Lithography

About: Lithography is a research topic. Over the lifetime, 23507 publications have been published within this topic receiving 348321 citations.

High-aspect-ratio resist for thick-film applications

Abstract: In recent years, increased activity in micromachining has driven the need for high aspect ratio thick films resist systems. This paper discusses a new epoxy based resist that can be used to achieve high aspect ratios (> 10:1) using UV lithography. The resulting negative resist system provides sharp, clean images in thick films (> 200 micrometers ). Because of the high aspect ratio and short exposure times, this material may be a viable candidate for producing the images required for micromachined parts. The resist images exhibit straight sidewalls and developed patterns, have excellent thermal stability, good adhesion, and chemical resistance. The high aspect ratio and high thermal stability make these epoxy resists suitable for other packaging applications such as plating stencils and optical wave guides.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Hybrid Nanoimprint−Soft Lithography with Sub-15 nm Resolution

Abstract: We developed a hybrid nanoimprint-soft lithography technique with sub-15 nm resolution. It is capable of patterning both flat and curved substrates. The key component of the technology is the mold, which consists of rigid features on an elastic poly(dimethylsiloxane) (PDMS) support. The mold was fabricated by imprinting a reverse image onto the PDMS substrate using a UV-curable low-viscosity prepolymer film. Patterns with sub-15-nm resolution were faithfully duplicated on a flat substrate without applying external pressure. Gratings at 200 nm pitch were also successfully imprinted onto the cylindrical surface of a single mode optical fiber with a 125 microm diameter.

Holder, system, and process for improving overlay in lithography

Abstract: A deformable holder, system, and process where long range errors (any of lithography, metrology, or overlay errors) between the image of a mask and an existing pattern on a wafer from a number of potential sources are corrected The long range errors are determined using either a through-the-lens alignment metrology system or an around-the-lens metrology system Deformation values are determined to compensate for the longe range errors The deformation values are determined by either solving simultaneous equations or by finite-element linear-stress-analysis (FEA) The mask or wafer is then distorted, in-plane, by an amount related to the determined deformation values using an actuator such an a piezoelectric ceramic to push or pull the mask or wafer to substantially realign the projected image of the mask and the existing pattern on the wafer

Fabrication of High-Performance Ultrathin In2O3 Film Field-Effect Transistors and Biosensors Using Chemical Lift-Off Lithography.

Abstract: We demonstrate straightforward fabrication of highly sensitive biosensor arrays based on field-effect transistors, using an efficient high-throughput, large-area patterning process. Chemical lift-off lithography is used to construct field-effect transistor arrays with high spatial precision suitable for the fabrication of both micrometer- and nanometer-scale devices. Sol-gel processing is used to deposit ultrathin (∼4 nm) In2O3 films as semiconducting channel layers. The aqueous sol-gel process produces uniform In2O3 coatings with thicknesses of a few nanometers over large areas through simple spin-coating, and only low-temperature thermal annealing of the coatings is required. The ultrathin In2O3 enables construction of highly sensitive and selective biosensors through immobilization of specific aptamers to the channel surface; the ability to detect subnanomolar concentrations of dopamine is demonstrated.

Sublithographic nanofabrication technology for nanocatalysts and DNA chips

Abstract: We describe parallel processes for nanometer pattern generation on a wafer scale with resolution comparable to the best electron beam lithography. Sub-10 nm linewidth is defined by a sacrificial ultrathin film deposited by low pressure chemical vapor deposition (LPCVD), in a process similar to formation of gate sidewall spacers in CMOS processing. We further demonstrate a method called iterative spacer lithography (ISL), in which the process is repeated multiple times with alternating materials in order to multiply the pattern density. Silicon structures with sub-10 nm width fabricated by this process were used as a mold in nanoimprint lithography and lift-off patterning of sub-30 nm platinum nanowires for use in experiments on chemical catalysis. We also demonstrate a similar process called reversed spacer lithography (RSL) to form sub-10 nm fluid channels in poly-Si. This nanogap fluid channel device was used for label-free detection of DNA hybridization based on electrical sensing of dielectric changes...