WO2010106589A1 - Instrument de mesure optique et procédé de mesure optique - Google Patents

Instrument de mesure optique et procédé de mesure optique Download PDF

Info

Publication number
WO2010106589A1
WO2010106589A1 PCT/JP2009/005142 JP2009005142W WO2010106589A1 WO 2010106589 A1 WO2010106589 A1 WO 2010106589A1 JP 2009005142 W JP2009005142 W JP 2009005142W WO 2010106589 A1 WO2010106589 A1 WO 2010106589A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
sample
terahertz
angle
reflected
Prior art date
Application number
PCT/JP2009/005142
Other languages
English (en)
Japanese (ja)
Inventor
松本直樹
Original Assignee
株式会社村田製作所
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Publication of WO2010106589A1 publication Critical patent/WO2010106589A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
    • G01N21/3581—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared light; using Terahertz radiation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
    • G01N21/3563—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing solids; Preparation of samples therefor

Definitions

  • the present invention relates to a light measurement apparatus and a light measurement method for measuring physical properties such as dielectric constant, absorption coefficient, electrical conductivity, etc. of dielectric materials, semiconductors, magnetic materials, etc. in a non-contact manner using pulsed light in the terahertz frequency region. .
  • Patent Document 1 discloses a measuring device in which a device that detects the intensity and phase difference of transmitted light and a device that detects the intensity and phase difference of reflected light are configured as independent devices.
  • Patent Document 3 discloses an ellipsometer capable of deriving a complex optical constant spectrum of a sample in the terahertz region without performing a reference measurement.
  • Patent Document 3 employs an ellipsometry method that uses the property that the reflectance and phase of s-polarized light and p-polarized light differ depending on the complex dielectric constant of the sample, and calculates the physical property value based on the polarization change of the reflected light with respect to the incident light. is doing.
  • JP 2002-277393 A Japanese Patent Laying-Open No. 2005-227021 JP 2003-014620 A
  • the terahertz light measurement device disclosed in Patent Document 2 needs to include a transmitted light detection unit and a reflected light detection unit separately. Since all of these light detection units are expensive, there is a problem that it is difficult to reduce the cost of the entire measuring apparatus.
  • the incident angle of the terahertz light incident on the sample is originally based on the principle of the ellipsometry method, and the ratio of the amplitude reflection coefficient between the s-polarized light and the p-polarized light is the maximum. It is necessary to set near the Brewster angle. Since the Brewster angle changes depending on the complex dielectric constant of the sample, it is desirable to make the incident angle to the sample variable when employing the ellipsometry method.
  • the present invention has been made in view of such circumstances, and can switch between transmitted light detection and reflected light detection with a simple configuration, and changes the incident angle of the terahertz light incident according to the type of measurement sample.
  • An object of the present invention is to provide a light measuring device and a light measuring method capable of measuring a physical property value with high accuracy.
  • an optical measurement apparatus measures a terahertz light source that emits pulsed light in the terahertz frequency region, a photodetector that detects the pulsed light, and pulsed light emitted from the terahertz light source.
  • a symmetric position across the sample which is composed of at least two or more mirrors for guiding the transmitted light transmitted through the sample or the reflected light reflected by the sample to the photodetector.
  • the operation is controlled so as to change the incident angle of the pulsed light emitted from the terahertz light source to the sample by changing the position and angle of the two pairs of mirrors arranged in the mirror and the two pairs of mirrors.
  • a control mechanism is controlled so as to change the incident angle of the pulsed light emitted from the terahertz light source to the sample by changing the position and angle of the two pairs of mirrors arranged in the mirror and the two pairs of mirrors.
  • control mechanism is configured to change the position and angle of the two pairs of mirrors by a support arm having a center portion of the sample as a rotation center. It is characterized by being.
  • the control mechanism changes the position and angle of the two pairs of mirror groups so that the light detector transmits the transmitted light. It is characterized by switching between detection and detection of reflected light.
  • the optical measurement device is the optical measurement device according to any one of the first to third aspects, wherein the mirror group includes at least one curved mirror, and the pulsed light emitted from the terahertz light source in the vicinity of the sample. It is characterized by being collimated.
  • the light measurement device is characterized in that, in the third or fourth invention, a polarizer is provided on an optical path through which the pulsed light emitted from the terahertz light source propagates.
  • the light measurement device is based on the amplitude reflection coefficient ratio and phase difference of the s-polarized light and the p-polarized light of the sample when the control mechanism is switched to detect the reflected light in the fifth invention. And calculating a physical property value.
  • control mechanism is configured such that the incident angle of the pulsed light emitted from the terahertz light source to the sample substantially coincides with the Brewster angle of the sample. The operation is controlled.
  • the pulse light emitted from the terahertz light source incident on the sample has the same light intensity of s-polarized light and p-polarized light.
  • the amplitude detection coefficient ratio and the phase difference between the s-polarized light and the p-polarized light reflected by the sample are linearly polarized light, and the signal detected when the angle of the polarizer is set to 0 degree or 90 degrees. It is characterized by acquiring based on.
  • the terahertz light source is a photoconductive antenna that generates pulsed light in the terahertz frequency region using an optical rectification method.
  • the photoconductive antenna is arranged so that the polarization of the generated pulsed light is inclined by 45 degrees.
  • an optical measurement method includes a terahertz light source that emits pulsed light in the terahertz frequency region, a photodetector that detects the pulsed light, and pulses emitted from the terahertz light source.
  • the light is guided to the sample to be measured, and the transmitted light transmitted through the sample or the reflected light reflected by the sample is guided to the photodetector.
  • the sample is composed of at least two or more mirrors. Two pairs of mirror groups arranged at symmetrical positions, and changing the incident angle of the pulsed light emitted from the terahertz light source to the sample by changing the position and angle of the two pairs of mirror groups The operation is controlled so that
