JP2007101189A - Transmission-type electromagnetic wave imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission-type electromagnetic wave imaging device of a simple structure for measuring, with high accuracy, two-dimensional distribution of transmissivity of a specimen under measurement as to an electromagnetic wave. <P>SOLUTION: The imaging device includes an electromagnetic wave emission source 2 with electromagnetic-wave emission elements disposed in an array shape, an electromagnetic wave signal generation/phase adjustment part 1 for independently adjusting the phases of electromagnetic waves emitted by respective electromagnetic wave generation elements, a first collimating lens 4 of a focal distance f disposed in a position at a forward distance f from the emission source 2 for applying the electromagnetic wave to the specimen 6 under measurement, a second collimating lens 7 for condensing the electromagnetic wave transmitted by the specimen 6, an electromagnetic wave detection part 8 having a detection surface 8a at a condensing position of the electromagnetic wave, and an arithmetic control/storage part 11 for measuring the two-dimensional distribution of transmissivity of the electromagnetic wave as to the specimen 6 based on the intensity of a detected electromagnetic wave. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、物質の電磁波に対する透過率の２次元分布を測定して、非破壊で被測定試料の物理的、化学的性質の２次元分布を明らかにする透過型電磁波イメージング装置に関する。   The present invention relates to a transmission-type electromagnetic wave imaging apparatus that measures a two-dimensional distribution of transmittance of a substance with respect to electromagnetic waves, and reveals a two-dimensional distribution of physical and chemical properties of a sample to be measured in a non-destructive manner.

従来の透過型電磁波イメージング装置として、例えば特許文献１に開示されたものがある。図５は従来の透過型電磁波イメージング装置を示す構成図である。   As a conventional transmission electromagnetic wave imaging apparatus, for example, there is one disclosed in Patent Document 1. FIG. 5 is a block diagram showing a conventional transmission electromagnetic wave imaging apparatus.

図５に示す透過型電磁波イメージング装置は、測定室１０１と、テラヘルツパルス光源１０２と、測光光学系１０３Ａ, １０３Ｂと、Ｘ−Ｙステージ１０４と、被測定試料１０５と、テラヘルツパルス検出部１０６と、計測・記憶部１０７と、データ処理部１０８と、演算部１０９と、画像処理部１１０とを備える。   A transmission electromagnetic wave imaging apparatus shown in FIG. 5 includes a measurement chamber 101, a terahertz pulse light source 102, photometric optical systems 103A and 103B, an XY stage 104, a sample 105 to be measured, a terahertz pulse detector 106, A measurement / storage unit 107, a data processing unit 108, a calculation unit 109, and an image processing unit 110 are provided.

テラヘルツパルス光源１０２から発生したテラヘルツパルス光は、測光光学系１０３Ａにより集光光束となり被測定試料１０５の一点に照射され、被測定試料１０５を透過し、測光光学系１０３Ｂで集光されてテラヘルツパルス検出部１０６に入射する。   The terahertz pulse light generated from the terahertz pulse light source 102 becomes a condensed light beam by the photometric optical system 103A, irradiates one point of the sample 105 to be measured, passes through the sample 105 to be measured, and is collected by the photometric optical system 103B and collected by the terahertz pulse. The light enters the detection unit 106.

Ｘ−Ｙステージ１０４は、被測定試料１０５を載置し、被測定試料１０５の２次元投影画像を得るためのＸ−Ｙ走査をする。Ｘ−Ｙ走査に応じてテラヘルツパルス検出部１０６は透過パルス光を順次検出し、電場強度の信号を計測・記憶部１０７へ送出する。   The XY stage 104 mounts the sample 105 to be measured and performs XY scanning for obtaining a two-dimensional projection image of the sample 105 to be measured. In response to the XY scanning, the terahertz pulse detection unit 106 sequentially detects the transmitted pulse light, and sends an electric field strength signal to the measurement / storage unit 107.

計測・記憶部１０７は、１画素毎にテラヘルツパルス光の電界強度の時系列信号を計測し、記憶する。データ処理部１０８は、１画素毎に時系列信号をフーリエ変換し、周波数スペクトルに変換する演算を行い、分光透過率を算出する。   The measurement / storage unit 107 measures and stores a time-series signal of the electric field strength of the terahertz pulse light for each pixel. The data processing unit 108 performs an operation of Fourier transforming the time series signal for each pixel and converting it to a frequency spectrum, and calculates the spectral transmittance.

演算部１０９は、分光透過率の周波数依存性から、被測定試料１０５の特徴的なパラメータを算出する。画像処理部１１０は、演算部１０９で得られた各画素に対応する数値データを用いてコンピュータで再構成して２次元画像化する。
特開２００２−５８２８ The calculation unit 109 calculates characteristic parameters of the sample 105 to be measured from the frequency dependence of the spectral transmittance. The image processing unit 110 uses a numerical data corresponding to each pixel obtained by the calculation unit 109 to reconstruct the image into a two-dimensional image.
JP2002-5828

しかし、図５に示す透過型電磁波イメージング装置は、テラヘルツパルス光を試料表面上の一点に集光させる構造であるため、被測定試料がテラヘルツパルス光の光軸上で前後した場合、テラヘルツパルス光が透過する被測定試料上の断面積が大きく変化する。また、ステージ動作による振動発生が測光光学系の位置ずれを誘発することがある。このため測定精度が低下するという問題があった。   However, since the transmission electromagnetic wave imaging apparatus shown in FIG. 5 has a structure for condensing terahertz pulse light at one point on the sample surface, when the sample to be measured moves back and forth on the optical axis of the terahertz pulse light, terahertz pulse light is used. The cross-sectional area on the sample to be measured that is transmitted through greatly changes. Further, the occurrence of vibration due to the stage operation may induce a position shift of the photometric optical system. For this reason, there was a problem that the measurement accuracy was lowered.

