Stephen Y. Chou

Joseph C. Elgin Professor of Engineering and
Professor of Electrical Engineering
Ph.D. 1986, Massachusetts Institute of Technology

Advances in nanotechnology are offering great opportunities for innovation and discovery in many engineering and scientific areas.  This is because as structures become smaller than some fundamental physical length scales, many conventional theories no longer apply.

My group, the NanoStructure Laboratory (NSL) at Princeton, has two primary missions: (A) to develop new nanotechnologies for fabricating structures substantially smaller, better, and cheaper than current technology permits; and (B) to explore innovative nanodevices and advanced materials in electronics, optics, optoelectronics, magnetics and biology, by combining cutting-edge nanotechnology with frontier knowledge from different disciplines.


6 nm half-pitch NIL


The first Si room- temperature single electron memory


17 nm fluidic channels


LISA patterns

Our current projects include:
1. Nanotechnology.  Nanoimprint technology, electron-beam lithography, reactive ion etching, guided self-assembly (i.e. lithographically induced self-assembly (LISA), fracture-induced self-assembly (FISA), stress-induced self-alignment (SISA) of diblock copolymers, self-perfection by liquefaction (SPEL), and many other innovative nanofabrication technology.

2.  Nanoelectronics.  Ultra-small MOSFETs, single electron transistors and memories, phase change memories, thin-film transistors, resonant tunneling diodes and transistors, and nanowire and carbon nanotube devices.

3.  Nanophotonics.  Subwavlength optical elements (i.e. feature size less light wavelength) and systems (i.e.  photonic crystals, negative index materials, plamonics, etc.), ultra-fast photodetectors, tunable lasers, liquid crystals, deep UV filters and modulators.

4.  Nanomagnetics.  Patterned signal domain magnetic structures, single-domain bit patterned magnetic media (originally quantized magnetic disks).

5.  Nanobiology. Innovative biological manipulators, separators, detectors and analyzers for DNAs, proteins and cells, that combine nanofluidic channels, nanopillars, nanoelectronics, nanooptics, and nanomagnetics.

6.  Nanomaterials.  Advanced meta-materials and nanocrystals on amorphous substrate via prepatterned substrates.

Our previous work includes used invention and pioneering developments of new nanofabrication methods (i.e. nanoimprint lithography (NIL), laser assisted direct imprint (LADI), lithographically induced self-assembly (LISA), and self-perfection by liquefaction (SPEL)); a new paradigm in magnetic data storage--quantized magnetic disks (QMDs)(now called patterned media); the first room-temperature Si single electron memories, the first sub20 nm fluidic channels for biodetections; the first SOE polarizers, phase-plates, switches by NIL; and the first 510GHz MSM photodetectors.

NSL is equipped with a variety of state-of-the-art nanofabrication and nanodevice characterization facilities from ultrahigh resolution electron beam lithography, nanoimprint lithography, interference lithography, thermal and e-beam evaporators and sputtering systems, and RIE etchers to scanning electron and scanning force microscopes, wavelength tunable femtosecond lasers, electric and magnetic measurement systems, and polymer characterization.