Dynamical study of surface photochemistry by VUV radiation

VUV辐射表面光化学的动力学研究

• 批准号: 03453024
• 负责人: TANAKA Kenichiro
• 金额: $ 0.64万
• 依托单位: National Laboratory for High Energy Physics
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03453024/
• 关键词: Synchrotron Radiation; Surface Photochemistry; Core excitation; Ion Desorption; Site Specific Reaction; 軟X線; イオン分光; 紫外光; 反応動力学

Photochemical reaction of the adsorbate molecules on the solid surface in a soft x-ray region is important for fundamental study of elementary chemical reactions as well as for application study of photochemical vapor deposition, etching catalysis and so on. Among these reactions, photon stimulated desorption (PSD) is a relatively simple reaction to investigate both theoretically and experimentally. From this point of view, in this project we have designed and constructed a new experimental apparatus involving an TOF ion specrtomater, Auger electron analyser and a mass spectrometer to elucidate the full mechanism of a soft x-ray photochemical reactions of the adsorbed molecules on the surfaces. Using this apparatus, we have succeeded in detecting both Auger electrons and ionic products of photon stimulated desorption in both H_2O/Si(100) and PMMA/Au/Si(100) systems. The results are summarized as follows.(1) H^+ and O^+ ions were observed in the photon stimulated ion desorption (PSID) f … More rom H_2O/Si(100) system in the range 500-700 eV. PSID yields of these ions indicate characteristic behavior near O K-edge; H^+ exhibits sharp rise at 530 eV and two broad maxima below and above O K-edge, O^+ exhibits a delayed threshold at 570 eV. These results have been discussed with the formation of multiple charged ions followed by reneutralization of the excess of charge with strong interaction with the surface.(2) Various ions involving the monomer ion were observed in PSD from PMMA/Au/Si(100) systems. Excitations of carbon 1s electron to pi^* and sigma^* resonance states at 287.9 eV show remarkable enhancement of CH^+ and CH_2^+ ions. In oxygen K-edge region, increase in COOCH_3^+ was not observed where as that in HCI^+ was observed. Some of fragment ions have been observed to occur specifically around the site of the atom where the core electron excitation takes place. Based on these observations, one might consider the use of tunable soft x-ray to stimulate chemical reactions or to selectively break large organic molecules, as one pleases. Less

柔软X射线区域中固体表面上的吸附物分子的光化学反应对于基本化学反应的基本研究以及光化学蒸气沉积，蚀刻催化剂等的应用研究很重要。在这些反应中，光子刺激的解吸（PSD）是一种相对简单的反应，用于在实验上研究理论和实验。从这个角度来看，在这个项目中，我们设计并构建了一种新的实验设备，其中涉及TOF离子Specrtomater，螺旋钻电子分析仪和质谱仪仪，以阐明表面上柔软的X射线光化学反应的完整机制。使用该设备，我们成功地检测了H_2O/SI（100）和PMMA/AU/AU/SI（100）系统的光子刺激解吸的螺螺电子和离子产物。结果总结如下。（1）在光子刺激的离子解吸（PSID）F中观察到H^+和O^+离子。在500-700 eV范围内，更多的ROM H_2O/SI（100）系统。这些离子的pSID产量表明在o k边缘附近的特征行为； H^+在530 eV时表现出急剧上升，在O k-gede上方和上方的两个宽最大值，O^+在570 eV时表现出延迟的阈值。已经讨论了这些结果，形成了多个带电离子，然后与表面相互作用的过量电荷进行了重中化。（2）在PMMA/AU/SI（100）系统的PSD中观察到涉及单体离子的各种离子。碳1S电子对PI^*的激发和Sigma^*共振状态为287.9 EV显示出CH^+和CH_2^+离子的显着增强。在氧气k边缘区域中，观察到hci^+中的cooch_3^+的增加。观察到一些碎片离子特别发生在发生核心电子兴奋的原子位点。基于这些观察结果，人们可能会考虑使用可调的软X射线来刺激化学反应或选择性地打破大型有机分子。较少的

项目成果

M.Ukai: "Ionizing and non-ionizing decays of superexcited acetylene molecules in the extreme-ultraviolet region." J.Chem.Phys.95. 4142-4153 (1991)

M.Ukai：“超激发乙炔分子在极紫外区域的电离和非电离衰变。”

H. Ikeura, T. Sekiguchi, K. Tanaka, K. Obi, N. Ueno and K. Honma: "The mechanism of ion desorption from H_2O/Si(100) by O 1s electron excitation." Jpn. J. Appl. Phys. (Suppl.). 32-2. 246-248 (1993)

H. Ikeura、T. Sekiguchi、K. Tanaka、K. Obi、N. Ueno 和 K. Honma：“通过 O 1s 电子激发从 H_2O/Si(100) 中离子解吸的机制。”

N. Ueno, Y. Kobayashi, T. Sekiguchi, H. Ikeura, K. Sugita, K. Honma, K. Tanaka, E. Orti and R. Viruela: "Valence bands of PMMA and photoion emission in VUV region." J. Appl. Phys.72-11. 5423-5428 (1992)

N. Ueno、Y. Kobayashi、T. Sekiguchi、H. Ikeura、K. Sugita、K. Honma、K. Tanaka、E. Orti 和 R. Viruela：“PMMA 的价带和 VUV 区域的光电离子发射。”

K.Kameta: "Photoabsorption,photoionization,and neutral dissociation cross sections of dimethylether and ethyl methyl ether in the extreme-ultraviolot range." J. Chem. Phys.96. 4911-4917 (1992)

K.Kameta：“二甲醚和乙基甲基醚在极紫外范围内的光吸收、光电离和中性解离截面。”

N.Ueno: "Site specific photochemical reaction of PMMA by core electron excitation." Jpn. J. Appl. Phys. 32-2. 229-231 (1993)

N.Ueno：“通过核心电子激发产生 PMMA 的位点特异性光化学反应。”