Allen school of electrical and computer engineering, georgia institute of technology, atlanta, ga, usa. To avoid photoresist contamination of the graphene surface, all subsequent lithography steps used a pmma 50 nm as a deep uv photoresist. Shinetsu microsi offers thick and thin 248nm excimer duv resist for specialty applications. Optical components and their coatings are being forced to operate at wavelengths below 400 nm and into the deep uv region. Uv regions308 nanometers nm from xecl, 249 nm from krf and 222 nm from krclto delineate images in a number of resists. This course provides a broad, deep treatment of lithography, the key driving technology in. Feature size in the photolithography sample is also limited by the wavelength of light generated by the optical mask aligner. Uvled lithography for 3d high aspect ratio microstructure patterning jungkwun jk kim, seungjoon paik, florian herrault, mark g. Mercury lamps were used earlier as illumination source. Uv led lithography for 3d high aspect ratio microstructure patterning jungkwun jk kim, seungjoon paik, florian herrault, mark g. The specific absorbance of the su8 layers have been measured in dependence on the wavelength to calculate the power of the absorbed radiation. Lithography for nanotechnology cmos ics this oneday course describes the stateoftheart and latest advances in lithography for todays most advanced cmos nanotechnology ics.
The following discusses the design considerations of producing a system that can achieve the optical and mechanical criteria of microlithography while still maintaining the simplicity and versatility for a research and development instrument. Extreme ultraviolet euv sources for lithography based on. Chapter 1 introducing optical lithography lithography creates a resist image on the wafer. Lithography, the technique for manufacturing microelectronic semiconductor devices such as processors or memory chips, presently uses deep uv duv radiation. Asml claims major euv lithography milestone extremetech.
Instead of hard xray proximity lithography, there has been substantial research in the past 15 years on soft xray projection lithography now called extreme uv euv lithography using. The main radiation source is the 193 nm line of an arf excimer laser 1. In addition, we demonstrated that a single 2 cm diameter metalens working in nearinfrared can ful. Fullert trochester institute of technology microelectronic engineering department rochester, new york 14623 exitech limited, hanborough park, long hanborough, oxford 0x8 8lh. Duv car processing why duv less diffraction with shorter wavelengths and less. Wavefront engineering issues for deepuv lithography. The current process used to pack more and more transistors onto a chip is called deep ultraviolet lithography, which is a photographylike technique that focuses light through lenses to carve circuit. The principal objective of this work is the investigation and development of wavefront engineering or optical resolution enhancement techniques using deepuv lithography. Lecture 7 lithography and pattern transfer reading. Current technologies used in optical microlithography allow the manufacture of microelectronic circuit features that are larger or about equal to about 23 of the wavelength. Shinetsu microsis sepr i032 duv resist is formulated for high resolution, straight side wall profiles with printing capability of less than 250 nm isolated trenches and semidense lines in 4 m thick film uv photoresist. However, as far as the fabrication process is considered, the minimum feature size is 100 nm in 193 nm deep uv photolithography 28.
Shorter wavelength lithography, known as next generation lithography ngl, has been studied in order to produce ic with even smaller features. It is designed with a cad software and converted to. Abstractlowexcessloss arrayed waveguide gratings are enabled by unique application of deep uv lithography in. Deep photolithography characterization of su8 resist layers. The process itself goes back to 1796 when it was a printing method using ink, metal plates and paper. Uv lithography systems based on mercury lamp sources have traditionally been used in micronano patterning.
This course provides a broad, deep treatment of lithography, the key driving technology in cmos ic fabrication. The hilo bilayer resist system exposure in ebeam lithography ebl process, intended for mushroomlike profile fabrication, was studied. Pushing deep ultraviolet lithography to its limits. Thermal conduction properties of mosi multilayers for. Carl zeiss manufactures lithography optics operated with deep ultraviolet light duv with a wavelength of 193 nanometers with or without immersion. In modern semiconductor manufacturing, photolithography uses optical radiation to image the mask on a silicon wafer using. Currently, and for the last several decades, optical projection lithography has been the lithographic technique used in the highvolume manufacture of integrated. Its optical absorption coefficient, dissolution rate, and sensitivity are given in the deep. The post exposure bake peb temperature was varied from 100c to 120c and the peb time was varied from 60s to 180s.
Lithographic and pattern transfer of a novel deepuv. Line patterns to illustrate principle of projection printing. Although the use of acid as a catalyst has eventually become the major foundation for the entire family of advanced resist systems, and the semiconductor industry is currently moving steadily toward deep uv lithography. Commonly used molecular transition lines in hgxe bulbs are 436 nm gline, 365 iline, 290, 280, 265 and 248 nm. Use of photosensitive polyimide for deep xray lithography. The mask can be placed far away from the wafer projection printing used in. Many are already looking at extreme ultraviolet lithography euvl as a way to extend the life of silicon at least until the end of the decade. Silicon nanophotonics using deepuv lithography invited paper. Nanoimprint lithography of al nanovoids for deepuv sers tao ding, daniel o. Uv proximity lithography, which is used to fabricate high aspect ratio mems normally, is investigated in this paper. Optical lithography at shorter wavelength why we needed deep uv.