  • the light measurement method according to the eleventh invention is characterized in that, in the tenth invention, the positions and angles of the two pairs of mirror groups are changed by a support arm having a central portion of the sample as a rotation center.
  • the light measurement method according to a twelfth aspect of the present invention is the light measurement method according to the tenth or eleventh aspect, wherein the light detector detects transmitted light or reflects light by changing the position and angle of the two pairs of mirror groups. It is characterized by switching whether to detect light.
  • a terahertz light source that emits pulsed light in the terahertz frequency region, a photodetector that detects pulsed light, and the pulsed light emitted from the terahertz light source is guided to the sample to be measured, and the sample And two pairs of mirrors arranged at symmetrical positions with the sample interposed therebetween, which guides the transmitted light that has passed through or reflected light reflected by the sample to the photodetector.
  • the incident angle of the pulsed light emitted from the terahertz light source to the sample can be changed by changing the position and angle of the two pairs of mirror groups.
  • the position and angle of the two pairs of mirrors are changed by the support arm having the center portion of the sample as the center of rotation, so the relative positions of the terahertz light source and the photodetector are changed according to the sample. Therefore, it is possible to detect transmitted light and reflected light with a single photodetector. Further, each time the incident angle to the sample is changed, it is not necessary to perform complicated operations such as optical axis alignment, and pulse light can be reliably guided to the photodetector.
  • the photodetector switches between detecting transmitted light and reflected light.
  • the transmitted light and the reflected light can be detected by the instrument, so that the structure of the entire optical measuring device can be simplified and the cost can be reduced.
  • the mirror group includes at least one curved mirror, and collimates the pulsed light emitted from the terahertz light source in the vicinity of the sample, so that the physical property value is reliably measured even when the light receiving area of the sample is small. It becomes possible.
  • a polarization measurement function can be provided, and polarization measurement using the ellipsometry method can be performed. . It is also possible to measure an anisotropic sample.
  • a reference measurement when switching to detect reflected light, a reference measurement is performed by using a so-called ellipsometry method that calculates a physical property value based on the amplitude reflection coefficient ratio and phase difference of s-polarized light and p-polarized light of a sample. Therefore, it is not necessary to execute the measurement every measurement, and the measurement accuracy can be maintained high.
  • the pulsed light is applied to the sample near the Brewster angle of the sample.
  • the incident angle can be adjusted. Therefore, measurement can be performed at an incident angle at which the ratio of the s-polarized light and p-polarized light to the amplitude reflection coefficient is maximized, and the physical property value can be measured with high accuracy.
  • the pulsed light emitted from the terahertz light source incident on the sample is 45-degree linearly polarized light having the same light intensity of s-polarized light and p-polarized light, and the s-polarized light and p of reflected light reflected by the sample.
  • the amplitude reflection coefficient ratio and the phase difference of the polarized light are acquired based on a signal detected when the angle of the polarizer is set to 0 degree or 90 degrees.
  • a slight change in polarization due to the complex dielectric constant of the sample can be detected, and the physical property value can be measured with high accuracy.
  • the rotation angle of the polarizer is fixed at the set angle during the measurement, it is possible to reduce the mechanical error as compared with the conventional measurement method in which the polarizer is continuously rotated.
  • the terahertz light source includes a photoconductive antenna that generates pulsed light in the terahertz frequency region using an optical rectification method. Since the photoconductive antenna is arranged so that the polarization of the generated pulsed light is inclined by 45 degrees, it is possible to increase the utilization efficiency of the pulsed light emitted from the terahertz light source.
  • the incident angle of the pulsed light emitted from the terahertz light source to the sample can be changed by changing the position and angle of the two pairs of mirror groups, so the terahertz light source and the photodetector are fixed.
  • the terahertz light source and the photodetector are fixed.
  • FIG. 2 It is a schematic diagram which shows the mode of the polarization change of the pulsed light in the optical measurement apparatus which concerns on this Embodiment 2.
  • FIG. It is a graph which shows the result of having measured the amplitude reflection coefficient ratio of the p-type Si substrate with the optical measurement apparatus which concerns on this Embodiment 2.
  • FIG. It is a graph which shows the result of having measured the phase difference of the p-type Si substrate with the optical measurement apparatus which concerns on this Embodiment 2.
  • FIG. It is the graph which compared the result of having calculated the complex dielectric constant with the result of theoretical calculation based on the amplitude reflection coefficient ratio and phase difference of the p-type Si substrate which were measured with the optical measurement apparatus which concerns on this Embodiment 2.
  • FIG. It is a graph which shows the example which computed complex electrical conductivity in the optical measurement apparatus which concerns on Embodiment 2 of this invention.
  • the sample is irradiated with pulsed light having a frequency component of 0.1 ⁇ 10 12 to 100 ⁇ 10 12 Hertz and transmitted through the sample, or the sample surface
  • pulsed light having a frequency component of 0.1 ⁇ 10 12 to 100 ⁇ 10 12 Hertz
  • An example of a so-called terahertz light measuring device that calculates a physical property value of a sample and obtains it as a measured value by detecting the intensity and phase difference of the reflected light reflected by the light source will be specifically described based on the drawings. .
  • FIG. 1 and 2 are schematic views showing the configuration of the light measurement apparatus according to Embodiment 1 of the present invention.
  • FIG. 1 is a schematic diagram showing the configuration of the light measurement device when measuring transmitted light
  • FIG. 2 is a schematic diagram showing the configuration of the light measurement device when measuring reflected light.
  • the light measurement apparatus splits the pulsed light L1 emitted from the pulsed laser 1 with the beam splitter 2, and supplies the one pulsed light L2 to the condenser lens 3a. Induce.
