Large-area, high-resolution pattern replication by the use of a two-aspherical-mirror system

Kinoshita, Hiroo; Kurihara, Kenji; Mizota, Tsutomu; Haga, Tsuneyuki; Takenaka, Hisataka; Torii, Yasuhiro

doi:10.1364/ao.32.007079

Cited by 27 publications

(12 citation statements)

References 6 publications

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“…4 were delivered; but the accuracy was only 1.5 nm for the concave mirror and 1.8 nm for the convex one. 9 A new metrological method was needed to fabricate a mirror with an accuracy of better than 1 nm. Figure 8 shows a Twyman-Green interferometer based on a computer generated hologram (CGH), which applies a Fourier transform to the aspherical surface.…”

Section: Optics Design and Fabricationmentioning

confidence: 99%

Euv Lithography for Semiconductor Manufacturing and Nanofabrication

Kinoshita

2007

COSMOS

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EUV lithography is the exposure technology in which even 15 nm node which is the limit of Si device can be achieved. Unlike the conventional optical lithography, this technology serves as a reflection type optical system, and a multilayer coated mirror is used. Development of manufacturing equipment is accelerated to aim at the utilization starting from 2011. The critical issues of development are the EUV light source which has the power over 115 W and resist with high sensitivity and low line edge roughness (LER).

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Section: Optics Design and Fabricationmentioning

confidence: 99%

Euv Lithography for Semiconductor Manufacturing and Nanofabrication

Kinoshita

2007

COSMOS

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“…[4][5][6] Formerly, a͒ Electronic mail: takeo@lasti.himeji-tech.ac.jp we had designed the two-aspherical-mirror optics for the imaging optics. Although these optics contain the minimum number of mirrors needed, the width of the ring field has to be reduced in order to obtain a small distortion when the mask and the wafer are both scanned.…”

Section: A Optical Systemmentioning

confidence: 99%

Development of the large field extreme ultraviolet lithography camera

Watanabe

Kinoshita

Nii

et al. 2000

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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Extreme ultraviolet focus sensor design optimizationa)We have developed a three-aspherical mirror system which is capable of replicating in a large exposure area ͑30 mmϫ28 mm͒. This system consists of the synchronized scanning mechanism of a mask and a wafer, the alignment optics between a mask and a wafer, the focus detector of a wafer position, and the load-lock chamber for exchanging wafers. The aspherical mirrors have a figure error of 0.58 nm and a surface roughness of 0.3 nm. To obtain a high efficiency mirror, a couple of mirrors were coated with a graded d spacing Mo/Si multilayer. The peak reflectivity is 65% at the wavelength of 13.5 nm. The wavelength matching of each mirror spans 0.45 nm. The mirrors were aligned with a Fizeau-type phase shift interferometer, and a final wave front error of less than 3 nm was achieved. Exposure experiments carried out at NewSUBARU synchrotron facility and a diffraction limited resolution of 56 nm was obtained in an exposure-field size of 10 mmϫ2 mm in static exposure. Furthermore, fine patterns in an area of 10 mmϫ5.2 mm were obtained using the mask and wafer synchronized scanning stages. These results revealed that this system can be applied to fabricate large scale integrated devices.

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“…Possible solutions to this problem include top surface imaging via silylation and pattern transfer from a thin imaging layer. 3 Alternatively, etch experiments using hard masks, i.e., thin film layers between the imaging layer and underlying material to be etched, have been demonstrated using germanium 4,5 and amorphous silicon 6 as the hard mask material. In addition, top surface imaging using a silylation process has become less desirable due to its excessive line edge roughness.…”

Section: Introductionmentioning

confidence: 99%

Demonstration of pattern transfer into sub-100 nm polysilicon line/space features patterned with extreme ultraviolet lithography

Cardinale¹,

Henderson²,

Goldsmith³

et al. 1999

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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In two separate experiments, we have successfully demonstrated the transfer of dense- and loose-pitch line/space (L/S) photoresist features, patterned with extreme ultraviolet (EUV) lithography, into an underlying hard mask material. In both experiments, a deep-UV photoresist (∼90 nm thick) was spin cast in bilayer format onto a hard mask (50–90 nm thick) and was subsequently exposed to EUV radiation using a 10× reduction EUV exposure system. The EUV reticle was fabricated at Motorola (Tempe, AZ) using a subtractive process with Ta-based absorbers on Mo/Si multilayer mask blanks. In the first set of experiments, following the EUV exposures, the L/S patterns were transferred first into a SiO2 hard mask (60 nm thick) using a reactive ion etch (RIE), and then into polysilicon (350 nm thick) using a triode-coupled plasma RIE etcher at the University of California, Berkeley, microfabrication facilities. The latter etch process, which produced steep (>85°) sidewalls, employed a HBr/Cl chemistry with a large (>10:1) etch selectivity of polysilicon to silicon dioxide. In the second set of experiments, hard mask films of SiON (50 nm thick) and SiO2 (87 nm thick) were used. A RIE was performed at Motorola using a halogen gas chemistry that resulted in a hard mask-to-photoresist etch selectivity >3:1 and sidewall profile angles ⩾85°. Line edge roughness (LER) and linewidth critical dimension (CD) measurements were performed using Sandia’s GORA© CD digital image analysis software. Low LER values (6–9 nm, 3σ, one side) and good CD linearity (better than 10%) were demonstrated for the final pattern-transferred dense polysilicon L/S features from 80 to 175 nm. In addition, pattern transfer (into polysilicon) of loose-pitch (1:2) L/S features with CDs⩾60 nm was demonstrated.

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Large-area, high-resolution pattern replication by the use of a two-aspherical-mirror system

Cited by 27 publications

References 6 publications

Euv Lithography for Semiconductor Manufacturing and Nanofabrication

Euv Lithography for Semiconductor Manufacturing and Nanofabrication

Development of the large field extreme ultraviolet lithography camera

Demonstration of pattern transfer into sub-100 nm polysilicon line/space features patterned with extreme ultraviolet lithography

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