JP2011169615A - Quasi-electrostatic field analyzer and quasi-electrostatic field analysis method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quasi-electrostatic field analyzer and analysis method, which detects the condition of a micro-fine place with high accuracy and can be applied to the analysis of defects generated in a semiconductor device. <P>SOLUTION: An object to be inspected 10 is irradiated with a light via a near-field probe 15 having a hole with a size smaller than the wavelength of a laser light. A quasi-electrostatic field detection probe 16 is disposed near the surface of the object to be inspected 10 and detects the quasi-electrostatic field generated by the light irradiation. A control part 20 outputs the position information corresponding to the light irradiation position of the object to be inspected 10 to an image processing part 19. The image processing part 19 performs signal processing by associating the quasi-electrostatic field intensity detected by the quasi-electrostatic field detection probe 16 to the position information inputted from the control part 20, and generates the image of the surface condition of the object to be inspected 10 along with the movement of a stage 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a quasi-electrostatic field analysis apparatus and a quasi-electrostatic field analysis method for analyzing the state of a test object (sample) using near-field light.

  In recent years, further miniaturization and higher integration of semiconductor devices such as LSIs have been promoted, and accordingly, the size of defects generated inside the semiconductor devices has become extremely small. A defect inside the semiconductor device can be detected by an abnormal current or an abnormal voltage generated thereby. However, in recent semiconductor devices, an abnormal current or an abnormal voltage caused by a defect is extremely small, and it has become difficult to detect a failure site with high accuracy and analyze the cause of the failure.

  As a defect inspection method of a semiconductor device, an Obark method (OBIRCH: Optical Beam Induced Resistance CHange) and an Obic method (OBIC: Optical Beam Induced Current) are known. In any of these methods, laser light is irradiated with a power supply connected to the semiconductor device. In the Obark method, a change in current, voltage, or resistance due to heat generated by laser irradiation is detected. In the Obic method, electrons and holes generated by laser irradiation are detected.

  As another method, an optical fiber including a near-field probe having a minute hole (aperture) is used, and a near-field light that oozes out from a hole of the near-field probe is used. There has also been proposed an inspection method for inspecting wiring defects based on the change of the wiring.

  However, any of the above-described methods can be applied only to the semiconductor device after the formation of the metal wiring is completed. On the other hand, analysis methods such as a laser squid method and a terahertz method that can analyze the state of a semiconductor device during wiring formation have been proposed. In the laser squid method, a closed loop including a metal wiring is formed by a photocurrent generated by excitation laser irradiation, and a magnetic field generated in the closed loop is detected. In the terahertz method, a semiconductor device is irradiated with pulsed laser light, and electromagnetic waves generated thereby are detected.

  However, in both the laser squid method and the terahertz method, it is necessary to form a metal wiring in order to detect a magnetic field and an electromagnetic wave. Therefore, a method capable of analyzing the state of a semiconductor device without metal wiring by detecting a quasi-electrostatic field generated when the semiconductor device is irradiated with laser light (hereinafter referred to as “quasi-electrostatic field detection method”). Has been proposed.

JP 2000-97839 A Japanese Patent Laid-Open No. 9-257882

Ito et al., “Failure analysis method using micro electrostatic field detection probe”, 29th LSI Testing Symposium (LSITS2009), H21.11.11-13, Proceedings of LSI Testing Society

  However, in the quasi-electrostatic field detection method described above, the spatial resolution is determined by the wavelength limit (light diffraction) of the laser light. For example, the spatial resolution is about 0.7 μm when a near-infrared laser having a wavelength of 1340 nm is used, and the spatial resolution is about 0.1 μm even when ultraviolet light having a wavelength of 200 nm is used. Since the size of elements included in recent semiconductor devices is extremely small, it is possible to detect a defect by the above-described method, but it is difficult to specify the defect location in detail.

  In view of the above, an object of the present invention is to provide a quasi-electrostatic field analysis apparatus and a quasi-electrostatic field analysis method that can detect the state of a minute place with high accuracy and can be applied to analysis of defects generated in a semiconductor device.

