JPH045135B2 - - Google Patents
Info
- Publication number
- JPH045135B2 JPH045135B2 JP22436083A JP22436083A JPH045135B2 JP H045135 B2 JPH045135 B2 JP H045135B2 JP 22436083 A JP22436083 A JP 22436083A JP 22436083 A JP22436083 A JP 22436083A JP H045135 B2 JPH045135 B2 JP H045135B2
- Authority
- JP
- Japan
- Prior art keywords
- infrared light
- absorption spectrum
- infrared
- plane
- infrared absorption
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000862 absorption spectrum Methods 0.000 claims description 26
- 238000005259 measurement Methods 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 14
- 230000010287 polarization Effects 0.000 claims description 12
- 239000010409 thin film Substances 0.000 claims description 6
- 238000001514 detection method Methods 0.000 claims description 5
- 239000007787 solid Substances 0.000 claims description 4
- 239000010408 film Substances 0.000 claims description 3
- 230000001678 irradiating effect Effects 0.000 claims description 2
- 238000000691 measurement method Methods 0.000 claims description 2
- 238000001228 spectrum Methods 0.000 description 8
- 230000035945 sensitivity Effects 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000013626 chemical specie Substances 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 238000004566 IR spectroscopy Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- 229940125730 polarisation modulator Drugs 0.000 description 2
- 238000001028 reflection method Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/28—Investigating the spectrum
- G01J3/447—Polarisation spectrometry
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、固体表面上における薄膜物質の反射
赤外吸収スペクトルを測定するための方法とその
装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method and apparatus for measuring the reflected infrared absorption spectrum of a thin film material on a solid surface.
これまで固体表面上に存在する化学種の反射赤
外吸収スペクトルの高感度測定には、専ら偏光反
射赤外吸収スペクトル法が採用されているのが実
状である。一般に高感度反射法と称されているこ
の方法は、入射面（試料表面に立てた法線と光の
進行方向とを含む面）に偏光面が平行とされた赤
外光（平行偏光）を大きな入射角度で試料表面に
照射せしめ、その試料表面からの反射光にもとづ
きその試料表面の赤外スペクトルを高感度にして
得るようにしたものである。試料表面には入射光
と反射光の干渉による定常波が形成され、この定
常波と試料表面の化学種との相互作用による反射
率の変化より試料表面の赤外スペクトルを高感度
にして測定しようというわけである。この方法で
は光を有効に利用し得ることから非平坦金属表面
に適用して有利であり、通常の反射赤外吸収スペ
クトル法に比し50倍以上の感度を有するが、フー
リエ変換赤外分光光度法と組合せる場合には更に
高感度な測定が可能となつている。しかしなが
ら、この方法は迷光や測定雰囲気、特に大気中に
含まれる水蒸気や二酸化炭素などの影響を強く受
け易く極薄膜試料の測定に適用するには困難とな
つている。
Up until now, polarized reflection infrared absorption spectroscopy has been exclusively employed for highly sensitive measurement of reflection infrared absorption spectra of chemical species present on solid surfaces. This method, which is generally referred to as high-sensitivity reflection method, uses infrared light (parallel polarized light) whose polarization plane is parallel to the plane of incidence (the plane that includes the normal to the sample surface and the direction of light propagation). The infrared spectrum of the sample surface is obtained with high sensitivity based on the reflected light from the sample surface by irradiating the sample surface at a large incident angle. A standing wave is formed on the sample surface due to interference between incident light and reflected light, and the interaction between this standing wave and chemical species on the sample surface changes the reflectance, which allows us to measure the infrared spectrum of the sample surface with high sensitivity. It is. Since this method can effectively utilize light, it is advantageous when applied to non-flat metal surfaces, and has a sensitivity more than 50 times that of ordinary reflection infrared absorption spectroscopy. When combined with other methods, even more sensitive measurements are possible. However, this method is easily influenced by stray light and the measurement atmosphere, especially water vapor and carbon dioxide contained in the atmosphere, making it difficult to apply to measurements of ultrathin film samples.
