The optimum detection levels that can be achieved by a secondary ion mass spectrometer are dependent on how efficiently a particular species of interest can be ionized and detected. One can determine in advance whether the analysis of a particular ion in the sample is possible, if the useful ion yield is known. The useful ion yield depends on the element, instrument transmission, the analytical conditions, the sample matrix, etc. The value of the useful ion yield for a species can diverge from one instrument type to another due to its different transmission and ionization probabilities. However, the same tendencies in the results may be expected for all types of instruments. In this paper, the authors present a quantitative secondary ion mass spectrometry analysis of the useful ion yield for the silicon dopant species in a gallium nitride matrix grown by metal organic chemical vapor deposition. Positively ionized cesium was used as the primary ion beam, and its energy was varied in the range from 0.5 to 5 kV. A quadrupole mass analyzer was utilized to collect secondary ion species of interest. The analysis results can be used to determine the primary beam energies for optimal Si sensitivity.

中文翻译：

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通过二次离子质谱法分析 GaN 中 Si 的有用离子产率

二级离子质谱仪可达到的最佳检测水平取决于电离和检测特定目标物质的效率。如果已知有用的离子产率，则可以预先确定是否可以分析样品中的特定离子。有用离子产率取决于元素、仪器传输、分析条件、样品基质等。由于其不同的传输和电离概率，物种的有用离子产率值可能因仪器类型而异。然而，对于所有类型的工具，结果中可能会出现相同的趋势。在本文中，作者对通过金属有机化学气相沉积生长的氮化镓基体中硅掺杂物质的有用离子产率进行了定量二次离子质谱分析。正电离的铯被用作初级离子束，其能量在 0.5 到 5 kV 的范围内变化。四极杆质量分析器用于收集感兴趣的次级离子种类。分析结果可用于确定最佳 Si 灵敏度的主光束能量。