数值模拟探针诱导表面等离子体共振耦合纳米光刻

采用有损耗介质和色散介质的二维时域有限差分方法，数值模拟了以光波长514.5nm的p偏振基模高斯光束为入射光源，激发Kretschmann型表面等离子体共振，并通过探针的局域场增强效应实现纳米光刻的新方法——探针诱导表面等离子体共振耦合纳米光刻.分别就探针与记录层的间距以及探针针尖大小，模拟分析了不同情况下探针的局域场增强效应和记录层表面的相对电场强度振幅分布.结果表明，探针工作在接触模式时，探针的局域场增强效应最明显，记录层表面的相对电场强度振幅的对比度最大；当探针针尖距记录层5nm时，针尖下方记录层表面的相对电场强度振幅大于光刻临界值的分布宽度与针尖尺寸相近.关键词：纳米光刻表面等离子体共振时域有限差分方法

Numerical simulation of probe induced surface plasmon resonance coupling nanolithography

A new nanolithographic technology, the probe induced surface plasmon resonance coupling nanolithography (PSPRN), is presented and analyzed numerically by using finite difference time domain method for the loss and dispersive materials. The PSPRN uses a fundamental mode Gaussian beam with wavelength of 514.5nm to excite the Kretschmann surface plasmon resonance, and utilizes the metal probe local-field enhancement effect to realize nanolithography. The influences of different distances between probe and recording layer and different sizes of tip on local field enhancement and the distribution of electric field intensity amplitude on the surface of recording layer were investigated. Results show that the local field enhancement effect is most significant and the electric field intensity amplitude contrast ratio is maximal when the probe is in contact with the recording layer. When the distance between tip and recording layer is 5nm, the distribution width of the relative electric field intensity amplitude above the critical value for near-field nanolithography on the surface of recording layer is close to the size of the tip.