  • the pulsed light L2 condensed on the terahertz light source element (terahertz light source) 4 by the condenser lens 3a is converted into pulsed light in the terahertz frequency region, and the converted terahertz light L4 is mirrored by the non-axial parabolic mirror 5 Guided to group 10a.
  • the pulse laser 1 for example, a mode-locked femtosecond (fs) unit ultrashort pulse laser is used, and the pulse width is preferably 10 to 150 femtoseconds.
  • the terahertz light source element 4 includes a photoconductive antenna formed on, for example, a low-temperature grown GaAs thin film.
  • FIG. 3 is an exemplary diagram showing a configuration of an antenna module when the terahertz light source element 4 includes a photoconductive antenna.
  • FIG. 3A is a schematic perspective view of the antenna module
  • FIG. 3B is an enlarged view of the vicinity of the antenna gap.
  • An antenna pattern 43 having an antenna gap 42 is formed on the photoconductive antenna substrate 41, and a bias voltage is applied to both ends of the electrodes forming the antenna gap 42 by a bias power supply 44.
  • a transient current flows instantaneously, and 0.1 ⁇ 10 12 to 100 ⁇ due to electric dipole radiation. 10 12 Hz, i.e.
  • terahertz light L4 pulsed light in the terahertz frequency range (terahertz light) L4 is generated.
  • the generated terahertz light L4 is radiated into free space by the silicon hemisphere lens 45 that is in close contact with the back surface of the photoconductive antenna substrate 41.
  • the mirror group 10a includes a plane mirror 11a and a non-axis parabolic mirror (curved mirror) 12a.
  • the plane mirror 11a is mounted on a rotation stage 13a that can rotate around the position irradiated with the terahertz light L4, and the rotation stage 13a can linearly move in a direction parallel to the terahertz light L4.
  • a moving rail (not shown) is provided in a direction parallel to the terahertz light L4, and the moving rail can be moved linearly.
  • the non-axial parabolic mirror 12a is connected to a support arm 14a whose center of rotation is the central portion of the sample 6 to be measured.
  • the support arm 14a is attached to the rotation center of the rotation stage 13b that rotates on the same rotation center axis as the rotation stage 13c on which the sample 6 is mounted and the rotation stage 13d to which the support arm 14b described later is attached.
  • the axial parabolic mirror 12a can be rotated and moved with the effective focal length EFL as the rotation radius. That is, the rotary stages 13b, 13c, and 13d are provided on the same rotation center axis in the direction perpendicular to the paper surface of FIGS. 1 and 2, and can rotate independently.
  • the terahertz light L4 is collimated at the center portion of the sample 6, that is, at the rotation center of the non-axial parabolic mirror 12a.
  • the position and tilt angle of the plane mirror 11a are controlled so that the angle formed between the incident light and the reflected light in the non-axis parabolic mirror 12a is always 90 degrees.
  • the rotation stage 13c on which the sample 6 is mounted is rotated so that the terahertz light L4 enters the sample 6 at an incident angle of 0 degree, and the inclination angle of the plane mirror 11a is 45 degrees.
  • the distance between the center portion of the sample 6 and the plane mirror 11a is equal to the effective focal length EFL of the non-axial parabolic mirror 12a.
  • the support arm 14a is controlled so as to be parallel to the direction orthogonal to the sample 6, that is, the terahertz light L4 incident on the plane mirror 11a.
  • the rotation angle of the support arm 14a, the horizontal axis position and tilt angle of the plane mirror 11a, and the rotation angle of the sample 6 are controlled by an actuator (not shown), such as a servo motor or a stepping motor, for controlling the respective operations. (Control mechanism).
  • the rotation stage 13c on which the sample 6 is mounted is rotated 90 degrees from the position at the time of transmitted light measurement so that the terahertz light L4 is incident on the sample 6 with an incident angle. is there.
  • the tilt angle of the plane mirror 11a, the position of the plane mirror 11a in the horizontal axis direction when the central portion of the sample 6 is the rotation center, the tilt angle, and the rotation position of the support arm 14a are determined by the incident light and the reflection at the non-axis parabolic mirror 12a.
  • the angle formed with the light is 90 degrees, and the distance between the center point of the sample 6 and the reflection position at the non-axial parabolic mirror 12a is controlled to be equal to the effective focal length EFL of the non-axial parabolic mirror 12a.
  • the FIG. 4 is an explanatory diagram for calculating the relationship between the position in the horizontal axis direction of the plane mirror 11a, the tilt angle, and the rotational position of the support arm 14a.
  • the distance in the horizontal axis direction from the reflection position of the terahertz light L4 on the plane mirror 11a to the center point of the sample 6 is x, and the distance in the vertical axis direction is h.
  • the incident angle of the terahertz light L4 to the sample 6 (inclination angle from the direction orthogonal to the surface of the sample 6) is ⁇ i
  • the inclination angle ⁇ m of the plane mirror 11a is equal to the angle A and the angle A ′ shown in FIG. Diagonal relationship). Since the angle A is (180 ⁇ i) / 2, the inclination angle ⁇ m of the plane mirror 11a can be expressed as (180 ⁇ i) / 2.
  • the distance x in the horizontal axis direction from the reflection position of the terahertz light L4 at the plane mirror 11a to the center point of the sample 6 is the extension direction of the sample 6 from the center point of the sample 6 (the incident direction of the terahertz light L4 to the plane mirror 11a).
  • y can be calculated as EFL / cos (90 ⁇ i) from a right triangle including EFL, and therefore x can be calculated by (Expression 1).
  • the transmitted light that has passed through the sample 6 or the reflected light that has been reflected by the sample 6 is guided to the photodetector 8 by the mirror group 10b that is arranged symmetrically with the sample 6 in between.
  • the mirror group 10b includes a plane mirror 11b and a non-axis parabolic mirror 12b.
  • the plane mirror 11b is mounted on a rotation stage 13e that can rotate around the position irradiated with the terahertz light L4, and the rotation stage 13e can linearly move in a direction parallel to the terahertz light L4.
  • a moving rail (not shown) is provided in a direction parallel to the terahertz light L4, and the moving rail can be moved linearly.
  • the non-axial parabolic mirror 12b is connected to a support arm 14b whose center of rotation is the central portion of the sample 6 to be measured.
  • the support arm 14b is attached to the rotary stage 13d, and can rotate and move with the effective focal length EFL of the non-axial parabolic mirror 12b as the rotation radius.
  • the terahertz light L4 collimated at the center portion of the sample 6, that is, the rotation center of the non-axial parabolic mirror 12b, is transmitted through the sample 6 and guided to the non-axial parabolic mirror 12b.
  • the inclination angle of the plane mirror 11b is 135 (45) degrees symmetrical to the plane mirror 11a, and the distance between the central portion of the sample 6 and the plane mirror 11b is the non-axial parabolic mirror 12b. Is equal to the effective focal length EFL.