  According to one aspect, a near-field probe provided with a light source and a hole having a size smaller than the wavelength of the light emitted from the light source, and irradiating the inspection object with the light emitted from the light source through the hole; , A quasi-electrostatic field detection probe for detecting a quasi-electrostatic field generated in the inspection object by capacitive coupling with the inspection object, a stage on which the inspection object is mounted, and the stage relative to the near-field probe And a control unit that controls the drive unit, and position information of the inspection target is input from the control unit, and the position information is associated with an output of the quasi-electrostatic field detection probe and processed. A quasi-electrostatic field analysis device having a signal processing unit is provided.

  According to the above aspect, light is irradiated to the inspection target through a hole having a size smaller than the wavelength of the light emitted from the light source provided in the near-field probe. Thereby, a quasi-electrostatic field is generated in the inspection object. The quasi-electrostatic field has a property of being widely distributed along the surface to be inspected. For this reason, even if the quasi-electrostatic field detection probe is arranged at a position away from the near-field probe, the quasi-electrostatic field can be detected. The strength of the quasi-electrostatic field depends on the surface state of the inspection object.

  If the output of the quasi-electrostatic field detection probe is made to correspond to the light irradiation position of the inspection object while moving the near-field probe relative to the inspection object, an image corresponding to the surface state of the inspection object can be obtained. . Based on this image, the state of the inspection object can be analyzed.

FIG. 1 is a block diagram showing an outline of a quasi-electrostatic field analysis apparatus according to the first embodiment. FIG. 2A is a schematic diagram showing an electric field created by carriers generated when a pn junction of a semiconductor device is irradiated with laser light, and FIG. 2B is composed of electrons and holes generated by laser irradiation. It is a schematic diagram which shows an electronic dipole. FIG. 3 is a schematic diagram showing a quasi-electrostatic field distributed near the surface of the inspection object. FIG. 4 is a diagram showing the relationship between the strengths of the quasi-electrostatic field, the induced electric field, and the radiated electric field and the distance from the electric field generation source (the distance in the direction away from the inspection object). FIG. 5 is a schematic diagram showing an example of a quasi-electrostatic field detection probe. FIG. 6 is a schematic diagram showing another example of the quasi-electrostatic field detection probe. FIG. 7 is a diagram showing the correspondence between the position of the near-field probe and the strength of the quasi-electrostatic field detected by the quasi-electrostatic field detection probe. FIG. 8 is a schematic diagram showing an example of the arrangement of the near-field probe and the quasi-electrostatic field detection probe. FIG. 9 is a diagram schematically illustrating an image of a semiconductor device obtained by the quasi-electrostatic field analysis apparatus of the embodiment. FIG. 10 is a block diagram showing an outline of a quasi-electrostatic field analysis apparatus according to the second embodiment.

  Hereinafter, embodiments will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a block diagram showing an outline of a quasi-electrostatic field analysis apparatus according to the first embodiment.

  The quasi-electrostatic field analysis apparatus according to the present embodiment includes a stage 11, a stage drive unit 12, a laser light source 13, an optical fiber 14 including a near-field probe 15, a quasi-electrostatic field detection probe 16, and an amplifier 18. The image processing unit 19, the control unit 20, and the display device 21 are included.

  A semiconductor device (LSI chip) 10 to be inspected is placed on a stage 11. The stage 11 is driven by a stage drive unit 12 controlled by the control unit 20 and moves in the horizontal biaxial direction (X-axis direction and Y-axis direction). The control unit 20 transmits position data indicating the position of the stage 11 in the X-axis direction and the Y-axis direction to the image processing unit 19 as the stage 11 is moved by the stage driving unit 12.

  The laser light source 13 is driven and controlled based on a signal from the control unit 20. The laser light source 13 is optically connected to the optical fiber 14, and the laser light emitted from the laser light source 13 propagates in the optical fiber 14 in the length direction. A near-field probe 15 is provided at the tip of the optical fiber 14, and a hole (aperture) having a diameter smaller than the wavelength of the laser light is provided at the tip of the near-field probe 15. When the semiconductor device 10 is irradiated with near-field light through the near-field probe 15, a quasi-electrostatic field is generated in the semiconductor device 10. The quasi-electrostatic field will be described later.

