Lithography

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

Visual analysis and verification system using advanced tools

Abstract: A system and method of analyzing defects on a mask used in lithography are provided. A defect area image is provided as a first input, a set of lithography parameters is provided as a second input, and a set of metrology data is provided as a third input. The defect area image comprises an image of a portion of the mask. A simulated image can be generated in response to the first input. The simulated image comprises a simulation of an image that would be printed on a wafer if the wafer were exposed to a radiation source directed at the portion of the mask. The characteristics of the radiation source comprise the set of lithography parameters and the characteristics of the mask comprise the set of metrology data.

Nanogap-Enhanced Terahertz Sensing of 1 nm Thick (λ/106) Dielectric Films

Abstract: We experimentally show that terahertz (THz) waves confined in sub-10 nm metallic gaps can detect refractive index changes caused by only a 1 nm thick (∼λ/106) dielectric overlayer. We use atomic layer lithography to fabricate a wafer-scale array of annular nanogaps. Using THz time-domain spectroscopy in conjunction with atomic layer deposition, we measure spectral shifts of a THz resonance peak with increasing Al2O3 film thickness in 1 nm intervals. Because of the enormous mismatch in length scales between THz waves and sub-10 nm gaps, conventional modeling techniques cannot readily be used to analyze our results. We employ an advanced finite-element-modeling (FEM) technique, Hybridizable Discontinuous Galerkin (HDG) scheme, for full three-dimensional modeling of the resonant transmission of THz waves through an annular gap that is 2 nm in width and 32 μm in diameter. Our multiscale 3D FEM technique and atomic layer lithography will enable a series of new investigations in THz nanophotonics that has not b...

Sub-50 nm feature sizes using positive tone molecular glass resists for EUV lithography

Abstract: Extreme ultra violet (EUV) lithography is one of the most promising next generation lithographic techniques for the production of sub-50 nm feature sizes with applications in the semiconductor industry. Coupling this technique with molecular glass resists is an effective strategy for high resolution lithographic patterning. In this study, a series of tert-butyloxycarbonyl (t-Boc) protected C-4-hydroxyphenyl-calix[4]resorcinarenes derivatives were synthesized and evaluated as positive tone molecular glass resists for EUV lithography. The amorphous nature of these molecules was confirmed using thermal analysis, FTIR and powder X-ray diffraction. Feature sizes as small as 30 nm with low line edge roughness (4.5 nm, 3σ) were obtained after patterning and development.

Extreme ultraviolet interference lithography at the Paul Scherrer Institut

Abstract: We review the performance and applications of an extreme ultraviolet interference lithography (EUV-IL) system built at the Swiss Light Source of the Paul Scherrer Institut (Villigen, Switzerland). The interferometer uses fully coherent radiation from an undulator source. 1-D (line/space) and 2-D (dot/hole arrays) patterns are obtained with a transmission-diffraction-grating type of interferometer. Features with sizes in the range from one micrometer down to the 10-nm scale can be printed in a variety of resists. The highest resolution of 11-nm half-pitch line/space patterns obtained with this method represents a current record for photon based lithography. Thanks to the excellent performance of the system in terms of pattern resolution, uniformity, size of the patterned area, and the throughput, the system has been used in numerous applications. Here we demonstrate the versatility and effectiveness of this emerging nanolithography method through a review of some of the applications, namely, fabrication of metallic and magnetic nanodevice components, self-assembly of Si/Ge quantum dots, chemical patterning of self-assembled monolayers (SAM), and radiation grafting of polymers. (c) 2009 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3116559]

Study on the postbaking process and the effects on UV lithography of high aspect ratio SU-8 microstructures

Abstract: In recent years, a relatively new type of negative photoresist, EPON SU-8, has received a lot of attention in the MEMS field because of its excellent lithography properties. Significant research efforts have been made to study the lithographic properties of SU-8 to obtain high aspect ratio microstructures with good sidewall quality. Currently, selection of optimal wavelengths of the UV light for lithographic and reduction of the diffraction effects are believed to be the two most important factors for achieving high-quality lithography of SU-8 as reported in the literature. Other reported efforts also include modifications of the chemical properties of SU-8 for better lithographic quality. We report a study on stress reduction during the postbaking process and the effects on lithography of ultra-thick high aspect ratio SU-8 microstructures. Our research proves that aspect ratios up to 40:1 in isolated open field structures of thicknesses between 1 and 1.5 mm can be obtained without any modifications of the resist chemistry or changes in light spectrum applied from a standard broadband UV source. The principal factor in this achievement is the reduction of internal stress during the postexposure bake process that eliminates large plastic deformations present during standard bake procedures. This process may be used for the fabrication of ultra-thick high aspect ratio microstructures that have to date only been obtainable using x-ray lithography-based LIGA processes.