  • the support arm 14b is controlled to be parallel to the direction orthogonal to the sample 6, that is, the terahertz light L4 emitted from the plane mirror 11b.
  • the rotation angle of the support arm 14b, the horizontal axis position and the inclination angle of the plane mirror 11b are controlled by an actuator (not shown), such as a servo motor or a stepping motor, which controls the respective operations (control mechanism).
  • the inclination angle of the plane mirror 11b, the position in the horizontal axis direction of the plane mirror 11b when the central portion of the sample 6 is the rotation center, the inclination angle, and the rotation position of the support arm 14b are non-axial.
  • the angle formed by the incident light and the reflected light at the parabolic mirror 12b is 90 degrees, and the distance between the center point of the sample 6 and the reflection position at the non-axial parabolic mirror 12b is the same as that of the non-axial parabolic mirror 12b. It is controlled to be equal to the effective focal length EFL.
  • the inclination angle of the plane mirror 11b can be expressed by 180 ⁇ (180 ⁇ i) / 2, and the terahertz light L4 from the plane mirror 11b can be expressed.
  • the distance x to the reflection position can also be calculated by (Equation 1) described above with the central portion of the sample 6 as the rotation center.
  • the position and inclination angle of the plane mirror 11b in the horizontal axis direction, and the rotation position of the support arm 14b are symmetric with respect to the plane mirror 11a and the sample 6 by the actuator (not shown) that controls the respective operations. Further, the plane mirror 11b is controlled so that the tilt angle of the plane mirror 11b is symmetric with the plane mirror 11a, and the rotational position of the support arm 14b is symmetric with the support arm 14a.
  • the terahertz light L4 parallel to the terahertz light L4 can be reflected by the plane mirror 11b.
  • the incident angle to the sample 6 is changed, it is not necessary to perform complicated adjustment work such as optical axis alignment of reflected light each time by automatically controlling the operation of the actuator according to the method described above.
  • the reflected light can be easily guided to the photodetector 8.
  • the reflected light reflected by the sample 6 is reflected and guided to the plane mirror 11b so that the angle formed by the incident light and the reflected light in the non-axial parabolic mirror 12b of the mirror group 10b is 90 degrees.
  • the terahertz light L4 guided by the plane mirror 11b to the non-axial parabolic mirror 7 disposed at a position substantially symmetrical to the non-axial parabolic mirror 5 and at least parallel to the terahertz light L4 is detected by the photodetector 8. Is incident on.
  • the pulsed light L3 dispersed by the beam splitter 2 is condensed by the condenser lens 3b via the optical delay line 9, and enters the photodetector 8.
  • the signal according to the electric field strength at the time of the terahertz light L4 reaching the photodetector 8 can be detected.
  • the pulse waveform of the terahertz light L4 can be acquired by delay sweeping the arrival time of the pulsed light L3 reaching the photodetector 8 to the photodetector 8 by the optical delay line 9.
  • the positions and angles of the two pairs of mirror groups 10a and 10b arranged at symmetrical positions with the sample 6 in between are changed in cooperation, thereby providing a terahertz light source element. Since the incident angle of the pulsed light (terahertz light) L4 emitted from 4 to the sample 6 can be changed, either transmitted light or reflected light is detected with the terahertz light source element 4 and the photodetector 8 fixed. It is possible to adjust the incident angle of the pulsed light (terahertz light) L4 to the sample 6 when the reflected light is detected.
  • FIG. 5 is a schematic diagram showing a configuration of a light measurement apparatus according to Embodiment 2 of the present invention.
  • FIG. 5 shows the configuration of the light measurement device at the time of reflected light measurement.
  • the same reference numerals are given to the same configurations as those in the first embodiment, and detailed description thereof is omitted.
  • the light measurement device splits the pulsed light L1 emitted from the pulsed laser 1 with the beam splitter 2, and guides one pulsed light L2 to the condenser lens 3a.
  • the pulsed light L2 collected by the condensing lens 3a is converted into pulsed light of 0.1 ⁇ 10 12 to 100 ⁇ 10 12 hertz, that is, a terahertz frequency region through a terahertz light source element (terahertz light source) 4;
  • the converted terahertz light L4 is guided to the mirror group 10a by the non-axis parabolic mirror 5.
  • the terahertz light L4 is incident on the polarizer 21, and only linearly polarized light L5 that oscillates in a direction inclined by 45 degrees from a plane perpendicular to the incident surface is extracted.
  • the “polarizer” is, for example, a wire grid in which fine metal wires are periodically arranged.
  • the 45-degree linearly polarized light L5 is a vector sum of s-polarized light and p-polarized light having the same electric field amplitude intensity.
  • FIG. 6 is a schematic diagram showing a change in polarization of pulsed light in the light measurement device according to the second embodiment.
  • FIG. 6A is a schematic diagram showing 45-degree linearly polarized light L5 extracted by the polarizer 21.
  • the mirror group 10a is composed of a plane mirror 11a and a non-axis parabolic mirror 12a.
  • the plane mirror 11a is mounted on a rotation stage 13a that can rotate around the position irradiated with the terahertz light L4, and the rotation stage 13a can linearly move in a direction parallel to the terahertz light L4.
  • a moving rail (not shown) is provided in a direction parallel to the terahertz light L4, and the moving rail can be moved linearly.
  • the non-axial parabolic mirror 12a is connected to a support arm 14a whose center of rotation is the central portion of the sample 6 to be measured.
  • the support arm 14a is attached to the rotary stage 13b, and can rotate and move with the effective focal length EFL of the non-axial parabolic mirror 12a as the rotation radius.
  • the terahertz light L4 is collimated at the center portion of the sample 6, that is, the rotation center of the non-axial parabolic mirror 12a.
  • the position and tilt angle of the plane mirror 11a are controlled so that the angle formed between the incident light and the reflected light in the non-axial parabolic mirror 12a is always 90 degrees.
  • the terahertz light L4 since the terahertz light L4 is collimated in the vicinity of the sample 6, it is possible to reliably measure the physical property value even when the light receiving area of the sample 6 is small.
  • the rotation position of the rotation stage 13c on which the sample 6 is mounted is the position at the time of reflected light measurement, that is, the rotation stage on which the sample 6 is mounted so that the 45-degree linearly polarized light L5 is incident on the sample 6 with an incident angle. 13c is rotated 90 degrees from the position at the time of transmitted light measurement.
