{"_buckets": {"deposit": "41e2c824-f74d-498c-ad54-f3aa02af2f90"}, "_deposit": {"created_by": 1, "id": "1255", "owners": [1], "pid": {"revision_id": 0, "type": "depid", "value": "1255"}, "status": "published"}, "_oai": {"id": "oai:ir.soken.ac.jp:00001255", "sets": ["24"]}, "author_link": ["0", "0", "0"], "item_1_biblio_info_21": {"attribute_name": "書誌情報（ソート用）", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "2008-03-19", "bibliographicIssueDateType": "Issued"}, "bibliographic_titles": [{}]}]}, "item_1_creator_2": {"attribute_name": "著者名", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "田中, 桃子"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_1_creator_3": {"attribute_name": "フリガナ", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "タナカ, モモコ"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_1_date_granted_11": {"attribute_name": "学位授与年月日", "attribute_value_mlt": [{"subitem_dategranted": "2008-03-19"}]}, "item_1_degree_grantor_5": {"attribute_name": "学位授与機関", "attribute_value_mlt": [{"subitem_degreegrantor": [{"subitem_degreegrantor_name": "総合研究大学院大学"}]}]}, "item_1_degree_name_6": {"attribute_name": "学位名", "attribute_value_mlt": [{"subitem_degreename": "博士（工学）"}]}, "item_1_description_1": {"attribute_name": "ID", "attribute_value_mlt": [{"subitem_description": "2008072", "subitem_description_type": "Other"}]}, "item_1_description_12": {"attribute_name": "要旨", "attribute_value_mlt": [{"subitem_description": "Owing to the recent progress in laser technology, highly intense extreme ultraviolet\u003cbr /\u003e (EUV) sources based on laser-produced plasma have been receiving strong interest for \u003cbr /\u003e various applications, such as the processing technique of next generation semiconductor \u003cbr /\u003ebased on EUV lithography, and spatially and temporally highly resolved imaging of \u003cbr /\u003eliving cells.. Due to the variation of the applications, improvement of EUV sources to \u003cbr /\u003esuit each use has been intensively studied. Among these laser plasma EUV sources, an \u003cbr /\u003ex-ray laser is a characteristic source with short pulse duration of several pico-seconds, \u003cbr /\u003enarrow spectral width of less than 10\u003csup\u003e-4\u003c/sup\u003efor Δλ/λ, and possibility of high coherence. The \u003cbr /\u003ehigh spatial coherence is especially an important factor because the x-ray beam can be \u003cbr /\u003efocused to a spot diameter of the wavelength order if the focusing system has sufficient \u003cbr /\u003eprecision. With pulse duration of several pico-seconds, the small focal-size realizes the \u003cbr /\u003eimaging of high-speed phenomenon in the micro domain. Furthermore, x-ray lasers are \u003cbr /\u003eexpected as a source of interference measurements for evaluating EUV optical system \u003cbr /\u003eand surface accuracy of optics in the field of EUV lithography. For the present \u003cbr /\u003emeasurement, synchrotron radiation is used by inserting a monochromator and pinholes \u003cbr /\u003ein the undulator line. This can also be done in a laboratory scale by using an x-ray laser \u003cbr /\u003eas EUV source. . \u003cbr /\u003e　　　At the Advanced Photon Research Center, the x-ray lasers generated with \u003cbr /\u003etransient gain collisional excitation (TCE) method have been studied and have achieved \u003cbr /\u003ethe saturation amplification of a nickel-like silver x-ray laser at the wavelength of 13.9 \u003cbr /\u003enm. The TCE scheme have several advantages, such as short pulse duration less than \u003cbr /\u003eten pico-seconds, and a high gain generation with low excitation energy of several tens \u003cbr /\u003eof Joules. In particular, EUV with the wavelength of around 13 nm is useful for \u003cbr /\u003elithography, imaging, and interference measurement because the multilayer mirror with \u003cbr /\u003ehigh reflectance is commercially prepared. However, the beam divergence of the x-ray \u003cbr /\u003elaser generated with TCE method is as large as 10 mrad and spatial coherence is not \u003cbr /\u003esufficient. In this study, the beam divergence and spatial coherence of the TCE x-ray \u003cbr /\u003elaser