このため迷光や測定雰囲気の影響を受けること
なくスペクトルを得べく、薄膜物質が存在しない
試料の参照用の赤外吸収スペクトルと薄膜物質が
存在する試料の赤外吸収スペクトルとを時間を異
にして測定したうえその比を求めるといつたシン
グルビーム法や光路が試料側と参照側とに分離さ
れたダブルビーム法が採用されるようになつてい
る。しかしながら、前者の方法による場合はスペ
クトルの測定が時間的にずれたものとなり完全に
同一測定条件下でスペクトル測定を行ない得な
く、また、後者の方法による場合は試料側光路と
参照側光路との長さを完全に一致させることは困
難となつている。これがために極薄膜試料のスペ
クトル測定では雰囲気の影響を完全に除去し得な
いでいるのが実状である。 Therefore, in order to obtain a spectrum without being affected by stray light or the measurement atmosphere, the reference infrared absorption spectrum of a sample without a thin film substance and the infrared absorption spectrum of a sample with a thin film substance are separated at different times. Single-beam methods, in which measurements are made and then their ratios determined, and double-beam methods, in which the optical path is separated into a sample side and a reference side, are being adopted. However, when using the former method, the spectra are measured with a time lag, making it impossible to measure spectra under exactly the same measurement conditions, and when using the latter method, the optical path on the sample side and the optical path on the reference side are different. It has become difficult to perfectly match the lengths. For this reason, the actual situation is that the influence of the atmosphere cannot be completely removed when measuring spectra of ultra-thin film samples.
よつて本発明の目的は、迷光や測定雰囲気の影
響を受けることなく極薄膜試料の赤外吸収スペク
トルを高感度にして測定し得る反射赤外吸収スペ
クトル測定方法とその装置を供するにある。
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method and apparatus for measuring a reflection infrared absorption spectrum that can measure the infrared absorption spectrum of an ultrathin film sample with high sensitivity without being affected by stray light or the measurement atmosphere.
この目的のため本発明は、入射面に平行に偏光
された赤外光を大きな入射角度で試料表面上で反
射させればその表面に存在する化学種によつて赤
外光の吸収が著しく大きくなるが、垂直に偏光さ
れた赤外光（垂直偏光）では赤外光の吸収は大き
くないことに着目し、垂直に偏光された赤外光と
平行に偏光された赤外光とによつて時間ずれ極小
にして交互にスペクトル測定を行ない、測定され
たスペクトルの比より赤外吸収スペクトルを求め
るようにしたものである。また、本発明は、多重
繰り返し測定、積算が可能とされたフーリエ変換
赤外分光光度計に、偏光変調を行なうための直線
偏光手段および偏光変調手段を組合せることによ
つて反射赤外吸収スペクトル測定装置となしたも
のである。
For this purpose, the present invention proposes that if infrared light polarized parallel to the plane of incidence is reflected on the sample surface at a large angle of incidence, the absorption of the infrared light will be significantly increased by the chemical species present on the surface. However, we focused on the fact that vertically polarized infrared light (vertically polarized light) does not have a large absorption of infrared light, and by combining vertically polarized infrared light and parallelly polarized infrared light. In this system, spectra are measured alternately with the minimum time difference, and an infrared absorption spectrum is obtained from the ratio of the measured spectra. Furthermore, the present invention combines a Fourier transform infrared spectrophotometer that is capable of multiple repeated measurements and integration with linear polarization means and polarization modulation means for performing polarization modulation to obtain a reflected infrared absorption spectrum. This is a measuring device.
以下、本発明を第１図、第２図により説明す
る。
The present invention will be explained below with reference to FIGS. 1 and 2.
