The ENEA discharge produced plasma extreme ultraviolet source and its patterning applications (original) (raw)
Related papers
The ENEA Discharge Produced Plasma EUV Source: Description and Applications
Proceedings FOTONICA 2016, 2016
After a brief description of the extreme ultraviolet (EUV) radiation peculiarities, the main characteristics of the ENEA Discharge Produced Plasma (DPP) EUV source are described. An efficient debris mitigation system has been developed and tested on the DPP source, to protect delicate objects from plasma emitted debris bombardment. The DPP source has been successfully utilized for pattern generation by EUV irradiation of photonic materials like lithium fluoride crystals and various innovative photoresists. A simple contact EUV lithography technique has been demonstrated to be effective for sub–micrometric resolution patterning on the above mentioned materials. Examples of obtained patterns are presented and discussed.
Enea Euv Discharge Produced Plasma Source: Diagnostics, Characterization And Applications
Proceedings of 1st EPS conference on Plasma Diagnostics — PoS(ECPD2015), 2016
Extreme Ultraviolet (EUV) radiation (photon energy hν = 20 − 284 eV, wavelength λ 4.4 − 62 nm) can be used to efficiently modify the structure of photonic materials, photoresists etc. In fact, the EUV short wavelength, its short penetration length in matter (typically few tens of nm) and the availability of high-reflectivity (≥ 70% at λ = 13 − 15 nm) normal-incidence multilayer mirrors allow high-spatial-resolution patterning on the aforementioned materials. This is leading to the development of the next generation lithography for microelectronics. Consequently, EUV sources are a main object of study and they are largely exploited for metrology and tests on mirrors, innovative materials etc. Excluding large facilities like synchrotron machines, plasma sources are needed to efficiently generate EUV radiation. An EUV discharge produced plasma source is operating at the ENEA Frascati Research Centre. The source characterization by means of various diagnostic tools will be reported after a brief description of its principle of operation. Finally, some source applications involving the treatment of both photonic materials and innovative photoresists will be illustrated.
Applied Surface Science 272 (2013) 13–18, 2013
While developing a laboratory-scale micro-exposure tool for extreme ultraviolet (EUV) projection lithography which uses a laser-produced plasma emitting EUV pulsed radiation, we faced the problem of suppressing the various debris (ions, neutrals, particulate, clusters, droplets) emitted by the plasma target. The suppression of debris is a crucial task in the frame of EUV projection lithography, mainly because debris seriously limit both lifetime and performance of the expensive optics and filters put close to the plasma source. In this paper we present the experimental measurements of main debris characteristics (velocity, size, charge, momentum, spectral energy, spatial distribution). Then, we present the operating results of a patented debris mitigation system (DMS) specifically designed to suppress debris with the measured characteristics. We achieved reduction factors ∼ 800 for atoms and nm-size clusters, and ∼ 1600 for particles larger than 500 nm. These results are at the forefront in this field. The excellent performance of our DMS was a breakthrough to achieve a 90-nm patterning on commercial resists by our micro-exposure tool EUV projection lithography.
ENEA EXTREME ULTRAVIOLET LITHOGRAPHY MICRO-EXPOSURE TOOL: MAIN FEATURES
Short Wavelength Laboratory Sources : Principles and Practices , 2015
The laboratory-scale Micro-Exposure Tool (MET) for Extreme Ultraviolet projection Lithography (EUVL), realised at the Frascati ENEA Centre within the context of a National Project, was successfully operated in 2008 by achieving a 160-nm resolution imaging of mask patterns onto a polymethylmethacrylate (PMMA) photoresist through 14.4-nm radiation (EPL 84, 58003 (2008)). The MET uses a laser-produced plasma as EUV radiation source, a couple of twin ellipsoidal mirrors as collecting optics to gather the 14.4-nm radiation from the source to the mask, an efficient combination of ambient gas and mechanical device as Debris Mitigation System and flnally a low-cost Schwarzschild objective as projection optics to image the patterned mask onto the wafer. The paper gives details of the ENEA MET components and of the aforementioned successful operation along with subsequent related investigations.
