JP2010181352A

JP2010181352A - Raman spectroscopic device

Info

Publication number: JP2010181352A
Application number: JP2009026845A
Authority: JP
Inventors: Akira Saito; 明斎藤
Original assignee: Fuji Electric Holdings Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2009-02-09
Filing date: 2009-02-09
Publication date: 2010-08-19

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Raman spectroscopic device capable of stably enhancing Raman scattering intensity, and obtaining a Raman spectrum of a material having a smaller size and a smaller amount. <P>SOLUTION: In the Raman spectroscopic device, a sample substrate 17 having an analyte 22 placed thereon is covered with a metal film 23 and irradiated with laser light 2, and thereby Raman scattered light 3 is stably enhanced, and the Raman spectrum of the material having a smaller size and smaller amount is obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

この発明は、半導体や磁性媒体などクリーンルームで製造されるデバイスの製造環境から発生する１μｍ程度の微小な物質の解析に用いられるラマンスペクトルを取得する顕微ラマン分光器において、そのラマン信号強度を数桁大きくすることによって、より微小、微量な物質のラマンスペクトルの取得を実現するラマン分光装置に関する。 This invention is a microscopic Raman spectrometer that acquires a Raman spectrum used for analyzing a minute substance of about 1 μm generated from a manufacturing environment of a device manufactured in a clean room such as a semiconductor or a magnetic medium. The present invention relates to a Raman spectroscopic device that realizes acquisition of a Raman spectrum of a finer and trace amount of material by increasing the size.

ラマン散乱は、近赤外から紫外域の一定周波数（(₁）のレーザ光を物質に照射したときに発生する(₁(Ωの散乱光（入射光の振動数に対して物質の固有振動数Ωだけ異なる振動数の散乱光）を検出するものである。ここでΩは分子や格子の固有振動数である。ラマン散乱の散乱断面積は１０^-35〜１０^-30ｃｍ²程度と非常に小さいため、ラマン散乱光はワット換算で１×１０^-14Ｗ〜１×１０^-9Ｗ程度と非常に微弱な光である。 Raman scattering occurs when a material is irradiated with laser light of a constant frequency (( ₁ ) from the near infrared to the ultraviolet region ( ₁ (Ω scattered light (the natural frequency of the material relative to the frequency of the incident light Scattered light having a different frequency by Ω), where Ω is the natural frequency of the molecule or lattice, and the scattering cross section of Raman scattering is about 10 ⁻³⁵ to 10 ⁻³⁰ cm ^2. Since it is small, the Raman scattered light is very weak light of about 1 × 10 ⁻¹⁴ W to 1 × 10 ⁻⁹ W in terms of watts.

しかし、レーザ光源およびＣＣＤ（ＣｈａｒｇｅＣｏｕｐｌｅｄＤｅｖｉｃｅ）など半導体センサの改良により微弱な光（１秒間に数１０個程度の光子）のスペクトルを短時間で検出できるようになったため、微小な物質の同定法として利用されるようになってきている。
同じように分子や格子の固有振動数を検出する赤外分光法と比較すると、赤外分光法は赤外線（波長は１０μｍ程度）を試料に照射しその吸収または反射を検出する手法であるため、１μｍ以下の微小異物に効率的にビームを照射して信号を取り出すにはラマン分光よりも不利である。 However, the improvement of semiconductor sensors such as laser light source and CCD (Charge Coupled Device) makes it possible to detect the spectrum of faint light (several tens of photons per second) in a short time. It has come to be used as.
Similarly, compared with infrared spectroscopy that detects the natural frequency of molecules and lattices, infrared spectroscopy is a technique that irradiates a sample with infrared rays (wavelength is about 10 μm) and detects its absorption or reflection. It is more disadvantageous than Raman spectroscopy to extract a signal by efficiently irradiating a minute foreign object of 1 μm or less with a beam.

一方、ラマン分光法では可視光域（波長７００ｎｍ〜４００ｎｍ）の光を試料にフォーカスできるため、より小さな物質に対して空間的に分離してスペクトルを取得できる。
しかし、前述したように基本的には非常に微弱な光であることから、１μｍ以下の粒子の物質同定は困難と考えられている（なぜならば、散乱強度が物質の体積の減少にともなって減少していくためである）。 On the other hand, in Raman spectroscopy, light in the visible light region (wavelength 700 nm to 400 nm) can be focused on the sample, so that a spectrum can be acquired by spatially separating a smaller substance.
However, as described above, since it is basically very weak light, it is considered difficult to identify the substance of particles of 1 μm or less (because the scattering intensity decreases as the volume of the substance decreases). To do it).

微弱なラマン強度を増強する手法としてＳＥＲＳ（ＳｕｒｆａｃｅＥｎｈａｎｃｅｄＲａｍａｎＳｃａｔｔｅｒｉｎｇ）という現象の利用が考えられている。ＳＥＲＳという現象は、その発生機構についてはまだ解明されていないが、以下のような状況下で発現することが知られている。
Ｃｕ、Ｐｔ、Ａｇなどの金属表面におもに有機分子が吸着した場合、ラマン散乱強度が自由分子の散乱断面積から予想されるよりも数桁高くなる。この現象を利用して微小な異物のラマン散乱強度を取得する場合、基板上に物質が付着している必要があるが、例えば適当な金属基板に付着していない微小異物の強度を増強したい場合などは、一度適当な金属基板上に異動しなければならないなど、対象となる微小な異物を汚染または破壊してしまう危険性がある。 The use of a phenomenon called SERS (Surface Enhanced Raman Scattering) has been considered as a technique for enhancing weak Raman intensity. Although the phenomenon of SERS has not yet been elucidated about the generation mechanism, it is known that it appears in the following situations.
When organic molecules are mainly adsorbed on a metal surface such as Cu, Pt, or Ag, the Raman scattering intensity is several orders of magnitude higher than expected from the scattering cross section of free molecules. When acquiring the Raman scattering intensity of a minute foreign object using this phenomenon, it is necessary to have a substance attached on the substrate, but for example, if you want to increase the strength of a minute foreign object not attached to an appropriate metal substrate There is a risk of contaminating or destroying a minute foreign object, such as having to be moved once onto an appropriate metal substrate.

