast, EPR-active vacancy defects in the silicon-28 crystal were not detected at the detection sensitivity of the present measurements (around 1× 10 12 cm− 3), although at the Si/SiO 2 interface, dangling-bond defects (P b0 centers) were detected with an areal density between 0.4× 10 12 cm− 2 and 1.7× 10 12 cm− 2. The experimental detection of a larger amount of phosphorus donors under illumination indicates the presence of compensation centers (electronic levels acting as acceptors) with a concentration of at most 1.6× 10 12 cm− 3. We determined that such a concentration is mainly compensated by the boron acceptors, and that there is little contribution of electrically active vacancy defects, 0.0 (6)× 10 12 cm− 3. This value is much smaller than the previously reported concentrations of 1× 10 14 cm− 3 to 4× 10 14 cm− 3 for vacancy defects determined by positron annihilation spectroscopy.