technology Technology is the application of Conceptual model, conceptual knowledge to achieve practical goals, especially in a reproducible way. The word ''technology'' can also mean the products resulting from such efforts, including both tangible too ...

, soft lithography is a family of techniques for fabricating or replicating

structure A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

s using "elastomeric stamps, molds, and conformable photomasks". It is called "soft" because it uses

elastomer An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus (E) and high failure strain compared with other materials. The term, a portmanteau of ''ela ...

ic materials, most notably PDMS. Soft lithography is generally used to construct features measured on the micrometer to

nanometer 330px, Different lengths as in respect to the Molecule">molecular scale. The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm), or nanometer (American spelling Despite the va ...

scale. According to Rogers and Nuzzo (2005),

development Development or developing may refer to: Arts *Development (music), the process by which thematic material is reshaped * Photographic development *Filmmaking, development phase, including finance and budgeting * Development hell, when a proje ...

of soft lithography expanded rapidly from 1995 to 2005. Soft lithography tools are now commercially available.

Types

* PDMS stamp * Microcontact printing * Multilayer soft lithography * Nanosphere lithography * Patterning by etching at the nanoscale

Advantages

Soft lithography has some unique advantages over other forms of lithography (such as

photolithography Photolithography (also known as optical lithography) is a process used in the manufacturing of integrated circuits. It involves using light to transfer a pattern onto a substrate, typically a silicon wafer. The process begins with a photosensiti ...

and

electron beam lithography Electron-beam lithography (often abbreviated as e-beam lithography or EBL) is the practice of scanning a focused beam of electrons to draw custom shapes on a surface covered with an electron-sensitive film called a resist (exposing). The electron ...

). They include the following: *Lower cost than traditional photolithography in mass production *Well-suited for applications in

biotechnology Biotechnology is a multidisciplinary field that involves the integration of natural sciences and Engineering Science, engineering sciences in order to achieve the application of organisms and parts thereof for products and services. Specialists ...

*Well-suited for applications in plastic electronics *Well-suited for applications involving large or nonplanar (nonflat) surfaces *More pattern-transferring methods than traditional lithography techniques (more "ink" options) *Does not need a photo-reactive surface to create a nanostructure *Smaller details than

in laboratory settings (~30 nm vs ~100 nm). The resolution depends on the mask used and can reach 6 nm.

Types

Advantages

See also

References

Further reading