Nanolithography : Introduction to nanolithography head points: Optical lithography Optical laser nanolithography Multiphoton lithography https://www.linkedin.com/in/preeti-choudhary-266414182/ https://www.instagram.com/chaudharypreeti1997/ https://www.facebook.com/profile.php?id=100013419194533 https://twitter.com/preetic27018281 Please like, share, comment and follow. stay connected If any query then contact: chaudharypreeti1997@gmail.com Thanking-You Preeti Choudhary

1. Nano-Lithography
Presented by: Preeti Choudhary
M.Sc. (Applied Physics)

2. Introduction to nano-lithography

3. Optical lithography
Main article: Photolithography
 Optical lithography, which has been the predominant patterning technique since the
advent of the semiconductor age, is capable of producing sub-100-nm patterns
with the use of very short optical wavelengths. Several optical lithography
techniques require the use of liquid immersion and a host of resolution
enhancement technologies like phase-shift masks(PSM) and optical proximity
correction (OPC). Multiple patterning is a method of increasing the resolution by
printing features in between pre-printed features on the same layer by etching or
creating sidewall spacers, and has been used in commercial production
of microprocessors since the 32 nm process node e.g. by directed self-
assembly (DSA). Extreme ultraviolet lithography (EUVL) uses ultrashort wavelengths
(13.5 nm) and as of 2015, is the most popularly considered Next-generation
lithography (NGL) technique for mass-fabrication.
 Ref: "ASML: Press - Press Releases - ASML reaches agreement for delivery of
minimum of 15 EUV lithography systems". www.asml.com. Retrieved 2015-05-11.

4. Optical laser nanolithography
 Optical lithography is referred to as a method for replicating patterns used to create
IC configuration on a photoresist layer sensitive to radiation exposure and coated
over a silicon or other semiconductor wafer.
 Lithography includes imprinting the circuit pattern (template), photoresist
technology, and mask making.
 There are a few variants of realizing optical lithography (Fig. ): contact or shadow
printing (a), shadow printing with a gap (b), and projection printing (c).
 optical lithography made use of visible (l ˆ436 nm) and UV (l ˆ365 nm) light emitted
by a mercury vapor lamp.
 Nanolithography is the branch of nanotechnology concerned with the study and
application of fabricating nanometer-scale structures, meaning patterns with
at least one lateral dimension between 1 and 1,000 nm. Different approaches can be
categorized in serial or parallel, mask or maskless/direct-write, top-down or
bottom-up, beam or tip-based, resist-based or resist-less methods.

5.  Applications of nanolithography include among
others: Multigate devices such as Field effect
transistors (FET), Quantum dots, Nanowires, Gratings, Zone
plates and Photomasks, nanoelectromechanical systems
(NEMS), or semiconductor integrated
circuits (nanocircuitry).

6.  Electron-beam lithography
 Main article: Electron beam lithography
 Electron beam lithography (EBL) or electron-beam direct-write lithography
(EBDW) scans a focused beam of electrons on a surface covered with an
electron-sensitive film or resist(e.g. PMMA or HSQ) to draw custom shapes. By
changing the solubility of the resist and subsequent selective removal of
material by immersion in a solvent, sub-10 nm resolutions have been
achieved. This form of direct-write, maskless lithography has high resolution
and low throughput, limiting single-column e-beams
to photomask fabrication, low-volume production of semiconductor devices,
and research&development. Multiple-electron beam approaches have as a
goal an increase of throughput for semiconductor mass-production.
 EBL can be utilized for selective protein nanopatterning on a solid substrate,
aimed for ultrasensitive sensing.

7.  Nanoimprint lithography
 Main article: Nanoimprint lithography
 Nanoimprint lithography (NIL), and its variants, such as Step-and-
Flash Imprint Lithography, LISA and LADI are promising
nanopattern replication technologies where patterns are created
by mechanical deformation of imprint resist, typically
a monomer or polymer formulation that is cured by heat
or UV light during imprinting. This technique can be combined
with contact printing and cold welding.

8. Multiphoton lithography
Multiphoton lithography (also known as direct laser lithography or direct
laser writing) patterns surfaces without the use of a photomask,
whereby two-photon absorption is utilized to induce a change in
the solubility of the resist.
 Scanning probe lithography
Scanning probe lithography (SPL) is a tool for patterning at the nanometer-
scale down to individual atoms using scanning probes. Dip-pen
nanolithography is an additive, diffusive method, thermochemical
nanolithography triggers chemical reactions, thermal scanning probe
lithography creates 3D surfaces from polymers, and local oxidation
nanolithographyemploys a local oxidation reaction for patterning purposes

10. Thank you