We have successfully prepared multilayered sculptured thin films with various combinations of the layer thicknesses using a shutter system specially designed for the oblique angle deposition. A series of different thicknesses were realized on a single substrate by moving a step-shaped shutter incrementally across the sample during the oblique angle deposition, while an ordinary straight shutter was used during normal deposition. This deposition process has been applied to fabricate local plasmon resonators comprised of the sandwich of Au nanorod array (NRA)/structured dielectric layer/Ag mirror. The fundamental optical properties of the local plasmon resonators have been already reported [1]. Briefly, the reflectance in NIR region can be controlled between 10^-4 and 1 due to the strong interference. At low reflectance conditions, Au nanorods absorb most of the incident light and are expected to enhance the local electric field in their close vicinity. However, detailed relation between the optical properties of the local plasmon resonators and the combination of the thicknesses of Au and dielectric layers has never been clarified. In this study, we prepared 4x6 arrays of the local plasmon resonators which have four and six different thicknesses of Au and the dielectric layers, respectively, on a single substrate of 50x50 mm². The surface enhanced Raman scattering intensity measured on the element with low reflectance is about 50 times stronger than that on the Au NRA prepared on the glass substrate (without Ag mirror). This indicates that the local electric field in the NIR region is controllable by using interference. Therefore, the NRA fabricated on the mirror with appropriate spacer layers is useful not only for improving conventional biochemical sensing but also for the novel applications using spatiotemporal control of the local plasmons. For optimization of the multilayered sculptured thin films, the combinatorial approach is quite useful.

[1] M. Suzuki et al., Journal of Nanophotonics 3, 031502 (2009).