このため、対象となる異物を金属基板上に移動させるのではなく、例えば形状がナノオーダの針状の金属プローブを異物に押し当てた状態で、その金属と異物の界面にレーザ光を照射するなどの方法が考えられている（非特許文献１など）。
また、特許文献１には、プラズモンによるラマン散乱増強を利用したラマン分光分析を行なう分子センシング装置において、センサーの高感度化、安定化、および小型化を実現するためのラマン散乱増強用チップについて記載されている。 For this reason, instead of moving the target foreign matter onto the metal substrate, for example, a laser beam is applied to the interface between the metal and the foreign matter while a needle-shaped metal probe having a nano-order shape is pressed against the foreign matter. The method of this is considered (nonpatent literature 1 etc.).
Patent Document 1 describes a chip for enhancing Raman scattering for realizing high sensitivity, stabilization, and miniaturization of a sensor in a molecular sensing device that performs Raman spectroscopic analysis using Raman scattering enhancement by plasmons. Has been.

特開２００６−２０８２７１号公報JP 2006-208271 A

表面科学Ｖｏｌ．２６Ｎｏ．１１ｐｐ６６７−６７４（２００５）Surface Science Vol. 26 No. 11 pp 667-674 (2005)

上述の金属針を微小異物に押し当てることによってＳＥＲＳという現象を発現させることによってラマン散乱強度を増強する方法は、異物と金属針との機械的な接触をともなうため、同種の異物分子であったとしても接触面積や接触圧などを一定にすること、または一定である確認をとることが困難である。
この発明の目的は、前記の課題を解決して、安定してラマン散乱強度を増強し、より微小、微量な物質のラマンスペクトルを取得できるラマン分光装置を提供することにある。 The above-described method for enhancing the Raman scattering intensity by causing the phenomenon of SERS by pressing the metal needle against the minute foreign material involves the mechanical contact between the foreign material and the metal needle, and is therefore the same kind of foreign material molecule. However, it is difficult to make the contact area and the contact pressure constant or to confirm that they are constant.
An object of the present invention is to solve the above-mentioned problems and to provide a Raman spectroscopic device that can stably enhance the Raman scattering intensity and acquire a Raman spectrum of a finer and trace amount of substance.

前記の目的を達成するために、特許請求の範囲の請求項１記載の発明であって、金属膜を透過して分析物にレーザ光を照射しＳＥＲＳ（ＳｕｒｆａｃｅＥｎｈａｎｃｅｄＲａｍａｎＳｃａｔｔｅｒｉｎｇ）現象で増強したラマン散乱光のスペクトルを観察する試料観察室と、分析物に前記金属膜を被覆する前処理室と、前記前処理室と前記試料観察室とを連結する連結部と、前記試料基板を前記前処理室から前記試料観察室に搬送する搬送手段と、を備えるラマン分光装置とする。 In order to achieve the above object, the invention according to claim 1 of claim 1, wherein the Raman is enhanced by a SERS (Surface Enhanced Raman Scattering) phenomenon by irradiating the analyte with laser light through the metal film. A sample observation chamber for observing the spectrum of scattered light; a pretreatment chamber for coating the metal film on an analyte; a connecting portion for connecting the pretreatment chamber and the sample observation chamber; and the pretreatment of the sample substrate. A Raman spectroscopic device comprising a transporting means for transporting from the chamber to the sample observation chamber.

また、特許請求の範囲の請求項２記載の発明であって、請求項１記載の発明において、前記試料観察室が、レーザ光源と、増強されたラマン散乱光をスペクトルに分光する分光器と、前記金属膜を被覆した前記分析物のある試料基板を載せる第１試料台と、該第１試料台を支持する第１支持台と、前記レーザ光源から出射される前記レーザ光を前記金属膜で被覆された前記分析物の方向へ導き、前記分析物からのラマン散乱光を前記分光器の方向に導くビームスプレッターと、前記分析物に照射される前記レーザ光を前記金属膜で被覆された前記分析物に焦点を合わせ該分析物からの増強されたラマン散乱光を前記ビームスプレッターに導く対物レンズと、前記ビームスプレッターを通過する前記ラマン散乱光を絞るレンズと、該レンズで絞られたラマン散乱光を通過させて前記分光器に入射させるピンホールを有するスリットと、前記第１試料台と前記第１支持台を収納し前記対物レンズの端部が気密固着される第１チャンバーと、該第１チャンバー内の空気を排気する第１排気口と、を具備するとする。 Further, in the invention according to claim 2 of the claim, in the invention according to claim 1, the sample observation chamber includes a laser light source, a spectroscope for spectrally analyzing the enhanced Raman scattered light, A first sample stage on which a sample substrate having the analyte coated with the metal film is placed; a first support stage that supports the first sample stage; and the laser light emitted from the laser light source is formed by the metal film. A beam spreader for guiding the coated analyte in the direction of the analyte, and Raman scattering light from the analyte in the direction of the spectrometer, and the laser light applied to the analyte coated with the metal film. An objective lens that focuses the analyte and guides the enhanced Raman scattered light from the analyte to the beam spreader, a lens that throttles the Raman scattered light that passes through the beam spreader, A slit having a pinhole for allowing the Raman scattered light to pass through and entering the spectroscope, a first chamber in which the first sample stage and the first support stage are housed and the end of the objective lens is hermetically fixed And a first exhaust port for exhausting the air in the first chamber.

