JP6868084B2 - Image generation method, image generation device, image generation program and recording medium - Google Patents

Description

The present invention relates to an image generation method, an image generation device, an image generation program, and a recording medium.

Conventionally, for inspection of a semiconductor device, a detection device for detecting the strength of a current or a portion where a current is flowing in the semiconductor device has been known. For example, Patent Document 1 discloses a non-destructive analysis device that detects magnetism induced by an electric current generated from a semiconductor device using a magnetic detector (superconducting quantum interfering element: SQUID). In this device, the semiconductor device is irradiated with a modulation beam whose intensity is modulated by a modulation signal synchronized with the reference signal. Then, a phase difference image is obtained based on the detection signal and the reference signal output from the magnetic detector. Further, Non-Patent Document 1 discloses a method of obtaining the current density in the plane direction from the magnetic flux density detected by a magnetic detector such as SQUID. In Non-Patent Document 1, a method is proposed in which the relationship between a current and a magnetic field is mathematically expressed using Biot-Savart's law, and the current density is obtained from the magnetic field.

Japanese Unexamined Patent Publication No. 2005-134196

Bradley J. Roth, Nestor G. Sepulveda, and John P. Wikswo, Jr., “Using a magnetometer to image atwo-dimensional current distribution,” J. Appl. Phys., 65 (1), 1 January 1989.

However, in Patent Document 1, the difference between a good product and a defective product is simply discriminated with high sensitivity by using a phase difference image. Further, Non-Patent Document 1 only discloses a theoretical formula for obtaining the current density from a magnetic field. As described above, neither document discloses a method or the like for determining the direction in which a current flows in a semiconductor device. Therefore, an object of the present invention is to provide an image generation method and an image generation device capable of generating a current direction image which is an image showing the direction of a current in a semiconductor device.

The image generation method according to one aspect is an image generation method that generates an image indicating the direction of the current flowing through the semiconductor device, and detects a step of applying a stimulus signal to the semiconductor device and a magnetism generated by the application of the stimulus signal. Then, the step of outputting the detection signal, the step of generating the phase image data including the phase component indicating the phase difference based on the phase difference between the reference signal and the detection signal generated based on the stimulation signal, and the phase. It includes a step of generating a current direction image indicating the direction of the current based on the image data.

Further, the image generator according to one aspect is an image generator that acquires an image indicating the direction of the current flowing through the semiconductor device, and is generated by a signal application unit that applies a stimulus signal to the semiconductor device and an application of the stimulus signal. Based on the phase difference between the reference signal and the detection signal generated based on the stimulation signal and the magnetic detection unit that outputs the detection signal based on the magnetism, the phase image data including the phase component indicating the phase difference is generated. , An image generation unit that generates a current direction image indicating the direction of the current based on the phase image data.

Further, the image generation program according to one aspect is a program for causing a computer to execute a process of acquiring an image indicating the direction of the current flowing through the semiconductor device by applying a stimulus signal to the semiconductor device. , A phase image data generator that generates phase image data including a phase component indicating the phase difference from the phase difference between the detection signal based on the magnetism generated by the application of the stimulation signal and the reference signal generated based on the stimulation signal. And, it functions as an image generation unit that generates a current direction image indicating the direction of the current based on the phase image data. The recording medium according to the other aspect is a computer-readable recording medium for recording an image generation program.

In this image generation method, image generation device, and image generation program, magnetism is generated by a stimulus signal applied to a semiconductor device. Then, based on the phase difference between the reference signal generated based on the stimulus signal and the detection signal based on magnetism, phase image data including a phase component indicating the phase difference is generated. Since the phase difference changes depending on the direction of the magnetic field, the phase image data includes information on the direction of the magnetic field. Since the direction of the magnetic field is determined by the direction of the current, it is possible to determine the direction of the current based on the phase image data. This makes it possible to generate an image showing the direction of the current using the determined direction of the current.

In one form, the current direction image may be configured such that the direction of the current is indicated by a plurality of colors set according to the direction. With such a configuration, the position and direction of the electric current can be easily grasped visually.

In one form, the plurality of colors may have at least different colors set for each of the four angular ranges divided according to the direction of the electric current. In general, the current path in a semiconductor device is often designed in the X-axis direction and the Y-axis direction in a plan view. In this case, there are four current directions: the X direction, the −X direction, the Y direction, and the −Y direction. Having at least four different colors as in the above configuration makes it easier to identify the four directions.

In one form, the step of generating the current direction image may include a step of changing the correspondence between the direction of the current and the plurality of colors. For example, the image generation unit has a color table having data of a plurality of colors and an angle table having data of an angle range divided according to the direction of the current, and the correspondence between the color table and the angle table. It may be a configuration in which the relationship can be changed. According to this configuration, for example, even when the orientation of the obtained image is tilted, the color scheme can be easily adjusted.

In one form, data is generated by adding data in the magnetic direction based on the phase image data to the intensity image data indicating the magnetic intensity generated from the detection signal, and the current indicating the current intensity based on the data is generated. The configuration may further include a step of generating an intensity image. In this case, the configuration may further include a step of generating a current image showing the current intensity and direction based on the current intensity image and the current direction image. In this case, the image generation unit generates data in which magnetic direction data based on the phase image data is added to the intensity image data indicating the magnetic intensity generated from the detection signal, and the current is generated based on the data. It may be configured to generate a current intensity image showing the intensity of. The magnetic strength corresponds to the magnitude of the electric current. Therefore, the magnitude of the current can be expressed in the image by adding the data in the magnetic direction to the intensity image data.

In one form, the step of generating a current direction image indicating the direction of the current is to add data in the magnetic direction based on the phase image data to the intensity image data indicating the magnetic intensity generated from the detection signal. It may be generated and a current direction image may be generated based on the data. In this case, the image generation unit generates data in which magnetic direction data based on the phase image data is added to the intensity image data indicating the magnetic intensity generated from the detection signal, and the current is based on the data. It may be configured to generate a directional image. By using the data including both the phase component and the magnetic intensity information, it is possible to obtain a current direction image showing the direction of the current with higher accuracy.

In one form, the magnetic detection unit irradiates the magneto-optical crystal with a light source that generates light, a magneto-optical crystal arranged opposite to the semiconductor device, and an irradiation that guides the light reflected from the magneto-optical crystal. The configuration may include an optical system and an optical detector that detects the light reflected from the magneto-optical crystal and outputs a detection signal.

According to this image generation method and the image generation device, it is possible to generate a current direction image which is an image showing the direction of the current in the semiconductor device.