  In the present embodiment, it is assumed that the wavelength of light emitted from the laser light source 13 is in the range of 320 nm to 1340 nm. The size (diameter) of the hole provided at the tip of the near-field probe 15 is 100 nm or less.

  The quasi-electrostatic field detection probe 16 has a detection electrode 16a. The detection electrode 16 a is disposed in the vicinity of the semiconductor device 10 and capacitively coupled to the semiconductor device 10 to detect a quasi-electrostatic field generated in the semiconductor device 10.

  A bias voltage is supplied from the bias power supply 17 to the quasi-electrostatic field detection probe 16. The output of the quasi-electrostatic field detection probe 16 is amplified by the amplifier 18 and transmitted to the image processing unit (signal processing unit) 19. The image processing unit 19 generates a surface image of the semiconductor device 10 based on the intensity of the quasi-electrostatic field detected by the quasi-electrostatic field detection probe 16 and the position data of the stage 11 transmitted from the control unit 20, The image data is transmitted to the display device 21.

  The display device 21 includes a display element capable of displaying an image, such as a cathode ray tube (CRT) or a liquid crystal display (LCD), and displays an image based on the image data transmitted from the image processing unit 19.

  Hereinafter, the quasi-electrostatic field will be described.

  In the present embodiment, the inspection object (semiconductor device 10) is irradiated with near-field light via the near-field probe 15. As a result, a very narrow range to be inspected is excited by heat or light energy from the laser beam, and positive and negative carriers (electron dipoles) are generated.

  FIG. 2A is a schematic diagram showing an electric field created by carriers generated when a pn junction of a semiconductor device is irradiated with laser light. FIG. 2B is a schematic diagram showing an electron dipole (dipole antenna) composed of electrons e and holes h generated by laser irradiation. Here, the charge of the electron e and the hole h is Q. In FIG. 2B, d indicates the distance between the electron e and the hole h of the electric dipole, P indicates an arbitrary point, r indicates the center point O and the point P of the electric dipole, .Theta. Represents the angle between the Z axis and the straight line connecting the center point O and the point P of the electric dipole.

  When the electric potential between the electric dipole and the point P is obtained by Maxwell's equation and differentiated by the distance r to obtain the electric field Eθ in the θ direction at the point P, the following equation (1) is derived.

  Here, β represents a wave number (frequency: β = 2π / λ), ε is a dielectric constant, and j is a constant.

  The electric field Eθ can be divided into three components: a quasi-electrostatic field, an induction field, and a radiation field. In the expression (1), the first term in the parentheses {} is a quasi-electrostatic field component, the second term is an induction field component, and the third term is a radiation field component. The intensity of the radiated electric field is inversely proportional (1 / r) to the distance r and reaches a relatively long distance. Radio waves used for wireless communication use this component.

Since the strength of the induced electric field is inversely proportional to the square of the distance r (1 / r ² ), it does not reach as far as the radiation electric field. An induced electric field is known as an electric field generated mainly around a low-frequency circuit element.

The strength of the quasi-electrostatic field is inversely proportional to the cube of the distance r (1 / r ³ ), and the reach distance is shorter than the induction electric field. However, when the distance r is sufficiently shorter than the wavelength, the strength of the quasi-electrostatic field is stronger than the radiation field and the induction field.

  The radiated electric field and the induced electric field have directivity according to the length of the wiring connected to the pn junction and the loop current circuit. Accordingly, within the directivity range, these electric fields can be detected even if the detection sensor is arranged at a position away from the inspection target (semiconductor device). On the other hand, although the quasi-electrostatic field does not reach far away, as schematically shown in FIG. 3, the quasi-electrostatic field is widely distributed in the vicinity of the surface of the inspection object 31 (including not only the front surface but also the back surface). . For this reason, if it is in the vicinity of the surface of the inspection object 31, it is possible to detect the quasi-electrostatic field even if the detection sensor is arranged at a location away from the electric field generation source.