この測定精度の低下を防ぐには、Ｘ−Ｙステージの走査機構に高い位置精度が要求される。また、ステージ動作による位置ずれを防ぐためには、走査機構に高い剛性を持たせる必要がある。このため複雑な可動機構が必要となり、装置の構成が複雑になるという問題があった。   In order to prevent this measurement accuracy from being lowered, a high positional accuracy is required for the scanning mechanism of the XY stage. In addition, in order to prevent displacement due to the stage operation, the scanning mechanism needs to have high rigidity. For this reason, there is a problem that a complicated movable mechanism is required and the configuration of the apparatus is complicated.

さらに、集光ビームを用いるため、被測定試料が厚くなるとテラヘルツパルス光が透過する被測定試料上の断面積が試料表面と裏面とで大きく変化する。このため試料厚さに制約が生じる。   Furthermore, since the focused beam is used, the cross-sectional area on the sample to be measured through which the terahertz pulse light is transmitted changes greatly between the sample surface and the back surface when the sample to be measured is thick. This limits the sample thickness.

本発明は上記に鑑みてなされたもので、被測定試料の電磁波に対する透過率の２次元分布を高い精度で測定することができ、測定できる試料の厚さに制約がなく、シンプルな構造の透過型電磁波イメージング装置を提供することを目的とする。   The present invention has been made in view of the above, and can measure the two-dimensional distribution of the transmittance of the sample to be measured with respect to the electromagnetic wave with high accuracy, has no restriction on the thickness of the sample that can be measured, and has a simple structure. An object of the present invention is to provide an electromagnetic wave imaging apparatus.

上記目的を達成するため、請求項１記載の発明は、電磁波の被測定試料に対する透過率の２次元分布を測定し、その結果から被測定試料の物理的、化学的性質の２次元分布を可視化する透過型電磁波イメージング装置において、電磁波信号を発生する電磁波信号発生手段と、この電磁波信号発生手段で発生した前記電磁波信号を複数に分配する分配手段と、この分配手段で分配された電磁波信号をそれぞれ位相調整する位相調整手段と、この位相調整手段で位相調整された電磁波信号を受けて電磁波を放射する複数の電磁波放射素子をアレイ状に配置した電磁波放射源と、前記電磁波放射源から電磁波の放射方向に所定の焦点距離だけ前方に設置され、前記電磁波放射源から放射された電磁波をコリメートする第１のコリメート光学系と、この第１のコリメート光学系を出射した後、前記被測定試料を透過した電磁波を収束する第２のコリメート光学系と、この第２のコリメート光学系から電磁波の進行方向に前記第２のコリメート光学系の焦点距離だけ前方に設置され、前記第２のコリメート光学系で収束された電磁波を検出する電磁波検出手段と、前記位相調整手段で調整される位相調整量を制御することにより前記電磁波放射源が放射する電磁波の前記被測定試料表面上での照射位置を走査させ、前記電磁波検出手段で検出した電磁波の強度に基づいて前記被測定試料に対する電磁波の透過率の２次元分布を測定する演算制御手段とを備えたことを特徴とする。   In order to achieve the above object, the invention described in claim 1 measures the two-dimensional distribution of the transmittance of the electromagnetic wave to the sample to be measured, and visualizes the two-dimensional distribution of the physical and chemical properties of the sample to be measured from the result. An electromagnetic wave signal generating means for generating an electromagnetic wave signal, a distributing means for distributing the electromagnetic wave signal generated by the electromagnetic wave signal generating means into a plurality, and an electromagnetic wave signal distributed by the distributing means, respectively Phase adjusting means for adjusting the phase, an electromagnetic wave radiation source in which a plurality of electromagnetic wave radiation elements that receive the electromagnetic wave signal phase-adjusted by the phase adjusting means and emit electromagnetic waves are arranged in an array, and radiation of electromagnetic waves from the electromagnetic wave radiation source A first collimating optical system which is installed in front of a predetermined focal length in the direction and collimates the electromagnetic wave radiated from the electromagnetic wave radiation source; A second collimating optical system for converging the electromagnetic wave transmitted through the sample to be measured after exiting the first collimating optical system, and the second collimating optical system in the traveling direction of the electromagnetic wave from the second collimating optical system The electromagnetic wave radiation source is controlled by controlling an amount of phase adjustment adjusted by the phase adjustment unit, and an electromagnetic wave detection unit that detects an electromagnetic wave that is placed forward by the focal length of the second collimating optical system. Arithmetic control means for scanning the irradiation position of the radiated electromagnetic wave on the surface of the sample to be measured and measuring the two-dimensional distribution of the transmittance of the electromagnetic wave with respect to the sample to be measured based on the intensity of the electromagnetic wave detected by the electromagnetic wave detecting means It is characterized by comprising.

請求項２記載の発明は、穴を１つ有し、この穴以外の位置では電磁波を透過しない位相調整量較正板を前記被測定試料の設置位置に設置した状態で、前記演算制御手段は、前記位相調整手段で位相量を調整した電磁波を前記電磁波放射源から放射し、前記穴を通過した電磁波を前記電磁波検出手段で検出し、この検出した電磁波の強度が最大値を得るときの位相量を前記穴の位置における位相調整量とし、それぞれ異なる位置に前記穴が設けられた複数の前記位相調整量較正板を用いたときに前記電磁波検出手段で検出した電磁波の強度が最大値を得るときの位相量をそれぞれの前記穴の位置における位相調整量として記憶することを特徴とする。   The invention according to claim 2 has one hole, and in a state where a phase adjustment amount calibration plate that does not transmit electromagnetic waves at positions other than the hole is installed at the installation position of the sample to be measured, The amount of phase when the electromagnetic wave whose phase amount has been adjusted by the phase adjusting unit is radiated from the electromagnetic wave radiation source, the electromagnetic wave that has passed through the hole is detected by the electromagnetic wave detecting unit, and the intensity of the detected electromagnetic wave has a maximum value Is the phase adjustment amount at the position of the hole, and when the plurality of phase adjustment amount calibration plates provided with the holes at different positions are used, the intensity of the electromagnetic wave detected by the electromagnetic wave detection means obtains the maximum value The phase amount is stored as a phase adjustment amount at each hole position.