It is a block diagram of the inspection apparatus which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the optical division optical system in the inspection apparatus of FIG. It is a figure for demonstrating the phase difference. It is a figure for demonstrating the outline of the procedure for obtaining a current image. It is an image which shows an example of an intensity image. It is an image which shows an example of a phase image. It is a figure for demonstrating the procedure for acquiring a current intensity image and a current direction image. It is a figure for demonstrating the procedure for acquiring a current intensity image and a current direction image. It is an image which shows an example of a current intensity image. It is an image which shows an example of the current direction image. It is a figure explaining the color assignment in the current direction image. It is a table showing the relationship between the angle and the color. It is a figure explaining the contrast adjustment of the current direction image by the current intensity image. It is an image which shows an example of a current image. It is a figure which shows an example of a color scheme adjustment screen. It is a figure for demonstrating the procedure for acquiring a current direction image. It is an image which shows an example of a current intensity image. It is an image which shows an example of a current image. It is a figure for demonstrating the procedure for acquiring a current intensity image. It is a figure for demonstrating the procedure for acquiring a current intensity image. It is an image which shows an example of a current intensity image. It is a figure which shows an example of the recording medium which records an image generation program.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 1, the image generation device 1 according to the present embodiment can be used for inspection of the semiconductor device D, for example, by identifying an abnormality occurrence location in the semiconductor device D. The image generation device 1 obtains the direction of the current flowing through the semiconductor device D by applying a stimulus signal to the semiconductor device D, and generates an image showing the direction of the current flowing through the semiconductor device D.

The semiconductor device D includes an integrated circuit having a PN junction such as a transistor (for example, a small integrated circuit (SSI: Small Scale Integration)), a medium scale integrated circuit (MSI: Medium Scale Integration), and a large scale integrated circuit (LSI: Large). Scale Integration), Very Large Scale Integration (VLSI), Ultra Large Scale Integration (ULSI), Giga Scale Integration (GSI), Large Current / High Pressure There are MOS transistors and bipolar transistors for power, semiconductor elements for power (power devices), and the like. Further, the semiconductor device D may be a package including the semiconductor device, a composite substrate, or the like.

A tester unit 11 (signal application unit) is electrically connected to the semiconductor device D via a device control cable. The tester unit 11 is operated by a power source (not shown) and applies a predetermined modulated current signal (stimulation signal) to the semiconductor device D. In the semiconductor device D, a modulated magnetic field is generated along with the modulated current signal. By detecting the light intensity-modulated according to the modulated magnetic field by the photodetector 22 described later, it is possible to detect the light modulated at a specific frequency. In this case, lock-in detection may be performed by generating light corresponding to the detection frequency from the light source 13 (described later) while applying the modulation current signal from the tester unit 11 to the semiconductor device D. The S / N can be improved. The tester unit 11 is electrically connected to the frequency analysis unit 12 via a timing signal cable. A modulated voltage signal may be applied as the stimulation signal.

The image generation device 1 includes a light source 13. The light source 13 is operated by a power source (not shown) to generate and output CW light or pulsed light irradiated to the MO crystal 18 (magneto-optical crystal) and the semiconductor device D, which will be described later. The light output from the light source 13 may be incoherent (non-coherent) light or coherent light such as laser light. As the light source 13 that outputs incoherent light, SLD (Super Luminescent Diode), ASE (Amplified SpontaneousEmission), LED (LightEmitting Diode) and the like can be used. When the light output from the light source 13 is incoherent light, it is possible to reduce the interference noise generated between the reflected light in the MO crystal 18 and the reflected light in the semiconductor device D. The reflected light in the MO crystal 18 includes both the reflected light on the light incident surface of the MO crystal 18 and the reflected light on the light reflecting surface of the MO crystal 18. The influence of the reflected light on the light incident surface of the MO crystal 18 may be reduced by applying antireflection processing to the light incident surface.

Further, as the light source 13 that outputs coherent light, a solid-state laser light source, a semiconductor laser light source, or the like can be used. The wavelength of the light output from the light source 13 is 530 nm or more, preferably 1064 nm or more. The light output from the light source 13 is guided to the optical division optical system 14 via a polarization-preserving single-mode optical coupler (not shown) and a polarization-preserving single-mode optical fiber for probe light. The details of the optical division optical system 14 will be described later. The light guided from the light source 13 to the optical division optical system 14 is further guided to the irradiation optical system including the optical scanner 15 and the objective lens 16. The optical scanner 15 and the objective lens 16 which are irradiation optical systems irradiate the MO crystal 18 with the light output from the light source 13.

The optical scanner 15 scans the irradiation spot on the light incident surface of the MO crystal 18. More specifically, the optical scanner 15 scans the irradiation spot by being controlled by a computer 24 described later. The optical scanner 15 is composed of optical scanning elements such as a galvano mirror and a MEMS (micro electro mechanical system) mirror.

The objective lens 16 concentrates the light guided by the optical scanner 15 on the MO crystal 18. The objective lens 16 is configured to be able to switch between a low-magnification objective lens and a high-magnification objective lens by means of a turret (not shown) or the like. The magnification of the low-magnification objective lens is, for example, 5 times, and the magnification of the high-magnification objective lens is, for example, 50 times. An objective lens driving unit 17 is connected to the objective lens 16. The focal position of the objective lens 16 can be adjusted by moving the objective lens driving unit 17 in the optical axis direction OD of the light from the light source 13.

The MO crystal 18 is arranged so as to face the semiconductor device D. Due to the magneto-optical effect, the refractive index of the MO crystal 18 changes according to the magnetic field generated by the semiconductor device D, and the polarization state (polarization direction) of the incident light is changed. For example, when a modulation current signal is applied to the semiconductor device D at the time of failure of the semiconductor device D, a current path through which a leak current flows according to the failure location may be generated. In this case, a magnetic field different from the location where the leak current is generated is generated at the location where the leak current is generated. The MO crystal 18 emits reflected light whose polarization direction has changed in response to such a change in the magnetic field. The difference in the polarization direction of the reflected light appears as a difference in the intensity of light acquired by the photodetector 22 described later. The reflected light in the MO crystal 18 is returned to the optical division optical system 14 via the objective lens 16 and the optical scanner 15, and is guided to the photodetector 22 via the optical fiber for the return light. With such a configuration, a magnetic detector for detecting magnetism is configured.

Here, the MO crystal 18 is connected to the holder 19 that holds the MO crystal 18 via the flexible member 21. The flexible member 21 is a ring-shaped elastic member including, for example, rubber or a spring. Further, the flexible member 21 may be a member whose shape is deformed, and may not necessarily be an elastic member. The flexible member 21 is fixed to the MO crystal 18 so as to cover at least a part of the outer edge of the MO crystal 18 when viewed from the optical axis direction OD. The flexible member 21 is fixed to the light incident surface side of the MO crystal 18. Further, the holder 19 has a ring shape, for example, and is fixed to the flexible member 21 so as to cover the outer edge of the flexible member 21 when viewed from the optical axis direction OD. Therefore, one surface of the flexible member 21 is fixed to the MO crystal 18, and the other surface of the flexible member 21 is fixed to the holder 19. Since the ring-shaped flexible member 21 covers the outer edge of the MO crystal 18 and the ring-shaped holder 19 covers the outer edge of the flexible member 21, the light incident of the MO crystal 18 is viewed from the optical axis direction OD. An opening for inputting light from the objective lens 16 is formed on the surface. A holder drive unit 20 is connected to the holder 19.