  In FIG. 4, the horizontal axis is the distance r, and the vertical axis is the electric field strength (relative value). This shows the relationship with the distance.

  As shown in FIG. 4, the intensity of the quasi-electrostatic field rapidly decreases as the distance from the inspection object increases. The distance r from the electron dipole (center point O) at the point where the strengths of the quasi-electrostatic field, the induction field, and the radiation field coincide with each other is about 0.16λ. When the frequency of the electric field is 3 GHz (gigahertz), the distance r is about 16 mm, and the quasi-electrostatic field is dominant in a range closer to it.

  The electric field generated by the laser beam irradiation is mainly an electron generated when a laser beam having an energy higher than the Seebeck effect (thermoelectromotive force) due to the irradiation heat of the near infrared laser beam or the band gap of the silicon substrate is irradiated. -It is due to the photocurrent caused by the hole pair. In addition, when a near-infrared laser is irradiated on a ferroelectric material such as PZT, an electric field is generated due to a pyroelectric current caused by heat generation. Changes in the electric field strength occur due to differences in reflection and absorption of the laser light from the circuit pattern of the semiconductor device circuit.

  FIG. 5 is a schematic diagram showing an example of the quasi-electrostatic field detection probe 16. As the quasi-electrostatic field detection probe 16, for example, a field effect transistor (hereinafter referred to as "FET") or a bridge circuit can be used. In the present embodiment, an example in which an FET 32 is used as the quasi-electrostatic field detection probe 16 is shown. The detection electrode 16 a is connected to the gate G of the FET 32. The gate itself of the FET 32 may be used as the detection electrode 16a.

  The source S and drain D of the FET 32 are connected to the amplifier 18. In this embodiment, a bias power source 17 is connected between the drain D and the amplifier 18. This bias power supply 17 supplies a bias voltage of 10 mV to 5 V to the FET 32.

  In this quasi-electrostatic field detection probe 16, the detection electrode 16 a is capacitively coupled to the inspection object 31 to detect the quasi-electrostatic field, whereby the gate voltage of the FET 32 changes and a current corresponding to the strength of the quasi-electrostatic field is generated in the source S. And between the drain D. This current is amplified (signal processing) by the amplifier 18 and converted into a luminance signal by the image processing unit 19 to generate an image. In order to obtain a good S / N (signal / noise) ratio, it is preferable to use an FET having a high carrier mobility and a low input capacitance (for example, 2.0 pF or less) as the quasi-electrostatic field detection probe 16.

  You may use the detection electrode 16a properly according to a test object. When the detection electrode 16a has a wide parallel area, the amount of electric field to be detected increases, and therefore, a quasi-electrostatic field can be detected even when the detection electrode 16a is several mm away from the electric field generation source. Therefore, it is possible to detect the quasi-electrostatic field even in a state where the semiconductor device is assembled (a state sealed with resin).

  Further, as shown in FIG. 6, when a member 33 made of a material having a high dielectric constant is interposed between the detection electrode 16a and the inspection object 31, the coupling capacitance between the detection electrode 16 and the inspection object 31 increases. The quasi-electrostatic field can be detected more efficiently. Further, by interposing a member made of a dielectric material between the detection electrode 16a and the inspection object 31, the inspection object 31 and the detection electrode 16a are short-circuited even if the metal wiring is exposed on the surface of the inspection object 31. The quasi-electrostatic field can be detected.

  FIG. 7 is a diagram showing the correspondence between the position of the near-field probe 15 and the strength of the quasi-electrostatic field detected by the quasi-electrostatic field detection probe 16. Here, it is assumed that a region 10 a where the semiconductor layer is exposed and a region 11 b where the element isolation layer is exposed exist on the surface of the semiconductor device 10. The near-field probe 15 is relatively moved on the surface of the semiconductor device 10 in the direction indicated by the arrow in the figure.

  When the semiconductor device 10 is irradiated with near-field light from the near-field probe 15, a quasi-electrostatic field is generated in a small area determined by the diameter of the hole (aperture) at the tip of the near-field probe 15 in the semiconductor device 10. This quasi-electrostatic field instantly spreads along the surface of the semiconductor device 10 and is detected by the quasi-electrostatic field detection probe 16.