第１図は本発明による反射赤外吸収スペクトル
測定装置の一例での構成を示したものである。こ
の図において、１は赤外光の光源、２は赤外光を
干渉させるマイケルソンの干渉計、３は直線偏光
子、４は後述するマイクロコンピユータ１２で制
御され偏光方向を水平方向と垂直方向とに交互に
切り換える偏光変調子、５は試料、６は反射赤外
光の検出器である。検出器６からの反射赤外光検
出信号はプリアンプ７によつて増幅かれるが、プ
リアンプ７とロツキングアンプ１０，１１の間に
はサンプリング用のゲート８，９が設けられるよ
うになつている。ゲート８，９は変調子４と同期
して制御されており水平偏光、垂直偏光での測定
結果は各々ロツキングアンプ１０，１１に振り分
けされロツキングアンプ１０，１１で更に増幅さ
れた信号はその後デイジタル変換された形でマイ
クロコンピユータ１２に取り込まれ所定に処理さ
れるものとなつている。マイクロコンピユータで
の処理結果は表示装置１３および記録計１４で記
録表示されるようになつているものである。 FIG. 1 shows the configuration of an example of a reflection infrared absorption spectrum measuring device according to the present invention. In this figure, 1 is an infrared light source, 2 is a Michelson interferometer that interferes with infrared light, 3 is a linear polarizer, and 4 is controlled by a microcomputer 12, which will be described later, to change the polarization direction horizontally and vertically. 5 is a sample, and 6 is a reflected infrared light detector. A reflected infrared light detection signal from the detector 6 is amplified by a preamplifier 7, and sampling gates 8 and 9 are provided between the preamplifier 7 and locking amplifiers 10 and 11. Gates 8 and 9 are controlled in synchronization with modulator 4, and the measurement results for horizontally polarized light and vertically polarized light are distributed to locking amplifiers 10 and 11, respectively, and the signals further amplified by locking amplifiers 10 and 11 are then sent to The digitally converted data is taken into the microcomputer 12 and processed in a predetermined manner. The results of processing by the microcomputer are recorded and displayed on a display device 13 and a recorder 14.
さて、以上のようにしてなる反射赤外吸収スペ
クトル測定装置での測定動作あるいは測定方法を
説明すれば、光源１からの赤外光はマイケルソン
の干渉計２によつて干渉された後直線偏光子３に
よつて直線（平面）偏光され、更にマイクロコン
ピユータ１２によつて制御されている偏光変調子
４によつてその偏光面が試料面に対して水平、垂
直の方向に交互に変調されるようになつている。
このようにして干渉、偏光、変調された赤外光は
高角度で試料５に照射されるが、試料５で吸収さ
れずに反射された赤外光は検出器６で検出される
ところとなるものである。検出器６からの反射赤
外光の検出信号はプリアンプ７によつて増幅され
た後ゲート８，９により垂直偏光での測定デー
タ、水平偏光での測定データにわけてロツキング
アンプ１０，１１に送られ更に増幅される。ロツ
キングアンプ１０，１１からの信号はデイジタル
変換されたうえマイクロコンピユータ１２によつ
て処理、フーリエ変換され最終的な処理結果は表
示装置１３および記録計１４によつて記録表示さ
れるところとなるものである。 Now, to explain the measurement operation or measurement method in the reflection infrared absorption spectrum measuring device constructed as above, the infrared light from the light source 1 is interfered by the Michelson interferometer 2 and then becomes linearly polarized. The light is linearly (plane) polarized by the polarizer 3, and the plane of polarization is alternately modulated horizontally and vertically with respect to the sample surface by the polarization modulator 4, which is controlled by the microcomputer 12. It's becoming like that.
The infrared light that has been interfered with, polarized, and modulated in this way is irradiated onto the sample 5 at a high angle, but the infrared light that is not absorbed by the sample 5 and is reflected is detected by the detector 6. It is something. The detection signal of the reflected infrared light from the detector 6 is amplified by a preamplifier 7, and then divided into vertically polarized measurement data and horizontally polarized measurement data by gates 8 and 9 and sent to locking amplifiers 10 and 11. sent and further amplified. The signals from the locking amplifiers 10 and 11 are digitally converted, processed by the microcomputer 12, and Fourier transformed, and the final processing results are recorded and displayed by the display device 13 and recorder 14. It is.
最後に本発明による効果の程を考察すれば、本
実施例による赤外吸収スペクトルの測定結果の一
例として、アルミナAl2O3の赤外吸収スペクトル
を第２図に示す。同図ａは従来の偏光反射法によ
る場合を、また、同図ｂは本実施例装置によつた
場合での赤外吸収スペクトルをそれぞれ示したも
のである。これらより判るようにａでは波数が
2300〜2400cm-1および1500〜1700cm-1の範囲に二
酸化炭素および水蒸気によると思われる顕著なピ
ークが生じているが、ｂではその範囲はフラツト
になつている。本実施例より推して本発明による
場合測定雰囲気の影響は完全に除去され得ること
は明らかである。 Finally, considering the extent of the effect of the present invention, as an example of the measurement results of the infrared absorption spectrum according to this embodiment, the infrared absorption spectrum of alumina Al 2 O 3 is shown in FIG. 2. Figure a shows the infrared absorption spectrum when using the conventional polarized light reflection method, and Figure b shows the infrared absorption spectrum when using the apparatus of this embodiment. As can be seen from these, the wave number at a is
Remarkable peaks, which are thought to be caused by carbon dioxide and water vapor, occur in the ranges of 2300 to 2400 cm -1 and 1500 to 1700 cm -1 , but the range becomes flat in b. Based on this example, it is clear that the influence of the measurement atmosphere can be completely eliminated in accordance with the present invention.