また、特許請求の範囲の請求項３記載の発明であって、請求項１または２記載の発明において、前記前処理室が、ターゲット電極と、該ターゲット電極と対向して配置され前記分析物のある前記試料基板を載せる第２試料台と、該第２試料台を支持する第２支持台と、前記ダーゲット電極と前記第２試料台との間に直流電圧を印加して前記第２試料台に載せた前記分析物がある前記試料基板にスパッタで前記金属膜を被覆する電源と、前記ターゲート電極と前記第２試料台と前記第２支持台を収納した第２チャンバーと、該第２チャンバー内の空気を排気する第２排気口と、を具備する構成とする。 Further, in the invention according to claim 3 of the claims, in the invention according to claim 1 or 2, the pretreatment chamber is disposed to face the target electrode and the target electrode. A second sample stage on which the sample substrate is placed; a second support stage that supports the second sample stage; and a DC voltage applied between the target electrode and the second sample stage to apply the second sample stage. A power source that coats the metal film by sputtering on the sample substrate on which the analyte is placed, a second chamber that houses the targate electrode, the second sample stage, and the second support stage, and the second chamber And a second exhaust port for exhausting the air inside.

また、特許請求の範囲の請求項４記載の発明であって、請求項１〜４のいずれか一項に記載の発明において、前記連結部が、前記前処理室と前記試料観察室を分離する分離ゲート、または、該分離ゲートと前記搬送手段とを具備する構成とする。
また、特許請求の範囲の請求項５記載の発明であって、請求項１または４に記載の発明であって、前記搬送手段が、前記金属膜が被覆した前記分析物のある前記試料基板を前記前処理室の前記第２試料台から持ち上げ、前記試料観察室の前記第１試料台に移動し、前記試料基板を前記第１試料台に設置する機能を有する保持機構および移動機構を具備する構成とする。 Moreover, it is invention of Claim 4 of Claims, Comprising: In invention of any one of Claims 1-4, The said connection part isolate | separates the said pre-processing chamber and the said sample observation chamber. The separation gate or the separation gate and the transfer means are provided.
Moreover, it is invention of Claim 5 which is the invention of Claim 1, Comprising: It is invention of Claim 1 or 4, Comprising: The said conveyance means is the said sample substrate with the said analyte coat | covered with the said metal film. A holding mechanism and a moving mechanism having functions of lifting from the second sample stage in the pretreatment chamber and moving to the first sample stage in the sample observation chamber and placing the sample substrate on the first sample stage are provided. The configuration.

また、特許請求の範囲の請求項６記載の発明であって、請求項１〜４のいずれか一項に記載の発明において、前記金属膜の厚さが、１０ｎｍ〜２００ｎｍであるとよい。
また、特許請求の範囲の請求項７記載の発明であって、請求項１〜３、５、６のいずれか一項に記載の発明において、前記金属膜の材質が、少なくともＣｕ、Ａｇ、Ａｕ、ＰｄおよびＲｕのいずれかであるとよい。 Moreover, it is invention of Claim 6 of Claim, Comprising: In the invention as described in any one of Claims 1-4, it is good in the thickness of the said metal film being 10 nm-200 nm.
Further, in the invention according to claim 7 of the claims, in the invention according to any one of claims 1 to 3, 5 and 6, the material of the metal film is at least Cu, Ag, Au. , Pd and Ru.

また、特許請求の範囲の請求項８記載の発明であって、請求項１または２に記載の発明において、前記分析物に分極を誘起するラマン散乱の励起光としての前記レーザ光を出射する前記レーザ光源が、近赤外から紫外までの連続光源またはパルス光源を用いるとよい。
また、特許請求の範囲の請求項９記載の発明であって、請求項８記載の発明において、前記分析物に分極を誘起するラマン散乱の励起光としての前記レーザ光を出射する前記レーザ光源が、２種以上の周波数からなる近赤外から紫外までの連続光源またはパルス光源を用いるとよい。 Further, in the invention according to claim 8, the laser beam is emitted as excitation light of Raman scattering that induces polarization in the analyte in the invention according to claim 1 or 2. The laser light source may be a continuous light source or a pulsed light source from near infrared to ultraviolet.
The invention according to claim 9 is the invention according to claim 8, wherein the laser light source that emits the laser light as excitation light of Raman scattering that induces polarization in the analyte is provided. A continuous light source or a pulsed light source from near infrared to ultraviolet having two or more frequencies may be used.

また、特許請求の範囲の請求項１０記載の発明であって、請求項９記載の発明において、前記の２種類の光源において，第１の光源は近赤外から紫外までの範囲にあるいずれかの一定周波数であり、第２の光源は第１の光の周波数を含み第１の周波数のまわりに広がる連続スペクトルをもつ光源であるとよい。 Further, in the invention according to claim 10 of the claims, in the invention according to claim 9, in the two kinds of light sources, the first light source is any one in the range from near infrared to ultraviolet. The second light source may be a light source having a continuous spectrum that includes the frequency of the first light and extends around the first frequency.