  As shown in FIG. 7, if there are a region 10 a where the semiconductor layer is exposed and a region 10 b where the element isolation layer is exposed on the surface of the semiconductor device 10, the temperature gradient and electric field gradient due to near-field light increase at the boundary portion between them. The output of the quasi-electrostatic field detection probe 16 changes greatly.

  Hereinafter, an analysis method using the near-field light quasi-electrostatic field analysis apparatus according to the present embodiment will be described with reference to the block diagram shown in FIG.

  First, the semiconductor device 10 to be inspected is placed on the stage 11. Then, the tip of the near-field probe 15 is arranged near the surface of the semiconductor device 10. Further, the detection electrode 16 a of the quasi-electrostatic field detection probe 16 is disposed near the surface of the semiconductor device 10.

  The near-field probe 15 and the detection electrode 16a do not need to be arranged close to each other, and the near-field probe 15 and the detection electrode 16a may be separated from each other. For example, as shown in FIG. 8, the near-field probe 15 may be disposed on the upper surface side of the semiconductor device 10, and the quasi-electrostatic field detection probe 16 may be disposed on the side surface or the lower surface side of the semiconductor device 15.

  Next, the laser light source 13 operates based on a signal from the control unit 20, and the near-field light is irradiated from the near-field probe 15 to the semiconductor device 10. Thereby, a quasi-electrostatic field is generated in the portion irradiated with near-field light. This quasi-electrostatic field instantly spreads along the surface of the semiconductor device 10, and the quasi-electrostatic field detection probe 16 detects the quasi-electrostatic field. A signal corresponding to the intensity of the quasi-electrostatic field detected by the quasi-electrostatic field detection probe 16 is output from the amplifier 18 connected to the quasi-electrostatic field detection probe 16. The image processing unit 19 receives the output signal of the amplifier 18 and generates a luminance signal having an intensity corresponding to the output signal of the amplifier 18.

  On the other hand, the control unit 20 controls the stage driving unit 12 to move the stage 11 in the X-axis direction and the Y-axis direction so that the near-field probe 15 scans the surface of the semiconductor device 10. As the stage 11 moves, the position data of the stage 11 is transmitted from the control unit 20 to the image processing unit 19. Thereby, in the image processing unit 19, the position of the semiconductor device 10 irradiated with the near-field light is associated with the luminance signal, and the movement of the stage 11 in the X-axis direction and the Y-axis direction causes the semiconductor device 10 to move. A surface image is generated. The surface image data is sent to the display device 21, and the surface image of the semiconductor device 10 is displayed on the display device 21.

  FIG. 9 is a diagram schematically showing an image of a semiconductor device (LSI chip) obtained by the quasi-electrostatic field analysis apparatus of this embodiment. Here, an example of an image obtained when the semiconductor device 10 is cut and the near-field probe 15 is arranged on the cut surface is shown. As shown in FIG. 9, according to the quasi-electrostatic field analysis apparatus of this embodiment, it is possible to visualize differences in the cross-sectional shape and impurity diffusion concentration of fine elements. Thereby, for example, an abnormal shape of the impurity diffusion region, an abnormal impurity concentration distribution, or the like can be detected.

  The spatial resolution of the quasi-electrostatic field analysis apparatus according to this embodiment is almost the same as the diameter of the hole of the near-field probe 15 (100 nm or less), and the state of a region smaller than the wavelength of the laser beam can be analyzed. Further, the quasi-electrostatic field analysis apparatus of the present embodiment can also be applied to inspection of a semiconductor device before forming a metal wiring. Further, the quasi-electrostatic field analysis apparatus of the present embodiment can analyze the state of the inspection object without bringing the inspection electrode 16a into contact with the inspection object (semiconductor device 10). Therefore, the quasi-electrostatic field analysis apparatus according to this embodiment is extremely useful for analyzing the cause of failure of a semiconductor device.

