以SiH_(4)为介质扩散法生产^(28)Si技术研究  

Research on the Production of^(28)Si Isotope with SiH_(4)by Gas Diffusion Method

作　　者：孙旺 周明胜[1] 姜东君[1] 潘建雄 SUN Wang;ZHOU Mingsheng;JIANG Dongjun;PAN Jianxiong(Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学,北京100084

出　　处：《同位素》2024年第3期203-210,共8页Journal of Isotopes

摘　　要：^(28)Si同位素主要应用于半导体领域,在量子计算、计量学领域也有一定应用。采用99%以上丰度^(28)Si制备硅晶体,可以降低声子散射、提高热导率,并且降低门电压、提高开关速度、提高芯片频率,可用于制造高速CPU、大功率器件、高性能传感器等。在室温下,99.85%以上丰度^(28)Si半导体元件的热导率比天然丰度Si材料增加10%~60%。高丰度^(28)Si可用于制备量子信息长自旋相干时间器件,去除29Si干扰。本研究采用气体扩散法,以SiH_(4)为介质,开展^(28)Si同位素的分离研究。目前廉价优质的高分子有机膜已得到大规模工业应用。用于负压条件下的高速磁悬浮压缩机可以有效压缩SiH_(4)气体。通过4级扩散级联实验测得SiH_(4)的基本全分离系数可达1.010。采用多元分离理论进行级联分析计算,以天然SiH_(4)为原料,通过一次不超过300级的相对丰度匹配级联,可将轻馏分中的^(28)Si同位素丰度浓缩到99%以上。本研究验证了以SiH_(4)为介质扩散分离^(28)Si同位素可行。Stable isotopes are currently widely used in medical,biological,agricultural,environmental,industrial manufacturing,scientific research and other fields.There are three isotopes of silicon in nature,namely^(28)Si,29Si,and 30Si,with natural abundances of 92.22%,4.69%,and 3.09%,respectively.^(28)Si isotopes are mainly used in the semiconductor field and also have certain applications in quantum computing and metrology.Silicon crystals made from pure^(28)Si isotope with an abundance of over 99%have a perfect lattice structure,which can reduce phonon scattering,improve thermal conductivity,lower gate voltage,increase switching speed,and increase chip frequency.^(28)Si can be used to manufacture high-speed CPUs,high-power devices,high-performance sensors,and more.Different experimental studies have shown that using^(28)Si materials with an abundance of over 99.85%to prepare semiconductor components can increase their thermal conductivity by 10%-60%compared to Si materials of natural abundance at room temperature.High abundance^(28)Si is a key material for preparing long spin coherent time devices in the field of quantum information,which can remove interference from 29Si.Silicon quantum bit is a promising quantum computing platform with advantages such as long coherence time,small device size,and compatibility with industrial manufacturing technology.In addition,^(28)Si isotope can also be applied in metrology to define the exact values of the Avogadro constant and kilogram units.With SiH_(4)as the medium,the separation of^(28)Si isotope was studied by gas diffusion method in this paper.At present,research on the separation of silicon isotopes using cryogenic distillation methods(SiH_(4),SiCl4,or SiH3CH3 systems),gas centrifugation methods(SiF4 or SiHCl3),chemical exchange methods(systems of SiF4 and different complexing agents),laser methods(Si2F6,SiF4),and electromagnetic methods(SiH_(4))has achieved certain results both domestically and internationally.However,industrial production of silicon isotopes has not yet a

关 键 词：硅同位素 甲硅烷 气体扩散法 基本全分离系数 

分 类 号：TL92[核科学技术—核燃料循环与材料]