この発明によれば、分析物のある試料基板を金属膜で被覆し、レーザ光を照射することで、ラマン散乱光を安定して増強できて、より微小、微量な物質のラマンスペクトルを取得できるラマン分光装置を提供することができる。 According to the present invention, a sample substrate with an analyte is covered with a metal film and irradiated with laser light, so that the Raman scattered light can be stably enhanced and a Raman spectrum of a finer and trace amount of substance can be acquired. A Raman spectroscopic device can be provided.

この発明の一実施例のラマン分光装置の要部構成図である。It is a principal part block diagram of the Raman spectroscopy apparatus of one Example of this invention. 分析物２２に金属膜２３を被覆する様子を示す図であり、（ａ）は金属膜２２を被覆する前の図、（ｂ）は金属膜２２を被覆した後の図である。It is a figure which shows a mode that the analyte 22 is coat | covered with the metal film 23, (a) is a figure before coat | covering the metal film 22, (b) is a figure after coat | covering the metal film 22. FIG. 連結部１０に分離ゲートのみを設ける場合の搬送手段の構成図である。It is a block diagram of a conveyance means in the case of providing only a separation gate in the connection part.

実施の形態を以下の実施例で説明する。 Embodiments will be described in the following examples.

図１は、この発明の一実施例のラマン分光装置の要部構成図である。この発明のラマン分光装置１００は、顕微ラマン分光分析を行なう試料観察室２６と分析物２２に金属膜２３を被覆する前処理室２７および試料観察室２６と前処理室２７を連結する連結部１０から構成されている。図１では試料観察室２６と前処理室２７は点線で示し、それらの具体的な外枠は示していない。また、図１では、レーザ光源および分光器は省略されている。 FIG. 1 is a block diagram of the main part of a Raman spectroscopic device according to an embodiment of the present invention. The Raman spectroscopic device 100 according to the present invention includes a sample observation chamber 26 for performing micro-Raman spectroscopic analysis, a pretreatment chamber 27 for covering the analyte 22 with the metal film 23, and a connecting portion 10 for connecting the sample observation chamber 26 and the pretreatment chamber 27. It is composed of In FIG. 1, the sample observation chamber 26 and the pretreatment chamber 27 are shown by dotted lines, and their specific outer frames are not shown. In FIG. 1, the laser light source and the spectroscope are omitted.

試料観察室２６は、レーザ光源と、レーザ光源からレーザ光２を対象物質（金属膜２３で被覆され分析物２２）へ照射する光学系（対物レンズ４）と、金属膜２３で被覆された分析物２２からのラマン散乱光３を集光する光学系（レンズ５）、分析物２２がある試料基板１７を設置する観察ステージ２４（第１試料台）、この観察ステージ２４を支持する支持台１８（第１支持台）、レンズ５を通過したラマン散乱光３を通すピンホール２０を有するスルット２５と、ラマン散乱光３をスペクトルに分離する分光器（検出器を含む）と、観察ステージ２４と支持台１８とを収納するチャンバー７（第１チャンバー）およびチャンバ７内の空気を排気する真空排気口８（第１排気口）から構成される。尚、真空排気口８は図示しない真空ポンプに接続する。また、試料基板１７とは、分析物２２を載せる基板または分析の対象となる試料をいう。また、図中の符号において、１は入射レーザ光とラマン散乱光が導かれる光路である。 The sample observation chamber 26 includes a laser light source, an optical system (objective lens 4) that irradiates the target substance (analyte 22 coated with the metal film 23) with the laser light 2 from the laser light source, and an analysis coated with the metal film 23. An optical system (lens 5) for condensing the Raman scattered light 3 from the object 22, an observation stage 24 (first sample stage) on which the sample substrate 17 with the analyte 22 is placed, and a support base 18 that supports the observation stage 24 (First support), a slut 25 having a pinhole 20 through which the Raman scattered light 3 passed through the lens 5 passes, a spectrometer (including a detector) for separating the Raman scattered light 3 into a spectrum, and an observation stage 24 A chamber 7 (first chamber) for housing the support base 18 and a vacuum exhaust port 8 (first exhaust port) for exhausting air in the chamber 7 are configured. The vacuum exhaust port 8 is connected to a vacuum pump (not shown). The sample substrate 17 refers to a substrate on which the analyte 22 is placed or a sample to be analyzed. Moreover, in the code | symbol in a figure, 1 is an optical path where incident laser light and Raman scattered light are guide | induced.

