Study on interaction between molecules adsorbed on silicon surface using quartz crystal microbalance and the multi-component organic species adsorption-induced contamination model

研究了一种评价物理吸附在硅表面的有机分子之间相互作用的方法和过程。为此，使用石英晶体微天平（QCM）；结合速率理论（Multi-component Organic Species absorption - induced pollution， MOSAIC）模型)对QCM得到的数据进行了分析。在本研究中，采用了以下流程。(a)水、异丙醇（IPA）和邻苯二甲酸二乙酯（DEP）以蒸汽的形式用氮气稀释到QCM的硅表面。(b)各单组分IPA和DEP体系在有湿度的氮气环境下，由其在硅表面浓度的增减行为得到物理吸附和解吸速率常数。(c)然后，在有湿度的氮气环境中将IPA蒸汽和DEP蒸汽的混合物供给硅表面。(d)在这个多组分系统中，利用从每个单组分系统得到的速率常数，在MOSAIC模型的…More基础上计算了增减行为。由于计算结果与测量结果相吻合，故得出以下结论：(1)双组分体系的吸附和解吸行为可以用各单组分体系的速率常数来描述。(2)物理吸附有机化合物表面浓度的较大限值是速率常数和存在于气相的有机化合物浓度的函数。(3)通过测量得到有机分子所占的面积。DEP的面积是IPA的2倍。根据C、H和0原子之间的键长估算，这种关系是可以接受的。(4)用单组分系统中IPA和DEP的面积来解释双组分系统（IPA和DEP）所占的面积。这表明IPA和DEP分子之间没有明显的相互作用。由此，利用QCM方法测量有机分子所占面积的相对值以及有机分子之间的相互作用等信息。少

A method and a process are studied for evaluating an interaction between organic molecules which are physisorbed on silicon surface. For this purpose, the quartz crystal microbalance (QCM) is used; the data obtained by the QCM is analyzed linked with the rate theory (The Multi-component Organic Species Adsorption-Induced Contamination (MOSAIC) model).In this study, the following processes are employed.(a) Water, isopropanol (IPA) and diethyl phthalate (DEP) are supplied to silicon surface of the QCM in the form of vapor diluted with gas nitrogen.(b) In each single-component system of IPA and DEP, the rate constants of physisorption and desorption are obtained in nitrogen ambient having humidity, from the behavior of increase and decrease in its concentration on silicon surface.(c) Next, the mixture of IPA vapor and DEP vapor is supplied to the silicon surface in nitrogen ambient having humidity.(d) In this multi-component system, the increase and decrease behavior is calculated on the … More basis of the MOSAIC model using the rate constants obtained from each single-component system.Because the calculation agreed with the measurement, the following conclusions are stated.(1) The adsorption and desorption behavior in a two-component system can be described using the rate constants obtained in each single-component system.(2) The larger limit of the surface concentration of physisorbed organic compounds is functions of rate constants and concentration of the organic compounds existing in the gas phase.(3) The area occupied by organic molecule is obtained by the measurement. The area for DEP is 2 times larger than that for IPA. This relationship is acceptable on the basis of the estimation accounting for bond length between C, H and 0 atoms.(4) The area occupied in the two component system (IPA and DEP) is explained using the area for IPA and DEP in a single-component system. This indicates that there is not a significant interaction between IPA and DEP molecules.From these, the measurement using the QCM method can provide with the information of a relative value of an area occupied by an organic molecule and an interaction between organic molecules. Less