  • the tilt angle of the plane mirror 11a, the position of the plane mirror 11a in the horizontal axis direction when the central portion of the sample 6 is the rotation center, the tilt angle, and the rotation position of the support arm 14a are determined by the incident light and the reflection at the non-axis parabolic mirror 12a.
  • the angle formed by the light is 90 degrees, and the distance between the center point of the sample 6 and the reflection position at the non-axial parabolic mirror 12a is controlled to be equal to the effective focal length EFL of the non-axial parabolic mirror 12a.
  • the inclination angle of the plane mirror 11a can be expressed by (180 ⁇ i) / 2, and the sample is measured from the reflection position of the 45-degree linearly polarized light L5 on the plane mirror 11a.
  • the distance x to the center point 6 can also be calculated by the above-described (Expression 1).
  • FIG. 6B is a schematic diagram showing elliptically polarized light L6.
  • the elliptically polarized light L6 is guided to the mirror group 10b arranged symmetrically with the sample 6 in between.
  • the mirror group 10b includes a plane mirror 11b and a non-axis parabolic mirror 12b.
  • the plane mirror 11b is mounted on a rotation stage 13e that can rotate around a position irradiated with terahertz light, and the rotation stage 13e can linearly move in a direction parallel to the terahertz light L4.
  • a moving rail (not shown) is provided in a direction parallel to the terahertz light L4, and the moving rail can be linearly moved.
  • the non-axial parabolic mirror 12b is connected to a support arm 14b whose center of rotation is the central portion of the sample 6 to be measured.
  • the support arm 14b is attached to the rotary stage 13d, and can rotate and move with the effective focal length EFL of the non-axial parabolic mirror 12b as the rotation radius.
  • the 45-degree linearly polarized light L5 collimated at the center portion of the sample 6, that is, the rotation center of the non-axial parabolic mirror 12b, is reflected by the surface of the sample 6 and guided to the non-axial parabolic mirror 12b.
  • the tilt angle of the plane mirror 11b, the position of the plane mirror 11b in the horizontal axis direction when the center portion of the sample 6 is the center of rotation, the tilt angle, and the rotation position of the support arm 14b are determined by incident light and reflection at the non-axis parabolic mirror 12b.
  • the angle formed by the light is 90 degrees, and the distance between the center point of the sample 6 and the reflection position at the non-axial parabolic mirror 12b is controlled to be equal to the effective focal length EFL of the non-axial parabolic mirror 12b.
  • the inclination angle of the plane mirror 11b can be expressed by 180 ⁇ (180 ⁇ i) / 2, and the elliptically polarized light L6 at the plane mirror 11b
  • the distance x to the reflection position can also be calculated by (Equation 1) described above with the central portion of the sample 6 as the rotation center.
  • the position and inclination angle of the plane mirror 11b in the horizontal axis direction, and the rotation position of the support arm 14b are symmetric with respect to the plane mirror 11a and the sample 6 by the actuator (not shown) that controls the respective operations. Further, the plane mirror 11b is controlled so that the tilt angle of the plane mirror 11b is symmetric with the plane mirror 11a, and the rotational position of the support arm 14b is symmetric with the support arm 14a.
  • the terahertz light L4 parallel to the terahertz light L4 can be reflected by the plane mirror 11b.
  • the incident angle to the sample 6 is changed, it is not necessary to perform complicated adjustment work such as optical axis alignment of reflected light each time by automatically controlling the operation of the actuator according to the method described above.
  • the reflected light can be easily guided to the photodetector 8.
  • the reflected light reflected by the sample 6 is reflected and guided to the plane mirror 11b so that the angle formed by the incident light and the reflected light in the non-axial parabolic mirror 12b of the mirror group 10b is 90 degrees.
  • the elliptically polarized light L6 reflected by the plane mirror 11b is guided to the non-axial parabolic mirror 7 disposed at a position symmetrical to the non-axial parabolic mirror 5 via the polarizer 22 and the polarizer 23. .
  • the elliptically polarized light L6 is extracted as linearly polarized light L7 separated by the polarizer 22 into an s-polarized component and a p-polarized component. That is, by setting the angle of the polarizer 22 to 0 degree or 90 degrees, only s-polarized light or p-polarized light is extracted.
  • FIG. 6C is a schematic diagram showing s-polarized light or p-polarized linearly polarized light L7. In FIG.6 (c), the arrow has shown the oscillating direction of the electric field vector, and has shown s polarized light or p polarized light.
  • the linearly polarized light L7 is incident on the photodetector 8 through the polarizer 23.
  • the polarizer 23 is set at an angle of ⁇ 45 degrees with respect to a plane perpendicular to the incident plane, whereby both the s-polarized component and the p-polarized component can be detected by the photodetector 8.
  • the linearly polarized light L7 is reflected by the non-axial parabolic mirror 7 and enters the photodetector 8.
  • the pulsed light L3 dispersed by the beam splitter 2 is also condensed by the condenser lens 3b via the optical delay line 9 and is incident on the photodetector 8.
  • the pulse waveform of the terahertz light L4 can be acquired by delay sweeping the arrival time of the pulsed light L3 to the photodetector 8 by the optical delay line 9.
  • the time waveforms of s-polarized light and p-polarized light are acquired by attaching the polarizer 22 to the rotary stage and switching the rotation angle to 0 degree or 90 degrees. That is, when the acquisition of the time waveform of s-polarized light or p-polarized light is completed, the rotation angle of the polarizer 22 is switched to acquire the time waveform of s-polarized light or p-polarized light.
  • the complex reflection coefficients r s and r p of s-polarized light and p-polarized light can be obtained by performing Fourier transform on the acquired time waveform, the order of s-polarized light and p-polarized light that can be measured by the ellipsometry method.
  • the ratio ⁇ of the complex reflection coefficients r s and r p in the complex plane can be defined as shown in (Equation 2).
  • Equation 2 the absolute value of the phase [delta] p and the amplitude reflection coefficient of the s-polarized light of the phase [delta] s, p-polarized light
  • the complex permittivity ⁇ cn of the sample 6 is obtained.
  • FIG. 7 is a graph showing the result of measuring the amplitude reflection coefficient ratio tan ⁇ of a p-type Si substrate having a resistivity of 1.1 to 1.4 ⁇ ⁇ cm as the sample 6 in the optical measurement device according to the second embodiment.
  • FIG. 8 shows the result of measuring the phase difference ⁇ of a p-type Si substrate having a resistivity of 1.1 to 1.4 ⁇ ⁇ cm as the sample 6 by the light measurement apparatus according to the second embodiment. It is a graph.
  • the complex permittivity ⁇ cn of Si is (12 ⁇ i ⁇ 0.5)
  • the Brewster angle is approximately 73 degrees. Therefore, when the measurement in FIGS. 7 and 8 is performed, the terahertz light L4 is incident on the sample 6.
