DPN Technology / What is DPN?

What is DPN®?

Dip Pen Nanolithography® (DPN®) is NanoInk's patented process for deposition of nanoscale materials onto a substrate. The vehicle for deposition can include pyramidal scanning probe microscope tips, hollow tips, and even tips on thermally actuated cantilevers.

Dip Pen Nanolithography

Features & Benefits:

High Resolution and Accuracy

  • 14 nm line widths, 5 nm spatial resolution
  • Unmatched automated nanoscale registry

Extremely Versatile Chemical and Material Flexibility

  • A wide variety of chemical inks can be tailored to pattern onto numerous substrates (see figure below)
  • Capable of depositing multiple chemical compounds on the same substrate with nanoscale registration

Simple Operation and Experimental Procedures

Click to download a video showing the DPN process.
  • Can deposit direct-write, without need for resists
  • Operates in ambient conditions (no UHV necessary)
  • Patterning and imaging can be accomplished with the same instrument

Efficient and Scalable

  • Sophisticated design tools available with customized software (NanoInk's InkCAD™ )
  • Patterning and imaging routines are automated via InkCAD
  • Commercially available parallel pen arrays scale to 52 parallel pens; the 2D nano PrintArray™ provides massively, parallel DPN patterning with two-dimensional arrays of 55,000 pens

 

Table 1: Overview of the various DPN ink-substrates that have been reported

Ink Substrate Notes References
Alkylthiols (e.g. ODT & MHA) Au 15 nm resolution with sharp tips on single crystal surfaces, < 50 nm on polycrystalline surfaces [1-7, 22, 23, 33, 87, 92, 110, 111]
Ferrocenylthiols Au redox active nanostructures [59]
Silazanes SiOx GaAs patterning on oxides [81, 111]
Proteins Au, SiOx both direct write and indirect assembly [3b, 10, 11, 30, 34, 46, 47, 67, 77, 111]
Conjugated polymers SiOx polymer deposition verified spectroscopically and electrochemically [8-10]
DNA Au, SiOx sensitive to humidity and tip-silanization conditions [12, 64]
Fluorescent dyes SiOx luminescent patterns [10, 68]
Sols SiOx solid-state features [17, 18, 112]
Metal salts Si, Ge electrochemical and electroless deposition [14-16]
Colloidal particles SiOx viscous solution patterned from tip [13, 31, 65]
Alkynes Si C-Si bond formation [66]
Alkoxysilanes SiOx humidity control important [109, 111]
ROMP materials SiOx combinatorial polymer brush arrays [108]

Angew. Chem. Int. Ed. 2004, 43, 30-45

 

While the figure above speaks to DPN's material flexibility in terms of inks and substrates, the table below provides an instructive look at DPN's place among nanopatterning techniques. DPN's throughput far surpasses e-beam lithography through the use of highly scalable multi-pen arrays. The technique enables both bottom-up nanofabrication (self-assembly and templating) and top down resist-based techniques. Also, as a high resolution direct-write technique, materials of interest can be placed exactly, and only, where desired. DPN is the only sub-50 nm technique that can directly deposit molecules under ambient conditions because its environmental process controls allows precise control over many varieties of ink deposition. In addition, because NanoInk's nanolithography platform, the NSCRIPTOR™, is based on scanning probe microscopy technology, it is capable of both pattern fabrication and immediate verification of the result by imaging. DPN leverages the extremely accurate and precise positioning of scanning probe technology to achieve alignment registry between consecutively written nanoscale chemical patterns, or between a DPN pattern and microscale structures. The ability to precisely align multiple structures, consisting of distinct chemical or biomolecule functionalities, is a feature that makes DPN the ideal technique for bottom-up nanofabrication.

APPROACH Top Down Enables Both Top Down and Bottom Up Bottom Up
NanoPatterning Technique Photolithography E-beam Lithography NanoImprint Lithography Dip Pen Nanolithography MicroContact Printing Scanning Tunneling Microscopy
Serial/Parallel Parallel Serial Parallel Serial or Parallel Parallel Serial
Material Flexibility No No No Yes Yes Limited
Resolution ~35 nm ~15 nm ~10 nm 14 nm ~100 nm Atomic?
Registration Accuracy High High High Extremely High Low Extremely High
Speed Very Fast Moderate Fast Slower, but scalable Fast Very Slow
Cycle Time Weeks Days? Days-Week Hours—Change on the Fly Days-Week Days
Cost Purchase › $10 M › $1 M › $500 K ‹ $250 K ~$200 K › $250 K
Operation High-Masks High Moderate-Molds Low Moderate-Masks Low

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