Mione M A, Vandalon V, Mameli A, Kessels W M M, Roozeboom F
Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
TNO-Holst Centre, High Tech Campus 31, 5656 AE Eindhoven, The Netherlands.
J Phys Chem C Nanomater Interfaces. 2021 Nov 18;125(45):24945-24957. doi: 10.1021/acs.jpcc.1c07980. Epub 2021 Nov 8.
An atmospheric-pressure plasma-enhanced spatial atomic layer deposition (PE-s-ALD) process for SiO using bisdiethylaminosilane (BDEAS, SiH[NEt]) and O plasma is reported along with an investigation of its underlying growth mechanism. Within the temperature range of 100-250 °C, the process demonstrates self-limiting growth with a growth per cycle (GPC) between 0.12 and 0.14 nm and SiO films exhibiting material properties with those reported for low-pressure PEALD. Gas-phase infrared spectroscopy on the reactant exhaust gases and optical emission spectroscopy (OES) on the plasma region are used to identify the species that are involved in the ALD process. Based on the identified species, we propose a reaction mechanism where BDEAS molecules adsorb on -OH surface sites through the exchange of one of the amine ligands upon desorption of diethylamine (DEA). The remaining amine ligand is removed through combustion reactions activated by the O plasma species leading to the release of HO, CO, and CO in addition to products such as NO, NO, and CH-containing species. These volatile species can undergo further gas-phase reactions in the plasma as indicated by the observation of OH*, CN*, and NH* excited fragments in OES. Furthermore, the infrared analysis of the precursor exhaust gas indicated the release of CO during precursor adsorption. Moreover, this analysis has allowed the quantification of the precursor depletion yielding values between 10 and 50% depending on the processing parameters. Besides providing insights into the chemistry of atmospheric-pressure PE-s-ALD of SiO, our results demonstrate that infrared spectroscopy performed on exhaust gases is a valuable approach to quantify relevant process parameters, which can ultimately help evaluate and improve process performance.
报道了一种使用双二乙氨基硅烷（BDEAS，SiH[NEt]）和O等离子体通过大气压等离子体增强空间原子层沉积（PE-s-ALD）制备SiO的工艺，并对其潜在的生长机制进行了研究。在100-250°C的温度范围内，该工艺表现出自限性生长，每个周期的生长速率（GPC）在0.12至0.14nm之间，且SiO薄膜的材料性能与低压PEALD报道的性能相当。对反应废气进行气相红外光谱分析以及对等离子体区域进行光发射光谱分析（OES），以识别参与ALD工艺的物种。基于所识别的物种，我们提出了一种反应机制，其中BDEAS分子在二乙胺（DEA）解吸时通过交换一个胺配体吸附在-OH表面位点上。剩余的胺配体通过由O等离子体物种激活的燃烧反应被去除，除了NO、NO和含CH物种等产物外，还会释放出HO、CO和CO。如在OES中观察到OH*、CN和NH激发碎片所示，这些挥发性物种可在等离子体中进一步进行气相反应。此外，对前驱体废气的红外分析表明在前驱体吸附过程中会释放出CO。而且，该分析能够根据工艺参数对前驱体消耗进行定量，其值在10%至50%之间。除了深入了解大气压PE-s-ALD制备SiO的化学过程外，我们的结果表明对废气进行红外光谱分析是量化相关工艺参数的一种有价值的方法，这最终有助于评估和改进工艺性能。
