Semiconductor failure analysis device

Abstract

The semiconductor failure analysis device (1) of the present invention includes: a tester (2) that applies a stimulation signal to a semiconductor device (100); a light source (3) that generates irradiation light (L1) irradiated onto the semiconductor device (100); a solid immersion lens (4) that is disposed on the optical path of the irradiation light (L1); a light detection unit (5) that receives the reflected light (L2) and outputs a detection signal corresponding to the reflected light (L2); an optical system (6) that is disposed between the light source (3) and the solid immersion lens (4), emits the irradiation light (L1) to the semiconductor device (100) via the solid immersion lens (4), and is disposed between the solid immersion lens (4) and the optical detection unit (5), and emits the reflected light (L2) received via the solid immersion lens (4) to the light detection unit (5); and a computer (7) that obtains information related to the failure location of the semiconductor device (100) using the detection signal. The light source (3) emits irradiation light (L1) having a center wavelength of 880 nm or more and 980 nm or less. The solid immersion lens (4) is formed of GaAs.

Description

Technical Field

[0001] The present invention relates to a semiconductor failure analysis device. Background Art

[0002] The miniaturization of semiconductor devices has been continuously progressing. Due to the miniaturization of semiconductor devices, it is desired to improve the exposure technology and patterning technology for manufacturing semiconductor devices. A technology for checking whether a semiconductor device manufactured by these technologies operates normally is also important. Also, in the case where a semiconductor device does not operate normally, a technology for clarifying the cause of the defect is also important.

[0003] Patent Documents 1 and 2 disclose devices for checking semiconductor devices. The checking devices disclosed in Patent Documents 1 and 2 irradiate light on a semiconductor device to which an electrical signal is applied. The light irradiated on the semiconductor device becomes reflected light corresponding to the state of the semiconductor device. Also, the checking devices disclosed in Patent Documents 1 and 2 use the reflected light to obtain information about the operating state of the semiconductor device. The checking device of Patent Document 1 obtains information about a part of a semiconductor device operating at a specified frequency. The checking device of Patent Document 2 obtains information about a heat source generated at a failure part of a semiconductor device.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 2014-92514

[0007] Patent Document 2: International Publication No. 2016 / 056110 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] In the technical field of semiconductor failure analysis devices, in order to analyze a finer region, a further improvement in resolution is desired.

[0010] The present invention provides a semiconductor failure analysis device capable of improving resolution.

[0011] Means for Solving the Problems

[0012] One aspect of the present invention is a semiconductor fault analysis device that analyzes a fault location included in a semiconductor device in response to a stimulus signal. The semiconductor fault analysis device includes: a signal generation unit that applies a stimulus signal to the semiconductor device; a light source that generates irradiation light irradiated onto the semiconductor device; a solid immersion lens disposed on the optical path of the irradiation light; a light detection unit that receives reflected light generated by reflection of the irradiation light on the semiconductor device and outputs a detection signal corresponding to the reflected light; an optical system disposed between the light source and the solid immersion lens, emits the irradiation light to the semiconductor device via the solid immersion lens, and is disposed between the solid immersion lens and the optical detection unit, and emits the reflected light received via the solid immersion lens to the light detection unit; and an analysis unit that obtains information related to the fault location of the semiconductor device from the detection signal. The light source emits irradiation light having a central wavelength of 880 nm or more and 980 nm or less, and the solid immersion lens is formed of gallium arsenide (GaAs).

[0013] In the case of determining the fault location of a semiconductor device to which a stimulus signal is applied, the semiconductor fault analysis device irradiates the semiconductor device with irradiation light having a central wavelength of 880 nm or more and 980 nm or less via a solid immersion lens formed of gallium arsenide. The irradiation light having a central wavelength of 880 nm or more and 980 nm or less sufficiently passes through the semiconductor device, which is the object to be analyzed. Therefore, reflected light having a light intensity capable of determining the fault location can be obtained. In addition, the refractive index of the solid immersion lens formed of gallium arsenide is higher than the refractive index of air. Therefore, the numerical aperture (NA) can be increased. As a result, since the spot diameter of the irradiation light can be reduced, the resolution can be improved.

[0014] In one aspect, the light source may also emit irradiation light having a central wavelength of 900 nm or more and 960 nm or less. According to this configuration, the resolution can be appropriately improved.