請求項３記載の発明は、前記演算制御手段は、事前に測定した前記電磁波放射源から放射される電磁波の各放射方向の放射プロファイルデータを記憶し、この放射プロファイルデータ用いて前記被測定試料に対する電磁波の透過率の２次元分布データに対する逆畳み込み演算を行うことを特徴とする。   According to a third aspect of the present invention, the calculation control means stores radiation profile data of each radiation direction of the electromagnetic wave radiated from the electromagnetic wave radiation source measured in advance, and the radiation profile data is used for the sample to be measured. A deconvolution operation is performed on two-dimensional distribution data of electromagnetic wave transmittance.

本発明によれば、電磁波を放射する複数の電磁波放射素子をアレイ状に配置し、それぞれの電磁波放射素子が放射する電磁波の位相を調整することにより被測定試料に当たる電磁波の位置を２次元走査するので、被測定試料を載置したステージが移動することによる振動、試料の位置ずれなどがなくなり、被測定試料の電磁波に対する透過率の２次元分布を高い精度で測定することができる。また、集光ビームを用いないため、測定できる試料の厚さに制約がない。   According to the present invention, a plurality of electromagnetic wave radiating elements that radiate electromagnetic waves are arranged in an array, and the position of the electromagnetic wave that strikes the sample to be measured is two-dimensionally scanned by adjusting the phase of the electromagnetic waves radiated by each of the electromagnetic wave radiating elements. As a result, vibration due to movement of the stage on which the sample to be measured is moved, sample position displacement, and the like are eliminated, and the two-dimensional distribution of the transmittance of the sample to be measured with respect to electromagnetic waves can be measured with high accuracy. Further, since a focused beam is not used, there is no restriction on the thickness of the sample that can be measured.

さらに、複雑な可動機構の排除が可能となり、シンプルな構造の透過型電磁波イメージング装置を提供することができる。   Furthermore, a complicated movable mechanism can be eliminated, and a transmission electromagnetic wave imaging apparatus having a simple structure can be provided.

以下、本発明の透過型電磁波イメージング装置を実施するための最良の形態について、図面を参照して説明する。図１は本発明の実施の形態の透過型電磁波イメージング装置を示す構成図である。   The best mode for carrying out the transmission electromagnetic wave imaging apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a transmission electromagnetic wave imaging apparatus according to an embodiment of the present invention.

図１において、電磁波信号発生・位相調整部１は電磁波信号を発生し、その位相を独立に制御して供給する。   In FIG. 1, an electromagnetic wave signal generating / phase adjusting unit 1 generates an electromagnetic wave signal and supplies the electromagnetic wave signal by independently controlling the phase.

電磁波放射源２は電磁波信号発生・位相調整部１から供給される電磁波を放射する。電磁波放射源２には電磁波放射素子がアレイ状に配置され、電磁波放射源マウンタ３に搭載されている。   The electromagnetic wave radiation source 2 radiates an electromagnetic wave supplied from the electromagnetic wave signal generation / phase adjustment unit 1. The electromagnetic radiation source 2 has electromagnetic radiation elements arranged in an array and is mounted on the electromagnetic radiation source mounter 3.

第１のコリメートレンズ４は電磁波放射源２から放射される電磁波ビームを平行ビームにコリメートする。第１のコリメートレンズ４の焦点距離をｆとすると、第１のコリメートレンズ４は電磁波放射源２から電磁波放射方向にｆの位置に設置される。   The first collimating lens 4 collimates the electromagnetic wave emitted from the electromagnetic radiation source 2 into a parallel beam. When the focal length of the first collimating lens 4 is f, the first collimating lens 4 is installed at a position f in the electromagnetic wave radiation direction from the electromagnetic wave radiation source 2.

試料台５は被測定試料６を載置する。試料台５の中央には穴が設けられ、第１のコリメートレンズ４から到来する放射電磁波ビームが透過するようになっている。   The sample stage 5 mounts the sample 6 to be measured. A hole is provided in the center of the sample stage 5 so that a radiated electromagnetic wave beam coming from the first collimating lens 4 is transmitted.

第２のコリメートレンズ７は被測定試料６を透過した電磁波ビームを一点に収束させる。   The second collimating lens 7 converges the electromagnetic wave beam transmitted through the sample 6 to be measured at one point.

電磁波検出部８は第２のコリメートレンズ７から到来する電磁波ビームを検出する。第２のコリメートレンズ７の焦点距離をｆ’とすると、電磁波検出部８の検出面８ａが第２のコリメートレンズ７から電磁波進行方向にｆ’の位置になるように設置される。   The electromagnetic wave detection unit 8 detects an electromagnetic wave beam coming from the second collimating lens 7. Assuming that the focal length of the second collimating lens 7 is f ′, the detection surface 8 a of the electromagnetic wave detection unit 8 is installed so as to be located at the position f ′ from the second collimating lens 7 in the electromagnetic wave traveling direction.

測定室９は電磁波放射源２、電磁波放射源マウンタ３、第１のコリメートレンズ４、試料台５、被測定試料６、第２のコリメートレンズ７、電磁波検出部８を収納し、電磁波の通過する空間を覆うようになっている。   The measurement chamber 9 houses the electromagnetic wave radiation source 2, the electromagnetic radiation source mounter 3, the first collimator lens 4, the sample stage 5, the sample to be measured 6, the second collimator lens 7, and the electromagnetic wave detector 8, through which electromagnetic waves pass. It is designed to cover the space.

Ａ／Ｄ変換部１０は電磁波検出部８で検出した電磁波信号をデジタルデータに変換して出力する。   The A / D converter 10 converts the electromagnetic wave signal detected by the electromagnetic wave detector 8 into digital data and outputs it.

