In situ observation of nucleation and subsequent growth of clusters in silane radio frequency discharges
In situ observation of nucleation and subsequent growth of clusters in silane radio frequency discharges
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原位观察硅烷射频放电中团簇的成核和随后的生长
DOI：
10.1063/1.126922
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发表时间：
2000
影响因子：
4
通讯作者：
Yukio Watanabe
中科院分区：
文献类型：
--
作者：
K. Koga;Yasuhiro Matsuoka;Kenichi Tanaka;M. Shiratani;Yukio Watanabe
用新研制的双脉冲放电方法研究了低气压、低功率硅烷射频放电中团簇的生长过程，实现了0.5-4 nm尺寸范围内团簇尺寸和密度的原位测量。在放电开始后约10ms，团簇开始由两个尺寸群组成：小尺寸群中的团簇在整个放电期内的平均尺寸几乎不变，约为0.5 nm，而大尺寸群中的团簇以单分散的方式以约4 nm/S的方式生长。假设小群的SinHx团簇密度随Si原子数n的增加呈指数下降，而大群的尺寸分布服从对数正态分布，则测量到的群中平均尺寸和密度的时间演化转化为尺寸分布的时间演化。结果表明，成核的临界团簇尺寸为SinHx (n∼4)。
Growth processes of clusters in low-pressure and low-power silane radio frequency discharges are studied by using the newly developed double-pulse-discharge method which realizes in situ measurement of their size and density in a size range of 0.5–4 nm. The clusters begin to be composed of two size groups at about 10 ms after the discharge initiation: clusters in the small size group have an almost constant average size of about 0.5 nm through the discharge period, while those in the large one grow at about 4 nm/s in a monodisperse way. Time evolution of the measured average sizes and densities in the groups is transformed into that of size distributions assuming that the density of SinHx clusters for the small group decreases exponentially with the increase in the number of Si atoms, n, of them, and the size distribution for the large group is the lognormal one. The results show that a critical cluster size for nucleation is SinHx (n∼4).