JP2011258509A - Electron beam detector, electron beam application device and observation method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem for an electron beam application device that, spacial restriction makes it difficult to simultaneously arrange a plurality of electron beam detectors and electromagnetic wave generation means, even though that will enhance performance.SOLUTION: A electron beam application device has a configuration 100 in which electron beam detectors (102, 105) and electromagnetic wave generation means (102, 104, 108, 109) are simultaneously arranged, whereby a plurality of electron beam detectors and electromagnetic wave generation means can be arranged inside the electron beam application device to enable stable image observation in a long term due to potential control of a sample surface and/or removing contaminant by the electromagnetic wave generation means.

Description

  The present invention relates to an electron beam application apparatus for observing, inspecting, and processing a fine sample and an observation method using the same.

  Electron beam application apparatuses that perform observation, inspection, and processing of minute samples include electron microscopes, electron beam inspection and measurement apparatuses, and electron beam drawing apparatuses. These devices have means to detect the electron beam, and detect the shape, surface state, and internal structure of the sample by detecting the electrons that pass through the sample, secondary electrons generated from the sample, Auger electrons, backscattered electrons, etc. Observe, inspect and process.

  Furthermore, in order to perform high-precision observation, inspection, and processing, the shape, position, and current of the electron beam itself are calibrated by detecting primary electrons and backscattered electrons. In particular, in the observation, inspection, and processing of semiconductor devices, high resolution and measurement accuracy of the electron beam are improved to cope with the miniaturization and diversification that is progressing year by year, and high throughput and long time are maintained to maintain productivity. It is necessary to realize the stability. For this reason, electron beam detectors require high sensitivity, low noise, long-term stability, and fast response.

  Conventionally, as means for detecting an electron beam, a Faraday cup, a phosphor and a photomultiplier tube (see, for example, Patent Document 2), a semiconductor detector, an MCP (Microchannel Plate), and the like are used. Furthermore, as disclosed in Patent Document 1, an electron beam detector of a type that detects an electromagnetic wave generated by irradiating a compound semiconductor with an electron beam has been proposed. Furthermore, in scanning electron microscopes (SEM), electron beam inspection devices, etc., various sample information can be obtained according to the emission energy and emission angle of the generated electrons, so a detector with high S / N, long-term stability, and high response can be obtained. Arrangement of a plurality is effective in an electron microscope.

  On the other hand, when an electron beam is irradiated onto a sample containing an insulator, the sample is charged, resulting in misalignment of the electron beam and changes in the amount of secondary electrons that can be detected, which are also highly accurate for observation, inspection, and processing. It will be a big evil. In particular, when acquiring a potential contrast image according to the potential state of the sample, since it is sensitive to changes in the charged potential of the sample, the image change during irradiation is large, making stable observation difficult.

  Furthermore, in the SEM and the electron beam inspection apparatus, it is possible to acquire the electrical characteristics of the sample by actively controlling the potential state of the sample. As these means, as disclosed in Patent Document 3, charging control means using electromagnetic waves of various wavelengths is effective. Furthermore, as disclosed in Patent Document 4, electromagnetic waves such as ultraviolet light are effective for removing contamination by electron beams, and in an electron beam application apparatus, having an electromagnetic wave light source such as ultraviolet light greatly improves apparatus performance. .

  Laser light sources and the like have been proposed for ultraviolet light and other electromagnetic wave irradiation means. The laser light source generally includes an excitation source, a laser medium that causes stimulated emission by light emission from the excitation source, and a resonator that resonates the amplified light emission by a reflecting mirror or the like. A small and relatively inexpensive semiconductor laser is advantageous as a light source that can be mounted on an electron beam application apparatus having a large spatial restriction. In recent years, as disclosed in Patent Document 5, a semiconductor laser using electron beam excitation has also been proposed.

Japanese Patent No. 04466995 Japanese Patent No. 04365255 JP 2008-16858 A JP 2004-14960 A Japanese Patent No. 3667188

  However, it is extremely difficult to arrange a high-performance electron beam detector and a light source at appropriate positions in an electron beam application apparatus for the following reason. The electron beam detector and the light source need to be arranged in the vicinity of the optical path of the sample and the electron for any purpose. These optical paths include a lens arrangement that maintains high resolution in the primary beam, a current adjustment mechanism, a beam ON / OFF mechanism, a control mechanism for the charged potential on the sample, and signals based on energy and angle such as secondary electrons and backscattered electrons. There is a discriminating mechanism (multiple electron beam detectors) and so on, and spatial restrictions are very large.

  In electron beam application equipment, these various functions are provided to improve the performance of the equipment. Therefore, it is extremely difficult to place multiple electron beam detectors and electromagnetic wave generation means such as ultraviolet light at appropriate positions. Have difficulty.

  As described above, the electron beam application apparatus can improve performance by having a plurality of electron beam detectors and electromagnetic wave generation. However, it is very difficult to properly arrange them in the optical path of primary electrons and detected electrons.

  An object of the present invention is to provide an electron beam application apparatus including an electron beam detector and an electromagnetic wave generating means, and an electron beam observation method capable of observing while irradiating electromagnetic waves.

  As one embodiment for achieving the above object, a semiconductor device that emits light when irradiated with an electron beam, a means for separating or selecting an electromagnetic wave emitted from the semiconductor device, and a means for detecting a part of the electromagnetic wave And an electron beam application apparatus having an electron beam detector with a built-in electromagnetic wave generating means that has both means for emitting another part of the electromagnetic wave and has both the electron beam detector and the electromagnetic wave generating means.

  In addition, an electron beam observation method using an electron beam application apparatus equipped with the electron beam detector with the built-in electromagnetic wave generating means is adopted.

  Provided is an electron beam application apparatus having a configuration in which both an electron beam detector and an electromagnetic wave generating means are provided by incorporating an electromagnetic wave generating means in an electron beam detector, and an electron beam observation method capable of observing while irradiating electromagnetic waves be able to. As a result, for example, a number of electron beam detectors with built-in electromagnetic wave generating means are placed in locations that cannot be placed conventionally due to spatial constraints, and the potential on the sample surface can be controlled by emitting electromagnetic waves therefrom. Become. This makes it possible to simultaneously observe samples made of various materials according to the use of the electron beam application apparatus without reducing the resolution of the electron beam. In addition, since the potential of the sample under observation can be controlled to be constant, it is possible to acquire a stable image with little image drift and sample information change. In addition, contamination of the specimen and reflector due to electron beam irradiation can be removed, enabling stable image observation over a long period of time.