  • the positions and rotation angles of the mirror groups 10a and 10b were adjusted so that the angle was 70 degrees.
  • the incident angle of the terahertz light L4 on the sample 6 is adjusted in the vicinity of the Brewster angle of the sample 6 because the complex reflection coefficients r s and r p of the s-polarized light and the p-polarized light of the sample 6 are adjusted in the vicinity of the Brewster angle. Because the ratio ⁇ is maximized, the complex permittivity ⁇ cn of the sample 6 can be obtained with high accuracy based on (Equation 5).
  • the incident angle to the sample 6 can be adjusted by changing the position and the rotation angle of the mirror groups 10a and 10b, so that the terahertz light source element 4 and The photodetector 8 can be fixed, and complicated adjustment work such as optical axis alignment becomes unnecessary when changing the incident angle. Therefore, even when the sample 6 is frequently replaced, a troublesome operation does not occur for the measurer, and the measurement result can be acquired in a relatively short time.
  • the amplitude reflection coefficient ratio tan ⁇ and the phase difference ⁇ of the p-type Si substrate are changed according to the frequency in the terahertz band. It can be seen that the changing state is clearly measured.
  • FIG. 9 shows the result of calculating the complex permittivity ⁇ cn based on the amplitude reflection coefficient ratio tan ⁇ and the phase difference ⁇ of the p-type Si substrate measured by the optical measurement apparatus according to the second embodiment and the theoretical calculation described later. It is the graph which compared the result.
  • the real part ⁇ ′ and the imaginary part ⁇ ′′ when the complex dielectric constant ⁇ cn is expressed as ⁇ cn ⁇ ′ ⁇ i ⁇ ′′ are calculated as a function of frequency.
  • the real part 91 calculated based on (Expression 5) indicated by ⁇ is substantially coincident with the real part 92 (solid line) obtained as a result of theoretical calculation based on the Drude model described later.
  • the imaginary part 93 obtained by calculation based on (Equation 5) indicated by a circle is substantially coincident with the imaginary part 94 (solid line) obtained by theoretical calculation based on the Drude model described later. It is clear that the tendency that the value of the imaginary part ⁇ ′′ increases in the region can be measured with high accuracy.
  • ⁇ cn ( ⁇ ) represents the complex electrical conductivity, and can be represented by the sum of the real part ⁇ ′ ( ⁇ ) and the imaginary part ⁇ ′′ ( ⁇ ).
  • Complex dielectric obtained by (Expression 5)
  • the following equation (7) is obtained.
  • the complex permittivity in vacuum is ⁇ 0
  • the complex permittivity in the high frequency limit is ⁇ ( ⁇ ).
  • the resistivity ⁇ can be obtained as the reciprocal of the real part ⁇ ′ ( ⁇ ) of the complex electrical conductivity ⁇ cn ( ⁇ ).
  • FIG. 10 is a graph showing an example in which the complex electrical conductivity ⁇ cn ( ⁇ ) is calculated by the optical measurement device according to the second embodiment of the present invention. As the sample 6, the p-type Si substrate described above is used.
  • ⁇ mark real sigma 'the (omega) of the complex electrical conductivity ⁇ cn ( ⁇ ), ⁇ mark imaginary part of the complex electrical conductivity ⁇ cn ( ⁇ ) ⁇ "the (omega), respectively
  • the complex electric conductivity ⁇ cn ( ⁇ ) since the carrier cannot follow the speed of the electric field change as the frequency becomes higher, the complex electric conductivity ⁇ cn ( ⁇ )
  • the resistivity ⁇ calculated as the reciprocal of the real part ⁇ ′ ( ⁇ ) of the complex electrical conductivity ⁇ cn ( ⁇ ) is low-frequency side (near ⁇ is 0). 1.0 to 1.1 ⁇ ⁇ cm, which is substantially equal to the resistivity ⁇ of the p-type Si substrate used.
  • the carrier concentration N, the carrier scattering time ⁇ , and the mobility ⁇ can be calculated based on the complex dielectric constant ⁇ cn calculated by (Equation 5).
  • the complex permittivity ⁇ cn is expressed as (Equation 8).
  • the complex permittivity in vacuum is ⁇ 0
  • the complex permittivity in the high frequency limit is ⁇ ( ⁇ ).
  • the plasma frequency ⁇ p can be expressed by (Equation 9) where N is the carrier concentration, m * is the effective mass, and e is the charge amount of electrons.
  • the carrier concentration N can be obtained.
  • the real part 92 and the imaginary part 94 (solid line) of the complex permittivity ⁇ cn in FIG. 9 indicate the real part ⁇ ′ and the imaginary part ⁇ ′′ derived by the fitting process using the above-described method.
  • the carrier concentration N is 1.3 ⁇ 10 16 cm ⁇ 3 and the carrier scattering time ⁇ is 1 ⁇ 10 ⁇ 13 sec.
  • the mobility ⁇ can be calculated from (Equation 14) based on the carrier scattering time ⁇ .
  • the mobility ⁇ can be a value of 436 cm 2 V ⁇ 1 sec ⁇ 1 . It was confirmed that the physical property values of the above-described p-type Si substrate were generally consistent with general values obtained by a conventional semiconductor physical property measurement method such as hole measurement.
  • the incident angle of the pulsed light emitted from the terahertz light source element 4 to the sample 6 is changed by changing the positions and angles of the two pairs of mirror groups 10a and 10b. Therefore, the incident angle when detecting reflected light can be freely adjusted. Therefore, it is not necessary to change the relative positions of the terahertz light source element 4 and the light detector 8 according to the sample 6, the reflected light can be detected by the single light detector 8, and the incident angle to the sample 6 is changed. Each time, it is not necessary to perform complicated adjustment work such as optical axis alignment.
  • the pulsed light emitted from the terahertz light source element 4 incident on the sample 6 is 45-degree linearly polarized light having the same intensity of s-polarized light and p-polarized light, and the s-polarized light and p of the reflected light reflected by the sample.
  • the amplitude reflection coefficient ratio tan ⁇ and the phase difference ⁇ of the polarized light are obtained based on a signal detected when the angle of the polarizer is set to 0 degree or 90 degrees.
  • a slight change in polarization that changes depending on the complex dielectric constant of the sample 6 can be detected, and measurement can be performed with high accuracy.
  • the rotation angle of the polarizer is fixed at the set angle during the measurement, it is possible to reduce the mechanical error as compared with the conventional measurement method in which the polarizer is continuously rotated.
  • Embodiments 1 and 2 described above can be modified without departing from the spirit of the present invention.
  • the configuration of the mirror groups 10a and 10b is particularly limited as long as the mirror groups 10a and 10b are arranged at symmetrical positions with the sample 6 interposed therebetween, have at least one curved mirror, and can be accommodated in a housing. Is not to be done.
  • SYMBOLS 1 Pulse laser 2 Beam splitter 3a Condensing lens 4 Terahertz light source element (terahertz light source) 6 Sample 5, 7 Non-axis parabolic mirror 8 Optical detector 9 Optical delay line 10a, 10b Mirror group 11a, 11b Plane mirror 12a, 12b Non-axis parabolic mirror (curved mirror) 13a, 13b, 13c, 13d, 13e Rotating stage 14a, 14b Support arm