  Conventionally, the failure location is narrowed down to the range of 1 μm to 100 μm by the above-mentioned Oberk method or Obic method, and then the failure location is further narrowed down to the range of 10 nm to 1 μm by the electron beam analyzer to analyze the cause of failure of the semiconductor device. The way to do was taken. In contrast to this method, in the analysis method using the quasi-electrostatic field analysis apparatus according to the present embodiment, the failure part can be analyzed in detail without using the electron beam analysis apparatus, and the time required for the analysis is shortened. There is also an advantage of being able to.

(Second Embodiment)
FIG. 10 is a block diagram showing an outline of a quasi-electrostatic field analysis apparatus according to the second embodiment. 10, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the quasi-electrostatic field analysis apparatus according to the present embodiment, a light modulation element 41 is disposed between the laser light source 13 and the optical fiber 14. A reference signal having a frequency f (for example, 10 kHz to 10 MHz) is supplied to the light modulation element 41 from a reference signal source (not shown). The light modulation element 41 modulates the laser light emitted from the laser light source 13 with the frequency f of the reference signal. As a result, the semiconductor device 10 is irradiated with near-field light modulated at the frequency f from the tip of the near-field probe 15. This near-field light generates a quasi-electrostatic field in the semiconductor device 10.

  In the quasi-electrostatic field detection probe 16, the detection electrode 16 a is capacitively coupled to the semiconductor device 10 and detects a quasi-electrostatic field generated in the semiconductor device 10. The output of the quasi-electrostatic field detection probe 15 is connected to a lock-in amplifier 42.

  The lock-in amplifier 42 also receives a reference signal having a frequency f from a reference signal source. The lock-in amplifier 42 extracts a signal component having the same frequency as the reference signal from the output of the quasi-electrostatic field detection probe 16 and outputs the signal component to the image processing unit 19.

  Thus, by operating the light modulation element 41 and the lock-in amplifier 42 in synchronization with the reference signal, the noise component can be removed from the output of the quasi-electrostatic field detection probe 16, and the S / N ratio is improved. To do. Thereby, the quasi-electrostatic field analysis apparatus according to the present embodiment has an advantage that the spatial resolution is further improved as compared with the quasi-electrostatic field analysis apparatus of the first embodiment.

  In the present embodiment, the case where the laser light emitted from the laser light source 13 is modulated using the light modulation element 41 has been described. However, a laser light source capable of direct modulation at the frequency of the reference signal may be used.

  The following additional notes are disclosed with respect to the above embodiments.

(Appendix 1) a light source;
A near-field probe provided with a hole having a size smaller than the wavelength of light emitted from the light source, and irradiating the inspection object with light emitted from the light source through the hole;
A quasi-electrostatic field detection probe for detecting a quasi-electrostatic field generated in the inspection object by capacitive coupling with the inspection object;
A stage on which the inspection object is placed;
A drive unit for moving the stage relative to the near-field probe;
A control unit for controlling the driving unit;
A quasi-electrostatic field analysis apparatus comprising: a signal processing unit that inputs position information of the inspection target from the control unit and performs signal processing in association with the output of the quasi-electrostatic field detection probe.

  (Supplementary note 2) The quasi-electrostatic field analysis apparatus according to supplementary note 1, wherein the quasi-electrostatic field detection probe includes a field-effect transistor, and a gate of the field-effect transistor is capacitively coupled to the inspection object.

  (Supplementary note 3) The quasi-electrostatic field analysis apparatus according to supplementary note 1 or 2, wherein an input capacitance of the quasi-electrostatic field detection probe is 2 pF or less.

(Appendix 4) A light modulation element that is disposed between the light source and the near-field probe and modulates light emitted from the light source;
And a lock-in amplifier that is disposed between the quasi-electrostatic field detection probe and the signal processing unit and processes the output of the quasi-electrostatic field detection probe at the modulation frequency of the light modulation element. The quasi-electrostatic field analysis apparatus according to any one of 1 to 3.

  (Supplementary note 5) The supplementary note 1, wherein the quasi-electrostatic field detection probe includes a detection electrode capacitively coupled to the inspection object, and a dielectric member interposed between the detection electrode and the inspection object. The quasi-electrostatic field analyzer described.