演算制御記憶部１１は電磁波信号発生・位相調整部１を制御して電磁波放射源２が放射する電磁波の被測定試料表面上での照射位置を走査させる。また、電磁波検出部８で検出される電磁波の強度と被測定試料６を電磁波が透過する位置との関係を記憶し、電磁波の走査終了後、電磁波の透過強度の２次元等高線図を表示させる。さらに、事前に測定し記憶しておいた電磁波放射源２から放射される電磁波の各放射方向の放射プロファイルデータを用いて、被測定試料６に対する電磁波の透過率の２次元分布データに対する逆畳み込み演算を行う。   The arithmetic control storage unit 11 controls the electromagnetic wave signal generation / phase adjustment unit 1 to scan the irradiation position on the surface of the sample to be measured of the electromagnetic wave emitted from the electromagnetic wave radiation source 2. Further, the relationship between the intensity of the electromagnetic wave detected by the electromagnetic wave detector 8 and the position where the electromagnetic wave passes through the sample 6 to be measured is stored, and after the scanning of the electromagnetic wave is completed, a two-dimensional contour map of the electromagnetic wave transmission intensity is displayed. Further, using the radiation profile data of each radiation direction of the electromagnetic wave radiated from the electromagnetic radiation source 2 measured and stored in advance, the deconvolution operation for the two-dimensional distribution data of the electromagnetic wave transmittance with respect to the measured sample 6 is performed. I do.

図２は図１に示す透過型電磁波イメージング装置の電磁波放射源を示す構成図である。図２に示すように電磁波放射源２は、半導体基板２１と、半導体基板２１上に形成された低誘電体層２２と、低誘電体層２２上に形成された３行×３列の電磁波放射素子アレイ２３とを備える。電磁波放射素子アレイ２３を構成する電磁波放射素子２３１〜２３９には、例えばパッチアンテナを用いる。   FIG. 2 is a block diagram showing an electromagnetic wave radiation source of the transmission electromagnetic wave imaging apparatus shown in FIG. As shown in FIG. 2, the electromagnetic wave radiation source 2 includes a semiconductor substrate 21, a low dielectric layer 22 formed on the semiconductor substrate 21, and 3 rows × 3 columns of electromagnetic radiation formed on the low dielectric layer 22. And an element array 23. For example, a patch antenna is used for the electromagnetic wave radiation elements 231 to 239 constituting the electromagnetic wave radiation element array 23.

図３は図１に示す透過型電磁波イメージング装置の電磁波信号発生・位相調整部を示す構成図である。図３に示すように電磁波信号発生・位相調整部１は、所望の周波数で発振する高周波発振器１２と、高周波発振器１２から発せられた高周波信号を分配する分配器１３と、分配器１３で分配された高周波信号をそれぞれ別々に位相調整する位相調整器１４１〜１４９とを備える。高周波発振器１２、分配器１３、電磁波放射源２の各要素は同軸配線１５で電気的に接続され、同軸配線１５は被覆１６で束ねられる。位相調整器１４１〜１４９は位相量制御線１７で演算制御記憶部１１に接続され、位相量制御線１７は被覆１８で束ねられる。   FIG. 3 is a block diagram showing an electromagnetic wave signal generation / phase adjustment unit of the transmission electromagnetic wave imaging apparatus shown in FIG. As shown in FIG. 3, the electromagnetic wave signal generating / phase adjusting unit 1 is distributed by a high frequency oscillator 12 that oscillates at a desired frequency, a distributor 13 that distributes a high frequency signal emitted from the high frequency oscillator 12, and a distributor 13. Phase adjusters 141 to 149 for individually adjusting the phases of the high-frequency signals. Each element of the high-frequency oscillator 12, the distributor 13, and the electromagnetic wave radiation source 2 is electrically connected by a coaxial wiring 15, and the coaxial wiring 15 is bundled by a coating 16. The phase adjusters 141 to 149 are connected to the calculation control storage unit 11 by a phase amount control line 17, and the phase amount control line 17 is bundled by a coating 18.

ここで、本実施の形態の透過型電磁波イメージング装置の動作を説明する。まず、高周波発振器１２は高周波の電磁波信号を発生し、分配器１３に出力する。分配器１３は高周波発振器１２から入力された電磁波信号を９チャンネルに分配し、位相調整器１４１〜１４９にそれぞれ出力する。   Here, the operation of the transmission electromagnetic wave imaging apparatus of the present embodiment will be described. First, the high frequency oscillator 12 generates a high frequency electromagnetic wave signal and outputs it to the distributor 13. The distributor 13 distributes the electromagnetic wave signal input from the high-frequency oscillator 12 to nine channels and outputs the signals to the phase adjusters 141 to 149, respectively.

次いで、位相調整器１４１〜１４９は、演算制御記憶部１１からの制御指示に基づいて、分配器１３から入力された電磁波信号の位相をそれぞれ独立に調整し、位相調整した電磁波信号を電磁波放射源２に供給する。そして、電磁波放射源２は電磁波を第１のコリメートレンズ４に放射する。   Next, the phase adjusters 141 to 149 independently adjust the phase of the electromagnetic wave signal input from the distributor 13 based on the control instruction from the arithmetic control storage unit 11, and the phase adjusted electromagnetic wave signal is converted into the electromagnetic wave radiation source. 2 is supplied. Then, the electromagnetic wave radiation source 2 radiates electromagnetic waves to the first collimating lens 4.

アレイ状に並べられた電磁波放射素子２３１〜２３９から放射された電磁波は互いに干渉し合い、特定の方向にのみ強く放射される。そこで、各電磁波放射素子２３１〜２３９を励起する位相を制御することによってその干渉波の放射分布を制御する。   The electromagnetic waves radiated from the electromagnetic radiation elements 231 to 239 arranged in an array interfere with each other and are radiated strongly only in a specific direction. Therefore, the radiation distribution of the interference wave is controlled by controlling the phase for exciting the electromagnetic wave radiation elements 231 to 239.

