Plasmonic Nanofocusing in Deep and Extreme Sub-Wavelength Scale for Scalable Nanolithography

Maskless nanolithography is an agile and cost effective approach if their throughputs can be scaled for mass production purposes. Using plasmonic nanolithography approach, direct pattern writing was successfully demonstrated with 22 nm half-pitch at high speed. Plasmonic nanolithography uses an array of plasmonic lenses to directly pattern features on a rotating substrate. Taking the advantage of air bearing surface techniques, the system can expose the wafer pixel by pixel with a speed of ∼10 m/s, much faster than any conventional scanning based lithography system. It is a low-cost, high-throughput maskless approach for the next generation lithography and also for the emerging nanotechnology applications, such as nanoscale metrology and imaging. A critical part of the PNL is to use plasmonic lens to deliver highly concentrated optical power at nanoscale. We have demonstrated such nanoscale process and achieved 22 nm resolution. Here, we report our recent efforts of designing new plasmonic nanofocusing structures that is capable of achieving optical confinement below 20 nm which can potentially support direct patterning at sub-10nm resolution.

Scalable Plasmonic Nanolithography: Prototype System Design and Construction

Maskless nanolithography is an agile and cost effective approach if their throughputs can be scaled for mass production purposes. Using plasmonic nanolithography (PNL) approach, direct pattern writing was successfully demonstrated with around 20 nm half-pitch at high speed. Here, we report our recent efforts of implementing a high-throughput PNL prototype system with unique metrology and control features, which are designed to use an array of plasmonic lenses to pattern sub-100 nm features on a rotating substrate. Taking the advantage of air bearing surface techniques, the system can expose the wafer pixel by pixel with a speed of ∼10 m/s, much faster than any conventional scanning based lithography system. It is a low-cost, high-throughput maskless approach for the next generation lithography and also for the emerging nanotechnology applications, such as nanoscale metrology and imaging.

PLASMONIC NANOLITHOGRAPHY: TOWARDS NEXT GENERATION NANOPATTERNING

Plasmonic nanolithography (PNL) is a surface plasmons (SPs)-based high resolution nanolithography technology. It has attracted great interests for its capability of forming sub-diffraction-limit patterns. It explores the properties of surface plasmons in tight light confinement, strongly localized optical field and the enhancement of evanescent filed for super-resolution imaging and lithography. SPs can be manipulated by the interaction of light with metallic structures to generate a strongly enhanced spatial distribution of an electric field in the proximity of metal surface. Once its resonance frequency falls into the photoresponse range of a resist, the resulting optical field would be recorded with nanoscale resolution. Using the low cost light sources, PNL has demonstrated high resolution comparable to the industrial achievement of sub-22 nm half-pitch resolution, which is accomplished using the costly state-of-the-art deep UV lithography tools. Upon the distinct interactions between the light and nanostructures, the PNL is categorized into three types, i.e. enhanced near-field lithography (ENL), superlens (planar lens) lithography (SLL) and focused plasmonic lithography (FPL). This paper will give an overview of the development of these technologies and the latest achievements.