1 is a schematic cross-sectional view of an electron beam detector with built-in electromagnetic wave generating means for an electron beam application apparatus according to a first embodiment of the present invention. It is a schematic sectional drawing of the electron beam semiconductor test | inspection and analysis apparatus provided with the electron beam detector with a built-in electromagnetic wave generation means based on 2nd Example of this invention. It is a schematic sectional drawing of the electron microscope which has an out lens type | mold objective lens based on the 2nd Example of this invention. It is a schematic sectional drawing of the electron microscope which has an in-lens type | mold objective lens based on the 2nd Example of this invention. It is a schematic sectional drawing of the electron beam detector with a built-in electromagnetic wave generation means for electron beam application apparatuses concerning the 3rd example of the present invention. FIG. 6 is a schematic cross-sectional view of an electron beam semiconductor inspection and analysis apparatus including the electron beam detector with built-in electromagnetic wave generating means shown in FIG. 5 according to a fourth embodiment of the present invention. It is a schematic sectional drawing of the electron beam application apparatus which has a gas introduction means based on the 5th Example of this invention. It is a schematic sectional drawing of the semiconductor inspection and analysis apparatus of the multi-beam system based on the 6th Example of this invention. It is a schematic sectional drawing of the electron beam detector which has a laser excitation structure with a built-in electromagnetic wave generation means for electron beam application apparatuses concerning the 7th example of the present invention. FIG. 6 is a correlation diagram between a bias current and laser output in laser excitation. It is the schematic of the secondary electron image in a semiconductor inspection apparatus.

  There are spatial restrictions in the housing, and it is difficult to provide a separate electromagnetic wave generating means. As a result of studying this problem, the inventors have come to realize that, in an electron beam detector that generates an electromagnetic wave by an electron beam, a part of the generated electromagnetic wave can be used as an electromagnetic wave generating means. The present invention was born from this finding.

  Hereinafter, the embodiment will be described.

  A first embodiment will be described with reference to FIG. FIG. 1 is a schematic sectional view of an electron beam detector with built-in electromagnetic wave generating means for an electron beam application apparatus according to the first embodiment. When the semiconductor device 102 is irradiated with the electron beam 101, an electromagnetic wave 103 is generated. The semiconductor device 102 includes a metal layer 102a, a semiconductor doped layer and active layer 102b, and a substrate layer 102c. Here, since the semiconductor device 102 has sensitivity to the electron beam 101, the electron beam 101 incident from the surface needs to reach the semiconductor doped layer and the active layer 102b. For this reason, the stacked thickness of the metal layer 102a, the semiconductor doped layer, and the active layer 102b in the semiconductor device is formed below the range of the irradiated electron beam.

  The metal layer 102a is configured to reflect the electromagnetic wave 103, and the semiconductor device 102b is configured of a direct transition type compound semiconductor such as a nitride semiconductor. Although a compound semiconductor is used here, any semiconductor that generates an electromagnetic wave by electron beam irradiation can be used. The substrate layer 102 c is configured to have a high transmittance with respect to the electromagnetic wave 103. In particular, InGaN having a quantum well structure in the semiconductor doped layer and the active layer in the active layer 102b has good light emission efficiency, and can be expected to be responsive and long-term stable. The electromagnetic wave 103 has a wavelength range from ultraviolet to infrared.

  The generated electromagnetic wave 103 is separated into electromagnetic waves 107a and 107b by an electromagnetic wave separating means 104 such as a half mirror. The electromagnetic wave 107a is detected by the electromagnetic wave detecting means 105, and the current amount and energy of the electron beam can be measured based on the detection signal. Reference numeral 106 denotes detection signal transmission means. The electromagnetic wave 107 b enters the electromagnetic wave emission means 109 via the electromagnetic wave reflection means 108. The electromagnetic wave emitting means 109 is made of a material having a high transmittance with respect to the electromagnetic wave 107b. The electromagnetic wave emitting means 109 has directivity and is radiated to the outside from the electron beam detector 100 built in the electromagnetic wave generating means. The electromagnetic wave emitting means 109 is a transmission window through which electromagnetic waves can be transmitted, and a lens may be disposed in this portion.

  Furthermore, the electromagnetic wave separation means 104 changes the transmission / reflectance by selecting a material, and adjusts the strength of the electromagnetic waves 107a and 107b. The present embodiment is not limited to the above embodiment, and various modifications are possible. For example, the electromagnetic wave separation unit 104 may be an electromagnetic wave selection unit such as a filter, or may be configured to freely select the electromagnetic waves 107a and 107b. Further, the light emission from the semiconductor device 102 may be taken out in the direction perpendicular to the electron beam, and the semiconductor device 102 and the electromagnetic wave separating means 104 are used together to separate the light emission from the front and back surfaces of the semiconductor device. Is also effective. Further, the active layer of the semiconductor device 102 may be formed with a double hetero structure in addition to the quantum well structure.

  As described above, according to the present embodiment, the electron beam application apparatus having a configuration in which the electron beam detector and the electromagnetic wave generating means are compatible and the electron beam observation method capable of observing while irradiating the electromagnetic wave can be used. An electron beam detector with built-in electromagnetic wave generating means can be provided.

  A second embodiment of the present invention will be described with reference to FIGS. The contents described in the first embodiment can also be applied to this embodiment unless there are special circumstances.

  FIG. 2 is a schematic cross-sectional view of an electron beam application apparatus (electron beam semiconductor inspection and analysis apparatus) having an electron beam detector with built-in electromagnetic wave generation means according to the present embodiment. The electron beam semiconductor inspection and analysis apparatus 200 includes a vacuum casing 201, an electron source 203, two condenser lenses 204a and 204b, a current limiting diaphragm 205, a blanking mechanism 206 including a blanking electrode 206a and a blanking diaphragm 206b, a reflector. 207, E × B deflector 208, deflector 209, semi-in-lens type objective lens 210, charge control electrode 211, stage 212 on which the sample is mounted, electron beam detectors 100a and 100b with built-in electromagnetic wave generating means, detection signal amplification Means 213a, 213b, means 214 for selecting signals from two or more amplifier circuits, converting analog signals from the amplifier circuits into digital signals, means for controlling these, and means for outputting images (control computer) 215 Composed.

  The electron beam emitted from the electron source is adjusted to focus on the sample using two condenser lenses and an objective lens, and scanned on the sample using a deflector 209. The acceleration voltage of the electron beam is adjusted by the retarding voltage applied to the stage 212 on which the sample is mounted. Secondary electrons and backscattered electrons are generated from the sample by the electron beam irradiated on the sample. The charged potential of the sample is determined by the balance of electrons in the sample, and the charged potential is adjusted by adjusting the ratio of secondary electrons returned to the sample.

  Part of the backscattered electrons generated from the sample reaches the electron beam detector 100a built in the electromagnetic wave generating means. As described in the first embodiment, the semiconductor device 102 of the electron beam detector 100a with built-in electromagnetic wave generating means emits light according to the amount of incident electrons. A part of this light emission is detected by the electromagnetic wave detection means 105, and the detection signal is amplified by the detection signal amplification circuit 213a and transmitted to the subsequent stage.

  Further, part of the emitted light is returned to the sample as electromagnetic waves 107 c by the electromagnetic wave emission means 109. Here, by selecting the wavelength of the electromagnetic wave by changing the material of the semiconductor device 102, only a specific insulator can be made conductive, and charging can be removed. Further, as in Patent Document 3, electrification is controlled by selecting a wavelength that is absorbed only by a specific material, generating photoelectrons, and adjusting a rate at which the photoelectrons are returned to the sample by the electric field of the charge control electrode. Is possible.

  On the other hand, secondary electrons generated from the sample are partially pulled up by the electric field generated by the charge control electrode 211 and partially returned to the sample. A portion of the secondary electrons and backscattered electrons that have passed through the objective lens 210 with a charging control electric field and are lifted by the retarding electric field are subjected to a deflection action by the E × B deflector 208, and are reflected on the reflector 207. Irradiated. Secondary electrons (hereinafter referred to as tertiary electrons) are newly generated by the electrons colliding with the reflector 207. A positive voltage is applied to the reflecting plate of the semiconductor device 102 in the electron beam detector 100b with built-in electromagnetic wave generating means. Due to this electric field, the tertiary electrons from the reflecting plate reach the electron beam detector and the electromagnetic wave generating means 100b. Here, the positive voltage of the electron beam detector 100 b with built-in electromagnetic wave generating means can be applied only to the semiconductor device 102.

  The semiconductor device 102 emits light according to the amount of tertiary electrons. As described in the first embodiment, a part of the light emission is detected by the electromagnetic wave detecting means 105, and the detection signal is amplified by the detection signal amplification circuit 213 and transmitted to the subsequent stage. Further, part of the emitted light is returned to the reflection plate 207 as electromagnetic waves 107 c by the electromagnetic wave emission means 109.

  Contamination adheres to the reflecting plate due to the electron beam, and the charging causes the detection rate and the electron yield of the reflecting plate 207 to decrease. By irradiating the reflector with electromagnetic waves such as ultraviolet rays, it is possible to remove the electrification of the reflector 207 and maintain a stable detection rate.

  In addition, since ultraviolet light ionizes a small amount of gas in a vacuum, it is possible to remove contamination with ionized gas, suppress the decrease in the electron yield of the reflector, and acquire a stable image for a long time. .

  The detection signals obtained by the electron beam detectors 100a and 100b incorporating these two electromagnetic wave generating means are mainly backscattered electrons, and the signal source 100a includes the shape and material information of the sample, and secondary electrons are the main. The signal source 100b can obtain the potential information of the sample. These can be freely selected by the user of the apparatus, and are input to the image output and control means (control computer) 215 so that the signal is selected by the signal selection means (and analog-digital conversion means) 214 and It is possible to output a desired image.

  The present embodiment is not limited to the above embodiment, and various modifications are possible. For example, in this embodiment, two electron beam detectors 100a and 100b with built-in electromagnetic wave generating means are used. However, in order to separate sample information of secondary electrons and backscattered electrons for each emission angle, two or more electron beam detectors are used. This is also effective in a configuration having a detector. When the number of detectors increases, the spatial restrictions in the SEM casing increase, and therefore application of an electron beam detector with built-in electromagnetic wave generating means is particularly effective. Further, FIG. 2 shows a semi-in-lens type objective lens, but the configurations of the out-lens type objective lens 301 and the in-lens type objective lens 401 shown in FIGS. In any case, an electron beam detector with built-in electromagnetic wave generating means can be applied. It is also effective in an electron beam application apparatus that irradiates a plurality of electron beams.

  As described above, according to the present embodiment, by incorporating the electromagnetic wave generating means in the electron beam detector, the electron beam application apparatus having the configuration in which the electron beam detector and the electromagnetic wave generating means are compatible, and the electromagnetic wave are irradiated. Thus, it is possible to provide an electron beam observation method that can be observed. In particular, an electron beam detector with a built-in electromagnetic wave generating means can be used regardless of the type of objective lens.

  A third embodiment will be described with reference to FIG. FIG. 5 is a schematic diagram of an example when the light emitting function by the electron beam in Example 1 is provided on both sides of the semiconductor device 102. The contents described in Example 1 or Example 2 can also be applied to this example unless there are special circumstances.

  The principle is almost the same as that of the first embodiment, and when the semiconductor devices 502 are irradiated with the electron beams 501a and 501b, an electromagnetic wave 503 is generated. Reference numeral 501c indicates electrons that have passed through the semiconductor device without being irradiated. The generated electromagnetic wave 503 is separated into electromagnetic waves 507a and 507b by the electromagnetic wave separating means 504. The electromagnetic wave 507a is detected by the electromagnetic wave detection means 505, and the current amount and energy of the electron beam can be measured based on the detection signal. Reference numeral 506 denotes detection signal transmission means. The electromagnetic wave 507b enters the electromagnetic wave emission means 508, and directs the electromagnetic wave, and is radiated from the double-sided electron beam detector 500 built in the electromagnetic wave generation means.

  The semiconductor device 502 includes a metal layer 502a, a doped layer 502b, an active layer 502c, 502d doped with a reverse polarity, and a substrate layer 502e. Here, since the semiconductor device 502 has sensitivity to the electron beams 501a and 501b from both sides, the electron beams 501a and 501b incident from the front surface and the back surface need to reach the active layer 502c. For this reason, the thickness t1 in which the metal layer 502a and the doped layer 502b in the semiconductor device are overlapped and the thickness t2 in which the substrate layer 502e and the doped layer 502d are overlapped are both formed below the range of the irradiated electron beam. ing.

  The range of the electron beam is almost determined by the acceleration voltage during irradiation and the atomic number of the irradiated material, so it is optimized for the detected electron beam. For example, when the material is composed of GaN, the range that the electron beam reaches is 600 nm or less, and the most scattered is around 200 nm. For this reason, the sensitivity to an electron beam can be improved by setting t1 and t2 to 600 nm or less.

  The present embodiment is not limited to the above embodiment, and various modifications are possible. For example, when the acceleration voltages of the electron beams incident on the front surface and the back surface of the semiconductor device are different, optimum values exist at t1 and t2. Also, when the materials are different, the optimum values are different for each. In any case, it is important to produce t1 and t2 in order to detect a desired electron beam.

  As described above, according to the present embodiment, the electron beam application apparatus having a configuration in which the electron beam detector and the electromagnetic wave generating means are compatible and the electron beam observation method capable of observing while irradiating the electromagnetic wave can be used. An electron beam detector with built-in electromagnetic wave generating means can be provided. In particular, since this detector has light receiving surfaces on both sides, the electron beam can be used effectively.

  A fourth embodiment will be described with reference to FIG. FIG. 6 shows an example in which the electron beam detector with a built-in electromagnetic wave generation function in the third embodiment is applied to an electron beam application apparatus. Note that the embodiments described so far can be applied to this embodiment as long as there are no special circumstances.

  The electron beam application apparatus according to the present embodiment shown in FIG. 6 is an electron having a built-in electromagnetic wave generating means between the two condenser lenses 204a and 204b shown in FIG. 2 instead of the current limiting diaphragm 205 and the blanking diaphragm 206b. Beam detectors 500a and 500b are installed. Since detection of secondary electrons, backscattered electrons, and the like from the sample is substantially the same as in Example 2, description thereof is omitted.

  In FIG. 2, the amount of current of the electron beam reaching the sample is determined by changing the condenser lens 204a and adjusting the amount of current passing through the current limiting diaphragm 205. In FIG. This function is used in combination with the electron beam detector 500a.

  In FIG. 2, when the electron beam is deflected, the sample is not irradiated with the electron beam during the time until it returns to a predetermined position every scan or every shot. Therefore, the blanking electrode 206a and the blanking stop 206b are used. The electron beam is interrupted. In FIG. 6, the function of the blanking stop 206b is used in combination with the electron beam detector 500b with built-in electromagnetic wave generating means.

  Normally, a current limiting diaphragm or a blanking diaphragm is irradiated with a large electron beam of several hundred nA. Contamination adhering to this part causes drift of the electron beam, which hinders stable image acquisition. However, it is possible to reduce or eliminate contamination by disposing an electron beam detector with built-in electromagnetic wave generating means and irradiating a part 507c of the electromagnetic wave generated from the semiconductor device 502 to the place where the contamination adheres. Become.

  Furthermore, the current amount of the irradiated electron beam is detected by the electromagnetic wave detecting means 505 and detected via the detection signal amplification circuits 601a and 601b, so that the state of the irradiated electron beam can be observed in real time. It becomes.

  As a newly added function by observing secondary electrons or backscattered electrons in FIG. 6, the electron beam detectors 500a and 500b with built-in electromagnetic wave generating means detect electrons of only a high angle that have passed through the reflector. Therefore, it is possible to obtain sample information different from the electron beam detectors 100a and 100b with built-in electromagnetic wave generating means in FIG. Furthermore, comparing images from all detectors is particularly effective when observing hole bottoms and groove bottoms with high aspect, which was difficult to observe in the past.

  The present embodiment is not limited to the above embodiment, and various modifications are possible. For example, FIG. 6 shows a semi-in-lens type objective lens, but the configuration of the out-lens type objective lens 301 and the in-lens type objective lens 401 shown in FIGS. In any case, an electron beam detector with built-in electromagnetic wave generating means can be applied. It is also effective in an electron beam application apparatus that irradiates a plurality of electron beams.

  As described above, according to the present embodiment, by incorporating the electromagnetic wave generating means in the electron beam detector, the electron beam application apparatus having the configuration in which the electron beam detector and the electromagnetic wave generating means are compatible, and the electromagnetic wave are irradiated. Thus, it is possible to provide an electron beam observation method that can be observed. In particular, it is possible to reduce or eliminate the contamination of the current limiting diaphragm and the blanking diaphragm.

  A fifth embodiment will be described with reference to FIG. In the present embodiment, an electron beam application apparatus having a gas introducing means in the second or fourth embodiment will be described. The contents described in any of the first to fifth embodiments can be applied to the present embodiment unless there are special circumstances.

  FIG. 7 is a schematic cross-sectional view of an electron beam application apparatus having gas introduction means according to the present embodiment. Backscattered electrons generated from the sample reach the electron beam detector 100a built in the electromagnetic wave generating means. On the other hand, secondary electrons generated from the sample collide with the reflecting plate 207 to generate tertiary electrons, which reach the electron beam detector 100b with built-in electromagnetic wave generating means. The electron beam detectors 500a and 500b with built-in electromagnetic wave generating means are also irradiated with an electron beam from an electron source or electrons that have passed through a reflector.

  In any case, as described in the previous embodiments, part of the light emitted from the semiconductor device is returned to the sample and the reflector as electromagnetic waves by the electromagnetic wave emission means 109 and 508 of the electron beam detector built in the electromagnetic wave generation means. It is. Select a semiconductor device so that the wavelength of the electromagnetic wave is near the ultraviolet. At this time, the gas 703 supplied from the gas tank 702 is introduced into the vacuum casing 201 by the gas introduction means 701. As the gas 703, an inert gas such as nitrogen, helium, neon, or argon, oxygen, hydrogen, or the like is preferable.

  The gas introducing means 701 adjusts the pressure of the vacuum casing 201 to such an extent that it does not significantly reduce the pressure. Since the electromagnetic wave in the ultraviolet region ionizes the gas 703, it is possible to remove contamination adhering to the sample and the reflecting plate by the ionized gas. It is possible to acquire a stable observation image for a long time by suppressing the change of sample information and the decrease of the reflector yield due to contamination.

  As described above, according to the present embodiment, by incorporating the electromagnetic wave generating means in the electron beam detector, the electron beam application apparatus having the configuration in which the electron beam detector and the electromagnetic wave generating means are compatible, and the electromagnetic wave are irradiated. Thus, it is possible to provide an electron beam observation method that can be observed. In particular, by introducing gas into the vacuum housing, it is possible to efficiently remove contamination and acquire stable images.

  A sixth embodiment will be described with reference to FIG. FIG. 8 is a schematic cross-sectional view of the multi-electron beam inspection and analysis apparatus according to the present embodiment.

  An electron beam 802 emitted from an electron source 801 in a vacuum casing (column) 800 is formed into a plurality of electron beams 807 by two condenser lenses 803a and 803b, a current limiting aperture 804, an aperture array 805, and a lens array 806. .

  The plurality of electron beams 807 are projected onto the sample 812 placed on the stage 813 by the first projection lens 808 and the second projection lens 809. At this time, the positions of the plurality of electron beams 807 on the sample 812 are scanned simultaneously using the deflector 810. In addition, the sample 812 is moved by the stage 813.

  At this time, the generated secondary electrons 814 are deflected by the E × B deflector 815 and guided to the detector array 816, respectively. The secondary electrons separated by the detector array 816 are imaged in accordance with the scanning of the electron beam, and a plurality of locations can be observed simultaneously. The effect of the fourth embodiment can be obtained by placing the electron beam detector with built-in electromagnetic wave generating means described in the first or third embodiment in the current limiting diaphragm 804 or the aperture array 805.

  In addition, one of the plurality is guided to an electron beam detector 811 with built-in electromagnetic wave generating means. As a result, the electromagnetic wave 883 is generated, and the charged potential of the sample can be controlled. By moving the stage 813, the entire surface of the sample can be irradiated with the electromagnetic wave 883. While secondary electrons and backscattered electrons vary depending on the yield and atomic number of the sample, the primary electron beam has a constant current, so that electromagnetic wave radiation is constant and stable charging control is possible. At the same time, by detecting the current amount, it is possible to predict the current amount of another electron beam immediately before the sample is irradiated. As a result, even in the multi-beam inspection and analysis apparatus, stable observation is possible by the electron beam detector built in the electromagnetic wave generating means.

  As described above, according to the present embodiment, by incorporating the electromagnetic wave generating means in the electron beam detector, the electron beam application apparatus having the configuration in which the electron beam detector and the electromagnetic wave generating means are compatible, and the electromagnetic wave are irradiated. Thus, it is possible to provide an electron beam observation method that can be observed. In particular, stable specimen observation is possible in multi-beam inspection and analysis equipment.

  A seventh embodiment will be described with reference to FIG. Note that items described in Examples 1 to 6 but not described in the present example can be applied to the present example as long as there are no special circumstances. FIG. 9 is a schematic cross-sectional view of an electron beam detector with built-in electromagnetic wave generating means for an electron beam application apparatus according to the present embodiment. In the electron beam detector 900 with built-in electromagnetic wave generating means, FIG. 5 has a mechanism for laser excitation.

  In this embodiment, a mechanism for laser excitation is added, and it can be similarly applied to the detection of an electron beam with built-in electromagnetic wave generating means described in the first embodiment. As shown in FIG. 9, a semiconductor device (electron beam pumped laser structure) 902 has a polarity opposite to that of a metal layer 902a, a substrate layer 902e, and a doped layer 902b that are made of a material having high reflectivity with respect to generated electromagnetic waves. An active layer 902c that causes light emission and laser excitation between the doped 902d and reflecting mirrors 902f and 902g that reflect the generated electromagnetic waves are formed.

  As electromagnetic waves reciprocate between the reflecting mirrors 902f and 902g, stimulated emission is promoted, laser oscillation occurs, and laser light 903 is emitted. The emitted laser beam 903 becomes laser beams 907a and 907b separated or selected by the laser beam separation or selection unit 904, the laser beam 907a is detected by the laser beam detection unit 905, and the laser beam 907b is laser beam emission unit 908. Will be released. Here, the intensity of the separated laser beams 907a and 907b can be adjusted by selecting the transmittance and reflectance of the laser beam separating or selecting means. Reference numeral 906 denotes a detection signal transmission means, and reference numeral 907c denotes an electromagnetic wave emitted from an electron beam detector built in the electromagnetic wave generation means.

  The present embodiment is not limited to the above embodiment, and various modifications are possible. For example, in the present embodiment, the semiconductor device shown in the fifth embodiment is shown with a reflecting mirror added to the side surface. However, the reflecting mirror may be added to the structure shown in the first embodiment. It may be between the front and back surfaces. Further, by applying the present embodiment to the electron beam application apparatus shown in FIGS. 2, 3, 4, 6 and 7, it is more oriented than the first and fifth embodiments, and has a high output and wavelength. Therefore, it is possible to detect an electron beam with a higher S / N and to observe stably for a long time than in the second, fourth, fifth, and sixth embodiments.

  When the intensity of the electromagnetic wave generated by the electron beam is weak in the electron beam detector built in the electromagnetic wave generating means, an electromagnetic wave having a desired intensity can be obtained by adding the laser excitation function shown in this embodiment. Can do. In particular, it is effective for neutralizing an insulator that is charged by irradiation with an electron beam.

  As described above, according to the present embodiment, by incorporating the electromagnetic wave generating means in the electron beam detector, the electron beam application apparatus having the configuration in which the electron beam detector and the electromagnetic wave generating means are compatible, and the electromagnetic wave are irradiated. Thus, it is possible to provide an electron beam observation method that can be observed. In particular, when the electron beam is weak, an electron beam detector with built-in electromagnetic wave generation means with a laser excitation function is useful.

  An eighth embodiment will be described with reference to FIGS. Note that the matters described in the first to seventh embodiments and not described in the present embodiment can be applied to the present embodiment unless there are special circumstances. In the present embodiment, another embodiment using the configuration shown in the seventh embodiment will be described.

  In this embodiment, as shown in FIG. 9, the electron beam excitation laser structure 902 has a mechanism for adjusting the bias current. This makes it possible to adjust the bias current so that laser oscillation occurs in accordance with the energy or current amount of the electron beams 901a and 901b. A bias current that causes laser excitation from the bias current source 910 is supplied to the electron beam excitation laser structure 902 via the transmission paths 909a and 909b.

FIG. 10 shows a relationship 1001 between the bias current and the laser output. Laser oscillation is caused by a current having a threshold current I _T 1002 or more. For example, in the linear mode in which linear light emission is required according to the number of electrons of the incident electron beams 901a and 901b, a linear mode current I _L 1003 having a bias current equal to or higher than the threshold current I _T 1002 is supplied (I _T < _IL ). Thereby, light emission according to the amount of current can be realized.

Further, in the threshold mode in which laser oscillation occurs only when a current amount equal to or greater than a value set by the user is applied, a set current I _N 1004 that is equal to or less than the threshold current I _T 1002 is supplied (I _T > I _N ). As a result, laser oscillation occurs according to the amount of current of the electron beams 901a and 901b only when electrons having a current larger than the set current are incident.

  The effect by this Example is demonstrated. When charging control and contamination removal are performed by the generated laser light, if an electromagnetic wave more than necessary is incident, damage to the irradiated part increases. Charging and contamination due to electron beam irradiation vary depending on the amount of current to be irradiated. Therefore, especially when the amount of current is large, charging increases and contamination increases. Therefore, in order not to irradiate the sample with more electromagnetic waves than necessary, the charging can be controlled by adjusting the bias current so that the electromagnetic waves are generated according to the amount of irradiated current, and the sample damage can be minimized. Is possible.

  Furthermore, if this embodiment is used, noise can be reduced even in electron beam detection. Normally, an electron beam detector is sensitive to electromagnetic waves such as X-rays, and background noise is generated by the electromagnetic waves in the SEM casing. In order to cut off the detection signal due to these electromagnetic noises, a detector sensitive only to the necessary detection signal is effective. By using this embodiment, laser oscillation occurs only when electrons of a set value or more are incident, so that background noise due to electromagnetic waves can be reduced.

  In the electron beam inspection apparatus, when a defective portion of a sample is determined, a threshold value of a defect signal is determined, and whether it is a normal portion or a defective portion is determined with respect to a higher (or lower) signal. Normally, as shown in FIG. 11, a secondary electron image 1100 is acquired, a pattern is recognized from the image, and the inspection is performed by digitally processing the difference in signal intensity between the normal portion 1101 and the defective portion 1102. This method is excellent in recognizing complex patterns using digital filter processing, etc., but it requires enormous data processing when using multiple electron beams or when the inspection area is large. , It leads to a decrease in throughput and high cost. By using this embodiment, analog threshold determination can be performed when electrons are detected, and throughput can be improved and costs can be reduced.

  As described above, according to the present embodiment, by incorporating the electromagnetic wave generating means in the electron beam detector, the electron beam application apparatus having the configuration in which the electron beam detector and the electromagnetic wave generating means are compatible, and the electromagnetic wave are irradiated. Thus, it is possible to provide an electron beam observation method that can be observed. In particular, by adjusting the bias current, it is possible to reduce sample damage when removing contamination, reduce background noise when detecting an electron beam, improve throughput and reduce costs in defect determination.

Although the present invention has been described in detail above, the main invention modes are listed below.
(1) A semiconductor device that generates an electromagnetic wave by irradiating an electron beam, means for separating the electromagnetic wave generated from the semiconductor device into two or more, means for detecting the separated electromagnetic wave, and separated electromagnetic wave An electron beam detector with built-in electromagnetic wave generating means, characterized by comprising electron beam detecting means or electromagnetic wave generating means having means for irradiating the light.
(2) In the electron beam detector according to (1) above,
2. The electron beam detector according to claim 1, wherein the semiconductor device is made of a direct transition type semiconductor.
(3) In the electron beam detector described in (1) above,
The semiconductor device has an active layer therein, and the thickness from the front surface and the back surface of the semiconductor device to the active layer is configured to be less than the range of the electron beam to be irradiated. vessel.
(4) In an electron beam application apparatus comprising an electron source and an electron beam detector for detecting an electron beam caused by electrons emitted from the electron source,
The electron beam detector is the electron beam detector according to the above item (1).
(5) In the electron beam application apparatus described in (4) above,
2. The electron beam application apparatus according to claim 1, wherein the semiconductor device is made of a direct transition type semiconductor.
(6) means for generating an electron beam, a lens for converging the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, a movable stage on which the sample is mounted and moved, In an electron beam application apparatus comprising a data control means for processing various data and a control computer for controlling these devices,
A semiconductor device that generates electromagnetic waves by irradiating secondary electrons and backscattered electrons generated from the sample, means for separating or selecting electromagnetic waves from the semiconductor devices, and part of the electromagnetic waves generated from the semiconductor devices An electron beam application apparatus, comprising: an electron beam detector with built-in electromagnetic wave generation means provided with a means for detecting the electromagnetic wave and means for returning a part of the electromagnetic wave generated from the semiconductor device to the sample.
(7) In the electron beam application apparatus described in (3) above,
A means for generating the electron beam, a lens for converging the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, and a movable stage on which the sample is mounted and moved are housed. An electron beam application apparatus, further comprising gas introduction means for introducing gas into the vacuum casing.
(8) means for generating an electron beam, a lens for converging the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, a movable stage on which the sample is mounted and moved, In an electron beam application apparatus comprising a data control means for processing various data, a control computer for controlling those devices, and a reflector for irradiating secondary electrons and backscattered electrons generated from the sample,
A semiconductor device that generates an electromagnetic wave by detecting electrons generated from the reflector, a means for separating or selecting an electromagnetic wave from the semiconductor device, and an electromagnetic wave detection that detects a part of the electromagnetic wave generated from the semiconductor device An electron beam detector with built-in electromagnetic wave generation means provided with means for returning a part of the electromagnetic waves generated from the semiconductor device to the sample or the reflector,
A means for generating the electron beam, a lens for converging the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, and a movable stage on which the sample is mounted and moved are housed. An electron beam application apparatus, further comprising gas introduction means for introducing gas into the vacuum casing.
(9) In the electron beam application apparatus described in (1) above,
The semiconductor device has an active layer therein, and the thickness from the front surface and the back surface of the semiconductor device to the active layer in the semiconductor device is less than the range of the electron beam to be irradiated. Beam application equipment.
(10) A means for generating an electron beam, a lens for converging the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, and a current amount of the electron beam on the sample are determined. Current limiting aperture, means for deflecting and blocking the electron beam, movable stage mounted with the specimen, data control means for processing various data, and a control computer for controlling these devices, In an electron beam application apparatus comprising a reflector for irradiating secondary electrons and backscattered electrons generated from the sample,
An electron beam application apparatus using the electron beam detector according to (1) above as the current limiting diaphragm or means for changing and blocking the electron beam.
(11) Means for generating a plurality of electron beams, a lens for converging at least one of the electron beams on the sample, and a deflector for determining the position of the at least one beam of the electron beam on the sample And an electron beam application apparatus comprising a movable stage mounted with the sample, a data control means for processing various data, and a control computer for controlling these devices.
An electron beam application apparatus, wherein an electron beam different from the electron beam irradiated onto the sample is irradiated onto the electron beam detector according to (1).
(12) In the observation method using the electron beam application apparatus described in (6) above,
By irradiating the electron beam detector built in the electromagnetic wave generating means with secondary electrons and backscattered electrons generated from the sample, dividing the electromagnetic waves generated from the semiconductor device, and irradiating a part of the electromagnetic waves on the sample An observation method comprising controlling a potential of a sample, simultaneously detecting another part of an electromagnetic wave generated from a semiconductor device, and observing the sample using the other part of the detected electromagnetic wave.
(13) In the observation method using the electron beam application apparatus described in (8) above,
By irradiating the electron beam detector with electrons generated from the sample or the reflecting plate, dividing the electromagnetic wave generated from the semiconductor device and irradiating a part of the electromagnetic wave on the sample, contamination of the sample or the reflecting plate is performed. An observation method characterized by suppressing a nation.
(14) In the observation method using the electron beam application apparatus described in (11) above,
Irradiating at least one of the plurality of electron beams onto the sample, observing the sample, and simultaneously irradiating at least one other of the plurality of electron beams onto the electron beam detector, and generated from the semiconductor device An observation method characterized by controlling the potential state of the sample by irradiating the sample with an electromagnetic wave.
(15) In the electron beam application apparatus described in (8) above,
An electron beam application apparatus characterized by amplifying an electromagnetic wave generated from the semiconductor device and having a laser excitation structure.
(16) In the electron beam application apparatus described in (15) above,
An electron beam application apparatus comprising means for supplying a bias current to the laser excitation structure.
(17) In the observation method using the electron beam application apparatus described in (16) above,
The bias current is adjusted so that laser oscillation occurs only when electrons exceeding the preset range are detected by the electromagnetic wave generating means built in the electron beam detector, and the laser excited electromagnetic wave is detected by the electromagnetic wave detector or the sample. Or the observation method characterized by irradiating a reflecting plate.
(18) In the electron beam application apparatus described in (4) above,
An electron beam application apparatus characterized by amplifying an electromagnetic wave generated from the semiconductor device and having a laser excitation structure.
(19) In the electron beam application apparatus described in (18) above,
An electron beam application apparatus comprising means for supplying a bias current to the laser excitation structure.

100, 100a, 100b: electron beam detector with built-in electromagnetic wave generating means, 101: electron beam, 102: semiconductor device, 103: electromagnetic wave, 104: electromagnetic wave separating means, 105: electromagnetic wave detecting means, 106: detection signal transmitting means, 107a , 100b: separated electromagnetic wave, 108: electromagnetic wave reflecting means, 109: electromagnetic wave emitting means, 200: electron beam semiconductor inspection and analysis device, 201: vacuum housing, 203: electron source, 204, 204a, 204b: condenser lens, 205: current limiting diaphragm, 206: blanking mechanism, 207: reflector, 208: E × B deflector, 209: deflector, 210: semi-in-lens objective lens, 211: charge control electrode, 212: stage with sample 213: Detection signal amplifier circuit 214: Signal selection and analog-digital conversion Stage: 215: Control computer, 301: Out-lens objective lens, 401: In-lens objective lens, 500, 500a, 500b: Double-sided electron beam detection with built-in electromagnetic wave generating means, 501: Electron beam, 502: Semiconductor 503: electromagnetic wave separation means, 505: electromagnetic wave detection means, 506: detection signal transmission means, 507a, 507b: separated electromagnetic waves, 508: electromagnetic wave emission means, 601a, 601b: detection signal amplification circuit, 701 : Gas introduction means, 702: Gas tank, 703: Gas, 800: Vacuum casing, 801: Electron source, 802: Electron beam, 803a, 803b: Condenser lens, 804: Current limiting diaphragm, 805: Aperture array, 806: Lens Array, 807: a plurality of electron beams, 808: first projection lens, 809: Second projection lens, 810: Deflector, 811: Electron beam detector with built-in electromagnetic wave generating means, 812: Sample, 813: Stage, 814: Secondary electron, 815: ExB deflector, 816: Detector Array, 900: Double-sided electron beam detector equipped with laser excitation with built-in electromagnetic wave generation means, 901a, 901b: Electron beam, 902: Electron beam excitation laser structure, 903: Laser light, 904: Laser light separation or selection Means: 905: Laser light detection means, 906: Detection signal transmission means, 907a, 907b: Separated or selected laser light, 908: Laser light emission means, 909: Bias current transmission path, 910: Bias current source, 1001: bias current and the correlation of the laser output, 1002: the threshold current _I T, 1003: linear mode current _I L, 1004: set Current _I N, 1100: 2-electron image, 1101: normal portion, 1102: the defect portion.

Claims (19)

  A semiconductor device that generates an electromagnetic wave by irradiating an electron beam, means for separating the electromagnetic wave generated from the semiconductor device into two or more, means for detecting the separated electromagnetic wave, and irradiating the separated electromagnetic wave An electron beam detector with built-in electromagnetic wave generating means. The electron beam detector according to claim 1,
2. The electron beam detector according to claim 1, wherein the semiconductor device is made of a direct transition type semiconductor. The electron beam detector according to claim 1,
The semiconductor device has an active layer therein, and the thickness from the front surface and the back surface of the semiconductor device to the active layer is configured to be less than the range of the electron beam to be irradiated. vessel. An electron beam application apparatus comprising an electron source and an electron beam detector for detecting an electron beam caused by electrons emitted from the electron source,
The electron beam detector according to claim 1, wherein the electron beam detector is an electron beam detector according to claim 1. The electron beam application apparatus according to claim 4,
2. The electron beam application apparatus according to claim 1, wherein the semiconductor device is made of a direct transition type semiconductor. Means for generating an electron beam, a lens for focusing the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, a movable stage on which the sample is mounted, and various data In an electron beam application apparatus comprising a data control means for processing and a control computer for controlling these devices,
A semiconductor device that generates electromagnetic waves by irradiating secondary electrons and backscattered electrons generated from the sample, means for separating or selecting electromagnetic waves from the semiconductor devices, and part of the electromagnetic waves generated from the semiconductor devices An electron beam application apparatus, comprising: an electron beam detector with built-in electromagnetic wave generation means provided with a means for detecting the electromagnetic wave and means for returning a part of the electromagnetic wave generated from the semiconductor device to the sample. The electron beam application apparatus according to claim 3,
A means for generating the electron beam, a lens for converging the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, and a movable stage on which the sample is mounted and moved are housed. An electron beam application apparatus, further comprising gas introduction means for introducing gas into the vacuum casing. Means for generating an electron beam, a lens for focusing the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, a movable stage on which the sample is mounted, and various data In an electron beam application apparatus comprising data control means for processing, a control computer for controlling these devices, and a reflector for irradiating secondary electrons and backscattered electrons generated from the sample,
A semiconductor device that generates an electromagnetic wave by detecting electrons generated from the reflector, a means for separating or selecting an electromagnetic wave from the semiconductor device, and an electromagnetic wave detection that detects a part of the electromagnetic wave generated from the semiconductor device An electron beam detector with built-in electromagnetic wave generation means provided with means for returning a part of the electromagnetic waves generated from the semiconductor device to the sample or the reflector,
A means for generating the electron beam, a lens for converging the electron beam on the sample, a deflector for determining the position of the electron beam on the sample, and a movable stage on which the sample is mounted and moved are housed. An electron beam application apparatus, further comprising gas introduction means for introducing gas into the vacuum casing. The electron beam application apparatus according to claim 1,
The semiconductor device has an active layer therein, and the thickness from the front surface and the back surface of the semiconductor device to the active layer in the semiconductor device is less than the range of the electron beam to be irradiated. Beam application equipment. Means for generating an electron beam; a lens for focusing the electron beam on the sample; a deflector for determining the position of the electron beam on the sample; and a current limit for determining an amount of current of the electron beam on the sample. A diaphragm, a means for deflecting and blocking the electron beam, a movable stage on which the sample is mounted and moved, a data control means for processing various data, a control computer for controlling these devices, and the sample An electron beam application apparatus comprising a reflector for irradiating secondary electrons and backscattered electrons generated from
2. An electron beam application apparatus according to claim 1, wherein the electron beam detector according to claim 1 is used as means for changing and blocking the current limiting diaphragm or the electron beam. Means for generating a plurality of electron beams; a lens for converging at least one of the electron beams onto a sample; a deflector for determining a position of the at least one beam of the electron beams on the sample; In an electron beam application apparatus comprising a movable stage mounted with a sample, data control means for processing various data, and a control computer for controlling those devices,
The electron beam application apparatus according to claim 1, wherein an electron beam different from the electron beam irradiated on the sample is irradiated to the electron beam detector according to claim 1. In the observation method using the electron beam application apparatus of Claim 6,
By irradiating the electron beam detector built in the electromagnetic wave generating means with secondary electrons and backscattered electrons generated from the sample, dividing the electromagnetic waves generated from the semiconductor device, and irradiating a part of the electromagnetic waves on the sample An observation method comprising controlling a potential of a sample, simultaneously detecting another part of an electromagnetic wave generated from a semiconductor device, and observing the sample using the other part of the detected electromagnetic wave. In the observation method using the electron beam application apparatus of Claim 8,
By irradiating the electron beam detector with electrons generated from the sample or the reflecting plate, dividing the electromagnetic wave generated from the semiconductor device and irradiating a part of the electromagnetic wave on the sample, contamination of the sample or the reflecting plate is performed. An observation method characterized by suppressing a nation. In the observation method using the electron beam application apparatus of Claim 11,
Irradiating at least one of the plurality of electron beams onto the sample, observing the sample, and simultaneously irradiating at least one other of the plurality of electron beams onto the electron beam detector, and generated from the semiconductor device An observation method characterized by controlling the potential state of the sample by irradiating the sample with an electromagnetic wave. The electron beam application apparatus according to claim 8,
An electron beam application apparatus characterized by amplifying an electromagnetic wave generated from the semiconductor device and having a laser excitation structure. The electron beam application apparatus according to claim 15,
An electron beam application apparatus comprising means for supplying a bias current to the laser excitation structure. In the observation method using the electron beam application apparatus of Claim 16,
The bias current is adjusted so that laser oscillation occurs only when electrons exceeding the preset range are detected by the electromagnetic wave generating means built in the electron beam detector, and the laser excited electromagnetic wave is detected by the electromagnetic wave detector or the sample. Or the observation method characterized by irradiating a reflecting plate. The electron beam application apparatus according to claim 4,
An electron beam application apparatus characterized by amplifying an electromagnetic wave generated from the semiconductor device and having a laser excitation structure. The electron beam application apparatus according to claim 18,
An electron beam application apparatus comprising means for supplying a bias current to the laser excitation structure.

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