位相調整器１４１〜１４９で調整される位相量は、電磁波放射素子２３１〜２３９から放射される電磁波が第１のコリメートレンズ４の任意の一点に絞られて向かうように、演算制御記憶部１１で制御される。   The amount of phase adjusted by the phase adjusters 141 to 149 is determined by the calculation control storage unit 11 so that the electromagnetic waves radiated from the electromagnetic wave radiating elements 231 to 239 are directed to any one point of the first collimating lens 4. Be controlled.

第１のコリメートレンズ４は、電磁波放射源２から放射される電磁波ビームを平行ビームにコリメートし、被測定試料６に照射する。電磁波放射源２は第１のコリメートレンズ４の焦点に位置している。したがって、電磁波放射源２から放射される電磁波はどの方向に向かったとしても、第１のコリメートレンズ４で絞られた平行ビームとしてコリメートされ、被測定試料６に向かうことになる。   The first collimating lens 4 collimates the electromagnetic wave beam emitted from the electromagnetic wave radiation source 2 into a parallel beam and irradiates the sample 6 to be measured. The electromagnetic radiation source 2 is located at the focal point of the first collimating lens 4. Accordingly, the electromagnetic wave emitted from the electromagnetic wave radiation source 2 is collimated as a parallel beam focused by the first collimating lens 4 and travels toward the sample 6 to be measured, regardless of the direction.

そして、第２のコリメートレンズ７は、被測定試料６を透過した電磁波ビームを一点に収束させる。次いで、電磁波検出部８は、第２のコリメートレンズ７から到来する電磁波ビームを検出する。   Then, the second collimating lens 7 converges the electromagnetic wave beam transmitted through the sample 6 to be measured at one point. Next, the electromagnetic wave detection unit 8 detects the electromagnetic wave beam coming from the second collimating lens 7.

ここで、第２のコリメートレンズ７に入射する電磁波は絞られた平行ビームであり、電磁波検出部８の検出面８ａは第２のコリメートレンズ７の焦点の位置に設置されている。したがって、被測定試料６のいずれの位置を透過した電磁波も必ず電磁波検出部８の検出面８ａに到達する。   Here, the electromagnetic wave incident on the second collimating lens 7 is a collimated parallel beam, and the detection surface 8 a of the electromagnetic wave detection unit 8 is installed at the focal point of the second collimating lens 7. Therefore, the electromagnetic wave transmitted through any position of the sample 6 to be measured always reaches the detection surface 8 a of the electromagnetic wave detection unit 8.

次いで、Ａ／Ｄ変換部１０は、電磁波検出部８で検出した電磁波信号をデジタルデータに変換して演算制御記憶部１１に出力する。   Next, the A / D conversion unit 10 converts the electromagnetic wave signal detected by the electromagnetic wave detection unit 8 into digital data and outputs the digital data to the arithmetic control storage unit 11.

そして、演算制御記憶部１１は、電磁波信号発生・位相調整部１を制御して電磁波放射源２が放射する電磁波の被測定試料６の表面上での照射位置を走査させる。また、電磁波検出部８で検出される電磁波の強度と被測定試料６を電磁波が透過する位置との関係を記憶し、電磁波の走査終了後、電磁波の透過強度の２次元等高線図を表示させる。   The arithmetic control storage unit 11 controls the electromagnetic wave signal generation / phase adjustment unit 1 to scan the irradiation position on the surface of the sample 6 to be measured of the electromagnetic wave emitted from the electromagnetic wave radiation source 2. Further, the relationship between the intensity of the electromagnetic wave detected by the electromagnetic wave detector 8 and the position where the electromagnetic wave passes through the sample 6 to be measured is stored, and after the scanning of the electromagnetic wave is completed, a two-dimensional contour map of the electromagnetic wave transmission intensity is displayed.

さらに、演算制御記憶部１１は、事前に測定して記憶した電磁波放射源から放射される電磁波の各放射方向の放射プロファイルデータを用いて、被測定試料の２次元透過率分布データに対する逆畳み込み演算を行う。   Further, the calculation control storage unit 11 uses the radiation profile data of each radiation direction of the electromagnetic wave radiated from the electromagnetic radiation source measured and stored in advance, and performs a deconvolution calculation on the two-dimensional transmittance distribution data of the sample to be measured. I do.

演算制御記憶部１１は、電磁波放射源から放射される電磁波の各放射方向の放射プロファイルデータｈ（ｘ，ｙ）のフーリエ変換関数Ｈ（ξ，η）の逆関数Ｈ^−１（ξ，η）を求める。また、電磁波信号発生・位相調整部１の位相量調整で得られた被測定資料の２次元透過率分布データｉ´（ξ，η）のフーリエ変換関数Ｉ´（ξ，η）を求める。 The calculation control storage unit 11 is an inverse function H ⁻¹ (ξ, η) of the Fourier transform function H (ξ, η) of the radiation profile data h (x, y) in each radiation direction of the electromagnetic wave radiated from the electromagnetic radiation source. Ask for. Further, the Fourier transform function I ′ (ξ, η) of the two-dimensional transmittance distribution data i ′ (ξ, η) of the measured material obtained by adjusting the phase amount of the electromagnetic wave signal generation / phase adjusting unit 1 is obtained.

そして、演算制御記憶部１１は、下記に示す（数式１）の関係から放射電磁波ビームのビーム径や電磁波放射素子アレイ２３から放射されるサイドローブの影響を除いた高い空間分解能の被測定資料の２次元透過率分布データｉ（ｘ，ｙ）を演算により得る。

Then, the arithmetic control storage unit 11 stores the measured material with high spatial resolution excluding the influence of the beam diameter of the radiated electromagnetic wave beam and the side lobe radiated from the electromagnetic wave radiating element array 23 from the relationship of (Equation 1) shown below. Two-dimensional transmittance distribution data i (x, y) is obtained by calculation.

ここで、位相調整器１４１〜１４９で与える位相調整量を求める方法について説明する。図４は位相調整量較正用金属板を示す図である。図４に示すように、位相調整量較正用金属板５１は小さな穴５２を１つ有し、この穴５２以外の場所では電磁波を透過しない。   Here, a method for obtaining the phase adjustment amount given by the phase adjusters 141 to 149 will be described. FIG. 4 is a view showing a metal plate for phase adjustment amount calibration. As shown in FIG. 4, the phase adjustment amount calibration metal plate 51 has one small hole 52, and does not transmit electromagnetic waves in places other than the hole 52.

そして、穴５２が特定の位置Ａにくるように位相調整量較正用金属板５１を試料台５に設置し、この状態で電磁波放射源２から電磁波を放射させ、電磁波検出部８でその強度を検出する。   Then, the phase adjustment amount calibration metal plate 51 is placed on the sample stage 5 so that the hole 52 is located at a specific position A. In this state, the electromagnetic wave is radiated from the electromagnetic wave radiation source 2, and the electromagnetic wave detection unit 8 increases its strength. To detect.

位相調整器１４１〜１４９のそれぞれに与える位相調整量を変化させると、電磁波放射源２から放射される電磁波の空間プロファイルが変化するため、電磁波検出部８で検出される電磁波強度は変化する。   When the amount of phase adjustment given to each of the phase adjusters 141 to 149 is changed, the spatial profile of the electromagnetic wave radiated from the electromagnetic wave radiation source 2 changes, so that the electromagnetic wave intensity detected by the electromagnetic wave detector 8 changes.

電磁波検出部８で検出される電磁波強度が最大値を得るとき、与えた位相調整量は、位相調整量較正用金属板５１の穴５２の位置に電磁波が向かうように電磁波放射源２の電磁波放射素子２３１〜２３９から放射される電磁波が第１のコリメートレンズ４の一点に絞られて放射されていると考えることができる。   When the electromagnetic wave intensity detected by the electromagnetic wave detection unit 8 obtains the maximum value, the applied phase adjustment amount is the electromagnetic wave radiation of the electromagnetic wave radiation source 2 so that the electromagnetic wave is directed to the position of the hole 52 of the metal plate 51 for phase adjustment amount calibration. It can be considered that the electromagnetic waves radiated from the elements 231 to 239 are radiated while being focused on one point of the first collimating lens 4.

したがって、このとき与えた位相調整量を演算制御記憶部１１に記憶し、位相調整器１４１〜１４９で与える位相調整量をこの演算制御記憶部１１に記憶された位相調整量に設定すれば、必ず試料台５上の位置Ａに電磁波を集中させることができる。   Therefore, if the phase adjustment amount given at this time is stored in the calculation control storage unit 11 and the phase adjustment amount given by the phase adjusters 141 to 149 is set to the phase adjustment amount stored in this calculation control storage unit 11, Electromagnetic waves can be concentrated at position A on the sample stage 5.

したがって、事前に異なる位置に穴を設けた位相調整量較正用金属板５１を複数準備しておき、それらを試料台５上に設置し、各穴の位置に対応して電磁波検出部８で検出される電磁波強度が最大値となる位相調整量を演算制御記憶部１１に記憶しておけば、試料台５に設置された被測定試料６に対する電磁波の透過強度の２次元等高線図を得るために、位相調整器１４１〜１４９で与えるべき位相調整量が事前に分かっていることになる。   Therefore, a plurality of phase adjustment amount calibration metal plates 51 with holes provided at different positions are prepared in advance, and these are installed on the sample stage 5 and detected by the electromagnetic wave detection unit 8 corresponding to the positions of the holes. In order to obtain a two-dimensional contour map of the transmission intensity of the electromagnetic wave with respect to the sample 6 to be measured placed on the sample stage 5 by storing the phase adjustment amount at which the electromagnetic wave intensity to be maximized is stored in the calculation control storage unit 11. Therefore, the amount of phase adjustment to be given by the phase adjusters 141 to 149 is known in advance.

このように本実施の形態の透過型電磁波イメージング装置によれば、電磁波放射素子２３１〜２３９が放射する電磁波の位相を制御することにより、測定中に被測定試料６の位置を動かすことなく被測定試料６に当たる収束電磁波ビームの位置を２次元走査することが可能となる。したがって、被測定試料６の位置を動かすための従来のＸ−Ｙステージが不要となり、ステージが移動することによる振動、試料の位置ズレなどがなくなり、精度の高い測定が実現できる。また、複雑な可動機構の排除が可能となり、小型でシンプルな構造の試料室を採用でき、システムのコストダウンも可能となる。さらに、集光ビームを用いないため、測定できる試料の厚さに制約がない。   As described above, according to the transmission electromagnetic wave imaging apparatus of the present embodiment, by controlling the phase of the electromagnetic wave radiated by the electromagnetic wave radiation elements 231 to 239, the measurement object can be measured without moving the position of the sample 6 to be measured during the measurement. It becomes possible to two-dimensionally scan the position of the convergent electromagnetic wave beam that hits the sample 6. Therefore, the conventional XY stage for moving the position of the sample 6 to be measured is not required, and vibrations due to the movement of the stage, displacement of the sample position, and the like are eliminated, and highly accurate measurement can be realized. In addition, a complicated movable mechanism can be eliminated, a sample chamber having a small and simple structure can be adopted, and the cost of the system can be reduced. Furthermore, since a focused beam is not used, there is no restriction on the thickness of the sample that can be measured.

また、事前に測定した電磁波放射源２から放射される電磁波の各放射方向の放射プロファイルデータを用いて、被測定試料６の２次元透過率分布データに対する逆畳み込み演算を行うことで、高い空間分解能で被測定試料６の２次元透過率分布データを得ることが可能となる。   Further, by using the radiation profile data of each radiation direction of the electromagnetic wave radiated from the electromagnetic radiation source 2 measured in advance, high spatial resolution is obtained by performing a deconvolution operation on the two-dimensional transmittance distribution data of the sample 6 to be measured. Thus, it is possible to obtain two-dimensional transmittance distribution data of the sample 6 to be measured.

また、通常１つの電磁波放射素子から放射されるビームは拡散的に広がるため、コリメートビームにするには別途光学系が必要になるが、本実施の形態では電磁波放射源２に電磁波放射素子２３１〜２３９をアレイ状に配置したので、そのような光学系が不要で構成が簡単になる。さらに、１つの電磁波放射素子から取り出せるパワーは限られているが、アレイ化によるパワー合成で得られるパワーを稼ぐことができる。   Further, since the beam radiated from one electromagnetic radiation element normally spreads diffusively, a separate optical system is required to make a collimated beam. In the present embodiment, the electromagnetic radiation element 231- Since 239 is arranged in an array, such an optical system is unnecessary and the configuration is simplified. Furthermore, although the power that can be extracted from one electromagnetic wave radiation element is limited, the power obtained by power synthesis by arraying can be earned.

なお、本実施の形態では、電磁波信号発生・位相調整部１は高周波発振器１２と位相調整器１４１〜１４９とを備え、放射電磁波を電磁波放射源２へ供給する方式としたが、これに限るものではない。   In the present embodiment, the electromagnetic wave signal generation / phase adjustment unit 1 includes the high frequency oscillator 12 and the phase adjusters 141 to 149 and supplies the radiated electromagnetic wave to the electromagnetic wave radiation source 2. However, the present invention is not limited thereto. is not.

例えば、電磁波発振・位相調整回路を集積した半導体基板を用いて位相制御された電磁波を電磁波放射素子アレイ２３の裏面から直接給電する方式を用いてもよい。この場合、電磁波信号発生・位相調整部１は電磁波発生及び位相調整に変わって、半導体基板上の電磁波発振・位相調整回路への電源供給及び位相調整用制御信号の供給を行うことになる。   For example, a method may be used in which an electromagnetic wave phase-controlled using a semiconductor substrate integrated with an electromagnetic wave oscillation / phase adjustment circuit is directly fed from the back surface of the electromagnetic wave radiation element array 23. In this case, the electromagnetic wave signal generation / phase adjustment unit 1 supplies power to the electromagnetic wave oscillation / phase adjustment circuit on the semiconductor substrate and supplies a control signal for phase adjustment instead of electromagnetic wave generation and phase adjustment.

別の例としては、電磁波放射源２に位相調整された光ビート信号を供給し、電磁波放射源２を構成する各電磁波放射素子２３１〜２３９で光電変換を行い、電磁波を発生させ、得られた電磁波を各電磁波放射素子２３１〜２３９から放射させる方式を用いても良い。この場合、電磁波信号発生・位相調整部１は電磁波発生及び位相調整に変わって、光ビート信号波発生及び光ビート信号の位相調整を行うことになる。   As another example, an optical beat signal whose phase was adjusted was supplied to the electromagnetic wave radiation source 2, and photoelectric conversion was performed by each of the electromagnetic wave radiation elements 231 to 239 constituting the electromagnetic wave radiation source 2 to generate an electromagnetic wave. You may use the system which radiates | emits electromagnetic waves from each electromagnetic wave radiation | emission element 231-239. In this case, the electromagnetic wave signal generation / phase adjustment unit 1 performs optical beat signal wave generation and phase adjustment of the optical beat signal instead of electromagnetic wave generation and phase adjustment.

また、電磁波放射素子アレイ２３を形成するアンテナの配列も３行３列に限るものではなく、何行何列でもよい。また、アンテナの形状もパッチアンテナに限るものではなく、ダイポール、ログペリなどほかの形状でもよい。   Further, the arrangement of antennas forming the electromagnetic wave radiation element array 23 is not limited to 3 rows and 3 columns, and may be any number of rows and columns. Further, the shape of the antenna is not limited to the patch antenna, but may be other shapes such as a dipole or log peri.

本発明の実施の形態の透過型電磁波イメージング装置を示す構成図である。It is a block diagram which shows the transmission electromagnetic wave imaging device of embodiment of this invention. 図１に示す透過型電磁波イメージング装置の電磁波放射源を示す構成図である。It is a block diagram which shows the electromagnetic wave radiation source of the transmission type electromagnetic wave imaging apparatus shown in FIG. 図１に示す透過型電磁波イメージング装置の電磁波信号発生・位相調整部を示す構成図である。It is a block diagram which shows the electromagnetic wave signal generation and phase adjustment part of the transmission type electromagnetic wave imaging apparatus shown in FIG. 位相調整量較正用金属板を示す図である。It is a figure which shows the metal plate for phase adjustment amount calibration. 従来の透過型電磁波イメージング装置を示す構成図である。It is a block diagram which shows the conventional transmission type electromagnetic wave imaging apparatus.

符号の説明Explanation of symbols

１ 電磁波信号発生・位相調整部
２ 電磁波放射源
３ 電磁波放射源マウンタ
４ 第１のコリメートレンズ
５ 試料台
６ 被測定試料
７ 第２のコリメートレンズ
８ 電磁波検出部
８ａ 検出面
９ 測定室
１０ Ａ／Ｄ変換部
１１ 演算制御記憶部
１２ 高周波発振器
１３ 分配器
１４１〜１４９ 位相調整器
２１ 半導体基板
２２ 低誘電体層
２３ 電磁波放射素子アレイ
２３１〜２３９ 電磁波放射素子
５１ 位相調整量較正用金属板
５２ 穴 DESCRIPTION OF SYMBOLS 1 Electromagnetic wave signal generation and phase adjustment part 2 Electromagnetic wave radiation source 3 Electromagnetic wave radiation source mounter 4 1st collimating lens 5 Sample stand 6 Sample to be measured 7 2nd collimating lens 8 Electromagnetic wave detection part 8a Detection surface 9 Measurement room 10 A / D Conversion unit 11 Arithmetic control storage unit 12 High-frequency oscillator 13 Distributor 141-149 Phase adjuster 21 Semiconductor substrate 22 Low dielectric layer 23 Electromagnetic radiation element array 231-239 Electromagnetic radiation element 51 Metal plate for phase adjustment amount calibration 52 Hole

Claims (3)

電磁波の被測定試料に対する透過率の２次元分布を測定し、その結果から被測定試料の物理的、化学的性質の２次元分布を可視化する透過型電磁波イメージング装置において、
電磁波信号を発生する電磁波信号発生手段と、
この電磁波信号発生手段で発生した前記電磁波信号を複数に分配する分配手段と、
この分配手段で分配された電磁波信号をそれぞれ位相調整する位相調整手段と、
この位相調整手段で位相調整された電磁波信号を受けて電磁波を放射する複数の電磁波放射素子をアレイ状に配置した電磁波放射源と、
前記電磁波放射源から電磁波の放射方向に所定の焦点距離だけ前方に設置され、前記電磁波放射源から放射された電磁波をコリメートする第１のコリメート光学系と、
この第１のコリメート光学系を出射した後、前記被測定試料を透過した電磁波を収束する第２のコリメート光学系と、
この第２のコリメート光学系から電磁波の進行方向に前記第２のコリメート光学系の焦点距離だけ前方に設置され、前記第２のコリメート光学系で収束された電磁波を検出する電磁波検出手段と、
前記位相調整手段で調整される位相調整量を制御することにより前記電磁波放射源が放射する電磁波の前記被測定試料表面上での照射位置を走査させ、前記電磁波検出手段で検出した電磁波の強度に基づいて前記被測定試料に対する電磁波の透過率の２次元分布を測定する演算制御手段と
を備えたことを特徴とする透過型電磁波イメージング装置。 In a transmission type electromagnetic wave imaging device that measures the two-dimensional distribution of the transmittance of an electromagnetic wave to a sample to be measured, and visualizes the two-dimensional distribution of physical and chemical properties of the sample to be measured
Electromagnetic wave signal generating means for generating an electromagnetic wave signal;
Distributing means for distributing the electromagnetic wave signal generated by the electromagnetic wave signal generating means to a plurality of;
Phase adjusting means for adjusting the phase of each electromagnetic wave signal distributed by the distributing means;
An electromagnetic wave radiation source in which a plurality of electromagnetic wave radiation elements that receive an electromagnetic wave signal phase-adjusted by this phase adjustment means and emit an electromagnetic wave are arranged in an array,
A first collimating optical system that is installed in front of the electromagnetic radiation source by a predetermined focal length in the radiation direction of the electromagnetic wave, and collimates the electromagnetic wave emitted from the electromagnetic radiation source;
A second collimating optical system for converging the electromagnetic wave transmitted through the sample to be measured after exiting the first collimating optical system;
An electromagnetic wave detection means for detecting an electromagnetic wave that is installed in front of the focal length of the second collimating optical system in the traveling direction of the electromagnetic wave from the second collimating optical system and is converged by the second collimating optical system;
By controlling the phase adjustment amount adjusted by the phase adjusting means, the irradiation position on the surface of the sample to be measured of the electromagnetic waves radiated from the electromagnetic wave radiation source is scanned, and the intensity of the electromagnetic waves detected by the electromagnetic wave detecting means is adjusted. And a calculation control means for measuring a two-dimensional distribution of the transmittance of the electromagnetic wave with respect to the sample to be measured. 穴を１つ有し、この穴以外の位置では電磁波を透過しない位相調整量較正板を前記被測定試料の設置位置に設置した状態で、前記演算制御手段は、前記位相調整手段で位相量を調整した電磁波を前記電磁波放射源から放射し、前記穴を通過した電磁波を前記電磁波検出手段で検出し、この検出した電磁波の強度が最大値を得るときの位相量を前記穴の位置における位相調整量とし、それぞれ異なる位置に前記穴が設けられた複数の前記位相調整量較正板を用いたときに前記電磁波検出手段で検出した電磁波の強度が最大値を得るときの位相量をそれぞれの前記穴の位置における位相調整量として記憶することを特徴とする請求項１に記載の透過型電磁波イメージング装置。   In a state where a phase adjustment amount calibration plate that has one hole and does not transmit electromagnetic waves at positions other than this hole is installed at the installation position of the sample to be measured, the calculation control means uses the phase adjustment means to calculate the phase amount. The adjusted electromagnetic wave is radiated from the electromagnetic wave radiation source, the electromagnetic wave that has passed through the hole is detected by the electromagnetic wave detecting means, and the phase amount when the intensity of the detected electromagnetic wave obtains the maximum value is adjusted at the position of the hole. The phase amount when the intensity of the electromagnetic wave detected by the electromagnetic wave detection means obtains the maximum value when using a plurality of the phase adjustment amount calibration plates provided with the holes at different positions, respectively. The transmission electromagnetic wave imaging apparatus according to claim 1, wherein the transmission electromagnetic wave imaging apparatus stores a phase adjustment amount at the position of the electromagnetic wave. 前記演算制御手段は、事前に測定した前記電磁波放射源から放射される電磁波の各放射方向の放射プロファイルデータを記憶し、この放射プロファイルデータ用いて前記被測定試料に対する電磁波の透過率の２次元分布データに対する逆畳み込み演算を行うことを特徴とする請求項１又は２に記載の透過型電磁波イメージング装置。

The arithmetic control means stores radiation profile data of each radiation direction of the electromagnetic wave radiated from the electromagnetic radiation source measured in advance, and using this radiation profile data, a two-dimensional distribution of the transmittance of the electromagnetic wave with respect to the sample to be measured The transmission electromagnetic wave imaging apparatus according to claim 1, wherein a deconvolution operation is performed on the data.

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