金刚石表面杂质的深度分布

THE SURFACE IMPURITIES DEPTH-PROFILING ON THE DIAMOND

利用二次离子质谱法(SIMS)测量和分析了金刚石的表面杂质,为获得表面杂质的深度分布,采用了离子剥蚀法,用15keV的Ar^+总共剥蚀了6400s。以N、Na、Mg和Si四种杂质作为研究对象。结果表明,各种杂质的浓度最大值均位于最外表面的一薄层内,它相当于剥蚀时间不足6.5min。对于某一给定的杂质,在不同样品的最外表面上的浓度可以相差很悬殊。但当Ar^+剥蚀30min以后,不同样品中的浓度相差不很大,且同一样品中,各种杂质的浓度随剥蚀时间的增大(即随深度的增加)变化不大。

The surface impurities on the diamond were determined and analysed by the secondary ion mass spectroscopy(SIMS). In order to obtain the depth-profiling of the surface Impurities,the ion erosion method was used. The total erosion time was 6400 s by Ar+ at 15 keV, and N,Na,Mg and Si were chosen as the impurities to be observed. The results indicate that the concentration maximums of the various impurities are situated in a thin layer near the most outward surface and its erosion time correspond to less than 6. 5 min; the concentrations for a given impurity,at the most outward surfaces of two different samples, may differ enourmously;if the erosion time exceed 30 min,however, this concentration difference in different samples is not large. Also variations in impurities concentrations are not obvious as the erosion time (i. e. as the depth) increases, in the same sample.