前処理室２７は、ターゲット電極１２と、該ターゲット電極１２と対向して配置され分析物２２がある試料基板１７を載せる成膜ステージ１４（第２試料台）と、この成膜ステージ１４を支持する支持台１９（第２支持台）と、ダーゲット電極１２と成膜ステージ１４との間に直流電圧を印加して分析物２２がある試料基板１７にスパッタで金属膜２３を被覆する電源２１と、ターゲート電極１２と成膜ステージ１４と支持台１９を収納したチャンバー９と、チャンバー９内の空気を排気する真空排気口１３（第２排気口）とおよびチャンバー９内に不活性ガスを導入するガス導入口１５から構成される。真空排気口１３は図示しない真空ポンプに接続し、ガス導入口１５は不活性ガス（または反応性ガス）を送る図示しないパイプに接続する。尚、ターゲット電極１２とはターゲット材で形成された電極またはターゲット材とターゲット材を載せた電極を合わせたものをいう。また、チャンバー９内が真空状態であれば、必ずしも不活性ガスや反応性ガスをチャンバー９内に導入しなくてもよい。 The pretreatment chamber 27 supports the target electrode 12, the film formation stage 14 (second sample stage) on which the sample substrate 17 having the analyte 22 disposed opposite to the target electrode 12 is placed, and the film formation stage 14. A power source 21 for applying a DC voltage between the target electrode 12 and the film forming stage 14 to coat the sample substrate 17 with the analyte 22 on the metal film 23 by sputtering. The chamber 9 containing the gate electrode 12, the film forming stage 14, and the support 19, the vacuum exhaust port 13 (second exhaust port) for exhausting the air in the chamber 9, and an inert gas are introduced into the chamber 9. It consists of a gas inlet 15. The vacuum exhaust port 13 is connected to a vacuum pump (not shown), and the gas introduction port 15 is connected to a pipe (not shown) for sending an inert gas (or reactive gas). The target electrode 12 refers to an electrode formed of a target material or a combination of a target material and an electrode on which the target material is placed. If the inside of the chamber 9 is in a vacuum state, it is not always necessary to introduce an inert gas or a reactive gas into the chamber 9.

図２は、分析物２２に金属膜２３を被覆する様子を示す図であり、同図（ａ）は金属膜２２を被覆する前の図、同図（ｂ）は金属膜２２を被覆した後の図である。金属膜２３はスパッタにより分析物２２に被覆される。このとき、試料基板１７にも金属膜２３が被覆される。
連結部１０は、試料観察室２６と前処理室２７を分離する図示しない分離ゲートのみ設置されている場合と、金属膜２３で被覆された分析物２２がある試料基板１７を前処理室２７から試料観察室２６へ搬送する搬送手段を合わせて設置されている場合がある。 2A and 2B are diagrams showing a state in which the analyte 22 is coated with the metal film 23. FIG. 2A is a diagram before the metal film 22 is coated, and FIG. 2B is a diagram after the metal film 22 is coated. FIG. The metal film 23 is coated on the analyte 22 by sputtering. At this time, the metal film 23 is also coated on the sample substrate 17.
The connection unit 10 includes a case where only a separation gate (not shown) that separates the sample observation chamber 26 and the pretreatment chamber 27 is installed, and a case where the sample substrate 17 having the analyte 22 covered with the metal film 23 is removed from the pretreatment chamber 27. There may be a case where transport means for transporting to the sample observation chamber 26 is installed together.

この分離ゲートの働きは、これを閉じることで、試料観察室２６と前処理室２７のそれぞれの雰囲気を独立に制御できるようにすることである。
図３は、連結部１０に分離ゲートのみを設ける場合の搬送手段の構成図である。この搬送手段は、チャック（保持機構）とこのチャックが固定している伸縮棒（移動機構）で構成される。試料基板１７を真空吸着などで脱着するチャックを、例えば、試料観察室２６内のチャンバー７に設け、開いてる連結部１０の分離ゲートを通してチャックが固定している伸縮棒を成膜ステージ１４まで伸ばし、成膜ステージ１４に載っている試料基板１７をチャックで吸着して持ち上げる。つぎに、伸縮棒を縮めて試料基板１７を観察ステージ２４上に移動させ、チャックから試料基板１７を離して観察ステージ２４に載せる。 The function of this separation gate is to make it possible to independently control the atmosphere of each of the sample observation chamber 26 and the pretreatment chamber 27 by closing it.
FIG. 3 is a configuration diagram of the transport means when only the separation gate is provided in the connecting portion 10. This conveying means is composed of a chuck (holding mechanism) and an extendable rod (moving mechanism) fixed to the chuck. A chuck for detaching the sample substrate 17 by vacuum suction or the like is provided, for example, in the chamber 7 in the sample observation chamber 26, and the extendable rod fixed to the chuck is extended to the film forming stage 14 through the separation gate of the open connecting portion 10. Then, the sample substrate 17 placed on the film forming stage 14 is adsorbed by a chuck and lifted. Next, the telescopic rod is contracted to move the sample substrate 17 onto the observation stage 24, and the sample substrate 17 is separated from the chuck and placed on the observation stage 24.

連結部１０に分離ゲートと搬送手段を設ける場合について説明する。図示しないが搬送手段は試料基板１７を搬送する搬送台（移動機構）と、成膜ステージ１４から試料基板１７を持ち上げ搬送台に移すチャック（保持機構）と、搬送台から観察ステージ２４に試料基板１７を移して設置するチャック（保持機構）とで構成される。搬送台とチャックの支持部は連結部１０から試料観察室２６と前処理室２７に延びている。分離ゲートは試料基板１７が搬送するときにのみ開けられ、それ以外は搬送台を挟み込むようにして閉まっており、試料観察室２６と前処理室２７のそれぞれの雰囲気は閉まった分離ゲートでそれぞれ独立に制御される。 A case where a separation gate and a conveying means are provided in the connecting portion 10 will be described. Although not shown, the transfer means includes a transfer stand (moving mechanism) for transferring the sample substrate 17, a chuck (holding mechanism) for lifting the sample substrate 17 from the film forming stage 14 and moving it to the transfer stand, and the sample substrate from the transfer stand to the observation stage 24. And a chuck (holding mechanism) to which 17 is installed. The carrier and chuck support portions extend from the connecting portion 10 to the sample observation chamber 26 and the pretreatment chamber 27. The separation gate is opened only when the sample substrate 17 is transported, and the others are closed so as to sandwich the transport table, and the atmosphere in the sample observation chamber 26 and the pretreatment chamber 27 is independent by the closed separation gate. Controlled.

