SCIL technology; from sample to production
Marc A. Verschuuren1* and Rob Voorkamp1
1Philips SCIL Nanoimprint Solutions,
De Lismortel 31, 5612 AR, The Netherlands. Email address: marc.verschuuren@philips.com

Substrate Conformal Imprint Lithography (SCIL), a full wafer based nanoimprint method thatuses soft PDMS stamps capable of sub-10nm resolution, is used since 2008 for production ofVCSEL lasers. In 2015 Philips started a dedicated technology venture to bring high volume
production solutions to the market. This is based on high volume production tooling, dedicatedresist and stamp material development and collaborating with customers to progress quickly
from initial demonstration to process development and verification, pilot production andtransfer to the end customer production line.
SCIL solves the limitations of soft-stamp based NIL techniques and allows low pressure, truly
wafer scale conformal contact and sub-10 nm resolution. The in-house developed imprint resist
offers additional functionality (chemical, physical) which lowers the total cost of ownership ofthe patterning process. [1] The combination of our sol-gel based resists with X-PDMS soft
conformal stamps has demonstrated industry leading stamp lifetime of up to 1100 imprints on
200mm wafers for sub-50nm patterns with sub-nm pattern variation. This is a significant
improvement compared other published results. [2]In the nanophotonics field nanoimprint can have a high added value, especially in theemerging fields of meta-lenses and augmented reality applications. This is due to thecombination of deep sub-micron patterns and typically high refractive index materials (n > 1.8,
pref. n > 2.3), all on large areas. SCIL is developing fully inorganic high index functional resists
which are directly patterned with high resolution, achieve a high refractive index and exhibit
low shrinkage. Fig. 1a. shows the range in refractive index of our NanoGlass resists and in 1b.
the direct replication of high aspect ratio slanted gratings in high index fully inorganic resist.
Inorganic resist materials have distinct advantages but are not always the best option for aprocess. SCIL has tested many organic UV curable resist materials available on the market but
found that none of these would provide the high resolution, fast curing and stamp lifetime of
our NanoGlass range. SCIL has therefore started the development of our own fully organic UV
curable resist material and in the contribution, we will update on the performance of thesesystems.
In the past, SCIL has demonstrated sub-10nm overlay performance for areas up to ~10cm2
using a table-top SCIL test setup with a piezo controlled stage. [1,3] Over the last year we havedesigned, built and integrated automatic overlay alignment functionality in our AutoSCIL
production platform. The system is designed to achieve ~ 1 µm overlay accuracy in x,y over
150mm and 200mm full wafers. The overlay alignment step will have negligible effect on theproduction throughput of ~40 and 35 wafers/hour for 150mm and 200mm wafers respectively.

Figure 2 shows an overlay error map of a 200mm wafer. The errors are on 16 points between
a 1st and 2nd imprinted and aligned pattern. A magnification error and shift is found which isdue to the imprints being made at slightly elevated temperatures and which is consistent withthe difference in the thermal expansion coefficient for the stamp back-plate and silicon wafer.
In this contribution, SCIL will share more and detailed information on the overlay performanceof the AutoSCIL platform.
References
1. Marc A. Verschuuren, Mischa Megens, Yongfeng Ni, Hans van Sprang and Albert
Polman, Adv. Opt. Techn. 6(3-4) 243–264 (2017)
2. Hubert Teyssedre, Stefan Landis, et. al. Adv. Opt. Techn. 6(3-4) 277 (2017)
3. M.A. Verschuuren, Thesis: Substrate Conformal Imprint Lithography forNanophotonics, 2010 Utrecht UniversityFig. 1. A. Optical dispersion of our NanoGlass resists. B. SEM images of directly imprinted slanted
cured at 200°C

Overlay error between 1st imprinted
layer and a 2nd, aligned imprinted
layer on a 200mm wafer.

Fig. 2. Overlay error map of a 200mm wafer for two imprinted patterns.