Silicon nanophotonics using deepuv lithography 635199. The pas 5500350c system provides a very costeffective mixandmatch lithography solution when used in conjunction with other asml pas 5500 iline and duv. As mask features shrink, shorter wavelengths became the choice. First lithography and etch tests on photonic crystallike structure show promising results. Deep uv is defined as deep ultraviolet lithography rarely. Providing highest resolution in highvolume manufacturing, our extreme ultraviolet lithography machines are pushing moores law forward. For the popular depo sition technique, magnetron sputtering, causes of common sputtered film defects in relation to target preparation are dis cussed. Photolithography, also called optical lithography or uv lithography, is a process used in microfabrication to pattern parts on a thin film or the bulk of a substrate also called a wafer. The high productivity and low cost of ownership allow capacity extensions in existing duv stepper fabs as well. Jun 01, 2015 deep uv microsphere projection lithography. To achieve high uniformity in large area on the mask of deep ultraviolet micro lithography lens, a deep study of duv micro lithography illumination system is expanded in both theoretical and experimental aspects in this paper. Modeling and prediction of thermally induced imaging. Duv lithography systems our deep ultraviolet lithography systems dive deep into the uv spectrum to print the tiny features that form the basis of the microchip. Deep uv lithography in short duv lithography is an optical projection type lithography technique where the pattern on a reticlemask is projected to the wafer surface through a 4x or 5x optical system.
Hybrid lithography based fabrication of 3d patterns by. It uses light to transfer a geometric pattern from a photomask also called an optical mask to a photosensitive that is, lightsensitive chemical. This masters project report deals with the process development for patterning thesubmicron features using deepuv photolithography. Ultrafast deep uv lithography using excimer lasers ultrafast deep uv lithography using excimer lasers jain, k rice, s lin, b. Lasers are used to increase resolution, and decrease the optical complexity for deep ultraviolet duv lithography systems. Soi photonic crystal fabrication using deep uv lithography.
We have developed a new quartermicron lithography technology. The deep lithography of thick resist layer is the primary step of liga technology. Allglass, large metalens at visible wavelength using deep. Extreme ultraviolet lithography euvl is a promising technique for scaling microelectronic devices beyond the 22nm node. Small mask features made mercury lamp unsuitable because of not possessing enough photon energy used for volume production. Tolerances of these techniques and their performance when used with 248 nm and 193 nm deep. Modifications of these basic systems, such as deep uv lithography and addition of uv filters, can further enhance fine resolution patterning. Patterning of the submicronstructures in the resists uv26 and zep520a7 has been demonstrated successfully. In this letter, we present a singleexposure deep uv projection lithography at 254nm wavelength that produces nanopatterns in a scalable area with a feature size of 80 nm.
These met both requirements of high photon energy and shorter wavelength. As time passed we moved to arf then f2 then to ar2 which used wavelength of 157nm. Fabrication approaches for generating complex micro and. The combination of uv lithography and ebeam lithography allows for a process time reduction while still retaining high resolution in critical areas. We found that the high potential of resolution improvement with krf excimer laser lithography can be enhanced using the surface imaging method. Hence, the thin film material on the wafer is selectively. Exitech limited, hanborough park, long hanborough, oxford. In proceedings of spie presented at asiapacific optical communications conference apoc 2006, 99. The wavelengths used for duv lithography are 248 nm or 193 nm. Lithography stepper optics university of california. This work is supported by the european union in the context of the ist project picco. In this letter, we demonstrate a centimeterscale, allglass metalens capable of focusing and imaging at visible wavelength, using deepultraviolet duv projection stepper lithography. Currently, the 193 nm lithography combined with immersion and double patterning technology is the state of the art. Baumberg, nanophotonics centre, cavendish laboratory, university of cambridge, cambridge cb3 0he, united kingdom.
A deep uv stepandrepeat photolithography system includes a narrowbandwidth pulsed excimer laser illumination source and an allfusedsilica lens assembly. This technology is characterized as a krf excimer laser lithography combined with silylation process. We have developed a novel chemically amplified deep uv photoresist called arch2. We present simple calculations of the transmission and index homogeneity requirements of the immersion liquid t 0. Photolithography procedure sop september 20 overview substrate cleaning prior to lithography hmds priming spin coating soft bake exposure post exposure bake developing hard baking and curing image reversal and liftoff photoresist stripping processes overview creating patterns in various materials relies on selective processing. The 2007 international technology roadmap for semiconductors itrs1 specifies extreme ultraviolet euv lithography as one leading technology option for the 32nm halfpitch node, and significant. Bonakdar a, rezaei m, brown rl, fathipour v, dexheimer e, jang sj, mohseni h. The requirements of liquids for use in immersion lithography are discussed.