was improved and applied to measurement of time resolved emission \u003cbr /\u003espectroscopy. \u003cbr /\u003e　　　As an application of the x-ray laser, the scintillation properties of a zinc oxide , \u003cbr /\u003e(ZnO) single crystal are evaluated for EUV using a 13.9 nm x-ray laser. For \u003cbr /\u003enext-generation lithography applications, various efforts have been made not only for \u003cbr /\u003edemonstration of efficient EUV sources, but also for the development of functional \u003cbr /\u003eoptical components in the EUV region. In particular, the development of efficient and \u003cbr /\u003efast imaging scintillator devices with sufiicient size is a key element for lithographic \u003cbr /\u003eapplications. in these aspects, hydrothermal method grown ZnO is a prominent \u003cbr /\u003ecandidate. Currently, its growth characteristics have been greatly improved in the aspect \u003cbr /\u003eof crystalline quality and size of up to 3-inch-diameter. ZnO has been intensively \u003cbr /\u003estudied for the past ten years as a light-emitting diode material and as nano-structured \u003cbr /\u003ematerial to improve the optical properties including response time. The advantage of \u003cbr /\u003ebulk ZnO is the availability of large sized homogeneous crystal with a reasonable \u003cbr /\u003efabrication cost. For the evaluation of hydrothermal method grown ZnO, a nickel-like \u003cbr /\u003esilver x-ray laser operating at 13.9 nm is the ideal light source; having large pulse \u003cbr /\u003eenergy up to about micro-joules level and a sufiiciently short pulse duration down to \u003cbr /\u003eseveral picoseconds. \u003cbr /\u003e　　　The improvement of the nickel-like silver x-ray laser at the wavelength of 13.9 \u003cbr /\u003enm is described in chapter 2. To decrease the beam divergence of the x-ray laser, we \u003cbr /\u003ehave used the double target configuration. On this technique, a part of the x-ray laser \u003cbr /\u003egenerated in the first medium is used as the seed x-ray laser, and it is injected into the \u003cbr /\u003esuccessive second medium, which is used as an amplifier with calm density gradient.\u003cbr /\u003eThe gain medium plasmas are generated with a chirped pulse amplification Nd:glass \u003cbr /\u003elaser system with two beam lines. Each beam consisted of two pulses; a pre-pulse with a \u003cbr /\u003epulse duration of 300 ps and a picosecond heating pulse with a temporal delay of 600 ps \u003cbr /\u003efrom the pm-pulse. The pulse duration of the heating pulse for the first target is 4 ps \u003cbr /\u003ewith the quasi-travelling wave arrangement and that for the second target is 12 ps \u003cbr /\u003ewithout the travelling wave. The total pumping energy is set to be 14 J for the first \u003cbr /\u003etarget and 11 J for the second target The energy ratio of the pre-pulse and the heating \u003cbr /\u003epulse is 1:8. The laser pulses are focused with a line shape of 6.5 mm × 20μm on flat. \u003cbr /\u003esilver targets with an irradiance of the heating pulse of ～10\u003csup\u003e15\u003c/sup\u003eW/cm\u003csup\u003e2\u003c/sup\u003e. The distance \u003cbr /\u003ebetween the two targets is 20 cm. The far field patterns of the x-ray laser are measured \u003cbr /\u003efor several seed timing by changing the optical delay of the pumping laser of the first\u003cbr /\u003etarget. At the timing of -15 ps, only the seed x-ray laser from the first target is observed. \u003cbr /\u003eThe beam divergence of the seed x-ray laser is approximately 6 mrad in full width at \u003cbr /\u003ehalf maximum (FWHM). The total energy of the seed x-ray laser is 270 nJ. For the \u003cbr /\u003eseed timing of 0 ps and +15 ps, the intense beams amplified in the second medium was \u003cbr /\u003eobserved. When the timing is adjusted to be 0 ps, an intense x-ray laser beam with little \u003cbr /\u003edivergence of 0.5 mrad in direction parallel to the target surface is observed outside the \u003cbr /\u003eshadow of the second plasma. The beam is spread in the direction perpendicular for 2.5 \u003cbr /\u003emrad. This means that the seed x-ray is amplified in the high gain