以上説明したように本発明は、入射面に対し垂
直に偏光された赤外光と平行に偏光された赤外光
とによつて交互にスペクトル測定を行ない、測定
されたスペクトルの比より赤外吸収スペクトルを
求め、また、そのように求めるべくなしたもので
ある。したがつて、本発明による場合は、迷光や
測定雰囲気の影響を受けることなく極薄膜試料の
赤外吸収スペクトルが高感度にして測定され得る
という効果がある。
As explained above, the present invention measures spectra alternately using infrared light polarized perpendicularly to the incident plane and infrared light polarized parallel to the plane of incidence, and determines the ratio of the measured spectra. This was done to determine the absorption spectrum, and to do so. Therefore, the present invention has the effect that the infrared absorption spectrum of an ultra-thin film sample can be measured with high sensitivity without being affected by stray light or the measurement atmosphere.
第１図は、本発明による反射赤外吸収スペクト
ル測定装置の一例での構成を示す図、第２図ａ，
ｂは、本発明による効果の程を考察するための赤
外吸収スペクトル測定結果の例を従来方法による
場合と対比して示す図である。
１……赤外光光源、２……マイケルソンの干渉
計、３……直線偏光子、４……偏光変調子、５…
…試料、６……検出器、８，９……ゲート、１
０，１１……ロツキングアンプ、１２……マイク
ロコンピユータ。
Fig. 1 is a diagram showing the configuration of an example of a reflection infrared absorption spectrum measuring device according to the present invention, Fig. 2a,
b is a diagram showing an example of an infrared absorption spectrum measurement result for considering the extent of the effect of the present invention in comparison with a case using a conventional method. 1... Infrared light source, 2... Michelson interferometer, 3... Linear polarizer, 4... Polarization modulator, 5...
...Sample, 6...Detector, 8, 9...Gate, 1
0, 11... Locking amplifier, 12... Microcomputer.
Claims (1)
をフーリエ変換方式によつて測定する反射赤外吸
収スペクトル測定方法にして、干渉された赤外光
を直線偏光した後該赤外光の偏光面を偏光変調す
ることによつて、試料表面に入射角大にして入射
面に偏光面がそれぞれ平行、垂直とされた赤外光
を交互に時間ずれ少なくして照射せしめ、偏光面
がそれぞれ平行、垂直とされた赤外光に対する試
料表面からの反射赤外光にもとづき試料表面での
赤外吸収スペクトルを測定することを特徴とする
反射赤外吸収スペクトル測定方法。 ２ 固体表面の極薄膜試料の赤外吸収スペクトル
をフーリエ変換方式によつて測定する反射赤外吸
収スペクトル測定装置にして、赤外光発生手段
と、該発生手段からの赤外光を干渉させる干渉手
段と、該干渉手段からの干渉された赤外光を直線
偏光する直線偏光手段と、該偏光手段からの直線
偏光された赤外光の偏光面を入射面に平行、垂直
に交互に変調したうえ試料表面に照射する偏光変
調手段と、試料表面からの反射赤外光を検出する
反射赤外光検出手段と、該検出手段からの、偏光
面が入射面に平行、垂直にそれぞれ変調された赤
外光に対応する反射赤外光検出信号を所定に処理
することによつて反射赤外吸収スペクトルを求め
る処理手段とからなる構成を特徴とする反射赤外
吸収スペクトル測定装置。[Claims] 1. A reflection infrared absorption spectrum measurement method in which the infrared absorption spectrum of an ultra-thin film sample on a solid surface is measured by a Fourier transform method, and the interfered infrared light is linearly polarized and then the infrared By polarization modulating the polarization plane of external light, infrared light with a large incident angle and a polarization plane parallel and perpendicular to the incident plane is alternately irradiated onto the sample surface with a small time lag. A method for measuring reflected infrared absorption spectra, which measures an infrared absorption spectrum on a sample surface based on infrared light reflected from the sample surface with respect to infrared light whose planes are parallel and perpendicular, respectively. 2. A reflection infrared absorption spectrum measurement device that measures the infrared absorption spectrum of an ultrathin film sample on a solid surface using the Fourier transform method, and an infrared light generation means and an interference method that causes the infrared light from the generation means to interfere with each other. means, a linear polarizing means for linearly polarizing the interfered infrared light from the interference means, and a plane of polarization of the linearly polarized infrared light from the polarizing means being alternately modulated parallel to and perpendicular to the plane of incidence. Furthermore, a polarization modulation means for irradiating the sample surface, a reflected infrared light detection means for detecting the reflected infrared light from the sample surface, and a plane of polarization from the detection means is modulated to be parallel and perpendicular to the plane of incidence, respectively. 