Low volatility precursors are widely utilized in chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes. Compared to gases and high volatility liquid precursors, delivery of low volatility liquid and solid precursors can be problematic, with solid precursors being particularly so. To investigate some of these delivery issues, the performance of a vapor draw vessel was characterized for the delivery of pentakis(dimethylamido) tantalum (PDMAT), a low-volatility solid precursor at preferable delivery temperatures, for reduced-pressure cyclical CVD and ALD processes. Vessel characterization involved determining (1) a source efficiency as a function of process conditions and (2) the degree of PDMAT decomposition as a function of temperature and vessel idle time. The PDMAT partial pressure, flow rate, and mass per injection used to determine the source efficiency were determined from measurements obtained using a custom-designed non-dispersive infrared gas analyzer. For a series of injections after an idle/purge sufficiently long to saturate the vessel head space, the source efficiency decreased from a maximum slightly less than unity for the first injection until a consistent value was reached that was approximately one half to one third of the maximum value. A comparable trend was observed for mass delivered per injection. For the conditions used in this investigation, the source efficiency decreased when the injection time was increased to longer than 1 s, when pressure was decreased, and when the carrier gas flow rate was increased. Although the corresponding mass per injection increased with these changes, the increase in mass was less than that predicted had the carrier gas been saturated. The source efficiency did not depend strongly on temperature and only moderately on vessel idle durations (4–16 s). The degree of PDMAT decomposition was evaluated by measuring the partial pressure of dimethylamine (the primary PDMAT decomposition product under the conditions of this investigation) using the same gas analyzer. For a given idle time, the amount of dimethylamine delivered more than doubled as vessel temperature was increased from 68 to 78 °C.

中文翻译：

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用于低挥发性固体前体输送的蒸汽抽取容器性能的表征

低挥发性前体被广泛用于化学气相沉积（CVD）和原子层沉积（ALD）工艺中。与气体和高挥发性液体前体相比，低挥发性液体和固体前体的输送可能会有问题，其中固体前体尤其如此。为了研究其中的一些输送问题，对抽气容器的性能进行了表征，以在优选的输送温度下输送五（二甲基氨基）钽（PDMAT）（一种低挥发性固体前体），用于减压循环CVD和ALD工艺。容器表征涉及确定（1）源效率与工艺条件的关系，以及（2）PDMAT分解程度与温度和容器闲置时间的关系。PDMAT分压，流量，通过使用定制设计的非分散红外气体分析仪获得的测量值确定用于确定源效率的每次进样质量和每次进样质量。对于在闲置/吹扫足够长的时间以使容器顶部空间饱和之后的一系列进样，源效率从第一次进样的最大值略微小于单位1降低，直到达到恒定值，约为进样口的一半到三分之一。最大值。每次注射的质量观察到类似的趋势。对于本研究中使用的条件，当注入时间增加到大于1 s，降低压力和增加载气流速时，源效率降低。尽管每次注射的相应质量随这些变化而增加，质量的增加小于载气饱和时的预测。源的效率与温度无关，在很大程度上不取决于容器的闲置时间（4–16 s）。通过使用相同的气体分析仪测量二甲胺（在此研究条件下的主要PDMAT分解产物）的分压来评估PDMAT的分解程度。在给定的闲置时间内，随着容器温度从68°C升高到78°C，输送的二甲胺数量增加了一倍以上。通过使用相同的气体分析仪测量二甲胺（在此研究条件下的主要PDMAT分解产物）的分压来评估PDMAT的分解程度。在给定的闲置时间内，随着容器温度从68°C升高到78°C，输送的二甲胺数量增加了一倍以上。通过使用相同的气体分析仪测量二甲胺（在此研究条件下的主要PDMAT分解产物）的分压来评估PDMAT的分解程度。在给定的闲置时间内，随着容器温度从68°C升高到78°C，输送的二甲胺数量增加了一倍以上。