The holder drive unit 20 moves the holder 19 in the optical axis direction OD by moving in the optical axis direction OD. By moving the holder drive unit 20 in the optical axis direction OD, the distance between the holder 19 and the semiconductor device D is shortened, and the MO crystal 18 is pressed against the semiconductor device D. That is, the MO crystal 18 can come into contact with the semiconductor device D. The light irradiation of the MO crystal 18 is performed in a state where the MO crystal 18 is in contact with the semiconductor device D. The light irradiation of the MO crystal 18 is not limited to the state of being in contact with the semiconductor device D, and may be performed in a state of having a predetermined distance between the MO crystal 18 and the semiconductor device D. .. Further, the objective lens driving unit 17 and the holder driving unit 20 may be integrated. In this case, the integrated configuration may have a mechanism for individually moving the objective lens 16 and the holder 19.

The photodetector 22 detects the reflected light from the MO crystal 18 in contact with the semiconductor device D according to the irradiated light, and outputs a detection signal. The photodetector 22 is, for example, a photodiode, an avalanche photodiode, a photomultiplier tube, an area image sensor, or the like. The photodetector 22 has at least one detector and detects the intensity of the light input to the detector.

Here, the optical division optical system 14 will be described with reference to FIG. The optical splitting optical system 14 includes collimators 141 and 146, a shutter 142, a deflecting beam splitter (hereinafter referred to as PBS: Polarization Beam Splitter) 143, and a Faraday rotator (hereinafter referred to as FR: Faraday Rotator) 144. It is composed of. As shown in FIG. 2, when the light from the light source 13 is applied to the MO crystal 18 via the optical scanner 15, the light from the light source 13 is first input to the shutter 142 via the collimator 141. .. The shutter 142 may be any as long as it can control ON / OFF of light. Then, the light output from the shutter 142 is input to the PBS 143. The PBS 143 is set so that the polarization component transmits 0 degree light and reflects 90 degree light. Further, the PBS 143 is set according to the polarization of the light from the shutter 142. Therefore, PBS 143 transmits the light from the shutter 142. Light having a polarization component of 0 degrees transmitted through PBS143 is input to FR144 which tilts (rotates) the polarization plane of the input light by 22.5 degrees, and the polarization component becomes 22.5 degrees. The light transmitted through the FR 144 is input to the optical scanner 15 as light having a polarization component of 22.5 degrees. The light irradiates the MO crystal 18.

The plane of polarization of the reflected light from the MO crystal 18 rotates according to the magneto-optical effect (Kerr effect, Faraday effect, etc.) proportional to the magnetic field (magnetic field strength) generated by the modulated current signal applied to the semiconductor device D. ing. The reflected light is tilted by 22.5 degrees on the plane of polarization by FR144 and input to PBS143. The reflected light is divided into light having a polarization component of 90 degrees and light having a polarization component of 0 degrees by PBS 143. Light having a polarization component of 90 degrees is reflected by PBS 143 and input to the detector of photodetector 22 via a collimator 146. In this way, the photodetector 22 detects the change in the polarizing surface according to the magnetic field (magnetic field intensity) generated in the semiconductor device D as the light intensity, and detects the detection signal of the intensity (amplitude) according to the light intensity. Output to the amplifier 23. Although only one PBS 143 is provided as the optical splitting optical system 14, the configuration of detecting only light having a polarization component of 90 degrees among orthogonal linearly polarized light has been described, but the present invention is not limited to this. That is, the optical division optical system 14 includes FR that tilts the polarization plane of the input light by 45 degrees between PBS 143 and FR 144, PBS that transmits the light of 45 degrees and reflects the light of 135 degrees, and a collimeter. And, both of the orthogonal linearly polarized light, that is, the light having a polarization component of 90 degrees and the light of 0 degrees may be captured and differentially detected. Further, a half mirror may be used as the optical division optical system 14.

Returning to FIG. 1, the amplifier 23 amplifies and outputs the detection signal output by the photodetector 22. The detected signal after the amplification is input to the frequency analysis unit 12. As the frequency analysis unit 12, a lock-in amplifier, a spectrum analyzer, a digitizer, a cross domain analyzer (registered trademark), or the like is used. The frequency analysis unit 12 extracts the measurement frequency component in the detected signal after amplification. The measurement frequency is set based on, for example, the modulation frequency of the modulation current signal applied to the semiconductor device D. Further, the frequency analysis unit 12 acquires a reference signal having the same period as the modulation current signal applied to the semiconductor device D. The reference signal is, for example, output from the tester unit 11 and input to the frequency analysis unit 12.

The frequency analysis unit 12 derives the phase difference between the detection signal from which the measurement frequency component is extracted and the acquired reference signal. As described above, the amplitude of the detection signal changes according to the magnetic field (magnetic field strength) generated in the semiconductor device D. Then, the frequency analysis unit 12 can specify the phase difference between the detection signal and the reference signal based on the amplitude of the detection signal. Here, the phase difference between the detection signal and the reference signal related to the reflected light at the current path location has a specific value. Specifically, the specific value is substantially one of two values depending on the positive and negative directions in which the magnetic field generated in response to the current penetrates the MO crystal 18. As shown in FIG. 3, the reference signal has the same period as the stimulation signal by the frequency analysis unit 12. Further, the phase difference between the detection signal at the current path location and the reference signal (hereinafter, may be referred to as current phase difference) is constant over a plurality of cycles. Specifically, the current phase difference is a value obtained by adding the phase difference θ1 between the reference signal and the stimulus signal and the phase difference θ2 between the stimulus signal and the detection signal. The phase difference θ1 can be changed by setting the frequency analysis unit 12 that generates the reference signal. In order to obtain the current phase difference more easily, it is preferable that the phase of the reference signal and the phase of the stimulation signal are equal to each other and the phase difference θ1 is zero. The phase difference θ2 is one of two values that differ by 180 degrees (π) depending on the positive and negative directions in which the magnetic field generated according to the current penetrates the MO crystal. That is, the phase difference θ2 between the detection signal and the stimulation signal at the current path location where the magnetic field direction is positive and the phase difference θ2 between the detection signal and the stimulation signal at the current path location where the magnetic field direction is negative are 180 degrees ( π) It is different. On the other hand, the phase difference between the detection signal and the reference signal other than the current path location in the semiconductor device D does not become a specific value but a random value. The frequency analysis unit 12 outputs an analysis signal including information indicating the specified phase difference to the computer 24 (image generation unit). Further, the frequency analysis unit outputs a detection signal of intensity (amplitude) according to the light intensity input from the amplifier 23 to the computer 24.

The computer 24 is, for example, a PC or the like. The computer 24 is connected to an input device 26 such as a keyboard or mouse into which measurement conditions and the like are input by the user, and a display device 25 such as a display for showing the measurement result and the like to the user. The computer 24 includes a CPU (Central Processing Unit) which is a processor, a RAM (RandomAccess Memory) or ROM (Read Only Memory) which is a recording medium, and an input / output module. The computer 24 is electrically connected (coupling) to a light source 13, an optical scanner 15, an objective lens driving unit 17, a tester unit 11, a photodetector 22, a frequency analysis unit 12, and the like via an input / output module, and is a CPU. Perform functions that control them.