[0015] In one aspect, the analysis unit may also include a heat source position determination unit. The heat source position determination unit may also determine the position of a heat source generated in the semiconductor device in response to the stimulus signal based on the detection signal and the stimulus signal. According to this configuration, the position of the heat source generated inside the semiconductor device can be determined.

[0016] In one aspect, the analysis unit may also include an operating frequency determination unit. The operating frequency determination unit may also determine a position that operates at a specified frequency generated in the semiconductor device in response to the stimulus signal based on the detection signal and the stimulus signal. According to this configuration, the position that operates at the specified frequency generated in the semiconductor device can be determined.

[0017] Effects of the Invention

[0018] According to the present invention, there is provided a semiconductor fault analysis device capable of improving the resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. 1 is a block diagram showing structural elements of a semiconductor failure analysis device.

[0020] Figure 2 FIG. 2 is a diagram for explaining an example of a means for determining a failure location of a semiconductor device.

[0021] Figure 3 FIG. 3 is a graph showing the relationship between the wavelength of light and the light transmittance for each material constituting a solid immersion lens.

[0022] Figure 4 FIG. 4 is a graph showing the relationship between the wavelength of light and the refractive index for each material constituting a solid immersion lens.

[0023] Figure 5 FIG. 5 is a graph showing the relationship between the wavelength of light and the light transmittance of a solid immersion lens formed of gallium arsenide.

[0024] Figure 6 FIG. 6 is a graph showing the light transmittance of silicon. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, a mode for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are given to the same elements, and redundant description is omitted.

[0026] As shown in Figure 1 FIG. 1, the semiconductor failure analysis device determines a failure location included in an object to be inspected, such as a semiconductor device 100. In the following description, the semiconductor failure analysis device is simply referred to as the analysis device 1.

[0027] Examples of the semiconductor device 100 include integrated circuits having a PN junction such as transistors (e.g., small-scale integration (SSI), medium-scale integration (MSI), large-scale integration (LSI), very large-scale integration (VLSI), ultra large-scale integration (ULSI), giga-scale integration (GSI)), power devices such as MOS transistors for high current / high voltage use and bipolar transistors, and memory / storage devices.

[0028] In addition, the object to be inspected is not limited to the fixed semiconductor device 100. The object to be inspected may also be a semiconductor wafer on which a plurality of semiconductor devices 100 are formed.

[0029] Figure 2 It is a diagram conceptually showing a method for determining a failure location. Figure 2 The state in which the semiconductor device 100 shown is arranged in the analysis device 1. In Figure 2 it, the surface receiving the irradiation light L1 is shown as the upper side. The semiconductor device 100, as an example, has a stacked structure including a protective layer 101, a wiring layer 102, a process layer 103, an insulating layer 104, and a substrate 105. The wiring layer 102 includes a wiring pattern made of a metal such as gold or aluminum. The process layer 103 includes a plurality of electrical functional parts such as MOS transistors 103a. The substrate 105 is formed of silicon. The thickness of the substrate 105 is 50 nm or more and about 200 nm. The thickness of the substrate 105, as an example, is 80 nm. If light is irradiated on the semiconductor device 100, the light passes through a certain layer. In addition, the light is reflected by other layers. For example, if light is irradiated from the side of the substrate 105, there is light passing through the substrate 105 and the insulating layer 104. In addition, if light is irradiated from the side of the substrate 105, there is light reflected by the process layer 103.

[0030] The intensity of the reflected light is basically less than the intensity of the irradiation light L1. That is, the intensity of the reflected light is attenuated because the light is received during passing through the substrate 105 and the insulating layer 104. For example, the light is affected by the light transmittance of the material constituting the substrate 105. In addition, the intensity of the light is also affected by the refractive index of the material constituting the optical path. And the intensity of the light is also affected by the electric field formed in the layer constituting the optical path. Therefore, the ratio of the intensity of the reflected light to the intensity of the incident light is defined as the apparent reflectance. The change in the reflectance reflects the change in the refractive index and the influence of the electric field. Therefore, by obtaining the distribution of the reflectance, the state inside the semiconductor device 100 can be known. For example, it is assumed that a portion 102a having a high resistance value is generated in the wiring layer 102, and Joule heat is generated at the portion 102a. As a result, a portion 105a where the refractive indices of the insulating layer 104 and the substrate 105 change due to the Joule heat and the temperature rises is generated. The change in the refractive index is manifested as a change in the reflectance. That is, by knowing the distribution of the reflectance, it becomes possible to determine the position of the portion where abnormal heat generation occurs. The position of the portion where abnormal heat generation occurs refers to the position of the failure location.

[0031] Refer to again Figure 1 . The analysis device 1 has: a tester 2 (signal generation unit), a light source 3, a solid immersion lens 4, a light detection unit 5, an optical system 6, and a computer 7. The analysis device 1 may also have other additional structural elements. For example, the analysis device 1 may have a stage for relatively moving the semiconductor device 100 with respect to the optical system 6.

[0032] The tester 2 outputs a stimulus signal. The tester 2 is connected to the semiconductor device 100. The tester 2 applies a stimulus signal to the semiconductor device 100. The tester 2 generates a stimulus signal based on the control signal input from the computer 7. The tester 2 starts and stops the output of the stimulus signal based on the control signal. The characteristics of the stimulus signal can also be determined according to the analysis method. In addition, a power supply or a pulse generator, etc. can also be used as the tester 2.

[0033] For example, one way of analysis is the determination of the heat source position. In the case of determining the heat source position, the tester 2 applies a modulation current with a relatively low frequency as the stimulus signal. For example, in the case where a short-circuited part is included inside the semiconductor device 100, the short-circuited part heats up due to the modulation current. As a result, a heat source is generated in the semiconductor device 100. The temperature of the heat source heated by the modulation current changes periodically according to the frequency of the modulation current. The change in temperature exists around the heat source and causes a change in the refractive index of the member through which the irradiated light and the reflected light pass. The change in the refractive index causes a change in the intensity of the reflected light. As a result, the reflectance, which is the degree of the intensity of the reflected light relative to the intensity of the irradiated light, changes. By using the change in reflectance caused by the temperature change of the heat source as the response to the stimulus signal, the short-circuited part, which is an example of the faulty part included in the semiconductor device 100, can be determined.

[0034] For example, another way of analysis is to determine the circuit position operating at the target frequency. As such an analysis technique, an optical detection technique is known. The optical detection technique is also called EOP (Electro Optical Probing) or EOFM (Electro-Optical Frequency Mapping). In the optical detection technique, the light emitted from the light source is irradiated onto the integrated circuit. Then, the reflected light reflected by the integrated circuit is detected by the optical sensor. Then, a detection signal is obtained from the optical sensor. And, a signal component having the target frequency is selected from the obtained detection signal. The amplitude energy of the signal component is expressed as a time process. In addition, the amplitude energy is expressed as a two-dimensional mapping. That is, in the optical detection technique, the fault analysis of the semiconductor device 1 for the semiconductor device 100 is performed based on the intensity modulation of the light emitted from the semiconductor device 100 during operation. Therefore, the tester 2 applies an electrical signal having a specified modulation frequency to the semiconductor device 100. The modulation frequency in this case can also be higher than the frequency of the stimulus signal for the analysis of determining the heat source device. For example, the tester 2 applies a drive current having the same frequency as the drive signal of the semiconductor device 100 as the stimulus signal.

[0035] As described above, there are several ways of analysis. However, the differences are, first, the way of applying the stimulation signal to the semiconductor device 100, and second, the content of processing the detection signal corresponding to the stimulation signal. That is, even if the ways of analysis are different, the structure of the analysis device 1 is substantially the same.

[0036] The light source 3 generates the irradiation light L1. The center wavelength of the irradiation light L1 may also be 880 nm or more and 980 nm or less. When the center wavelength is 880 nm or more and 980 nm or less, the irradiation light L1 may also have a frequency band of about 20 nm. The center wavelength of the irradiation light L1 may also be 900 nm or more and 960 nm or less. When the center wavelength is 900 nm or more and 960 nm or less, the irradiation light L1 may also have a frequency band of about 20 nm.

[0037] The light source 3 may also appropriately adopt a structure capable of emitting the irradiation light L1 having the above wavelength characteristics. For example, the light source 3 may be composed of an SLD (Super Luminescent Diode) or an LED (Light Emitting Diode). In addition, the light source 3 may be composed of an incoherent light source such as a combination of a lamp light source and an optical filter such as a band-pass filter. The light source 3 may also be a laser light source such as an LD (Laser Diode). The irradiation light L1 may also be CW light. The irradiation light L1 may also be pulsed light.

[0038] The irradiation light L1 output from the light source 3 first enters the optical system 6. The optical system 6 guides the irradiation light L1 to the solid immersion lens 4. For example, the optical system 6 includes a polarization beam splitter 61 and an objective lens 62. And, in addition to these, the optical system 6 may also appropriately adopt an optical system for the irradiation light L1. For example, the optical system 6 may also include an optical scanner. The optical scanner changes the irradiation position of the irradiation light L1 on the semiconductor device 100. The optical scanner is, for example, a galvanometer scanner, a polygon mirror scanner, a MEMS (Micro-Electro-Mechanical System) mirror scanner, etc. The optical scanner guides the irradiation light L1 to a desired position on the semiconductor device 100. The irradiation light L1 output from the optical system 6 is irradiated on the semiconductor device 100 via the solid immersion lens 4. More specifically, the irradiation light L1 is irradiated on the measurement point set for the semiconductor device 100.

[0039] The solid immersion lens 4 has a hemispherical shape or a super-hemispherical shape. The solid immersion lens 4 is optically closely attached to the semiconductor device 100. The solid immersion lens 4 irradiates the position to be analyzed in the semiconductor device 100 while condensing the irradiation light L1. Therefore, the material constituting the solid immersion lens 4 has the property of transmitting the irradiation light L1 irradiated on the semiconductor device 100. Similarly, the material constituting the solid immersion lens 4 has the property of transmitting the reflected light L2 emitted from the semiconductor device 100.

[0040] As a material having the property of transmitting light, the solid immersion lens 4 is made of gallium arsenide (GaAs). Hereinafter, the light transmittance as an optical characteristic of GaAs will be described. Figure 3 The light transmittance of GaAs is shown. In addition, in Figure 3 , as a comparative example, the light transmittances of gallium phosphide (GaP) and silicon (Si) are also shown together. The horizontal axis represents the wavelength of light. The vertical axis represents the light transmittance. The curves G3a to G3e show the light transmittance of GaAs. The curve G3f shows the light transmittance of GaP. The curve G3g shows the light transmittance of Si.

[0041] If reference is made to the curves G3a to G3e, it can be seen that GaAs has the property of transmitting light with a wavelength longer than 850 nm. More specifically, in the relationship between the light transmittance and the wavelength of light, GaAs has a frequency band in which the light transmittance changes sharply. The wavelength included in such a frequency band is also simply referred to as the cut-off wavelength. The cut-off wavelength of GaAs exists in the range of, for example, 880 nm or more and 980 nm or less. If the wavelength of light changes from the short wavelength side to the long wavelength side, the light transmittance increases sharply from 0% to 80% or more. And the relationship between the light transmittance and the wavelength of light also changes according to the temperature of GaAs. The curves G3a to G3e show the light transmittances at temperatures of 0 °C (curve G3a), 50 °C (curve G3b), 100 °C (curve G3c), 150 °C (curve G3d), and 200 °C (curve G3e), respectively. That is, as the temperature of GaAs becomes higher, the cut-off wavelength at which the light transmittance changes sharply shifts to the long wavelength side.

[0042] As the material of the solid immersion lens, GaP is sometimes used, for example. If reference is made to the curve G3f, it can be seen that GaP transmits light with a wavelength longer than 500 nm. For example, the cut-off wavelength of GaP is roughly included in the range of 500 nm or more and 600 nm. That is, the cut-off wavelength of GaP is shorter than that of GaAs. In other words, the cut-off wavelength of GaAs is longer than that of GaP.

[0043] As a material for a solid immersion lens, Si is sometimes used, for example. Referring to curve G3g, it can be seen that Si transmits light with a wavelength longer than 1000 nm. For example, the cut-off wavelength of Si with a thickness that can be effectively used as a solid immersion lens is included in the range of approximately 1000 nm or more and 1200 nm. That is, the cut-off wavelength of the Si solid immersion lens is longer than that of GaAs. In other words, the cut-off wavelength of GaAs is shorter than that of Si.

[0044] Another optical property of GaAs, namely the refractive index, will be described. Figure 4 It shows the relationship between the refractive indices of GaAs, GaP, and Si and the wavelength. Curve G4a shows the refractive index of GaAs. Curve G4b shows the refractive index of GaP. Curve G4c shows the refractive index of Si. For example, according to curve G4a, the refractive index of GaAs is in the range of 3.40 or more and 4.40 or less. For example, when the wavelength of the incident light is 1064 nm, the refractive index of GaAs is 3.47. In addition, when the wavelength of the incident light is 940 nm, the refractive index of GaAs is 3.57.

[0045] The refractive index of GaAs is higher than that of GaP shown by curve G4b, for example. More specifically, in the entire range of 500 nm to 1500 nm shown on the horizontal axis of Figure 4 , the refractive index of GaAs is higher than that of GaP. For example, when the wavelength of the incident light is 780 nm, the refractive index of GaP is 3.21. In addition, when the wavelength of the incident light is 670 nm, the refractive index of GaP is 3.27. Therefore, GaAs is more advantageous than GaP in terms of a higher refractive index for improving the resolution.

[0046] Referring again to Figure 1 . The light (reflected light L2) reflected at the measurement point corresponding to the irradiation light L, passes through the solid immersion lens 4 and the objective lens 62 and is input to the polarization beam splitter 61. At this time, by arranging a short-pass filter in the optical path of the reflected light L2, the infrared rays generated in the semiconductor device 100 can be blocked. And the light incident on the polarization beam splitter 61 passes through the λ / 4 plate twice. As a result, the polarization direction is inclined. The reflected light with the inclined polarization direction passes through the polarization beam splitter 61. The reflected light L2 that has passed through the polarization beam splitter 61 is input to the light detection unit 5.

[0047] Thus, the optical system of this embodiment is a confocal optical system. The optical system of this embodiment can detect the reflected light L2 from a limited focal range. As an element constituting the confocal optical system, a pinhole can also be used. In addition, as an element constituting the confocal optical system, a structure utilizing the refractive index difference between the core and the cladding of an optical fiber can also be used.

[0048] The light detection unit 5 detects the light intensity and the like of the reflected light L2 corresponding to the irradiated light L1 reflected by the semiconductor device 100. The light detection unit 5 converts the detected reflected light L2 into an analog signal, i.e., a detection signal. Further, the light detection unit 5 outputs the detection signal. The light detection unit 5 is an APD (Avalanche PhotoDiode), a PD (PhotoDiode), a PMT (PhotoMultiplier Tube), a SiPM (Silicon photomultipliers), or the like.

[0049] The computer 7 includes a data analysis unit 71 and a control unit 72. The data analysis unit 71 determines the failure location of the semiconductor device 100. The control unit 72 controls the operations of various elements constituting the analysis device 1. Physically, the computer 7 includes: memories such as RAM and ROM, a processor (arithmetic circuit) such as a CPU, a communication interface, and a storage unit such as a hard disk. Examples of the computer 7 include a personal computer, a cloud server, and an intelligent device (such as a smart phone or a tablet terminal). The computer 7 functions by executing a program stored in the memory by the CPU of the computer system. Further, the data analysis unit 71 may include a processing unit corresponding to the analysis method. For example, the data analysis unit 71 includes a heat source position determination unit 71a and / or an operation frequency determination unit 71b. The heat source position determination unit 71a performs processing for determining the heat source position. The operation frequency determination unit 71b performs processing for determining the position that operates at a specified frequency generated in the semiconductor device as a response to the stimulus signal based on the detection signal and the stimulus signal.

[0050] The control unit 72 includes, for example, a light control unit 72a and a tester control unit 72b. The light control unit 72a outputs a control signal to the light source 3 and the optical system 6. Examples of such a control signal include a signal for driving the light scanner to scan the irradiated light L (1). The tester control unit ](72b outputs a control signal for controlling the stimulus signal output from the tester 2 to the semiconductor device 100.

[0051] <Effect>

[0052] Analysis device 1, when determining the failure location of semiconductor device 100 to which a stimulation signal is applied, irradiates semiconductor device 100 with irradiation light L1 having a central wavelength of 880 nm or more and 980 nm or less via solid immersion lens 4 formed of GaAs. The irradiation light L1 having a central wavelength of 880 nm or more and 980 nm or less sufficiently penetrates semiconductor device 100 formed of silicon, which is the object to be analyzed. As a result, reflected light L2 having a light intensity capable of determining the failure location can be obtained. Further, the refractive index of solid immersion lens 4 formed of GaAs is higher than the refractive indices of air and GaP. Therefore, the numerical aperture (NA) can be increased. As a result, the spot diameter of irradiation light L1 can be reduced. Therefore, the resolution can be improved.

[0053] If a stimulation signal is applied to semiconductor device 100, heat is generated in the pattern wiring or the electrical functional part regardless of the mode of the stimulation signal. Further, at the failure location, there is a tendency for the degree of heat generation to increase. In the analysis using such heat generation, the combination of irradiation light L1 having a central wavelength of 880 nm or more and 980 nm or less and solid immersion lens 4 formed of GaAs is particularly advantageous.

[0054] Figure 5 And Figure 3 Similarly, the relationship between the wavelength of GaAs and the light transmittance is shown. Figure 5 The range from 890 nm to 960 nm is enlarged and shown. Curves G5a to G5f respectively show the light transmittance of GaAs when the temperature of GaAs is 60 °C (curve G5a), 70 °C (curve G5b), 80 °C (curve G5c), 90 °C (curve G5d), 100 °C (curve G5e), and 110 °C (curve G5f). For example, assume that the wavelength of irradiation light L1 is 920 nm. Further, assume that the temperature of solid immersion lens 4 varies between 60 °C and 110 °C. In this case, the light transmittance of solid immersion lens 4 varies in the range from 5% to 70%. That is, the light transmittance of solid immersion lens 4 varies significantly depending on the temperature of solid immersion lens 4.

[0055] The irradiation light L1 and the reflected light L2 pass not only through the substrate 105 of the semiconductor device 100 etc., but also through the solid immersion lens 4. Moreover, when the irradiation light L1 and the reflected light L2 pass through the solid immersion lens 4, they are affected by the change in light transmittance caused by the temperature change of the solid immersion lens 4. That is, the irradiation light L1 and the reflected light L2 are affected by the refractive index of the semiconductor device 100 whose temperature changes due to the heat emitted from the heat source. Also, the irradiation light L1 and the reflected light L2 are affected by the change in the light transmittance of the solid immersion lens 4. As a result, since the light intensity of the reflected light L2 changes significantly due to heat generation, the change in reflectivity also becomes large. Thus, even if the temperature difference at each measurement position is very small, it appears as a large change in reflectivity. Therefore, the resolution for temperature can be improved.

[0056] In short, since the central wavelength of the irradiation light L1 is included in the frequency band of the cut-off frequency of GaAs, the resolution for temperature is improved. That is, the central frequency of the irradiation light L1 can also be set to a value that obtains a large change in light transmittance within the temperature range including normal temperature and abnormal temperature. For example, in the case where the normal temperature is 60°C and a temperature of 100°C or higher is determined as abnormal, the central wavelength can also be set to 920 nm. According to this setting, in the case of a heat source that heats the solid immersion lens 4 to 100°C or higher, a phenomenon of a significant decrease in reflectivity occurs.

[0057] In addition, according to the combination of the irradiation light L1 with a central wavelength of 880 nm or more and 980 nm or less and the solid immersion lens 4 formed of GaAs, the reflected light L2 with sufficient light intensity for analysis can be obtained. For example, as Figure 2 shown, when the irradiation light L1 and the reflected light L2 pass through the substrate 105, they attenuate corresponding to the light transmittance of silicon. Figure 6 The curve G6 of [Figure number not provided] shows the relationship between the thickness of the substrate 105 formed of silicon and the light transmittance. In addition, the curve G6 shows the light transmittance when the wavelength of the light is 940 nm. The horizontal axis represents the thickness of the substrate 105. The vertical axis represents the light transmittance. As Figure 6 shown, if the thickness of the substrate 105 becomes thicker, the light transmittance decreases.

[0058] For example, when the thickness of the substrate 105 of the semiconductor device 100 is 80 μm which is commonly used, the light transmittance is about 23%. In addition, when the thickness of the substrate 105 of the semiconductor device 100 is 40 μm, it is about 48%. Based on these light transmittances, the reflected light L2 with a light intensity that can be used for various analyses can be obtained. That is, there is no need to thin the substrate 105 by grinding or the like in order to obtain the reflected light L2 with sufficient light intensity. As a result, when performing failure analysis of the semiconductor device 100, there is no need for additional operations such as grinding the substrate 105. Therefore, the failure analysis can be simply performed. And if the substrate 105 is thinned, the processing of the semiconductor wafer becomes difficult. However, according to the present embodiment, even for the semiconductor device 100 having the commonly used substrate thickness, the analysis can be performed without grinding the substrate 105. Therefore, the semiconductor wafer can be easily processed.

[0059] The above describes one embodiment of the present invention. The present invention is not limited to the above embodiment.

[0060] For example, regarding the arrangement of the optical system 6 and the solid immersion lens 4 with respect to the semiconductor device 100, in the above embodiment, an example is shown in which the irradiation light L1 is provided to the semiconductor device 100 on the substrate 105 side, and the reflected light L2 output from the substrate 105 side is detected. For example, the irradiation light L1 may also be provided to the semiconductor device from the upper side ( Figure 2 the protective layer 101 side). In this case, the solid immersion lens 4 is provided on the protective layer 101 of the semiconductor device 100. Or, it may be configured to irradiate the semiconductor device 100 with inspection light from one of the upper side and the lower side, and detect electromagnetic waves from the other side. In this case, the solid immersion lenses 4 are respectively provided on both the upper side and the lower side of the semiconductor device.

[0061] Symbol Description

[0062] 1... analysis device (semiconductor failure analysis device), 2... tester (signal generation unit), 3... light source, 4... solid immersion lens, 5... light detection unit, 6... optical system, 7... computer (analysis unit), 61... polarization beam splitter, 62... objective lens, 71... data analysis unit, 71a... heat source position determination unit, 71b... operation frequency determination unit, 72... control unit, 72a... light control unit, 72b... tester control unit, 100... semiconductor device, L1... irradiation light, L2... reflected light.

Claims

1. A semiconductor fault analysis device, wherein, it is a semiconductor fault analysis device that analyzes the fault location included in a semiconductor device by using the response to a stimulus signal, the semiconductor fault analysis device includes: a signal generation unit that applies a stimulus signal to the semiconductor device; a light source that generates CW light as irradiation light irradiated on the semiconductor device; a solid immersion lens disposed on the optical path of the irradiation light; a light detection unit that receives the reflected light generated by the reflection of the CW light on the semiconductor device and outputs a detection signal corresponding to the reflected light; an optical system disposed between the light source and the solid immersion lens, emits the CW light to the semiconductor device via the solid immersion lens, and is disposed between the solid immersion lens and the light detection unit, and emits the reflected light received via the solid immersion lens to the light detection unit; and an analysis unit that obtains information related to the fault location of the semiconductor device from the detection signal, the light source emits the CW light having a center wavelength of 880 nm or more and 980 nm or less, the solid immersion lens is formed of gallium arsenide (GaAs) having a characteristic of changing the light transmittance in a wavelength range of 880 nm or more and 980 nm or less, and the characteristic of the change in light transmittance moves to the long wavelength side as the temperature increases, the wavelength of the reflected light includes the center wavelength of the irradiation light, when the reflected light passes through the solid immersion lens, the light intensity changes due to the influence of the change in the light transmittance of the solid immersion lens caused by the temperature change of the solid immersion lens, the analysis unit uses the detection signal based on the reflected light to obtain information related to the fault location of the semiconductor device, and the reflected light generates a change in light intensity according to the light transmittance of the solid immersion lens corresponding to the temperature of the solid immersion lens.

2. The semiconductor fault analysis device according to claim 1, wherein, the light source emits the irradiation light having a center wavelength of 900 nm or more and 960 nm or less.

3. The semiconductor fault analysis device according to claim 1 or 2, wherein, the analysis unit has a heat source position determination unit, the heat source position determination unit determines the position of the heat source generated in the semiconductor device as a response to the stimulus signal based on the detection signal and the stimulus signal.

4. The semiconductor fault analysis device according to claim 1 or 2, wherein, the analysis unit has an operating frequency determination unit, the operating frequency determination unit determines the position that operates at a prescribed frequency generated in the semiconductor device as a response to the stimulus signal based on the detection signal and the stimulus signal.

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