region, where  the \u003cbr /\u003erefraction is dominant Delaying the pumping time of the seed x-ray from the timing of \u003cbr /\u003e0 ps, the spreading x-ray laser becomes weaker, and an intense and narrow spot appears \u003cbr /\u003einside the shadow of the plasma At the timing of -15 ps, only the narrow spot is \u003cbr /\u003eobserved, which can be fit well with a Gaussian profile. The beam divergence is \u003cbr /\u003eobtained to be a much-reduced value of 0.20 mrad (FWHM) for the directions \u003cbr /\u003eperpendicular and parallel to the target surface The diffraction limited beam divergence \u003cbr /\u003efor a coherent Gaussian beam with a source size of 50 μm is analytically calculated to\u003cbr /\u003ebe 0.11 mrad. The observed divergence is only 1.8 items greater than this value. This \u003cbr /\u003eimplies that the obtained x-ray beam is quite close to the diffraction-limited condition. \u003cbr /\u003eThe gain coefficient of the amplifier plasma at the timing of +15ps is estimated to be \u003cbr /\u003e7.9 cm\u003csup\u003e-1\u003c/sup\u003e with exponential fitting to the data. This value is smaller than the gain \u003cbr /\u003ecoefficient of the single target, which is observed to be 35 cm\u003csup\u003e-1\u003c/sup\u003e in a previous study. This \u003cbr /\u003esmall gain coefficient and small beam divergence suggest that the gain region of this\u003cbr /\u003ehighly directed beam is located in a low density area, where the influence of refraction \u003cbr /\u003eis negligible. \u003cbr /\u003e　　　In order to characterize the spatial coherence of the x-ray laser beam, we carried \u003cbr /\u003eout a Young\u0027s double slit experiment. A pair of slits with width Of 16μm-and separation \u003cbr /\u003eof 150-350 μm is placed 2.3 m away from the second target where the beam diameter is \u003cbr /\u003e460 μm. Even the 350 μm separated double slit, the interference pattern with high \u003cbr /\u003econtrast was observed for both parallel and perpendicular direction Assuming the \u003cbr /\u003eGaussian shell model for the x-ray laser source, the spatial coherence length can be \u003cbr /\u003edetermined by the visibility of the fringe patterns. For both the parallel and \u003cbr /\u003eperpendicular direction, the spatial coherent length is estimated to be about 600μm, \u003cbr /\u003ewhich is longer than the beam diameter at the position of the double slit. It means that \u003cbr /\u003ethis narrow beam is spatially fully coherent \u003cbr /\u003e　　　The evaluation of the scintillation properties of ZnO single crystal for EUV\u003cbr /\u003elithography is described in chapter 3. The x-ray laser operated at 13.9 nm was employed  \u003cbr /\u003eas the excitation source. The lasing scheme is the 4p4d transition of the nickel-like \u003cbr /\u003esilver ion pumped with TCE method. The typical energy of the x-ray laser \u003cbr /\u003eemission was 0.5 μJ and the duration was 7 ps. This value is sufficiently short for this \u003cbr /\u003eexperiment The single( crystal ZnO sample is grown by hydrothermal ｍethod combined\u003cbr /\u003ewith a platinum inner container. High-purity and transparent ZnO single crystal with a \u003cbr /\u003elarge size of 50×50×15mm3 was sliced with a (0001) surface orientation. The x-ray \u003cbr /\u003elaser was focused on the sample using a molybdenum/silicon multilayer spherical\u003cbr /\u003emirror suitable for 13.9 nm. In spite of the huge photon energy compared with the \u003cbr /\u003ebandgap, no visible co1or center was observed after about 50 shots irradiation. To \u003cbr /\u003eeliminate continuous emission from the plasma., a 0.2 μm-thick zirconium foil was\u003cbr /\u003eplaced before the EUV mirror. The fluorescence spectrum and the fluorescence lifetime \u003cbr /\u003eof the ZnO sample were measured using the 25 cm-focal-length spectrograph coupled \u003cbr /\u003ewith a streak camera with the temporal resolution of 100 ps in the fastest scanning range. \u003cbr /\u003eThe trigger pulse of the streak camera was provided by a pulse generator, which also \u003cbr /\u003eserved as the master clock of the x-ray laser. For