探针对表面等离子体共振的影响

Effect of Probe on Surface Plasmon Resonance

采用时域有限差分方法(FDTD)对探针诱导表面等离子体共振耦合纳米光刻(PSPRN)技术中探针的引入对表面等离子体共振(SPR)产生的影响进行了模拟分析,以获得最佳的光刻实验条件。结果表明,高斯光束聚焦光斑越小,SPR场增强效应也越小。接触模式下,针尖曲率半径为10 nm的硅(Si),35 nm,100 nm的金(Au)探针,分别使SPR共振角变化了0,0.8°和1°。且对于Au探针,针尖曲率半径大的,针尖处的局域场增强效应要小。分析表明,采用针尖曲率半径为10 nm的Si或35 nm的Au探针,在合适的SPR膜层上通过调整光入射角度,很有可能实现50 nm的光刻记录点。

In order to get the best lithography conditions,the effect of the probe on surface plasmon resonance（SPR）,which is utilized in probe induced surface plasmon resonance coupling nanolithography（PSPRN）,has been investigated by using finite difference time domain（FDTD） method.The results show that SPR field enhancement effect is small with a small waist radius of fundamental mode Gaussian beam.When working in contact mode,Si probe with a tip radius of curvature of 10 nm,and 35 nm and 100 nm for Au prodes,make the SPR resonance angle change 0,0.8°,1°respectively.For Au prodes,smaller tip radius of curvature can get stronger local field enhancement effect.Analysis showed that with a Si probe of 10 nm tip radius of curvature or a Au probe of 35 nm tip radius of curvature probe,by adjusting the incident angle,it is likely to realize experimentally a 50 nm recording spot with a suitable SPR film structure.