The computer 24 generates an amplitude image, a phase image, a current intensity image, a current direction image, and a current image by executing an image generation program P1 (described later) recorded on a recording medium on a CPU. As shown in FIG. 4, the computer 24 first generates an amplitude image (intensity image) and a phase image based on the measurement data (step S1). In the present embodiment, the measurement data includes the data of the detection signal detected from the photodetector 22 and the data of the analysis signal output from the frequency analysis unit 12. The amplitude image shows the strength of the magnetic field (magnetic flux density), and the phase image shows the direction of the magnetic field. Next, the computer 24 generates a current intensity image showing the current intensity (current density) based on the amplitude image and the phase image (step S2). In the current intensity image, for example, the intensity of the current is indicated by the brightness (luminance). Further, the computer 24 generates a current direction image indicating the direction of the current based on the amplitude image and the phase image (step S3). In the current direction image, for example, the direction of the current is indicated by color. Next, the computer 24 generates a current image showing the current intensity and direction based on the current intensity image and the current direction image (step S4).

The method of generating the amplitude image, the phase image, the current intensity image, the current direction image, and the current image will be specifically described below.

[Generation of amplitude image]
The computer 24 maps the light intensity for each irradiation spot based on the light intensity (amplitude) of the detection signal and the information of the irradiation spot on the light incident surface of the MO crystal 18, and generates an amplitude image. The amplitude image is an image in which the light intensity is mapped with a predetermined brightness value according to the light intensity. Therefore, although the amplitude image shows the strength of the magnetic field (magnetic flux density), it does not show the direction of the magnetic field. The correspondence between the light intensity and the brightness value is, for example, that the brightness value is 0 a.u. When the light intensity is 0, and the brightness value is 32000 a.u. When the light intensity is maximum. That is, as shown in FIG. 5, in the amplitude image, the larger the magnetic field strength is, the closer to white is drawn, and the smaller the magnetic field strength is, the closer to black is drawn. The computer 24 generates amplitude image data including the light intensity corresponding to each irradiation spot. In the amplitude image data, the light intensity corresponding to each irradiation spot is mapped to the position (reference pixel) in the image considering the position of each irradiation spot.

[Generation of phase image]
The computer 24 maps the phase component for each irradiation spot and generates a phase image based on the phase difference (phase component) included in the analysis signal and the information of the irradiation spot on the light incident surface of the MO crystal 18. .. The phase image is an image in which the phase difference is mapped with a predetermined luminance value according to the phase difference. Regarding the correspondence between the phase difference and the brightness value, for example, when the phase difference is −π, the brightness value is 0 a.u., and when the phase difference is 0, the brightness value is 16000 a.u. When the phase difference is + π, the luminance value is 32000 a.u. That is, as shown in FIG. 6, in the phase image, the closer the phase difference is to −π, the blacker it is drawn, and the closer the phase difference is to π, the whiter it is drawn. The computer 24 generates phase image data including a phase component corresponding to each irradiation spot. In the phase image data, the phase component corresponding to each irradiation spot is mapped to the position (reference pixel) in the image considering the position of each irradiation spot.

[Generation of current intensity image and current direction image]
In the present embodiment, a current intensity image and a current direction image are generated based on Biot-Savart's law represented by the equation (1).

As shown in FIG. 7, a principle for generating a current intensity image and a current direction image will be described using a semiconductor device having a thickness d as a model. In this example, the surface of the semiconductor device is defined as the xy plane, and the thickness direction of the semiconductor device is defined as the z-axis (the device surface is 0). Let B (r) be the magnetic flux density at the position r (x, y, z) in space. The position r is a constant distance from the surface of the device in the z-axis direction, and this distance is assumed to be sufficiently smaller than the thickness d of the device. Further, let J (r') be the current density at the point r'(x', y', 0) on the device surface that affects the magnetic field at the position r. In this case, the magnetic flux density B (r), the current density J (r'), and the distance r-r'from the position r to the point r'are as shown in FIG. In this model, only the z-axis magnetic flux at position r is detected as a detection signal. Therefore, the Biot-Savart law is expanded only in the z-axis direction to obtain Eq. (2).

On the other hand, assuming that the current is steady and there is no divergence or extinction, the sum of the surface current gradients is zero, and equations (3) to (4) can be obtained.

Thereby, the current density J (r') can be calculated by using the equations (2) and (4) and the measured magnetic flux density B (r). Hereinafter, a specific calculation flow will be described. As shown in FIG. 8, first, the computer 24 obtains an amplitude image as _{the magnetic flux density B z (absolute value) in the z-axis direction (step S11).} Next, the computer 24 uses the generated phase image to add positive and negative signs to the amplitude image _{to construct a magnetic flux density B z'including} information on the direction of the magnetic flux (step S12). In the present embodiment, for example, as shown in equation (5), the amplitude value of the reference pixel A _p, the phase values and P _p, the phase component of the phase image is "positive" space to 0~π , -Π to 0 is defined as "negative", and positive and negative signs are added to the amplitude image of the corresponding reference pixel.

Next, the computer 24 obtains a two-dimensional spectrum by Fourier transforming the _{constructed magnetic flux density B z'(step S13).} Then, according to the equation (4), the spectrum obtained in step S13 is decomposed into a spectrum jx (u, v) in the x-axis direction and a spectrum j _y (u, v) in the y-axis direction (step S14). .. Next, the obtained spectrum j _x (u, v) and the spectrum j _y (u, v) in the _{y-axis direction are inverse-Fourier-transformed to obtain a current density J x in the x-} axis direction and a current density J _{y in the y-axis direction.} Is obtained (step S15). Subsequently, the current intensity image data can be obtained by substituting the obtained real part of the current density J _{x and} the real part of the current density J _{y into the equation (6) (step S17).} In the current intensity image data, the position information of each reference pixel and the current intensity at the position are associated with each other. Further, by substituting the real part of the obtained current density J _{x and} the real part of the current density J _y into the equation (7), the current direction image data can be obtained (step S18). In the current direction image data, the position information of each reference pixel and the current direction at the position are associated with each other. The current direction is defined in the range of −π to π, with an arbitrary direction on the plane of the reference pixel (in the embodiment, the right direction in the image to be drawn) as the 0 degree direction.

In step S12, an I image (cosine image) and a Q image (sine image) may be constructed from the amplitude image and the phase image, and these may be Fourier transformed as _{B z'.} That is, the amplitude value of the reference pixel A _p, the phase values and P _p, I picture is calculated by the equation (8), Q image is calculated by the equation (9). The Fourier transform is a reversible mapping from a complex number to a complex number (so-called orthogonal transform). Therefore, I _p + iQ _p is set as B _{z'and is used} as the input of the Fourier transform. _{By constructing B z'in} this way, the time phase information can be retained, so that the phase lag can be detected.

The computer 24 maps the value of the current intensity image data for each reference pixel based on the obtained current intensity image data and the position information of the reference pixel, and generates a current intensity image. The current intensity image of the present embodiment is an image in which the current intensity is mapped with a predetermined luminance value according to the current intensity. Regarding the correspondence between the current intensity and the brightness value, for example, when the brightness value is represented by 16 bits, the brightness value is set to 0a.u. When the current intensity is 0, and the brightness value is 65535a when the current intensity is maximum. It is said to be .u. As shown in FIG. 9, in the current intensity image, the higher the current intensity (current density), the closer to white it is drawn.

The computer 24 maps the current direction image data for each reference pixel based on the obtained current direction image data and the position information of the reference pixel, and generates a current direction image. The current direction image (see FIG. 10) of the present embodiment is an image in which the current direction is mapped with a predetermined color according to the current direction. The correspondence between the current direction and the color is determined by assigning different colors to the angle range divided into a predetermined range. In the present embodiment, for example, as shown in FIG. 11, different colors are assigned to the angle ranges divided into four ranges. In this example, "red" is assigned to the range where the current direction is −π / 4 to π / 4. "Yellow" is assigned to the range where the current direction is π / 4 to 3π / 4. "Green" is assigned to the range where the current direction is 3π / 4 to π and −π3 / 4 to −π. Further, "cyan" is assigned to the range where the current direction is -3π / 4 to −π / 4. In this example, the colors indicating opposite directions have a complementary color relationship (red and green, yellow and cyan). The computer 24 may have, for example, a table in which the current direction and the color correspond to each other as shown in FIG. 12 (a). This table has an angle table in which the current direction is defined as an angle, and a color table in which colors corresponding to the angle range are defined. The angle table and the color table have a one-to-one correspondence, for example. In this case, the computer 24 can determine the color corresponding to the current direction by referring to the table.

For example, if the current in the reference pixel flows to the right in the image, the reference pixel is mapped in "red" corresponding to the current direction 0. When the current in the reference pixel flows upward in the image, the reference pixel is mapped in "yellow" corresponding to the current direction π / 2. If the current in the reference pixel flows to the left in the image, the reference pixel is mapped in "green" corresponding to the current direction π or −π. When the current in the reference pixel flows downward, the reference pixel is mapped with "cyan" corresponding to the current direction −π / 2. As shown in FIG. 10, in the current direction image, the regions drawn by yellow and cyan extend in the vertical direction in the image. In addition, the areas drawn by red and green extend in the left-right direction in the image. Further, since the portion that looks like a marble pattern is a region where no current path exists, it is randomly drawn by red, yellow, green, and cyan.

[Generation of current image]
The computer 24 generates a current image (current image data) indicating the current intensity and direction based on the obtained current intensity image (current intensity image data) and current direction image (current direction image data). For example, a current image is generated by combining a current intensity image and a current direction image. In the generation of the current image, the contrast enhancement by the brightness value of the current intensity image is added to the color forming the current direction image. That is, the color of the current direction image has a brightness corresponding to the brightness value of the current intensity image. For example, the computer 24 refers to the color in the reference pixel from the current direction image, and generates the brightness in the reference pixel from the brightness value of the current intensity image. The brightness is generated, for example, by associating the maximum luminance value (65535) in the current intensity image with the maximum luminance (255) of the color and the minimum luminance value (0) with the minimum brightness (0). To. For example, as shown in FIG. 13, when the color of the reference pixel is “yellow”, the brightness corresponding to the brightness value of the reference pixel is assigned. In this example, the values of R and G, which are the color components constituting "yellow" in RGB, are the values corresponding to the luminance value. That is, the values of R and G in the reference pixel are values obtained by multiplying 255 by the ratio of the brightness value of the reference pixel to the maximum brightness value. A current image is generated by mapping all reference pixels with contrast-enhanced colors. The current image may be displayed on the display device 25. In the above example, the maximum luminance value in the current intensity image corresponds to the maximum brightness of the color, and the minimum luminance value corresponds to the minimum brightness, but this is not the case. The user may freely change the correspondence according to the brightness distribution of the current intensity image so as to make it easier to see. For example, when the brightness of the current intensity image is distributed more toward the maximum brightness value, a brightness value larger than the minimum brightness value may correspond to the minimum brightness. Further, for example, when the brightness of the current intensity image is distributed more toward the minimum brightness value, a brightness value smaller than the maximum brightness value may be associated with the maximum brightness.

In the current image shown in FIG. 14, the region where the current density is small (the portion drawn in black in FIG. 9) in the current intensity image (see FIG. 9) is drawn in a color close to black. Further, in the region where the current density is high (the portion drawn in white in FIG. 9), the color of the current direction image is easily recognized. This makes it easier to check the current flowing in the vertical direction (cyan, yellow) and the current flowing in the horizontal direction (red, green) in the image as compared with the current direction image.

In the present embodiment, the color scheme can be changed (adjusted) before and after the generation of the current image. As shown in FIG. 15, for example, the computer 24 displays the operation icon 202 on the display device 25 together with the generated current image 201. In the operation icon 202 of the illustrated example, four different arrow images 202a, 202b, 202c, and 202d are drawn in a circle. The arrow images 202a, 202b, 202c, and 202d are drawn in different colors. Further, the arrow images 202a, 202b, 202c, and 202d indicate different directions. The respective colors and directions in the arrow images 202a, 202b, 202c, and 202d correspond to the relationship between the colors and the current direction in the current direction image. Therefore, in the case of the correspondence shown in FIGS. 11 and 12 (a), the arrow image 202a showing the right is drawn in red, the arrow image 202b showing the top is drawn in yellow, and the arrow image 202c showing the left is drawn. The arrow image 202d, drawn in green and pointing down, is drawn in cyan. Further, the operation icon 202 is drawn with a line 203 that divides the inside of the circle into an angle range in the current direction corresponding to each arrow image.

When there is an input from the input device 26 (for example, an operation with a mouse or an input of a rotation angle), the computer 24 rotates and displays the operation icon 202 according to the input operation. Then, the computer 24 changes the correspondence between the current direction and the color so as to correspond to the input operation. For example, when the initial state is the correspondence shown in FIG. 12A, it is assumed that the operation icon 202 is rotated 90 degrees (−π / 2) clockwise by the operation of the mouse. In this case, as shown in FIG. 12 (b), the table is updated so that the color table is deviated by −90 degrees with respect to the angle table. Then, the computer 24 refers to the updated table to generate a current direction image. As a result, the display device 25 displays the current image 201 changed to the updated color scheme. The rotation operation of the operation icon 202 may be performed in a state where the current intensity image and the current direction image are displayed on the display device 25. Further, the current image 201 may be rotated by the input from the input device 26. In this case, the table may be updated according to the rotation angle of the current image 201. For example, when the current image 201 is rotated 90 degrees counterclockwise, it is updated to the table shown in FIG. 12 (b).

Next, a modification relating to the generation of the current direction image and the current intensity image will be described. Instead of the method for generating the current direction image and the current intensity image in the above-described embodiment, the method in the following modification can be used. Further, in the present embodiment, the current image can be generated not only by the method exemplified in the present specification but also by the current direction image and the current intensity image generated by other methods.

[Modification 1 related to generation of current direction image]
The phase value in the phase image takes a negative value on the right side of the reference pixel and a positive value on the left side of the reference pixel with respect to the current direction of the reference pixel. Therefore, the current direction image can be obtained by obtaining the gradient vector with respect to the direction of the negative phase value from the positive phase value in the phase image and rotating the gradient vector by 90 degrees. As shown in FIG. 16A, in this modification, the phase image P is scanned by a window region W of a predetermined size. Then, within the range of the window region W, the current direction at the center (reference pixel) of the window region is calculated. In the window area W, as shown in FIG. 16B, the window area W is divided into left and right halves, and the left and right gradient vectors are calculated. When the sum of the phase values of the left half is L and the sum of the phase values of the right half is R, the gradient x is obtained by the equation (10).

Further, as shown in FIG. 16C, the window area W is divided into upper and lower halves, and the upper and lower gradient vectors are calculated. When the sum of the phase values of the upper half is T and the sum of the phase values of the lower half is B, the gradient y is obtained by the equation (11).

Then, a two-dimensional gradient vector (x, y) can be obtained from the equations (10) and (11). In this modified example, in order to improve the accuracy of the calculated current direction image, the calculation is further performed in the oblique direction.

As shown in FIG. 16D, the window area W is divided in half by the upper left and the lower right, and a gradient vector from the upper left to the lower right is calculated. When the sum of the phase values in the upper left half is LT and the sum of the phase values in the lower right half is RB, the gradient u is obtained by the equation (12).

Further, as shown in FIG. 16E, the window area W is divided in half by the lower left and the upper right, and a gradient vector from the lower left to the upper right is calculated. When the sum of the phase values in the lower left half is LB and the sum of the phase values in the upper right half is RT, the gradient v is obtained by the equation (13).

Then, a two-dimensional gradient vector (u, v) can be obtained from the equations (12) and (13). By rotating this gradient vector (u, v) by 45 degrees, a two-dimensional gradient vector (u', v') can be obtained. The two-dimensional gradient vector (u', v') and the two-dimensional gradient vector (x, y) give the gradient vector (x + u', y + v') in the reference pixel.

Then, this gradient vector (x + u', y + v') is calculated as in the equation (7). Since the gradient vector has a deviation of 90 degrees from the current direction, the current direction can be obtained by Eq. (14). By plotting the obtained current direction for each reference pixel, a current direction image can be obtained.

[Modification 1 related to generation of current intensity image]
In this modification, the current intensity image is generated based on Biot-Savart's law, as in the above embodiment. Unlike the above embodiment, in this modified example, the residual is minimized by the gradient method instead of using the equation (4). That is, the magnetic flux density is calculated by substituting _{the appropriate values of current densities J x} and J _y into the mathematical formula derived from Biot-Savart's law. The calculated magnetic flux density is compared with the actual value, and the current densities J _x and J _y that minimize the difference are obtained. As the gradient method, the steepest descent method, the conjugate gradient method and the like can be used. Hereinafter, a specific method will be described.

First, from the amplitude image and phase image obtained by the measurement of the semiconductor device D, an amplitude image to which Biot-Savart's law can be applied (hereinafter referred to as "amplitude image modification b") is generated. Reference pixel p = (x, y) amplitude value and _{a p} in the reference pixel p = (x, y) when the phase value and theta _p in the amplitude image breaks _{b p} in the reference pixel p of the formula (15) Obtained by.

Further, the direction of the current obtained by the above-mentioned "Modification 1 relating to the generation of the current direction image" is _defined as φ, and the current direction in the reference pixel p is defined as φ p. Then, the amplitude image of the current density in the reference pixel p is set as q _p, and initialization is performed at _{q p = 1.0.}

Then, according to Biot-Savart's law (Equation (16)) indicated by the sum and the current densities J _x , J _y indicated by the equations (17) and (18), convolution is performed in an appropriate window area. I do.

If this operation is A, it can be reduced to the inverse matrix problem. That is, the current intensity can be obtained by obtaining q in the equation (19). Then, the current intensity image can be obtained by plotting the obtained absolute value of q as the current intensity image data in the reference pixel. As shown in FIG. 17, in this current intensity image, as in the above-described embodiment, the higher the current intensity (current density), the closer to white it is drawn. Further, FIG. 18 is a current image synthesized by the present modification and the modification 1 related to the generation of the current direction image described above. In this current image, similarly to the current image shown in FIG. 14, the current flowing in the vertical direction (cyan, yellow) and the current flowing in the horizontal direction (red, green) can be confirmed.

[Modification 2 related to generation of current intensity image]
In this modification, a current intensity image is generated based on the spatial distribution of the magnetic flux density according to Biot-Savart's law. As shown in FIG. 19A, according to the spatial distribution of the magnetic flux density, the magnetic flux density is 0 immediately above the position where the current is flowing, and the maximum value is around (near) the position where the current is flowing. And a minimum value is formed. In the amplitude image obtained by observing the magnetic flux density, the magnetic flux density is obtained by an absolute value. In this case, if the current density at the position where the current is flowing is Amax and the value of the maximum value in the vicinity is Amax, the current density in the reference pixel R is the difference between the maximum value Amax and the amplitude value of the reference pixel R. Therefore, in this modification, the amplitude image A is scanned by the window region W having a predetermined size as shown in FIG. Then, the absolute value of the difference between the amplitude value in the reference pixel R (center of the window region W) and the maximum amplitude value (Amax) in the window region W becomes the current intensity in the reference pixel. The current intensity image can be obtained by plotting the obtained value as the current intensity image data in the reference pixel. As shown in FIG. 21, in this current intensity image, as in the above-described embodiment, the higher the current intensity (current density), the closer to white it is drawn.

Each process for generating the amplitude image, phase image, current intensity image, current direction image, and current image in the above-described embodiment and each modification can be executed by the computer 24 using, for example, the image generation program P1. As shown in FIG. 22, the image generation program P1 is recorded in the program recording area of the recording medium 50. The recording medium 50 is composed of, for example, a recording medium such as a CD-ROM, a DVD, or a ROM, or a semiconductor memory. The image generation program P1 includes a main module M1, an amplitude image data generation module M2, a phase image data generation module M3, a current intensity image data generation module M4, a current direction image data generation module M5, and a current image data generation module. It is equipped with M6.

The main module M1 is a part that comprehensively controls the image generation processing, and the computer 24 has an amplitude image data generation module M2, a phase image data generation module M3, a current intensity image data generation module M4, and a current direction image data generation module M5. And the current image data generation module M6 is executed. By executing the amplitude image data generation module M2, the computer 24 functions as an amplitude image data generation unit for generating an amplitude image (amplitude image data). Further, by executing the phase image data generation module M3, the computer 24 functions as a phase image data generation unit for generating a phase image (phase image data). By executing the current intensity image data generation module M4, the computer 24 functions as a current intensity image data generation unit for generating a current intensity image (current intensity image data). By executing the current direction image data generation module M5, the computer 24 functions as a current direction image data generation unit (image generation unit) for generating a current direction image (current direction image data). By executing the current image data generation module M6, the computer 24 functions as a current image data generation unit (image generation unit) for generating a current image (current image data). The image generation program P1 may be provided as a computer data signal superimposed on a carrier wave via a communication network.

In the image generation method (image generation device 1) described above, magnetism is generated by a stimulus signal applied to the semiconductor device D. Then, based on the phase difference between the reference signal generated based on the stimulus signal and the detection signal based on magnetism, phase image data including a phase component indicating the phase difference is generated. Since the phase difference changes depending on the direction of the magnetic field, the phase image data includes information on the direction of the magnetic field. Since the direction of the magnetic field is determined by the direction of the current, it is possible to determine the direction of the current based on the phase image data. This makes it possible to generate an image showing the direction of the current using the determined direction of the current.

Further, in the current direction image, the direction of the current is indicated by a plurality of colors set (color scheme) according to the direction, so that the position and direction of the current can be easily grasped visually. Also, the plurality of colors have different colors (red, yellow, green, cyan) set (assigned) for each of the four angular ranges (90 degrees) divided according to the direction of the electric current. doing. The current path in the semiconductor device D is often designed in the X-axis direction and the Y-axis direction so as to be orthogonal in a plan view. In this case, there are four current directions: the X direction, the −X direction, the Y direction, and the −Y direction. Therefore, having four different colors makes it easier to identify these four directions.

Further, in the step of generating the current direction image, the correspondence between the current direction and the plurality of colors can be changed. In the above embodiment, the computer 24 has a color table having color data of four colors and an angle table having data of angle ranges divided into four different angle ranges. Then, the correspondence between the color table and the angle table can be changed. According to this configuration, the color scheme can be easily adjusted. Further, by arbitrarily shifting the correspondence between the color table and the angle table, even if the orientation of the obtained image is tilted, the color scheme can be adjusted according to the tilt.

In addition, data in which magnetic direction data based on phase image data is added to intensity image data indicating magnetic intensity generated from the detection signal is generated, and current intensity indicating current intensity based on the data is generated. Generate an image. Then, a current image showing the intensity and direction of the current is generated based on the current intensity image and the current direction image. The magnetic strength corresponds to the magnitude of the electric current. Therefore, by adding the data in the magnetic direction (current direction image) to the intensity image data (current intensity image), the magnitude and direction of the current can be expressed as an image.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

For example, the reference signal has been described as being output from the tester unit 11, but the present invention is not limited to this, and the reference signal may be output from the semiconductor device D. In this case, the semiconductor device D may be directly connected to the frequency analysis unit 12 via the device control cable. Further, the reference signal may be input from the semiconductor device D to the frequency analysis unit 12 via the tester unit 11. A reference signal corresponding to the stimulus signal is output from the semiconductor device D to which the stimulus signal is applied, and the reference signal is input to the frequency analysis unit 12.

Further, an example of a color scheme in which four different colors correspond to four different angle ranges is shown, but the present invention is not limited to this. The color may be less than 4 colors or 5 or more colors. Further, the angle range to be divided may differ depending on the color. For example, the colors may be arranged by 6 colors, 3 colors each having a range of 90 degrees and 3 colors each having a range of 30 degrees. Further, the relationship between the angle indicating the current direction and the color may be set as a gradation like the color wheel. Further, the relationship between the angle and the color scheme may be freely changed by the input means.

Moreover, although the example which shows the direction by a color is shown, it is not limited to this. For example, an arrow indicating the current direction may be plotted on the obtained current intensity image. In this case, the arrow may be plotted for each adjacent region having the same current direction. Further, the arrow may be plotted only in the region of the current density of a predetermined size or more, and the size of the arrow may correspond to the magnitude of the current intensity. Further, for example, the current direction may be expressed by a dither pattern or a geometric pattern instead of the color.

1 ... image generator, 11 ... tester unit (signal application unit), 13 ... light source, 15 ... optical scanner (irradiation optical system), 18 ... MO crystal (magneto-optical crystal), 22 ... photodetector, 24 ... computer ( Image generator).

Claims (18)

An image generation method that generates an image showing the direction of the current flowing through a semiconductor device.
The step of applying a stimulus signal to the semiconductor device and
A step of outputting the magnetism in the thickness direction of the semiconductor device generated by the application of the stimulus signal as a detection signal, and
A step of generating phase image data including a phase component indicating the phase difference based on the phase difference between the reference signal generated based on the stimulus signal and the detection signal.
A step of generating a current direction image indicating the direction of the current based on the information of the magnetic direction in the thickness direction obtained from the phase image data, and a step of generating the current direction image.
Data is generated by adding magnetic direction data based on the phase image data to the intensity image data indicating the magnetic intensity generated from the detection signal, and the current intensity indicating the current intensity is generated based on the data. Steps to generate the image and
Including a step of generating a current image showing the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction based on the current intensity image and the current direction image. See,
An image generation method , wherein the plurality of colors have at least different colors set for four angle ranges divided according to the direction of electric current. An image generation method that generates an image showing the direction of the current flowing through a semiconductor device.
The step of applying a stimulus signal to the semiconductor device and
A step of outputting the magnetism in the thickness direction of the semiconductor device generated by the application of the stimulus signal as a detection signal, and
A step of generating phase image data including a phase component indicating the phase difference based on the phase difference between the reference signal generated based on the stimulus signal and the detection signal.
A step of generating a current direction image indicating the direction of the current based on the information of the magnetic direction in the thickness direction obtained from the phase image data, and a step of generating the current direction image.
Data is generated by adding magnetic direction data based on the phase image data to the intensity image data indicating the magnetic intensity generated from the detection signal, and the current intensity indicating the current intensity is generated based on the data. Steps to generate the image and
Including a step of generating a current image showing the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction based on the current intensity image and the current direction image. See,
An image generation method , wherein the step of generating the current direction image includes a step of changing the correspondence between the direction of the current and the plurality of colors. An image generation method that generates an image showing the direction of the current flowing through a semiconductor device.
The step of applying a stimulus signal to the semiconductor device and
A step of outputting the magnetism in the thickness direction of the semiconductor device generated by the application of the stimulus signal as a detection signal, and
A step of generating phase image data including a phase component indicating the phase difference based on the phase difference between the reference signal generated based on the stimulus signal and the detection signal.
A step of generating a current direction image indicating the direction of the current based on the information of the magnetic direction in the thickness direction obtained from the phase image data, and a step of generating the current direction image.
Data is generated by adding magnetic direction data based on the phase image data to the intensity image data indicating the magnetic intensity generated from the detection signal, and the current intensity indicating the current intensity is generated based on the data. Steps to generate the image and
Including a step of generating a current image showing the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction based on the current intensity image and the current direction image. See,
The step of generating the current image is an image generation method including a step of setting the correspondence between the direction of the current and the plurality of colors as a gradation like a color wheel. Step includes the step of changing the relationship between the direction and the plurality of colors of the current image generating method according to claim 1 to generate the current direction image. The step of generating the current image includes any one of claims 1, 2 and 4 , including a step of setting the correspondence between the direction of the current and the plurality of colors as a gradation like a color wheel. The described image generation method. Any of claims 1 to 5, wherein the step of generating the current image includes a step of setting the plurality of colors with respect to the direction of the current so that colors indicating directions opposite to each other have a complementary color relationship. The image generation method described in item 1. The step of generating the current direction image and the step of generating the current intensity image includes any of claims 1 to 6 including generating the current direction image and the current intensity image based on Biot-Savart's law. The image generation method according to item 1. An image generator that acquires an image showing the direction of the current flowing through a semiconductor device.
A signal application unit that applies a stimulus signal to the semiconductor device,
A magnetic detector that outputs a detection signal based on the magnetism in the thickness direction of the semiconductor device generated by the application of the stimulus signal, and a magnetic detector.
Based on the phase difference between the reference signal generated based on the stimulus signal and the detection signal, phase image data including a phase component indicating the phase difference is generated, and the phase image data obtained from the phase image data. An image generating unit, which is configured to generate a current direction image indicating the direction of the current based on the information of the magnetic direction in the thickness direction, is provided.
The image generation unit generates data in which magnetic direction data based on the phase image data is added to intensity image data indicating the magnetic intensity generated from the detection signal, and the current is generated based on the data. A current intensity image showing the intensity is generated, and based on the current intensity image and the current direction image, the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction are shown. It is configured to generate a current image and
An image generator , wherein the plurality of colors have at least different colors set for four angular ranges divided according to the direction of electric current. An image generator that acquires an image showing the direction of the current flowing through a semiconductor device.
A signal application unit that applies a stimulus signal to the semiconductor device,
A magnetic detector that outputs a detection signal based on the magnetism in the thickness direction of the semiconductor device generated by the application of the stimulus signal, and a magnetic detector.
Based on the phase difference between the reference signal generated based on the stimulus signal and the detection signal, phase image data including a phase component indicating the phase difference is generated, and the phase image data obtained from the phase image data. An image generating unit, which is configured to generate a current direction image indicating the direction of the current based on the information of the magnetic direction in the thickness direction, is provided.
The image generation unit generates data in which magnetic direction data based on the phase image data is added to intensity image data indicating the magnetic intensity generated from the detection signal, and the current is generated based on the data. A current intensity image showing the intensity is generated, and based on the current intensity image and the current direction image, the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction are shown. It is configured to generate a current image and has a color table containing the data of the plurality of colors and an angle table containing data of an angle range divided according to the direction of the current.
An image generator configured so that the correspondence between the color table and the angle table can be changed. An image generator that acquires an image showing the direction of the current flowing through a semiconductor device.
A signal application unit that applies a stimulus signal to the semiconductor device,
A magnetic detector that outputs a detection signal based on the magnetism in the thickness direction of the semiconductor device generated by the application of the stimulus signal, and a magnetic detector.
Based on the phase difference between the reference signal generated based on the stimulus signal and the detection signal, phase image data including a phase component indicating the phase difference is generated, and the phase image data obtained from the phase image data. An image generating unit, which is configured to generate a current direction image indicating the direction of the current based on the information of the magnetic direction in the thickness direction, is provided.
The image generation unit generates data in which magnetic direction data based on the phase image data is added to intensity image data indicating the magnetic intensity generated from the detection signal, and the current is generated based on the data. A current intensity image showing the intensity is generated, and based on the current intensity image and the current direction image, the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction are shown. An image generator that is configured to generate an electric current image and sets the plurality of colors so that the correspondence between the direction of the electric current and the plurality of colors becomes a gradation like a color wheel. .. The image generation unit has a color table including the data of the plurality of colors and an angle table including data of an angle range divided according to the direction of the electric current.
The image generator according to claim 8 , wherein the correspondence between the color table and the angle table can be changed. Any of claims 8, 9 and 11, wherein the image generation unit sets the plurality of colors so that the correspondence between the direction of the current and the plurality of colors has a gradation shape like a color wheel. The image generator according to the first paragraph. The image generation device according to any one of claims 8 to 12 , wherein the image generation unit sets the plurality of colors so that colors indicating directions opposite to each other have a complementary color relationship. The image generation device according to any one of claims 8 to 13 , wherein the image generation unit generates the current direction image and the current intensity image based on Biot-Savart's law. A program for causing a computer to execute a process of acquiring an image showing the direction of a current flowing through the semiconductor device when a stimulus signal is applied to the semiconductor device.
The computer
A phase component indicating the phase difference is included based on the phase difference between the detection signal based on the thickness direction of the semiconductor device generated by the application of the stimulation signal and the reference signal generated based on the stimulation signal. A phase image data generator that generates phase image data,
An image generator that generates a current direction image indicating the direction of the current based on information on the direction of the magnetism in the thickness direction obtained from the phase image data, and is a magnet generated from the detection signal. Data in which magnetic direction data based on the phase image data is added to the intensity image data indicating the intensity of the current is generated, a current intensity image indicating the intensity of the current is generated based on the data, and the current intensity image is generated. To function as the image generator that generates a current image showing the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction based on the current direction image and the current direction image .
An image generation program in which the plurality of colors have at least different colors set for four angle ranges divided according to the direction of electric current. A program for causing a computer to execute a process of acquiring an image showing the direction of a current flowing through the semiconductor device when a stimulus signal is applied to the semiconductor device.
The computer
A phase component indicating the phase difference is included based on the phase difference between the detection signal based on the thickness direction of the semiconductor device generated by the application of the stimulation signal and the reference signal generated based on the stimulation signal. A phase image data generator that generates phase image data,
An image generator that generates a current direction image indicating the direction of the current based on information on the direction of the magnetism in the thickness direction obtained from the phase image data, and is a magnet generated from the detection signal. Data in which magnetic direction data based on the phase image data is added to the intensity image data indicating the intensity of the current is generated, a current intensity image indicating the intensity of the current is generated based on the data, and the current intensity image is generated. To function as the image generator that generates a current image showing the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction based on the current direction image and the current direction image .
The image generation unit includes a color table including the data of the plurality of colors and an angle table including data of an angle range divided according to the direction of the current, and the color table and the angle table An image generation program that is configured to be able to change the correspondence between. A program for causing a computer to execute a process of acquiring an image showing the direction of a current flowing through the semiconductor device when a stimulus signal is applied to the semiconductor device.
The computer
A phase component indicating the phase difference is included based on the phase difference between the detection signal based on the thickness direction of the semiconductor device generated by the application of the stimulation signal and the reference signal generated based on the stimulation signal. A phase image data generator that generates phase image data,
An image generator that generates a current direction image indicating the direction of the current based on information on the direction of the magnetism in the thickness direction obtained from the phase image data, and is a magnet generated from the detection signal. Data in which magnetic direction data based on the phase image data is added to the intensity image data indicating the intensity of the current is generated, a current intensity image indicating the intensity of the current is generated based on the data, and the current intensity image is generated. To function as the image generator that generates a current image showing the intensity of the current and the direction of the current indicated by a plurality of colors set according to the direction based on the current direction image and the current direction image .
The image generation unit is an image generation program that sets the plurality of colors so that the correspondence between the direction of the electric current and the plurality of colors has a gradation shape like a color wheel. A computer-readable recording medium for recording the image generation program according to any one of claims 15 to 17.

Images