comparison, the scintillation properties \u003cbr /\u003ewere also evaluated using the 351 nm third harmonics from the 10S3 nm chirped \u003cbr /\u003epumping source for the x-ray laser. The ZnO was excited at energy slightly above the \u003cbr /\u003ebandgap. The pulse duration of the 351 nm excitation is measured to be 110ps. \u003cbr /\u003e　　　One shot of x-ray laser was enough to obtain an image of the time-resolved \u003cbr /\u003efluorescence spectrum. To reduce the noise level, three frames were integrated to obtain \u003cbr /\u003ea clear streak image. The time profile at the peak of the spectrum can be expressed by a \u003cbr /\u003edouble exponential decay with time constants of 1 ns and 3 ns. The two decay constants \u003cbr /\u003ehave been measured in several works for UV excited ZnO single crystals. The fast \u003cbr /\u003edecay is the lifetime of free exciton and the slower decay is assigned to be trapped \u003cbr /\u003ecarriers. The corresponding fluorescence spectrum and the time profile of UV excitation \u003cbr /\u003eis also measured. In both the excitation conditions, a prominent fluorescence peak of the \u003cbr /\u003eZnO exciton transition was observed at around 380 nm. This wavelength is still \u003cbr /\u003econvenient for high resolution imaging devices, since even BK7 glass is transparent at \u003cbr /\u003ethis wavelength. Moreover, the two decay lifetimes observed in both cases were almost \u003cbr /\u003esimilar regardless of the huge difference in the excitation photon energy. The \u003cbr /\u003efluorescence lifetime is sufficiently short for the characterization of the laser plasma \u003cbr /\u003eEUV source with nanoseconds duration for lithographic applications. Furthermore, a\u003cbr /\u003elarge-sized and homogeneous material is potentially attractive for EUV imaging\u003cbr /\u003eapplications including lithography.\u003cbr /\u003e", "subitem_description_type": "Other"}]}, "item_1_description_7": {"attribute_name": "学位記番号", "attribute_value_mlt": [{"subitem_description": "総研大甲第1181号", "subitem_description_type": "Other"}]}, "item_1_select_14": {"attribute_name": "所蔵", "attribute_value_mlt": [{"subitem_select_item": "有"}]}, "item_1_select_8": {"attribute_name": "研究科", "attribute_value_mlt": [{"subitem_select_item": "先導科学研究科"}]}, "item_1_select_9": {"attribute_name": "専攻", "attribute_value_mlt": [{"subitem_select_item": "22 光科学専攻"}]}, "item_1_text_10": {"attribute_name": "学位授与年度", "attribute_value_mlt": [{"subitem_text_value": "2007"}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "TANAKA, Momoko", "creatorNameLang": "en"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_files": {"attribute_name": "ファイル情報", "attribute_type": "file", "attribute_value_mlt": [{"accessrole": "open_date", "date": [{"dateType": "Available", "dateValue": "2016-02-17"}], "displaytype": "simple", "download_preview_message": "", "file_order": 0, "filename": "甲1181_要旨.pdf", "filesize": [{"value": "445.2 kB"}], "format": "application/pdf", "future_date_message": "", "is_thumbnail": false, "licensetype": "license_11", "mimetype": "application/pdf", "size": 445200.0, "url": {"label": "要旨・審査要旨", "url": "https://ir.soken.ac.jp/record/1255/files/甲1181_要旨.pdf"}, "version_id": "378102be-62c5-4ea0-9eef-06279fc3215e"}]}, "item_language": {"attribute_name": "言語", "attribute_value_mlt": [{"subitem_language": "jpn"}]}, "item_resource_type": {"attribute_name": "資源タイプ", "attribute_value_mlt": [{"resourcetype": "thesis", "resourceuri": "http://purl.org/coar/resource_type/c_46ec"}]}, "item_title": "Ｘ線レーザーを用いた固体の時間分解分光の研究", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "Ｘ線レーザーを用いた固体の時間分解分光の研究"}, {"subitem_title": "Time-resolved spectroscopy of solid-state materials using an x-ray laser", "subitem_title_language": "en"}]}, "item_type_id": "1", "owner": "1", "path": ["24"], "permalink_uri": "https://ir.soken.ac.jp/records/1255", "pubdate": {"attribute_name": "公開日", "attribute_value": "2010-02-22"}, "publish_date": "2010-02-22", "publish_status": "0", "recid": "1255", "relation": {}, "relation_version_is_last": true, "title": ["Ｘ線レーザーを用いた固体の時間分解分光の研究"], "weko_shared_id": -1}