Deep ultraviolet lithography how is deep ultraviolet. Lithography for nanotechnology cmos ics semiconductor. Design and analysis of deep ultraviolet microlithography. Argon fluoride arf is used as the fill gas for the lasers in both types of systems. It uses light to transfer a geometric pattern from a photomask also called an optical mask to a photosensitive that is, lightsensitive chemical photoresist on the substrate. Pdf photolithography at a wavelength of 193 nm in the deep uv with water immersion lenses can now produce microelectronics containing. We demonstrated that it is possible to use a 2d approach to fabricate complex 3d substrates by combining a hybrid lithography approach with deep reactive ion etching. Su8 layers of different thickness that were formed by spinning and soft baking or a casting process with a solvent content of not more than 4% were used for experimental investigation of deep uv lithography using modified radiation of a mercury lamp. Lithography for nanotechnology cmos ics semiconductor seminar. Shinetsu microsis sepr i032 duv resist is formulated for high resolution, straight side wall profiles with printing capability of less than 250 nm isolated trenches and. Tolerances of these techniques and their performance when used with 248 nm and 193 nm deep uv lithography are also of concern. We have developed a novel chemically amplified deepuv photoresist called arch2. Optimization of deepuv lithography process masters thesis in electrical engineering kamal kumar gupta school of information science, computer and electrical engineering ide halmstad university po box 823, s301 18 halmstad, sweden january 2012, 15 credit supervisors dr. Preliminary studies show that deep uv lithography is a good candidate for the massmanufacturing of photonic crystalbased pics.
One possible way of increasing the coupling is to decrease the gap g between the ring and the bus waveguide. Fabrication of photonic crystals in silicononinsulator using 248nm deep uv lithography. Electron beam lithography double step exposure technique. Hybrid lithography based fabrication of 3d patterns by deep. These deep uv resists are formulated for either super high resolution or very high aspect ratios. Eximer lasers deep uv lithography 8 photomasks glass plate with a patterned cr or feo 2 layer. Pdf in this letter, we present a singleexposure deepuv projection lithography at 254nm wavelength. Proximity effects, feature offset and pattern displacement issues, as well as sensitivity to lens aberrations and coherence of the light source are being investigated. Euv lithographythe successor to optical lithography. Here, we show sizescalability and potential for massproduction by fabricating 45 metalenses of 1 cm diameter on a 4 in. Volume 8 issue 4 journal of micronanolithography, mems. Ultrafast deep uv lithography using excimer lasers, polymer. Photoresist materials and lithographic patterning process in a typical photolithography process, a uv light is projected by a set of sophisticated lenses. Intensity uniformity has to be better than several % over the collection area.
Lithography is the transfer of geometric shapes on a mask to a smooth surface. Comprehensive simulations for ultraviolet lithography process of. Nanoimprint lithography of al nanovoids for deepuv sers. Pdf deepuv lithography fabrication of slot waveguides. The cni tool can perform both thermal replication and uv replication. A simple optical imaging system has been designed and built for printing subhalfmicron lithographic images at 248 nm. Immersion liquids for lithography in the deep ultraviolet. With the help of various resolution enhancement techniques, optical lithography using a deep ultraviolet excimer laser has been the workhorse patterning technology in the fab since the early 1980s. Dec 09, 2011 by comparison, for deep uv lithography when contamination from outgassing was not as great a concern resist manufacturers would test thousands of resists each month to refine lithographic.
Industrial products division supplies iline and deep uv duv lithography systems that are used in the fabrication and packaging of hightech devices including integrated circuits, hard disk readwrite heads, microelectromechanical systems mems devices, image sensors, displays, power devices and leds. Extreme ultraviolet lithography also known as euv or euvl is a lithography technology using a range of extreme ultraviolet euv wavelengths, roughly spanning a 2% fwhm bandwidth about. Pdf deepuv microsphere projection lithography researchgate. Mccaughan department of electrical and computer engineering, university of wisconsin, madison, wisconsin 53706.
A deep uv imaging system for lithography and process development. Continuing to rely on 193nm immersion lithography with multiple patterning is becoming much more difficult at 7nm and 5nm. A 1 93 nm deep uv lithography system using a linenarrowed arf excimer laser bruce w. Deep ultraviolet lithography, with secondandthirdgeneration products on that node transitioning to euv, at.