ラマン分光装置１００についてさらに詳細に説明する。平行なレーザ光２（ここでレーザ光の波長は１．５μｍ付近の近赤外光から０．３５μｍ付近の紫外光の範囲）がビームスプリッター６で対物レンズ４に導かれる。レーザ光２は対物レンズ４で試料基板２３にある分析物２２に光路１を通って集光される。
集光されたレーザ光２によって発生させられたラマン散乱光３は、光路１を通って対物レンズ４によって平行光にされレンズ５に導かれる。レンズ５に導かれたラマン散乱光３はピンホール２０を通過するように集光される。このピンホール２０によって、分析物２２以外からの妨害光（迷光）が除去される。 The Raman spectroscopic device 100 will be described in further detail. A parallel laser beam 2 (where the wavelength of the laser beam ranges from near infrared light near 1.5 μm to ultraviolet light near 0.35 μm) is guided to the objective lens 4 by the beam splitter 6. The laser beam 2 is condensed by the objective lens 4 onto the analyte 22 on the sample substrate 23 through the optical path 1.
The Raman scattered light 3 generated by the condensed laser light 2 is converted into parallel light by the objective lens 4 through the optical path 1 and guided to the lens 5. The Raman scattered light 3 guided to the lens 5 is condensed so as to pass through the pinhole 20. The pinhole 20 removes interference light (stray light) from other than the analyte 22.

ピンホール２２を通過したラマン散乱光３は図示しない分光器とのＦマッチング（焦点を合わせること）をとるようにレンズ系によって調整されたのち分光器で分光されラマンスペクトルとして取り出される。
この分光器では、回折格子に導かれ光の波長に応じて分散された光が半導体ＣＣＤ上に結像されスペクトルとして取り出される。 The Raman scattered light 3 that has passed through the pinhole 22 is adjusted by a lens system so as to be F-matched (focused) with a spectroscope (not shown), and then is dispersed by the spectroscope and extracted as a Raman spectrum.
In this spectrometer, the light guided to the diffraction grating and dispersed according to the wavelength of the light is imaged on the semiconductor CCD and taken out as a spectrum.

分析物２２を金属膜２３で被覆することで、ラマン散乱光３はＳＥＲＳ現象で増強されて分光器に入射する。
レーザ光２は、分析物２２に分極を誘起するラマン散乱の励起光であり、このレーザ光源には、近赤外から紫外までの連続光源またはパルス光源を用いる。
また、これらの光源には、２種以上の周波数からなる近赤外から紫外までの連続光源またはパルス光源を用いるとよい。 By covering the analyte 22 with the metal film 23, the Raman scattered light 3 is enhanced by the SERS phenomenon and enters the spectroscope.
The laser light 2 is Raman scattering excitation light that induces polarization in the analyte 22, and a continuous light source or a pulsed light source from near infrared to ultraviolet is used as the laser light source.
Moreover, it is good to use the continuous light source or pulse light source from near infrared to ultraviolet which consists of 2 or more types of frequency as these light sources.

また、この２種類の光源のうち第１の光源は近赤外から紫外までの範囲にあるいずれかの一定周波数（例えば、５．８×１０¹⁴Ｈｚ、 λ＝５１４．５ｎｍ）であり、第２の光源は第１の光の周波数を含み第１の周波数のまわりに広がる（例えば、第１の周波数を(₁とすると第２の光源の周波数は(₂＝(₁±１×１０¹⁴Ｈｚ程度の広がり）連続スペクトルをもつ光源であるとよい。 Of these two types of light sources, the first light source has any constant frequency in the range from near infrared to ultraviolet (for example, 5.8 × 10 ¹⁴ Hz, λ = 514.5 nm), The light source of 2 includes the frequency of the first light and spreads around the first frequency (for example, if the first frequency is ( ₁ , the frequency of the second light source is ( ₂ = ( ₁ ± 1 × 10 ¹⁴ Hz It is preferable that the light source has a continuous spectrum.