Landscapes

  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Toxicology (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

Cette invention concerne un instrument de mesure optique qui peut passer de la détection de la lumière transmise à la détection de la lumière reflétée, moyennant une configuration simple, et peut mesurer avec précision une propriété physique par modification de l'angle incident de la lumière térahertz rendue incidente selon le type de l'échantillon, ainsi qu'un procédé de mesure optique. L'instrument de mesure optique comprend : une source de lumière térahertz (4) qui émet une lumière pulsée dans la région de fréquence térahertz ; un détecteur de lumière (8) pour détecter la lumière pulsée ; et deux paires de groupes de miroirs (10a, 10b) utilisées pour guider la lumière pulsée émise par la source de lumière térahertz (4) vers un échantillon (6) qui doit être mesuré et pour guider la lumière transmise par l'échantillon (6) ou la lumière réfléchie sur l'échantillon (6) vers le détecteur de lumière (8), comprenant au moins deux miroirs ou plus, agencés en des positions symétriques autour de l'échantillon (6). L'angle incident de la lumière pulsée émise par la source de lumière térahertz (4) par rapport à l'échantillon (6) est modifié par modification des positions et des angles des deux paires de groupes de miroirs (10a,10b).
PCT/JP2009/005142 2009-03-18 2009-10-05 Instrument de mesure optique et procédé de mesure optique WO2010106589A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2009066355 2009-03-18
JP2009-066355 2009-03-18

Publications (1)

Publication Number Publication Date
WO2010106589A1 true WO2010106589A1 (fr) 2010-09-23

Family

ID=42739263

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/005142 WO2010106589A1 (fr) 2009-03-18 2009-10-05 Instrument de mesure optique et procédé de mesure optique

Country Status (1)

Country Link
WO (1) WO2010106589A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012108117A (ja) * 2010-10-25 2012-06-07 Olympus Corp イメージング装置
JP2014119448A (ja) * 2012-12-17 2014-06-30 Advantest Corp 光線入射装置および反射光測定装置
JP2015503750A (ja) * 2011-12-31 2015-02-02 ジェイ・エイ・ウーラム・カンパニー・インコーポレイテッドＪ．Ａ．Ｗｏｏｌｌａｍ Ｃｏ．，Ｉｎｃ． テラヘルツエリプソメーターシステム及びその使用方法
WO2017085863A1 (fr) * 2015-11-20 2017-05-26 パイオニア株式会社 Dispositif de mesure, procédé de mesure et programme informatique
JP2017142152A (ja) * 2016-02-10 2017-08-17 セイコーエプソン株式会社 計測装置
WO2017138061A1 (fr) * 2016-02-08 2017-08-17 パイオニア株式会社 Dispositif de mesure
JP2017207446A (ja) * 2016-05-20 2017-11-24 浜松ホトニクス株式会社 全反射分光計測装置及び全反射分光計測方法
WO2021122716A1 (fr) * 2019-12-20 2021-06-24 Helmut Fischer GmbH Institut für Elektronik und Messtechnik Appareil d'émission et/ou de réception de rayonnement térahertz et son utilisation

