Photolithography Electron beam lithography (EBL) X-ray lithography Extreme ultraviolet lithography (EUVL) Light coupling nanolithography (LCM) Scanning probe microscope lithography (SPM) Nanoimprint lithographyh Dip-Pen nanolithography Soft lithography Each nanolithography technique has varying factors of resolution, time consumption, and cost. There are three basic methods used by nanolithography. One involves using a resist material which acts as a "mask" to cover and protect the areas of the surface that are intended to be smooth. The uncovered portions can now be etched away, with the protective material acting as a stencil. The second method involves directly carving the desired pattern. Etching may involve using a beam of quantum particles, such as electrons or light, or chemical methods such as oxidation or SAM's (self-assembled monolayers) . The third method places the desired pattern directly on the surface, producing a final product that is ultimately a few nanometers thicker than the original surface. In order to visualize the surface to be fabricated, the surface must be visualized by a nano-resolution microscope, which include the scanning probe microscope (SPM) and the atomic force microscope (AFM) . Both microscopes can also be engaged in processing the final product. SAM's One of the methods of nanolithography is use of self-assembled monolayers (SAM) which develops soft methodology. SAMs are long chain alkanethiolates that are self-assembled on gold surfaces making a well-ordered monolayer films. The advantage of this method is to create a high quality structure with lateral dimensions of 5 nm to 500 nm. In this methodology a patterned elastomer made of polydimethylsiloxane (PDMS) as a mask is usually used. In order to make a PDMS stamp, the first step is to coat a thin layer of photoresist onto a silicon wafer. The next step is to expose the layer with UV light, and the exposed photoresist is washed away with developer. In order to reduce the thickness of the prepolymer, the patterned master is treated with perfluoroalkyltrichlorosilane. These PDMS elastomers are used to print micron and submicron design chemical inks on both planar and curved surfaces for different purposes. Medicine One highly researched application of nanochemistry is medicine. A simple skin-care product using the technology of nanochemistry is sunscreen. Sunscreen contains nanoparticles of zinc oxide and titanium dioxide. These nanochemicals protect the skin against harmful UV light by absorbing or reflecting the light and prevent the skin from retaining full damage by photoexcitation of electrons in the nanoparticle. Effectively, the excitation of the particle blocks skin cells from DNA damage. New developments in nanochemistry provide a variety of nanostructure materials with significant properties that are highly controllable. Some of the application of these nanostructure materials include SAMs and lithography, use of nanowires in sensors, and nanoenzymes. Shimon Weiss, a professor at the University of California, Los Angeles, is known for his research of fluorescent semiconductior nanocrystals, a subclass of quantum dots, for the purpose of biological labeling. Paul Alivisatos, from the University of California Berkeley, is also notable for his research on the fabrication and use of nanocrystals. This research has the potential to develop insight into the mechanisms of small scale particles such as the process of nucleation, cation exchange, and branching. A notable application of these crystals is the development of quantum dots.
Photolithography Electron-beam lithography X-ray lithography Extreme ultraviolet lithography Light coupling nanolithography Scanning probe microscope Nanoimprint lithography Dip-Pen nanolithography Soft lithography Each nanolithography technique has varying factors of resolution, time consumption, and cost. There are three basic methods used by nanolithography. One involves using a resist material which acts as a "mask" to cover and protect the areas of the surface that are intended to be smooth. The uncovered portions can now be etched away, with the protective material acting as a stencil. The second method involves directly carving the desired pattern. Etching may involve using a beam of quantum particles, such as electrons or light, or chemical methods such as oxidation or Self-assembled monolayers . The third method places the desired pattern directly on the surface, producing a final product that is ultimately a few nanometers thicker than the original surface. In order to visualize the surface to be fabricated, the surface must be visualized by a nano-resolution microscope, which include the scanning probe microscopy and the atomic force microscope . Both microscopes can also be engaged in processing the final product. Self-assembled monolayers One of the methods of nanolithography is use of self-assembled monolayers , which develops soft methodology. Self-assembled monolayers are long chain alkanethiolates that are self-assembled on gold surfaces making a well-ordered monolayer films. The advantage of this method is to create a high quality structure with lateral dimensions of 5 nm to 500 nm. In this methodology a patterned elastomer made of polydimethylsiloxane (PDMS) as a mask is usually used. In order to make a PDMS stamp, the first step is to coat a thin layer of photoresist onto a silicon wafer. The next step is to expose the layer with UV light, and the exposed photoresist is washed away with developer. In order to reduce the thickness of the prepolymer, the patterned master is treated with perfluoroalkyltrichlorosilane. These PDMS elastomers are used to print micron and submicron design chemical inks on both planar and curved surfaces for different purposes. Medicine One highly researched application of nanochemistry is medicine. A simple skin-care product using the technology of nanochemistry is sunscreen. Sunscreen contains nanoparticles of zinc oxide and titanium dioxide. These chemicals protect the skin against harmful UV light by absorbing or reflecting the light and prevent the skin from retaining full damage by photoexcitation of electrons in the nanoparticle. Effectively, the excitation of the particle blocks skin cells from DNA damage. New developments in nanochemistry provide a variety of nanostructure materials with significant properties that are highly controllable. Some of the application of these nanostructure materials include self-assembled monolayers and lithography, use of nanowires in sensors, and nanoenzymes. Shimon Weiss, a professor at the University of California, Los Angeles, is known for his research of fluorescent semiconductor nanocrystals, a subclass of quantum dots, for the purpose of biological labeling. Paul Alivisatos, from the University of California Berkeley, is also notable for his research on the fabrication and use of nanocrystals. This research has the potential to develop insight into the mechanisms of small scale particles such as the process of nucleation, cation exchange, and branching. A notable application of these crystals is the development of quantum dots.
R
Electron beam lithography (EBL)
Electron-beam lithography
D
(EUVL)
D
(LCM)
R
lithography (SPM) Nanoimprint lithographyh
Nanoimprint lithography
R
SAM's (self-assembled monolayers)
Self-assembled monolayers
R
microscope (SPM)
microscopy
D
(AFM)
R
SAM's
Self-assembled monolayers
R
(SAM)
,
R
SAMs
Self-assembled monolayers
R
nanochemicals
chemicals
R
SAMs
self-assembled monolayers
R
semiconductior
semiconductor