このように２種以上の周波数からなる光源を用いると単光源を用いる場合に比べて、以下のようなメリットがある。
ラマン散乱で、物質に第１のレーザ光(₁（例えば、５。８×１０¹⁴Ｈｚ、 λ＝５１４。５ｎｍ）を照射し、物質を構成する結晶格子の振動または分子振動を励起するとき、物質からはラマン散乱光(₁−Ω（ここで、Ωは格子振動または分子振動の周波数で１×１０¹³Ｈｚ程度）が発生する。このとき、物質に周波数が(₁−Ωの第２のレーザ光を照射すると、物質からは、(₁＋ΩのＣＡＲＳ（ＣｏｈｅｒｅｎｔＡｎｔｉ−ｓｔｏｋｅｓＲａｍａｎＳｃａｔｔｅｒｉｎｇ）と呼ばれるラマン散乱に比較して１０倍から１０００倍程度の強い散乱光が放出される。したがって、上述のように第１の周波数を(₁として、周波数 (₂＝(₁±１×１０¹⁴Ｈｚ程度の広がりを持つ第２の光源をフィルターを用いて、(₂の中の(₁よりも短波長側の成分をカットし、(₁よりも長波長側の連続光を物質に照射することによって、(₁よりも短波長側に強度の強いラマン散乱（Ａｎｔｉ−Ｓｔｏｋｅｓ散乱）スペクトルを得ることが可能となる。応用物理第７５巻、第６号ｐｐ６８２−６８８（２００６）には、上記ＣＡＲＳ現象を第１のレーザ光源（一定周波数）と第２のレーザ光源（連続光）を照射する方法の記載がある。 As described above, when a light source having two or more frequencies is used, there are the following merits as compared with the case of using a single light source.
When the material is irradiated with a _first laser beam ( ₁ (for example, 5.8 × 10 ¹⁴ Hz, λ = 514.5 nm)) by Raman scattering to excite vibrations of crystal lattices or molecular vibrations constituting the material, Raman scattered light from the material ₍₁ - [omega] (where, Omega about 1 × 10 ¹³ Hz at a frequency of lattice vibrations or molecular vibration) occurs. in this case, the frequency to the substance (the ₁ - [omega] second When irradiated with laser light, the substance emits intense scattered light of about 10 to 1000 times compared to Raman scattering called ( ₁ + Ω CARS (Coherent Anti-Stokes Raman Scattering). a first frequency as ₍₁ so, the second light source having a frequency ₍₂ = (of the order of ₁ ± 1 × 10 ¹⁴ Hz spread through a filter, the shorter wavelength side than the ₍₁ in ₍₂ The ingredients of And, (by irradiating continuous light of wavelengths longer than ₁ to the substance, it is possible to obtain a strong Raman scattering (Anti-Stokes scattering) spectrum intensity in the short wavelength side of _(1. Applied Physics Volume 75, No. 6 pp 682-688 (2006) describes a method of irradiating the CARS phenomenon with a first laser light source (constant frequency) and a second laser light source (continuous light).

本発明においては、分析物２２が置いてある試料基板１７は、観察試料室２６の観察ステージ２４上に設置する前に、前処理室２７の成膜ステージ１４上で金属膜２３がスパッタで成膜される。
図１では分析物２２が試料基板１７上に置かれてあるが、分析物２２は必ずしも試料基板１７上に置かれるような微小物質である必要はなく、試料基板１７程度の大きさのものでもかまわない。この場合は分析物２２を試料基板１７上に置く必要はなく、試料基板１７の代わりに分析物２２を成膜ステージ１４や観察ステージ２４に設置すればよい。 In the present invention, before the sample substrate 17 on which the analyte 22 is placed is placed on the observation stage 24 in the observation sample chamber 26, the metal film 23 is formed on the film formation stage 14 in the pretreatment chamber 27 by sputtering. Be filmed.
In FIG. 1, the analyte 22 is placed on the sample substrate 17, but the analyte 22 does not necessarily have to be a minute substance that is placed on the sample substrate 17, and may be as large as the sample substrate 17. It doesn't matter. In this case, it is not necessary to place the analyte 22 on the sample substrate 17, and the analyte 22 may be placed on the film forming stage 14 or the observation stage 24 instead of the sample substrate 17.

前処理室２７のチャンバー９はスパッタリングが可能な成膜室になっている。図１では、成膜ステージ１４が陽極、成膜材料で構成されたターゲット電極１２（勿論、ターゲット材を設置したターゲット台であってもよい）が陰極になっている。成膜においてはガス導入口１５からマスフローコントロールで流量制御された不活性ガスであるアルゴンガスがチャンバー９内に導入され、直流電界によってプラズマが発生される。尚、不活性ガスの代わりに反応性ガスも場合もある。 The chamber 9 of the pretreatment chamber 27 is a film forming chamber capable of sputtering. In FIG. 1, the film forming stage 14 is an anode, and a target electrode 12 composed of a film forming material (of course, a target table on which a target material is installed) is a cathode. In film formation, argon gas, which is an inert gas whose flow rate is controlled by mass flow control, is introduced from the gas inlet 15 into the chamber 9, and plasma is generated by a DC electric field. A reactive gas may be used instead of the inert gas.

ターゲット材であるターゲット電極１２の材質としてはＣｕ、Ａｇ、Ａｕ、Ｐｄ、Ｒｕなどの金属が挙げられる。成膜される金属膜２３の膜厚は、１０ｎｍ〜２００ｎｍの範囲であり、得られるＳＥＲＳの強度が最大となるように調整される。膜厚が１０ｎｍ未満では、ラマン散乱光３の増強が微弱になり、２００ｎｍを超えるとレーザ光２が金属膜２３を透過する程度が少なくなりやはりラマン散乱光３の増強が弱まり分析が困難になる。 Examples of the material of the target electrode 12 that is a target material include metals such as Cu, Ag, Au, Pd, and Ru. The film thickness of the metal film 23 to be formed is in the range of 10 nm to 200 nm, and is adjusted so that the strength of the obtained SERS is maximized. If the film thickness is less than 10 nm, the enhancement of the Raman scattered light 3 becomes weak, and if it exceeds 200 nm, the degree to which the laser light 2 is transmitted through the metal film 23 is reduced, and the enhancement of the Raman scattered light 3 is weakened and the analysis becomes difficult. .