EUV laser produced plasma source development for lithography (Invited Paper
2005
The ideal source of radiation for extreme ultraviolet lithography will produce intense light in a 2% bandwidth centred at 13.5 nm, while the debris and out-of-band radiation produced will be limited to prevent adverse effects to the multilayer optics in the lithography system. In this study ways to optimise plasma sources containing tin are presented. The optimum power density for a tin slab target, with a fixed spotsize, is determined, while the effects of power density on ceramic targets, where tin is present only as a few percent in a target of mainly low Z elements, is also investigated. It has been found that the in-band radiation is increased when the concentration is 5-6%, while the out-of-band radiation is dramatically reduced, due the the low average Z of the target constituents, with conversion effciencies of over 2.5% recorded. The power density needed to optimise the emission from ceramic targets was found to be greater than that required for the pure tin case. In addition, if the target is first irradiated with a pre-pulse, the conversion effciency is seen to increase.
2007
The application of extreme ultraviolet (EUV) lithography in large-scale semiconductor chip manufacturing requires high power EUV radiation sources. The wavelength of the emission should be between 13 and 14 nm according to the 13.4 nm roadmap. To this end, a versatile microwave plasma-based EUV light source type Compact Electron Cyclotron Resonance Ion Source (CECRIS) has been recently built at Lawrence Berkeley National Laboratory (LBNL). In this paper, we present a detailed study of the generation of xenon (Xe) EUV light by the CECRIS using a 1.5 grazing incidence EUV monochromator that has been absolutely calibrated at the advanced Light Source (ALS). For diagnostic purposes, a theoretical study of Xe EUV line emission was performed based on relativistic Hartree-Fock approximation. A major outcome of this work is the absolute calibration of the EUV diagnostic system, which can be used for calibration of other industrial lithography sources.
Xenon Discharge-Produced Plasma Radiation Source for EUV Lithography
IEEE Transactions on Industry Applications, 2000
Extreme ultraviolet (EUV) radiation with wavelengths of 11-14 nm is seen as the most promising candidate for a new lithographic technology. Compared with synchrotron radiation sources and laser-produced plasmas, gas dischargeproduced plasma sources for EUV radiation are expected to offer lower cost of ownership. Using xenon, a broadband emission in the investigated wavelength range from 10 to 17 nm is observed. Very short current pulses, having a fast rise time of 85-or 140-ns duration and 23-kA amplitude, were applied across the xenon-filled Z-pinch capillary (3-mm diameter and 5-mm length) to produce EUV radiation. An EUV radiation from the Z-pinch plasma was characterized, which is based on the temporal behavior of EUV intensity and the pinhole images. Two maximum EUV radiations occur, which are sensitive to the xenon flow rate and the discharge current. The first radiation is relatively of short duration, while the second radiation lasts as long as the first period of the current flows. The EUV source size due to the first radiation is approximately 300 µm, i.e., half of the one due to the second radiation.
A gas discharged based radiation source for EUV-lithography
Microelectronic Engineering, 1999
A new high repetitive, compact and low cost gas discharge based EUV ,,lamp" has been studied as an alternative to laser-produced plasmas as EUV sources. First results using oxygen in a fast discharge of electrically stored energy around 1 J lead to a conversion efficiency of about 0.1% for the emission at 13.0 nm which is suited for the use with Mo/Si-multilayer mirrors. Using Xenon a broadband emission in the investigated wavelength range from 10 nm to 18 nm is observed. With a first version a source with 40 W electrical input power could be demonstrated that emits about 50 mW/(4nsr) around 13 nm at a repetition rate of 150 Hz. No debris and no electrode erosion was observed after more than 107 pulses done up to now. Making use of the remaining optimisation potential this concept seems to be promising to fulfil the requirements of extremeultraviolet lithography