(Appendix 6) A step of placing an inspection object on the stage;
Irradiating the inspection object with light emitted from the light source via a near-field probe provided with a hole having a size smaller than the wavelength of light emitted from the light source;
Detecting a quasi-electrostatic field generated in the inspection object by a quasi-electrostatic field detection probe capacitively coupled to the inspection object;
And a step of associating the position of the inspection object irradiated with the light with the quasi-electrostatic field detected by the quasi-electrostatic field detection probe to perform signal processing, and generating an image of the inspection object. Quasi-electrostatic field analysis method.

  (Additional remark 7) The said near-field probe and the said quasi-electrostatic field detection probe are arrange | positioned on the same surface of the said test object, The quasi-electrostatic field analysis method of Additional remark 6 characterized by the above-mentioned.

  (Supplementary note 8) The quasi-electrostatic field analysis method according to supplementary note 6, wherein the near-field probe and the quasi-electrostatic field detection probe are arranged on different surfaces of the inspection object.

  (Additional remark 9) The light irradiated to the test object via the near-field probe is modulated at a predetermined frequency, and the output of the quasi-electrostatic field detection probe is signal-processed by a lock-in amplifier operating at the predetermined frequency. The quasi-electrostatic field analysis method according to any one of appendices 6 to 8, characterized in that:

  (Appendix 10) The quasi-electrostatic field according to any one of appendices 6 to 9, wherein a member made of a dielectric material is disposed between the detection electrode of the quasi-electrostatic field detection probe and the inspection object. analysis method.

  DESCRIPTION OF SYMBOLS 10 ... Semiconductor device (inspection object), 11 ... Stage, 12 ... Stage drive part, 13 ... Laser light source, 14 ... Optical fiber, 15 ... Near field probe, 16 ... Quasi-electrostatic field detection probe, 16a ... Detection electrode, 17 ... Bias power supply, 18 ... amplifier, 19 ... image processing unit, 20 ... control unit, 21 ... display device, 31 ... inspection object, 32 ... FET, 33 ... member made of dielectric material, 41 ... light modulation element, 42 ... lock In-amp.

Claims (5)

A light source;
A near-field probe provided with a hole having a size smaller than the wavelength of light emitted from the light source, and irradiating the inspection object with light emitted from the light source through the hole;
A quasi-electrostatic field detection probe for detecting a quasi-electrostatic field generated in the inspection object by capacitive coupling with the inspection object;
A stage on which the inspection object is placed;
A drive unit for moving the stage relative to the near-field probe;
A control unit for controlling the driving unit;
A quasi-electrostatic field analysis apparatus comprising: a signal processing unit that inputs position information of the inspection target from the control unit and performs signal processing in association with the output of the quasi-electrostatic field detection probe.   The quasi-electrostatic field analysis apparatus according to claim 1, wherein the quasi-electrostatic field detection probe includes a field effect transistor, and a gate of the field effect transistor is capacitively coupled to the inspection target. A light modulation element that is disposed between the light source and the near-field probe and modulates light emitted from the light source;
And a lock-in amplifier disposed between the quasi-electrostatic field detection probe and the signal processing unit and performing signal processing on the output of the quasi-electrostatic field detection probe at a modulation frequency of the light modulation element. Item 3. The quasi-electrostatic field analysis device according to Item 1 or 2.   The quasi-electrostatic field detection probe includes a detection electrode capacitively coupled to the inspection object, and a dielectric member interposed between the detection electrode and the inspection object. Electrostatic field analyzer. A process of placing an inspection object on the stage;
Irradiating the inspection object with light emitted from the light source via a near-field probe provided with a hole having a size smaller than the wavelength of light emitted from the light source;
Detecting a quasi-electrostatic field generated in the inspection object by a quasi-electrostatic field detection probe capacitively coupled to the inspection object;
And a step of associating the position of the inspection object irradiated with the light with the quasi-electrostatic field detected by the quasi-electrostatic field detection probe to perform signal processing, and generating an image of the inspection object. Quasi-electrostatic field analysis method.

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