Historically, in the mass production of semiconductor devices, exposure tools have been repeatedly replaced with those a shorter wavelength to meet resolution requirements projected International Technology Roadmap for Semiconductors issued by Semiconductor Industry Association. After ArF immersion lithography, extreme ultraviolet (EUV; 92.5 eV) radiation is expected be used as an tool at or below 22 nm technology node. If realized, eV EUV will first ionizing devices. In chemically amplified...

Raman spectra of n-type gallium nitride with different carrier concentrations have been measured. The LO phonon band shifted towards the high-frequency side and broadened an increase in concentration. Results showed that was coupled to overdamped plasmon nitride. damping constants were determined by line-shape fitting modes compared values obtained from Hall measurements. two methods agree well. As a result, dominant scattering mechanisms are deformation-potential electro-optic mechanisms.

Thermal stress in GaN epitaxial layers with different thicknesses grown on sapphire substrates by metalorganic vapor phase epitaxy using an AlN buffer layer was investigated. Biaxial compressive the layer, due to difference thermal expansion coefficients between and sapphire, obtained measuring curvature of wafer bending, observed agreed calculated stress. In Raman measurements, E2 phonon peak found shift broaden as a consequence change elastic constants strain. The frequency Δω (in cm−1)...

The radiation-induced reactions of onium salts in some kinds solutions and model compound chemically amplified electron beam (EB) X-ray resists have been studied by means picosecond nanosecond pulse radiolysis. following reaction mechanisms the EB elucidated. are complicated due to presence several proton donors. directly produce small amounts Brønsted acids exposure most formed from adducts base polymer. strong scavengers promote generation resists.

We measured the Schottky barrier heights and specific contact resistivities of four different metals on p-type GaN. The Pt, Ni, Au, Ti were obtained from current-voltage characteristics to be 0.50, 0.57, 0.65 eV, respectively. 0.013, 0.015, 0.026, 0.035 Ω⋅cm2, Our experimental results proved that decrease with increase in metal work function as expected theoretically.

The proton dynamics of poly(4-hydroxystyrene) (PHS) films were investigated using Coumarin 6 (C6). acid density was 0.022 nm -3 at the exposure dose 10 µC cm -2 (75 keV electron beam). absorption intensity C6 adducts saturated a certain concentration C6, indicating an almost complete addition protons this concentration. Protons can move in PHS near molecules even room temperature. Also, absorbed estimated 60 Co γ-rays. yield be well explained by generation model involving ionization base polymer.

Extreme ultraviolet (EUV) radiation, the wavelength of which is 13.5 nm, most promising exposure source for next-generation semiconductor lithography. The development EUV lithography has been pursued on a worldwide scale. Over past decade, significantly progressed and approached its realization. In this paper, resist materials processes among key technologies are reviewed. Owing to intensive development, technology already closely requirements 22 nm node. focus shifted 16 node beyond....

Acid generators are sensitized by secondary electrons in chemically amplified resists for ionizing radiation. As acid react with low-energy (as low as thermal energy), this sensitization mechanism generates a significant blur and an inhomogeneous distribution at the image boundary, which results line edge roughness (LER) formation. The evaluation of resolution intrinsic to reaction mechanisms is important optimization resist processes extreme ultraviolet (EUV) lithography, especially from...

Extreme ultraviolet (EUV) lithography is a promising technology for making chips beyond 7 nm node; however, it comes with its own challenges. One of them the need to find suitable EUV resist. Photoresist performance gauged by resolution, LER, and sensitivity trade-off. However, primary challenge photoresist in major shift reaction chemistry relative that deep (DUV) lithography. The interaction photon (92 eV) widely used conventional chemically amplified resist (CAR) different than DUV (5–6...

In chemically amplified resists for ionizing radiation such as an electron beam and EUV, protons of acids are mainly generated by the deprotonation base polymers. Therefore, acid generation efficiency depends highly on polymer structure. recent resist formulas, partially protected poly(4-hydroxystyrene) has often been used a polymer. this work, effects protecting groups were investigated. We found differences in caused groups. These likely to affect distribution.

With the shrinkage of feature sizes, ever precise accuracy has been required for process simulators because importance nanoscale resist topography such as line edge roughness. Formation processes latent images in chemically amplified electron beam (EB), x-ray, and EUV resists are different from both photoresists used optical lithography conventional, nonchemically EB resists. A new simulation scheme precisely based on reaction mechanisms is necessary to reproduce patterns postoptical...

A highly sensitive extreme ultraviolet (EUV) resist is strongly needed to reduce the development costs of high power EUV sources. Although chemically amplified resists based on acid-catalyzed reactions have been used in mass production lines, chain length acid catalytic must be suppressed within several nanometers meet resolution requirement below 32nm technology node. Under such circumstances, initial yield produced by exposure critical formation ultrafine patterns. Using an dye, authors...

In chemically amplified resists that utilize acid-catalytic reactions for pattern formation, proton dynamics is important from the viewpoints of insoluble layer formation due to acid loss, resolution decrease diffusion, and image quality improvement base-quencher effects. For electron-beam lithography, protons anions are initially generated at different places. Protons migrate in resist matrix toward counter anions, attracted by opposite electric charges. However, details migration still...

Protons generated in chemically amplified resists drive pattern formation reactions such as acid catalytic deprotection reactions. Proton dynamics is controlled by the addition of base quenchers so that ultrafine patterns are obtained. However, details interaction between protons and still unclear. In this study, we investigated with a model system typical backbone polymer, poly(4-hydroxystyrene). We confirmed an acid-base equilibrium was reached without elevating temperature films. The...

The absorption coefficient and acid generation efficiency are elemental key factors for the design of chemically amplified resist because distribution in films is primarily determined by these two factors. In this study, number molecules generated a model system extreme ultraviolet (EUV) resists [poly(4-hydroxystyrene) film dispersed with triphenylsulfonium-triflate (TPS-tf)] was evaluated using an sensitive dye. were changing thickness. 1.7 (5 wt % TPS-tf), 2.5 (10 3.1 per photon (20...

We investigated the relationship between line edge roughness (LER) and concentration gradient of chemical compounds that determines solubility resist (chemical gradient). Two-dimensional (half-pitch exposure dose) matrices width LER were analyzed on basis sensitization mechanisms chemically amplified resists for extreme ultraviolet (EUV) lithography. The latent images patterns successfully reproduced by assuming is inversely proportional to gradient. product normalized was 0.31.

The development of extreme ultraviolet (EUV) lithography has progressed owing to worldwide effort. As the status EUV approaches requirements for high-volume production semiconductor devices with a minimum line width 22 nm, extraction resist parameters becomes increasingly important from viewpoints accurate evaluation materials screening and process simulation mask designs. In this study, we demonstrated that (namely, quencher concentration, acid diffusion constant, proportionality constant...

The line width and edge roughness (LER) of resist patterns are related to the concentration its gradient chemical compounds that determine solubility resist, respectively. Therefore, latent images can be obtained from LER patterns. In this study, two-dimensional (exposure dose half-pitch) matrices were analyzed on basis sensitization mechanisms chemically amplified resists used for extreme ultraviolet (EUV) lithography. reconstruction images, effective reaction radius catalytic chain is an...

Extreme ultraviolet (EUV) lithography is promising for the high-volume production of semiconductor devices 16 nm node and below. However, stochastic effect a significant concern in using high-energy (92.5 eV) photons highly sensitive resists. In this study, we report technique evaluating on line edge roughness (LER). Resist patterns were analyzed Monte Carlo simulation basis sensitization reaction mechanisms chemically amplified EUV The contribution protected unit fluctuation to LER was...

Abstract The high-volume production of semiconductor devices with EUV lithography started in 2019. During the development lithography, resist materials had always been ranked high focus area for its realization. trade-off relationships between resolution, line width roughness, and sensitivity were most serious problem. use chemically amplified resists after material chemistry was optimized on basis radiation chemistry. increase numerical aperture has scheduled to enhance optical resolution....

The difference in photochemistry and radiation chemistry of sulfonium salt acid generator was investigated by product analysis time resolved spectroscopic methods for chemically amplified resist application. After KrF excimer laser electron beam irradiation salt, yields decomposed products including were determined. ultra fast in-cage reactions after directly observed the femtosecond flash photolysis method. Intermediates nanosecond pulse radiolysis. From both methods, contribution each...

Radiation-induced reactions in chemically amplified resists based on deprotection of t-butoxycarbonyl groups have been investigated by both time-resolved (the pulse radiolysis methods) and steady-state optical absorption spectroscopy. Upon exposure a partially tBOC-protected novolak electron synchrotron radiation beams, the yields intermediates contributing to acid generation (phenoxyl radical proton adducts base resin) decreased with increasing protection ratio hydroxyl groups. Therefore,...

Laser-induced and matrix-free desorption/ionization on various submicrometer structures was investigated. First, to examine the effect of surface roughness ionization, a silicon wafer or stainless steel scratched with sandpaper. The fluences 337-nm nitrogen laser, required for ionization synthetic polymers reserpine, were markedly reduced as compared corresponding untreated surface. Next, arrays grooves, which had been lithographically fabricated wafer, yielded protonated angiotensin,...

Acid-related matters are a critical issue in chemically amplified resist, which photo- or radiation (ionizing radiation)-generated acids drive pattern formation reactions exposed areas. The photosensitization of resist materials has been formulated by Dill et al. [IEEE Trans. Electron. Dev. 22, 445 (1975)]. applicability the formulation to acid generation photoresists proven many researchers. yields predicted well However, cannot be applied resists for ionizing such as electron beams and...