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62220834A (ja) * 1986-03-24 1987-09-29 Toshiba Corp 光分析装置
JPS63215923A (ja) * 1987-03-04 1988-09-08 Copal Co Ltd 分光測光装置における補助装置
JPH0815130A (ja) * 1994-06-29 1996-01-19 Jeol Ltd フーリエ変換分光位相変調偏光解析法
JP2003014620A (ja) * 2001-06-27 2003-01-15 Matsushita Electric Ind Co Ltd 偏光解析装置及び偏光解析方法
JP2004279352A (ja) * 2003-03-18 2004-10-07 Tochigi Nikon Corp テラヘルツ光を用いた測定装置
JP2008151618A (ja) * 2006-12-18 2008-07-03 Canon Inc テラヘルツ波を用いた対象物の情報取得装置及び方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62220834A (ja) * 1986-03-24 1987-09-29 Toshiba Corp 光分析装置
JPS63215923A (ja) * 1987-03-04 1988-09-08 Copal Co Ltd 分光測光装置における補助装置
JPH0815130A (ja) * 1994-06-29 1996-01-19 Jeol Ltd フーリエ変換分光位相変調偏光解析法
JP2003014620A (ja) * 2001-06-27 2003-01-15 Matsushita Electric Ind Co Ltd 偏光解析装置及び偏光解析方法
JP2004279352A (ja) * 2003-03-18 2004-10-07 Tochigi Nikon Corp テラヘルツ光を用いた測定装置
JP2008151618A (ja) * 2006-12-18 2008-07-03 Canon Inc テラヘルツ波を用いた対象物の情報取得装置及び方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
TAKESHI NAGASHIMA ET AL.: "Terahertz Ellipsometry ni Okeru Sokutei Seido no Nyushakaku Izonsei", 2002 NEN SHUNKI DAI 49 KAI EXTENDED ABSTRACTS, JAPAN SOCIETY OF APPLIED PHYSICS AND RELATED SOCIETIES, vol. 3, 27 March 2002 (2002-03-27), pages 1099 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012108117A (ja) * 2010-10-25 2012-06-07 Olympus Corp イメージング装置
JP2015503750A (ja) * 2011-12-31 2015-02-02 ジェイ・エイ・ウーラム・カンパニー・インコーポレイテッドＪ．Ａ．Ｗｏｏｌｌａｍ Ｃｏ．，Ｉｎｃ． テラヘルツエリプソメーターシステム及びその使用方法
JP2014119448A (ja) * 2012-12-17 2014-06-30 Advantest Corp 光線入射装置および反射光測定装置
US9568422B2 (en) 2012-12-17 2017-02-14 Advantest Corporation Light beam incident device and reflected light measurement device
WO2017085863A1 (fr) * 2015-11-20 2017-05-26 パイオニア株式会社 Dispositif de mesure, procédé de mesure et programme informatique
WO2017138061A1 (fr) * 2016-02-08 2017-08-17 パイオニア株式会社 Dispositif de mesure
JP2017142152A (ja) * 2016-02-10 2017-08-17 セイコーエプソン株式会社 計測装置
JP2017207446A (ja) * 2016-05-20 2017-11-24 浜松ホトニクス株式会社 全反射分光計測装置及び全反射分光計測方法
WO2021122716A1 (fr) * 2019-12-20 2021-06-24 Helmut Fischer GmbH Institut für Elektronik und Messtechnik Appareil d'émission et/ou de réception de rayonnement térahertz et son utilisation

Similar Documents

Publication Publication Date Title
WO2010106589A1 (fr) Instrument de mesure optique et procédé de mesure optique
US6847448B2 (en) Polarization analyzing apparatus and method for polarization analysis
TWI536014B (zh) 用於分析來自傾斜層的ｘ射線繞射之方法及設備
US9404855B2 (en) Method to obtain absorption spectra from near-field infrared scattering using homo-dyne detection
WO2006064653A1 (fr) Photodetecteur terahertz, procede pour detecter une lumiere terahertz et systeme d’imagerie terahertz
WO2002079760A3 (fr) Diffusiometre polarimetrique pour mesures de dimensions critiques de structures periodiques
US9134182B2 (en) Measurement apparatus and method, tomography apparatus and method
JPH02263105A (ja) 被膜厚さ測定器
JP2006300708A (ja) 近接場偏光測定装置
KR20150031827A (ko) 면감지 타원 계측기
JP2005129732A (ja) テラヘルツ光発生装置およびテラヘルツ光測定装置
TW200525271A (en) Differential evaluation of adjacent regions for change in reflectivity
CN116952380A (zh) 一种椭圆偏振测量装置及其测量方法
JP4091214B2 (ja) テラヘルツ波分光器
Lastras‐Martínez et al. A spectrometer for the measurement of reflectance‐difference spectra
JP2004125712A (ja) 分光分析装置
RU2466381C2 (ru) Система и способ обнаружения местного механического напряжения в интегральных устройствах
US6982791B2 (en) Scatterometry to simultaneously measure critical dimensions and film properties
Kovalev et al. LED broadband spectral ellipsometer with switching of orthogonal polarization states
JP2004279352A (ja) テラヘルツ光を用いた測定装置
WO2022126676A1 (fr) Dispositif de détection à semi-conducteur et procédé de détection
WO2011052295A1 (fr) Dispositif de mesure optique et procédé de mesure optique
WO2003036362A1 (fr) Systeme optique generant une lumiere terahertzienne, systeme optique de detection d'une lumiere terahertzienne et dispositif optique terahertzien utilisant un tel systeme
JP2005227021A (ja) テラヘルツ光測定装置
RU2384835C1 (ru) Эллипсометр

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09841797

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09841797

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP