JP2004020404A - Method for measuring and observing semiconductor device and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an analyzing technique having high resolving power which enables measurement and observation of electrical or physical properties inside a fine semiconductor device while using light having a long wavelength. <P>SOLUTION: A solid lens is brought into close contact with a sample and used along with an object lens to measure and observe the pattern in the sample, enhanced in resolving power in proportion to the refractive index of the solid lens. This method is used to enable the probing of the operation state of a circuit, the distribution due to a light emitting position at the time of application of a signal, the distribution of light induced current due to position, the distribution of change in light induced resistance due to place or the like. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for analyzing a semiconductor device using light and a technique for performing the analysis at high resolution, and an apparatus therefor. Analysis techniques include the technique of observing the distribution of light emission with a signal applied to the semiconductor device, the technique of observing the distribution of photoinduced current generated by condensing and scanning spot light on the semiconductor device, Technology for observing the distribution of changes in wiring resistance caused by focusing and scanning spot light on a device. Transistor by focusing spot light on a transistor section of a semiconductor device and observing the change in reflected light. A technique for observing a change in the operating state of the device without contact is included.
[0002]
[Prior art]
2. Description of the Related Art As a system for analyzing a fine circuit formed on a semiconductor wafer or the like, a technique of observing a shape inside a device surface, a physical property, an operation state, and the like using light is often used. For example, a technique for observing the distribution of light emission while a signal is being applied to a semiconductor device, and an OBIC (Optical Beam Induced Current) for observing the distribution of a photoinduced current generated by condensing and scanning a spot light on the semiconductor device. ) Technology, OBIRCH (Optical Beam Induced Resistance Change) technology for observing distribution of change in wiring resistance caused by condensing and scanning spot light on a semiconductor device, and collecting spot light on a transistor portion of a semiconductor device. A technique for observing a change in the operating state of a transistor in a non-contact manner by observing a change in reflected light is included.
[0003]
For example, in Japanese Patent Application Laid-Open No. 10-326817, a pattern to be analyzed is searched for by observing the device from the back surface with infrared light using a sample in which the back surface of a semiconductor device is polished, and this is cut with an ion beam or the like. A method for exposing a desired circuit is shown. In this known example, while an operation signal is applied to the sample, a beam of infrared light is focused on the circuit element from the back surface and the intensity of the reflected light is measured to monitor the voltage state of the circuit element. A technique of observing the laser back surface potential for observing the operation of the circuit in a non-contact manner is described as a known example.
[0004]
Further, the OBIRCH technology is described in, for example, the proceedings of the LSI Testing Symposium 2000, pp 191-196.
[0005]
Further, in the proceedings of the LSI Testing Symposium 2000, pp. 203-208, a scanning laser SQUID microscope that detects a small change in a magnetic field due to an OBIC current using a highly sensitive magnetic field detecting SQUID element is reported.
[0006]
In recent years, semiconductor circuit patterns have been shrinking, and line widths of 0.2 micrometers or less have been used. Is running out. This is because the resolution of light is limited by approximately λ / 2NA, so that a fine pattern formed using ultraviolet light having a short wavelength of about 0.2 micrometer has a sufficient resolution unless observed with light having the same short wavelength. This is because they cannot be obtained. Here, λ is the wavelength of light, NA is the numerical aperture of the lens, and is expressed as NA = n · sin θ. n is the refractive index of air between the lens and the sample, which is approximately 1. θ is the aperture angle, which is the converging angle determined by the lens. For a high-power microscope objective lens, NA is around 0.9, and for an exposure lens for exposing a semiconductor pattern, NA is around 0.7.
[0007]
However, in the above-described technology for observing the inside of a semiconductor device, conventionally, it has been widely used to observe from the front side of a semiconductor device by utilizing the fact that silicon oxide, which is a material of an insulating film on the surface, is transparent. Had been However, in recent years, the total number of wirings has increased with the increase in the degree of integration of semiconductors, and power supply and ground patterns have been densely arranged to improve electrical characteristics. In addition, dummy wiring has been required for CMP (chemical mechanical polishing). A wiring pattern is arranged. For this reason, when observing the inside from the surface with light, the inside is interrupted by an opaque metal wiring pattern, and the inside becomes difficult to see. For this reason, it has become important to observe the transistor and the lower wiring from the back surface of the semiconductor device without obstructing the upper wiring.
[0008]
It is necessary to use infrared light having a wavelength of more than 0.7 micrometers, for example, light of 1.3 micrometers, as light transmitted through the silicon substrate constituting the back side of the semiconductor device. Generally, silicon is transparent to light in the wavelength range of 0.9 to 1.9 micrometers. Further, in the technology for detecting a light-induced change in wiring resistance, the use of visible light having large photon energy causes not only a change in wiring resistance but also a photoinduced current effect generated at a PN junction of a semiconductor element. Therefore, it is necessary to use infrared light. Therefore, the resolution determined by λ / 2NA is, for example, 1 micrometer when a lens and light of NA = 0.65 and λ = 1.3 micrometers are used, and a sufficient resolution for the pattern size is obtained. I can't. For this reason, it is difficult to narrow down on a circuit when a problematic part is on a fine pattern in observation of light emission distribution, OBIC, and OBIRCH technology. There is also a problem that the light shines on other places and that the operation state of a desired part cannot be monitored.
[0009]
[Problems to be solved by the invention]
As described above, in the related art, when observing and measuring the inside of a semiconductor using light, there is a problem that a required resolution cannot be obtained because of a resolution limit determined by a wavelength of light. In order to solve this problem, a method of shortening the wavelength of the light used can be considered by analogy with the semiconductor pattern exposure technology. Silicon, which is frequently used in semiconductors, transmits infrared light, but when the wavelength is shortened, it rapidly transmits. The light emission intensity when operating the device is higher as infrared light, so the sensitivity is worse at short wavelengths, and the way physical phenomena occur when the device is irradiated with light changes. There was a problem that it was not something.
[0010]
An object of the present invention is to provide a high-resolution analysis method capable of optically measuring and observing a finer pattern than a resolution determined by the specifications of the light wavelength and the objective lens without shortening the light wavelength, in order to solve the above-described problems. It is to provide a device.
[0011]
[Means for Solving the Problems]
FIG. 1 is a diagram showing a problem of optical measurement and observation of a semiconductor device in a conventional method. As described above, when the inside of the semiconductor device 900, for example, the source or drain portion 901 of the transistor, is observed by the objective lens 100, even if the detection light 200 is to be narrowed down by the objective lens 200, the refractive index on the surface of the sample 900 is air. The light is refracted from 1 to enter a high refractive index region determined by the material. In the case of the figure, since the refractive index is as high as about 3.4 with the silicon substrate 905, the critical angle is arcsin (1 / 3.4) = 17 degrees. It becomes close to parallel light and cannot be stopped down. Conversely, in the case where light from the inside of the sample is imaged, similarly, light that spreads outside the illustrated angle cannot be taken into the objective lens 100, and the resolution cannot be increased.
[0012]
On the other hand, if light can be guided into the sample at a wide angle, the resolution can be improved. That is, when the wavelength of light is represented by λ and the numerical aperture of the objective lens is represented by NA (Numerical Aperture), the apparent NA is increased by increasing the apparent NA with respect to the resolution represented by λ / (2 · NA). Can be improved. As shown in FIG. 2, the lens 101 is brought into close contact with the sample 900 and placed between the sample 101 and the objective lens 100. For example, a lens 101 having a hemispherical shape and a refractive index close to the material constituting the surface 905 of the sample 900 is selected. Then, since the light 200 emitted from the objective lens 100 is incident on the lens 101 in a state almost perpendicular to the lens 101, the light 200 enters the lens 101 without changing the direction so much that the lens 101 and the sample surface 905 have similar refractive indexes. Therefore, at the interface between 101 and 905, the incident light 200 enters the inside of 905 without being refracted much. Therefore, the incident light 200 can be narrowed to the observation surface 901 at a large angle, and the NA of the lens 101 increases in appearance. Therefore, the resolution is improved as compared with FIG.
[0013]
The method of attaching a hemispherical lens to a sample is generally known as a solid immersion lens. This is a method of observing a fine pattern on the surface of a sample by arranging an objective lens and a hemispherical lens so as to form an image on the surface of a hemispherical lens. Since the resolution is inversely proportional to the numerical aperture: NA = n · sin θ, the resolution is improved in inverse proportion to the refractive index of the hemispherical lens. In a semiconductor device, a target to be observed / measured is a pattern inside the device, so that a generally known solid impregnated lens cannot be used.
[0014]
For this reason, in the present invention, the solid immersion lens is designed to use an immersion lens having a refractive index similar to the refractive index of the sample, and is designed so that the lens and the sample are integrated to function as an immersion lens, and an image is formed inside the sample. Now you can narrow down. As a result, the resolution is improved, and a high-resolution analysis method and device capable of optically measuring and observing a pattern finer than the resolution determined by the wavelength of light have been realized.
[0015]
In addition, in order to prevent reflection at the interface between the solid lens and the sample, the present invention is a high-resolution analysis method and apparatus using a liquid having a high refractive index in a state of being immersed between the solid lens and the sample.
[0016]
In addition, in order to prevent reflection at the interface between the solid lens and the sample, the present invention provides a high-resolution analysis method and a device therefor, wherein the lens is brought into close contact with the sample using a flat and elastic diffraction lens. is there.
[0017]
In addition, optical measurement / observation is first performed by the conventional method with a wide field of view, and after narrowing down the analysis point, a solid immersion lens is inserted to perform optical measurement / observation at high resolution. A high-resolution analysis method and apparatus.
[0018]
Further, there is provided a high-resolution analysis method and apparatus for performing high-resolution optical measurement and observation by using a liquid having a high refractive index instead of solid impregnation.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 2 is a diagram showing the principle of high-resolution measurement and observation of a semiconductor device according to the present invention. The lens 101 is brought into close contact with the sample 900 and placed between the sample 101 and the objective lens 100. For example, a lens 101 having a hemispherical shape and a refractive index close to the material constituting the surface 905 of the sample 900 is selected. Then, since the light 200 emitted from the objective lens 100 is incident on the lens 101 in a state almost perpendicular to the lens 101, the light 200 enters the lens 101 without changing the direction so much that the lens 101 and the sample surface 905 have similar refractive indexes. Therefore, at the interface between 101 and 905, the incident light 200 enters the inside of 905 without being refracted much. Therefore, the incident light 200 can be narrowed down to the observation surface 901 at a large angle.
[0020]
Here, the lens 101 is designed in consideration of the thickness of the silicon substrate 905 so that an image is formed by combining the lenses 101 and 905. That is, for example, when a hemispherical lens is used as the lens 101 and the same material as that of the lens 905 is used, the center of curvature of the lens 101 and the observation surface 901 are configured to be coincident. This is because the lens 101 is designed to match the thickness of the lens 905, or the sample 900 is polished and the thickness is adjusted to match the curvature of the lens 101 so that the lens and the sample are integrated to improve the resolution. To work for. The material of the lens need not be the same as that of the sample, but may be any material having substantially the same refractive index. Alternatively, a lens 101 made of a material having an intermediate value between the refractive index of the material and the refractive index of air 1 may be used. In any case, the resolution is improved in inverse proportion to the refractive index of the lens 101. Here, if the thickness of 905 is different from the expected value, the focus position changes, and it is necessary to focus. This can be achieved by adjusting the distance between the objective lens 100 and the lens 101.
[0021]
If the interface between the lens 101 and the sample 900 is poorly bonded, light is reflected here and the effect of improving the resolution is reduced. For this reason, it is possible to suppress reflection at the interface by filling a liquid having a high refractive index between the lens 101 and the sample 900 as another form of the embodiment.
[0022]
In addition, if the interface at the interface between the lens 101 and the sample 900 is poor, light is reflected here and the effect of improving the resolution is reduced, and at least one of the lens 101 and the sample 900 is provided with an anti-reflection coating. As a result, it is possible to suppress the reflection at the interface as another form of the embodiment.
Further, as another embodiment, instead of polishing the 900 flat, the shape of the lens 101 is formed into the sample by polishing, and the sample itself is used as a lens to avoid the problem of the interface and to obtain a high resolution sample. It is also possible to observe and measure the inside of the device.
[0023]
Further, as another embodiment, by filling a high-refractive-index liquid between the objective lens 100 and the sample 900 without using the lens 101, the resolution is improved in inverse proportion to the refractive index of the liquid, and the inside of the sample is improved. Can be observed and measured.
[0024]
FIG. 3 is a diagram showing an example of a configuration when a diffractive lens is used in the present invention. A diffraction lens 111 is used instead of a spherical lens. This also works in the same way as the lens 101 in the embodiment shown in FIG. 2, and works to observe and measure the inside of the sample 900 with high resolution. The advantage of using the diffractive lens 111 is that it is easy to give elasticity because the lens is thin, and it is easy to deform it and bring it into close contact with the sample 900.
[0025]
FIG. 4 shows another embodiment for improving the adhesion to the sample. Of the flat surface of the hemispherical lens, the only part that needs to be flat is the central part through which the light ray 200 passes. For this reason, it is also possible to use the lens 112 which has been cut off while leaving the center of the flat surface to improve the adhesion to the sample.
[0026]
FIG. 5 shows another example of the configuration of the present invention, in which an air inlet / outlet port is provided in order to obtain both the adhesion between the lens and the sample and the ease of removal. In the hemispherical lens 101 or the diffractive lens 111, a tube 120 for taking in and out of air is provided, and the lens is brought into close contact with the sample 900 by drawing air from there. , It is possible to easily remove the lens from the sample 900. Alternatively, the lens 101 or 111 can be slid with respect to the sample 900 and moved to the next observation field while blowing air instead of removing. Alternatively, instead of air, it is also possible to inject a liquid having a high refractive index for suppressing reflection at the interface and improving the slip between the lens 101 or 111 and the sample 900 from the tube 120.
[0027]
FIG. 6 shows an embodiment of the present invention in which the objective lens and the lens that is in close contact with the sample are elastically connected to each other to facilitate the arrangement when the objective lens is pressed against the sample. In this figure, reference numeral 130 denotes a member for elastically supporting the lens 101 or 111 with respect to the objective lens. By pressing the objective lens 100 against the sample 900, the lens 101 or 111 can be easily moved to the sample 900. Can be brought into close contact. The elastic support member 130 may be formed using a spring-like member, or may be formed by filling the space between the objective lens 100 and the lens 101 or 111 with a gel-like substance.
[0028]
FIG. 7 shows an embodiment in which measurement and observation are performed from the front surface side of the semiconductor device in the present invention. The material 904 on the front side is usually made of silicon oxide or silicon nitride. These refractive indexes are about 1.5 to 2.0 and not as high as silicon. Therefore, a silicon lens may be used as the lens 112 to be in close contact with the sample, but a silicon oxide or silicon nitride lens may be used. It is sufficient to use.
[0029]
An example in which the present invention is applied to actual observation and measurement will be described below.
[0030]
FIG. 8 illustrates the principle of OBIRCH (Optical Beam Induced Resistance Change) and OBIC (Optical Beam Induced Current).
[0031]
In OBIRCH, as shown in FIG. 8A, a probe is applied to a semiconductor device, and a current flowing between terminals is monitored while a voltage is applied. In this state, the laser beam is scanned as indicated by an arrow, and a change in current corresponding to the scan position is obtained as an image. Since the current corresponds to the resistance of the circuit, this reveals where the resistance changes when exposed to light. The point where the resistance is easily changed by light exposure corresponds to an abnormal point in the circuit such as a thin wiring.
[0032]
In the OBIC, a probe is applied to a semiconductor device as shown in FIG. 8B, and a flowing current is monitored. In this state, a laser beam is scanned, and a change in current corresponding to the scan position is obtained as an image. In a semiconductor circuit, there is a portion such as a PN junction where a photo-induced current is likely to be generated by light irradiation. When the OBIC image is different from the normal one, the different part and the part connected thereto often have an abnormality. Note that in OBIC, it is necessary to irradiate light of a short wavelength having energy larger than the band gap of the semiconductor in order to generate a photo-induced current, but in OBIRCH, energy is smaller than the band gap of the semiconductor so as not to cause the OBIC phenomenon. Light, often infrared, must be applied.
[0033]
An embodiment in which the present invention is used to implement OBIRCH and OBIC at high resolution is shown in FIG. The light beam emitted from the laser light source 150 is redirected by the deflecting means 151 and reflected by the mirror 153, and then passes through the objective lens 100, passes through the close contact lens 101, and irradiates the sample 900. The current image forming apparatus 303 controls the deflecting means 151 and at the same time acquires a current change obtained from the probe 310 by the current amplifier 304 as an image corresponding to the deflection position. With this configuration, it is possible to acquire an OBIC image or an OBIRCH image with high resolution. This image is displayed on the user interface 307 via the overall control device 302.
[0034]
Further, the semiconductor device 900 may be set to a predetermined circuit operation state by the signal applying device 306 before the image acquisition. Further, a normal optical observation image can be obtained by the image sensor 152. The main image and the OBIC image or the OBIRCH image are analyzed by the image analyzer 301. In addition, in order to narrow down the observation place first by using the wide-field image, observation is performed only with the normal objective lens 100 without using the lens 101, and then the observation place is narrowed down and observation is performed with a narrow field of view and high resolution. For this reason, a lens handling device 309 is provided so that the lens 101 can be easily inserted and removed. Alternatively, the objective lens 100 with the lens 101 and the normal objective lens 100 may be switched by a revolver. This switching is realized by the general control device 302 issuing a command to the lens handling device 309. An X, Y, and Z stage 350 is provided for setting the observation position of the sample and adjusting the focus, and this is controlled by the overall controller 302 via the stage controller 305.
[0035]
FIG. 10 shows an embodiment for realizing high resolution of the scanning laser SQUID microscope in the present invention. The light beam emitted from the laser light source 150 is redirected by the deflecting means 151 and reflected by the mirror 153, and then passes through the objective lens 100, passes through the close contact lens 101, and irradiates the sample 900. The current image forming apparatus 303 controls the deflecting means 151 and simultaneously obtains a weak magnetic field signal, that is, a current signal, obtained by the magnetic field sensor 364 by the magnetic field sensor amplifier 314 as an image corresponding to the deflection position. With this configuration, a scanning laser SQUID image can be obtained with high resolution. This image is displayed on the user interface 307 via the overall control device 302.
[0036]
Further, a normal optical observation image can be obtained by the image sensor 152. The main image and the scanning laser SQUID image are analyzed by the image analyzer 301. In addition, in order to narrow down the observation place first by using the wide-field image, observation is performed only with the normal objective lens 100 without using the lens 101, and then the observation place is narrowed down and observation is performed with a narrow field of view and high resolution. For this reason, a lens handling device 309 is provided so that the lens 101 can be easily inserted and removed. Alternatively, the objective lens 100 with the lens 101 and the normal objective lens 100 may be switched by a revolver. This switching is realized by the general control device 302 issuing a command to the lens handling device 309. An X, Y, and Z stage 350 is provided for setting the observation position of the sample and adjusting the focus, and this is controlled by the overall controller 302 via the stage controller 305.
[0037]
FIG. 11 shows an embodiment in which the present invention is used to obtain an emission map with high resolution. An optical image of the sample 900 is obtained by the image sensor 152. At this time, an image in a state where the semiconductor device 900 is set to a predetermined circuit operation state is obtained by the signal application device 306, and a difference image with respect to a reference image in another state is obtained by the image analysis device 301, thereby reducing circuit operation. The accompanying light emission distribution is obtained. The above operation is controlled by the overall control device 302, and the result is displayed on the user interface 307. This makes it possible to analyze the light emission map with high resolution. In particular, since the sensitivity of the emission map is high when infrared light is used, the present invention, in which the emission state inside the sample can be observed with high resolution while using infrared light having a long wavelength, is particularly effective.
[0038]
In addition, in order to narrow down the observation place first by using the wide-field image, observation is performed only with the normal objective lens 100 without using the lens 101, and then the observation place is narrowed down and observation is performed with a narrow field of view and high resolution. For this reason, a lens handling device 309 is provided so that the lens 101 can be easily inserted and removed. Alternatively, the objective lens 100 with the lens 101 and the normal objective lens 100 may be switched by a revolver. This switching is realized by the general control device 302 issuing a command to the lens handling device 309. An X, Y, and Z stage 350 is provided for setting the observation position of the sample and adjusting the focus, and this is controlled by the overall controller 302 via the stage controller 305.
[0039]
FIG. 12 shows an embodiment for executing the probing of the laser back surface potential observation at a high resolution in the present invention. The light beam emitted from the laser light source 150 is redirected by the deflecting means 151 and reflected by the half mirror 163, passes through the objective lens 100, passes through the contact lens 101, and irradiates the sample 900. By controlling the deflecting means 151, the irradiation position control means 340 can irradiate an arbitrary portion in the sample 900 with a beam or scan the sample 900 two-dimensionally. Since the contact lens 101 is used, the above-described beam irradiation and beam scanning can be performed with high resolution. The laser beam reflected by the sample passes through the half mirror 163 through the contact lens 101 and the objective lens 100, and the wavelength of the laser beam is reflected by the wavelength selection mirror 169, and is detected by the light amount sensor 165. By placing a quarter-wave plate on the objective lens 100 and replacing 163 with a deflecting beam splitter, it is also possible to improve the utilization efficiency of the laser beam and the S / N ratio of the detection signal.
[0040]
Since the signal obtained by the light amount sensor 165 changes depending on the operation state of the circuit, the dynamic characteristics of the circuit can be measured by observing the signal with the signal observation device 341. Further, by obtaining an image of the signal of the light amount sensor 165 as a function of the scan position by the signal observation device 341 while scanning by the sample position control device 340, it is possible to operate as a laser microscope. The image inside the sample 900 reaches the image sensor 152 through the contact lens 101, the objective lens 100, the half mirror 163, and further passes through the wavelength selection mirror 169. Obtaining this image by the image analysis device 301 enables image observation of the probe location at the same time.
[0041]
The signal application device 306 gives a signal to the semiconductor device 900, and at this time, performs the above-described operation to measure the operation of the circuit. In addition, in order to narrow down the observation place first by using the wide-field image, observation is performed only with the normal objective lens 100 without using the lens 101, and then the observation place is narrowed down and observation is performed with a narrow field of view and high resolution. For this reason, a lens handling device 309 is provided so that the lens 101 can be easily inserted and removed. Alternatively, the objective lens 100 with the lens 101 and the normal objective lens 100 may be switched by a revolver. This switching is realized by the general control device 302 issuing a command to the lens handling device 309. The apparatus also has an X, Y, and Z stage 350 for positioning the observation position of the sample and adjusting the focus, and this is controlled by the overall controller 302 via the stage controller 305.
[0042]
As described above, by using the contact lens so that the lens and the sample are integrated and function as an immersion lens, an image can be narrowed down inside the sample. This technique improves the resolution and enables optical measurement and observation of patterns finer than the resolution determined by the wavelength of light. OBIC (Optical Beam Induced Current) technology for observing the distribution of photo-induced current generated by condensing and scanning spot light, and the wiring resistance generated by concentrating and scanning spot light on a semiconductor device. OBIRCH (Optical Beam Induced Resistance Change) technology for observing the distribution of change, non-contact observation of a change in the operating state of a transistor by focusing spot light on a transistor portion of a semiconductor device and observing a change in reflected light. Technology as an example Having described Te, the present invention is not limited to this, it is naturally applicable widely when observing and measuring at high resolution by using light inside the semiconductor device.
[0043]
【The invention's effect】
According to the present invention, an image can be narrowed down inside the sample by using the contact lens so that the lens and the sample are integrated and function as an immersion lens. As a result, the resolution has been improved, and optical measurement and observation of patterns finer than the resolution determined by the wavelength of light have become possible. The optical measurement / observation here refers to the technology of observing the distribution of light emission while a signal is applied to the semiconductor device, and the light-induced current generated by condensing and scanning a spot light on the semiconductor device. OBIC (Optical Beam Induced Current) technology for observing distribution, OBIRCH (Optical Beam Induced Resistance Change) technology for observing distribution of change in wiring resistance generated by condensing and scanning spot light on a semiconductor device, semiconductor device And the like, in which a change in the operating state of a transistor is observed in a non-contact manner by condensing spot light on a transistor portion or the like and observing a change in reflected light.
[0044]
Further, according to the present invention, by using a liquid having a high refractive index in a state of being immersed between the solid lens and the sample, reflection at an interface between the solid lens and the sample is prevented, and optical measurement of a fine pattern is performed. -The effect that observation can be performed stably is also obtained.
[0045]
Further, according to the present invention, the lens is brought into close contact with the sample by using a flat and elastic diffractive lens, thereby preventing reflection at an interface between the solid lens and the sample, thereby enabling optical measurement of a fine pattern. The effect that observation can be performed stably is also obtained.
[0046]
Further, according to the present invention, by providing a mechanism for attaching and detaching the solid immersion lens, first, optical measurement and observation are performed by a conventional method having a wide field of view with the solid immersion lens removed, and then the solid It is possible to perform high-resolution optical measurement and observation after narrowing down the analysis point with the impregnated lens attached, and perform high-resolution optical measurement and observation from a relatively wide field of view. The effect that the location can be relatively easily achieved is also obtained.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing the principle of optical measurement and observation of a semiconductor device in a conventional method.
FIG. 2 is a front sectional view showing the principle of high-resolution measurement and observation of a semiconductor device according to the present invention.
FIG. 3 is a front sectional view showing the principle of high-resolution measurement / observation of a semiconductor device when the diffraction lens according to the present invention is used.
FIG. 4 is a front sectional view showing the principle of high-resolution measurement / observation of a semiconductor device when the flat surface of a hemispherical lens is scraped off leaving a central portion to improve the adhesion to a sample according to the present invention. FIG.
5 (a) and 5 (b) show a high resolution of a semiconductor device according to the present invention, which is provided with an air inlet / outlet port in order to obtain both adhesion between a lens and a sample and ease of removal. It is front sectional drawing which shows the principle of measurement and observation.
6 (a) and 6 (b) are front views showing the principle of high-resolution measurement / observation of a semiconductor device using a configuration in which an objective lens and a lens which is in close contact with a sample are elastically coupled according to the present invention. It is sectional drawing.
FIG. 7 is a front sectional view showing the principle of high-resolution measurement and observation of a semiconductor device when measurement and observation are performed from the front surface side of the semiconductor device in the present invention.
8A is a diagram illustrating the principle of OBIRCH, and FIG. 8B is a diagram illustrating the principle of OBIC.
FIG. 9 is a front view showing a schematic configuration of an apparatus for executing OBIRCH and OBIC at high resolution according to the present invention.
FIG. 10 is a front view showing a schematic configuration of an apparatus for realizing high resolution of a scanning laser SQUID microscope according to the present invention.
FIG. 11 is a front view showing a schematic configuration of an apparatus for obtaining a light emission map with high resolution according to the present invention.
FIG. 12 is a front view showing a schematic configuration of an apparatus for performing probing for observing the laser back surface potential at a high resolution according to the present invention.
[Explanation of symbols]
Reference numeral 100: objective lens, 101: solid immersion lens, 111: diffractive solid immersion lens, 112: solid immersion lens for observation from the surface, 120: air pipe, 130: elastic support, 150: laser light source, 151: deflection Means 152 image sensor 153 half mirror 163 deflection beam splitter 164 λ / 4 plate 165 light intensity sensor 301 image analyzer 302 overall controller 303 current image forming device 304 ... Warm current amplifier, 305 stage control device, 306 signal applying device 307 terminal, 340 irradiation position control device, 341 signal observation device, 309 lens handling device, 900 semiconductor device sample, 901 drain, source unit , 902: gate portion, 903: wiring portion, 904: oxide insulating film portion, 906: silicon Substrate portion

Claims (31)

Irradiating the sample with illumination light from a light source through an objective lens and a proximity lens disposed between the objective lens and the semiconductor device that is the sample, and forming an optical image of the sample irradiated with the illumination light on the near Measuring the semiconductor device pattern finer than the resolution determined by the wavelength of the illumination light and the specification of the objective lens by detecting through a lens and the objective lens, and measuring the semiconductor device. Or observation method. 2. The method for measuring or observing a semiconductor device according to claim 1, wherein the proximity lens is arranged in proximity to or in contact with the semiconductor device as the sample. The method for measuring or observing a semiconductor device according to claim 1, wherein the proximity lens has substantially the same refractive index as a semiconductor device as the sample. 2. The method according to claim 1, wherein the proximity lens is made of the same material as the semiconductor device as the sample. 2. The method according to claim 1, wherein the proximity lens has an intermediate refractive index between a refractive index of the semiconductor device as the sample and a refractive index of air. 3. The method for measuring or observing a semiconductor device according to claim 1, wherein a liquid having a high refractive index is filled between the semiconductor device as the sample and the proximity lens. From the back surface side of the substrate to the semiconductor device having a circuit pattern formed on the surface of the substrate, irradiating illumination light through an objective lens and a proximity lens disposed between the objective lens and the semiconductor device, Detecting reflected light from the semiconductor device irradiated with the illumination light through the proximity lens and the objective lens to measure or observe an optical image of a pattern formed on the substrate; Of measuring or observing a semiconductor device. 7. The method for measuring or observing a semiconductor device according to claim 6, wherein the proximity lens is arranged so as to be close to or in contact with the back surface of the substrate of the semiconductor device. 7. The method according to claim 6, wherein the proximity lens has substantially the same refractive index as a substrate of the semiconductor device. 7. The method according to claim 6, wherein the proximity lens is made of the same material as the substrate of the semiconductor device. The method for measuring or observing a semiconductor device according to claim 6, wherein the proximity lens has an intermediate refractive index between a refractive index of a substrate of the semiconductor device and a refractive index of air. The method for measuring or observing a semiconductor device according to claim 6, wherein a liquid having a high refractive index is filled between the semiconductor device and the proximity lens. A voltage is applied to a desired portion of the circuit pattern of a semiconductor device having a circuit pattern formed on a substrate, and illumination light is applied to the surface of the semiconductor device with the voltage applied through an objective lens and a proximity lens. Irradiation is performed while scanning, a current flowing through the desired portion of the circuit pattern irradiated with the illumination light is detected in synchronization with the scanning, and a signal of the detected current flowing through the desired portion and the illumination light are detected. A method for measuring or observing a semiconductor device, comprising: obtaining an image of the circuit pattern by using the information of the above scanning; and measuring or observing the circuit pattern by using the image. A desired area including the circuit pattern of a semiconductor device having a circuit pattern formed on a substrate is irradiated with illumination light while scanning through an objective lens and a proximity lens, and the desired area irradiated with the illumination light is irradiated. The current flowing in the circuit pattern is detected in synchronization with the scanning, and an image of the circuit pattern is obtained using the detected signal of the current flowing in the circuit pattern in the desired area and the information on the scanning of the illumination light. And measuring or observing the circuit pattern using the image. A desired portion including the circuit pattern of a semiconductor device having a circuit pattern formed on a substrate is irradiated with illumination light while scanning through an objective lens and a proximity lens, and the desired portion irradiated with the illumination light is irradiated. Measurement of a semiconductor device, wherein an image of the circuit pattern is obtained by detecting reflected light from the object through the objective lens and the proximity lens, and the circuit pattern is measured or observed using the image. Observation method. The method for measuring or observing a semiconductor device according to claim 12, wherein the proximity lens is arranged so as to approach or contact the semiconductor device as the sample. The method for measuring or observing a semiconductor device according to claim 12, wherein the proximity lens has substantially the same refractive index as a semiconductor device as the sample. The method for measuring or observing a semiconductor device according to claim 12, wherein the proximity lens is made of the same material as the semiconductor device as the sample. The method for measuring or observing a semiconductor device according to claim 12, wherein the proximity lens has an intermediate refractive index between a refractive index of a semiconductor device as the sample and a refractive index of air. . The method for measuring or observing a semiconductor device according to claim 12, wherein a liquid having a high refractive index is filled between the semiconductor device as the sample and the proximity lens. A light source that emits illumination light, an objective lens unit, a table unit on which a semiconductor device as a sample is mounted, and a proximity lens unit disposed between the objective lens unit and the sample mounted on the table unit. Irradiating means for irradiating the sample with illumination light emitted from the light source through the objective lens and the proximity lens means; and reflecting the reflected light from the sample irradiated with the illumination light by the irradiation means in the proximity Detecting means for detecting through the lens means and the objective lens means, and image obtaining means for obtaining an image of the sample from a signal obtained by detecting reflected light from the sample with the detecting means. Characteristic semiconductor device measurement or observation equipment. The measurement or measurement of a semiconductor device according to claim 20, wherein the image acquisition unit obtains an image of the pattern of the semiconductor device that is finer than a resolution determined by the wavelength of the illumination light and the specification of the objective lens unit. Observation device. 21. The apparatus according to claim 20, wherein the irradiation unit scans and irradiates the sample with the illumination light via the objective lens and the proximity lens unit. 21. The apparatus for measuring or observing a semiconductor device according to claim 20, wherein the proximity lens means is arranged in proximity to or in contact with the semiconductor device as the sample. 21. The apparatus for measuring or observing a semiconductor device according to claim 20, wherein the proximity lens unit has substantially the same refractive index as the semiconductor device as the sample. 21. The apparatus for measuring or observing a semiconductor device according to claim 20, wherein the proximity lens unit is made of the same material as the semiconductor device as the sample. 21. The apparatus for measuring or observing a semiconductor device according to claim 20, wherein the proximity lens unit has an intermediate refractive index between a refractive index of the semiconductor device as the sample and a refractive index of air. A light source for emitting illumination light, an objective lens means, a table means for mounting a semiconductor device having a circuit pattern formed on a substrate as a sample, and a table means for mounting the objective lens means and the sample mounted on the table means. Proximity lens means disposed therebetween, and irradiation means for scanning and irradiating illumination light emitted from the light source to a desired area including a circuit pattern of the semiconductor device via the objective lens and the proximity lens means Current detecting means for detecting, in synchronization with the scanning, a current flowing in a circuit pattern of the desired area irradiated with the illumination light by the irradiating means, and a circuit pattern of the desired area detected by the current detecting means A device for acquiring an image of the circuit pattern using a signal of a current flowing through the circuit and information of scanning of the illumination light. Vinegar measurement or viewing apparatus. Optical image detection means for detecting the optical image of the area irradiated with the illumination light by the irradiating means via the proximity lens and the objective lens, the reflected light from the area irradiated with the illumination light by the irradiating means, The measuring or observing apparatus for a semiconductor device according to claim 27, further comprising: 29. The measurement or observation of a semiconductor device according to claim 27, further comprising a voltage application unit configured to apply a voltage to a circuit pattern in a desired region of the semiconductor device to which the irradiation unit irradiates the illumination light. apparatus. 28. The apparatus for measuring or observing a semiconductor device according to claim 27, wherein the proximity lens means is arranged in proximity to or in contact with the semiconductor device as the sample.

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