1. A reflection infrared absorption spectrum measuring device comprising a processing means for obtaining a reflection infrared absorption spectrum by predetermined processing of a reflection infrared light detection signal corresponding to infrared light.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58224360A JPS60117119A (en) | 1983-11-30 | 1983-11-30 | Measurement and apparatus of reflected infrared absorption spectrum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58224360A JPS60117119A (en) | 1983-11-30 | 1983-11-30 | Measurement and apparatus of reflected infrared absorption spectrum |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60117119A JPS60117119A (en) | 1985-06-24 |
| JPH045135B2 true JPH045135B2 (en) | 1992-01-30 |
Family
ID=16812537
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58224360A Granted JPS60117119A (en) | 1983-11-30 | 1983-11-30 | Measurement and apparatus of reflected infrared absorption spectrum |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60117119A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR0171637B1 (en) * | 1993-09-13 | 1999-03-20 | 사또오 후미오 | Apparatus for evaluating orientation film |
| JP5835101B2 (en) * | 2012-05-24 | 2015-12-24 | コニカミノルタ株式会社 | Fourier transform spectrometer, Fourier transform spectroscopic method, and attachment for Fourier transform spectrometer |
| JP2015187587A (en) * | 2014-03-27 | 2015-10-29 | 国立大学法人山梨大学 | Polarization modulation fourier transform infrared spectroscope, polarization modulation measurement unit for fourier transform infrared spectroscope, and polarization modulation fourier transform infrared spectroscopy |
-
1983
- 1983-11-30 JP JP58224360A patent/JPS60117119A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60117119A (en) | 1985-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3994586A (en) | Simultaneous determination of film uniformity and thickness | |
| US4015127A (en) | Monitoring film parameters using polarimetry of optical radiation | |
| US4105338A (en) | Reflection type ellipsometer for measuring thin film phase difference and thickness | |
| US4170416A (en) | Apparatus for analyzing coherent radiation | |
| US3631526A (en) | Apparatus and methods for eliminating interference effect errors in dual-beam infrared measurements | |
| JPS6217167B2 (en) | ||
| JPH04506998A (en) | optical equipment | |
| EP0233215A4 (en) | Photodetector arrangement for measuring the state of polarization of light. | |
| US5485271A (en) | Dual-modulation interferometric ellipsometer | |
| GB1382081A (en) | Transmission spectra | |
| JP3311497B2 (en) | Fourier transform spectral phase modulation ellipsometry | |
| JPH045135B2 (en) | ||
| JPS62291547A (en) | Method for measuring concentration of substance | |
| JP2004138499A (en) | Gas concentration detection sensor | |
| JP2004020539A (en) | Infrared circular dichroism measuring instrument and infrared circular dichroism measuring method | |
| US3211051A (en) | Optical measuring device for obtaining a first derivative of intensity with respect to wavelength | |
| JPH07502344A (en) | Reflection-free polarimetry system for small volume sample cells | |
| JPS61200407A (en) | Fourier transformation type infrared film thickness measuring apparatus | |
| JPS60224002A (en) | Infrared thickness gage | |
| JPH029290B2 (en) | ||
| US5210417A (en) | Modulated high sensitivity infrared polarimeter | |
| JPH0663842B2 (en) | Polarization modulation infrared spectrophotometer | |
| JPS62289749A (en) | Reflection factor measuring instrument | |
| CN114018850B (en) | Fourier infrared polarized spectrum measuring system and measuring method | |
| JPH04120404A (en) | Apparatus and method for estimating thickness of semiconductor multilayer thin film |