Open AccessWafer scale fabrication of highly dense and uniform array of sub-5 nm nanogaps for surface enhanced Raman scatting substrates
Author(s) -
Haiwen Cai,
Yanping Wu,
Yanmeng Dai,
Nan Pan,
Yangchao Tian,
Yi Luo,
Xiaoping Wang
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.020808
Subject(s) - materials science , fabrication , atomic layer deposition , wafer , nanotechnology , substrate (aquarium) , nanometre , plasmon , optoelectronics , layer (electronics) , nanophotonics , raman spectroscopy , optics , medicine , oceanography , alternative medicine , physics , pathology , geology , composite material
Metallic nanogap is very important for a verity of applications in plasmonics. Although several fabrication techniques have been proposed in the last decades, it is still a challenge to produce uniform nanogaps with a few nanometers gap distance and high throughput. Here we present a simple, yet robust method based on the atomic layer deposition (ALD) and lift-off technique for patterning ultranarrow nanogaps array. The ability to accurately control the thickness of the ALD spacer layer enables us to precisely define the gap size, down to sub-5 nm scale. Moreover, this new method allows to fabricate uniform nanogaps array along different directions densely arranged on the wafer-scale substrate. It is demonstrated that the fabricated array can be used as an excellent substrate for surface enhanced Raman scatting (SERS) measurements of molecules, even on flexible substrates. This uniform nanogaps array would also find its applications for the trace detection and biosensors.