このように、分析物２２がある試料基板１７を金属膜２３で被覆し、レーザ光２を照射することで、ラマン散乱光３を安定して増強することができて、より微小、微量な分析物２２のラマンスペクトルを取得できる。 Thus, by covering the sample substrate 17 with the analyte 22 with the metal film 23 and irradiating the laser beam 2, the Raman scattered light 3 can be stably enhanced, and the analysis can be performed more minutely and minutely. The Raman spectrum of the object 22 can be acquired.

１入射レーザ光とラマン散乱光が導かれる光路（試料観察室）
２平行に入射するレーザ光（試料観察室）
４端物レンズ（試料観察室）
５レンズ（試料観察室）
６ビームスプレッター（試料観察室）
７チャンバー（試料観察室）
８真空排気口（試料観察室）
９チャンバー（前処理室）
１０連結部
１２ターゲット電極（前処理室）
１３真空排気口（前処理室）
１４成膜ステージ（前処理室）
１５ガス導入口（前処理室）
１６支持台（ターゲット電極用）
１７試料基板
１８支持台（観察ステージ用）
１９支持台（成膜ステージ用）
２０ピンホール
２１電源
２２分析物
２３金属膜
２４観察ステージ
２５スリット
２６試料観察室
２７前処理室
１００ラマン分光装置
1 Optical path for guiding incident laser light and Raman scattered light (sample observation room)
2 Parallel incident laser light (sample observation room)
4. End lens (sample observation room)
5 Lens (sample observation room)
6 Beam splitter (sample observation room)
7 Chamber (sample observation room)
8 Vacuum exhaust (sample observation room)
9 Chamber (Pretreatment room)
10 connecting part 12 target electrode (pretreatment chamber)
13 Vacuum exhaust port (pretreatment chamber)
14 Deposition stage (pretreatment chamber)
15 Gas inlet (Pretreatment room)
16 Support base (for target electrode)
17 Sample substrate 18 Support base (for observation stage)
19 Support stand (for film formation stage)
20 Pinhole 21 Power Supply 22 Analyte 23 Metal Film 24 Observation Stage 25 Slit 26 Sample Observation Room 27 Pretreatment Room 100 Raman Spectrometer

Claims

A sample observation chamber for observing the spectrum of Raman scattered light enhanced by the SERS (Surface Enhanced Raman Scattering) phenomenon by irradiating a sample substrate with an analyte through the metal film and irradiating the sample with the metal film, and covering the analyte with the metal film A pretreatment chamber, a connecting portion that connects the pretreatment chamber and the sample observation chamber, and a transport unit that conveys the analyte from the pretreatment chamber to the sample observation chamber. Raman spectrometer.

The sample observation room has a laser light source, a spectroscope for spectrally analyzing the enhanced Raman scattered light, a first sample stage on which the sample substrate with the analyte coated with the metal film is placed, and the first A first support for supporting a sample stage; and the laser light emitted from the laser light source is guided toward the analyte covered with the metal film, and Raman scattered light from the analyte is transmitted to the spectroscope. A beam splitter that guides the analyte in a direction and an objective that focuses the laser light applied to the analyte on the analyte coated with the metal film and guides the enhanced Raman scattered light from the analyte to the beam splitter. A slot that includes a lens, a lens that squeezes the Raman scattered light passing through the beam splitter, and a pinhole that allows the Raman scattered light squeezed by the lens to pass through and enter the spectroscope. A first chamber in which the first sample stage and the first support stage are accommodated and an end of the objective lens is hermetically fixed, and a first exhaust port for exhausting air in the first chamber. The Raman spectroscopic apparatus according to claim 1, further comprising:

The pretreatment chamber is a target electrode; a second sample stage placed opposite to the target electrode and on which the sample substrate with the analyte is placed; a second support stage for supporting the second sample stage; A power source for applying the DC voltage between the target electrode and the second sample stage to coat the metal film by sputtering on the sample substrate on which the analyte is placed on the second sample stage; The said 2nd sample stand and the 2nd chamber which accommodated the said 2nd support stand, The 2nd exhaust port which exhausts the air in this 2nd chamber is comprised, The 1st or 2 characterized by the above-mentioned. Raman spectrometer.

The said connection part comprises the isolation | separation gate which isolate | separates the said pre-processing chamber and the said sample observation chamber, or this isolation | separation gate and the said conveyance means. Raman spectrometer.

The transport means lifts the sample substrate with the analyte coated with the metal film from the second sample stage in the pretreatment chamber, moves the sample substrate to the first sample stage in the sample observation chamber, and moves the sample substrate. The Raman spectroscopic apparatus according to claim 1, further comprising a holding mechanism and a moving mechanism that have a function of installing a first on the first sample stage.

The Raman spectroscopic apparatus according to claim 1, wherein the metal film has a thickness of 10 nm to 200 nm.

The Raman spectroscopic apparatus according to claim 1, wherein a material of the metal film is at least one of Cu, Ag, Au, Pd, and Ru.

3. The laser light source that emits the laser light as excitation light of Raman scattering that induces polarization in the analyte uses a continuous light source or a pulse light source from near infrared to ultraviolet. The Raman spectroscopic apparatus according to 1.

The laser light source that emits the laser light as excitation light of Raman scattering that induces polarization in the analyte uses a continuous light source or pulse light source from near infrared to ultraviolet having two or more frequencies. The Raman spectroscopic apparatus according to claim 8.

In the above two types of light sources, the first light source has any constant frequency in the range from near infrared to ultraviolet, and the second light source includes the frequency of the first light and around the first frequency. The Raman spectroscopic apparatus according to claim 9, wherein the light source has a continuous spectrum extending in a wide range.