JP4877318B2 - Inspection / analysis method and sample preparation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection/analysis method where a substrate is not vainly disposed of for evaluation, and although a wafer from which a sample is taken up for inspection is returned to a process, no defect is caused, and to provide a method for manufacturing an electronic part. <P>SOLUTION: The method for inspecting/analyzing the substrate is that a region including at least a region irradiated with a first ion beam on a substrate is irradiated with a second ion beam to remove at least part of the sample surface where a seed of the first ion beam is contained. This allows an inspection halfway to be performed without cutting off the substrate for improving yield in a semiconductor device and the like, and allows the reduction of smearing including an element seed that has constituted the ion beam and smearing including an element seed that constitutes a depository film to be achieved. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an inspection / analysis method for an electronic component such as a semiconductor device, an electronic component manufacturing method, and a sample preparation apparatus for realizing the inspection / analysis method.

  High-yield manufacturing is required in the manufacture of semiconductor components such as dynamic random access memories, semiconductor devices such as microprocessors and semiconductor lasers, and electronic components such as magnetic heads. That is, a decrease in product yield due to the occurrence of defects leads to a deterioration in profitability. For this reason, the early detection and early countermeasures of the defect, foreign material, and processing defect which cause a defect become a big subject. For example, in the manufacturing field of semiconductor devices, efforts are focused on finding defects by careful inspection and analyzing the cause of occurrence. In an actual electronic component manufacturing process using a wafer, a completed wafer is inspected, and a countermeasure method is investigated by searching for the cause of an abnormal portion such as a defect in a circuit pattern or a foreign object.

  In order to efficiently manage so as not to produce defective products regarding the manufacture of electronic parts as described above, the following problems to be solved remain.

Usually, a high-resolution scanning electron microscope (hereinafter abbreviated as SEM) is used to observe the microstructure of a sample. However, as the integration of semiconductors increases, the object cannot be observed at the SEM resolution. Instead, a transmission electron microscope (hereinafter abbreviated as TEM) with high observation resolution is used.

  Conventional TEM sample preparation involves the work of crushing or cutting the sample into small pieces, and when the sample is a wafer, in most cases the wafer has to be cleaved.

  Recently, there is an example of using a focused ion beam (hereinafter abbreviated as FIB) processing that applies the action of irradiating a sample with an ion beam and applying the action that particles constituting the sample are sputtered and emitted from the sample. is there. First, a submillimeter strip-shaped pellet including a region to be observed is cut out from a sample such as a wafer using a dicing apparatus or the like. Next, a part of the strip-shaped pellet is FIB processed into a thin wall shape to obtain a TEM sample. Here, a characteristic of the FIB-processed sample for TEM observation is that a part of the test piece is processed into a thin film having a thickness of about 100 nm for TEM observation. Although this method makes it possible to locate and observe a desired observation portion with micrometer level accuracy, the wafer must still be cleaved.

  As described above, monitoring the results of a certain process during the manufacture of semiconductor devices and the like has a great advantage in terms of yield management. However, in sample preparation as described above, the wafer is cleaved and the wafer fragments are the next. It is discarded without proceeding to the process. In particular, in recent years, the diameter of wafers has been increasing in order to reduce the manufacturing cost of semiconductor devices. That is, the number of semiconductor devices that can be manufactured with one wafer is increased to reduce the unit price. However, on the contrary, the wafer becomes expensive, and the number of semiconductor devices lost by discarding the wafer also increases. Therefore, the conventional inspection method including the division of the wafer is very uneconomical.

On the other hand, there is a method capable of producing a sample without dividing the wafer. This method is disclosed in Japanese Patent Application Laid-Open No. 05-52721 “a method for separating a sample and a method for analyzing a separated sample obtained by this separation method”. In this method, as shown in FIG. 2, first, the posture of the sample 2 is maintained so that the FIB 1 is irradiated at a right angle to the surface of the sample 2, the FIB 1 is scanned in a rectangular shape on the sample, and the required depth is formed on the sample surface. The square hole 101 is formed (FIG. 3A). Next, the sample 2 is tilted to form the bottom hole 102. The inclination angle of the sample 2 is changed by a sample stage (not shown) (FIG. 3B). The posture of the sample 2 is changed, the sample 2 is placed so that the surface of the sample 2 is again perpendicular to the FIB 1, and a notch groove 103 is formed (FIG. 2 (c)). A manipulator (not shown) is driven, and the tip of the probe 3 at the tip of the manipulator is brought into contact with a portion where the sample 2 is separated (FIG. 3 (d)). The deposition gas 5 is supplied from the gas nozzle 104 and the FIB 1 is locally irradiated to the region including the tip of the probe 3 to form an ion beam assisted deposition film (hereinafter abbreviated as a deposition film 4). A separation portion of the sample 2 in contact with the tip of the probe 3 is connected by a deposition film 4 (FIG. 3 (e)). The remaining part is cut out with FIB 1 (FIG. 3 (f)), and a micro sample 6 as a separated sample is cut out from sample 2. The separated sample 6 cut out is supported by the connected probe 3 (FIG. 3 (g)). When this micro sample 6 is processed with FIB 1 and the region to be observed is wall processed, a TEM sample (not shown) is obtained. This is a method of separating a micro sample piece including a desired analysis region from a sample such as a wafer by using FIB processing and a micro sample transport means. Analysis can be performed by introducing a micro sample separated by this method into various analyzers.
If this method is used, it is possible to take out a micro sample for inspection from a sample without dividing the wafer and return the wafer to the next process. Therefore, there is no semiconductor device lost by dividing the wafer as in the prior art, and the total manufacturing cost of the semiconductor device can be reduced.

  However, in this method, since the FIB is used when separating a minute sample, the element type constituting the FIB remains in the processing region where the minute sample is taken out. In addition to the FIB processing region, the element species constituting the FIB and some fragments of the sample are scattered due to the sputtering effect by FIB irradiation. Moreover, when using a deposition film, the element type | mold which comprises deposition gas remains in a process area | region and its periphery. The presence of these element species is likely to cause defects for semiconductor device manufacturing. That is, if these contaminations are left as they are and the wafer is returned to the next process, these elemental species diffuse and invade semiconductor elements that have normally undergone the manufacturing process, resulting in poor electrical characteristics and poor contacts. There was a problem. As a countermeasure, it is conceivable to perform cleaning using a chemical solution on the wafer from which the micro sample has been taken out. However, there was a problem that the number of processes was increased and the manufacturing cost was high. Further, when FIB was irradiated at an acceleration of 30 kV, for example, about 10 nm from the sample surface was incident on the inside, and only the surface was cleaned. However, there is a serious problem that the contamination including the ion beam element species embedded in the sample cannot be completely removed.

  For this reason, in order to improve the yield of semiconductor devices and the like, an intermediate inspection can be carried out without cleaving the wafer, and at that time, contamination including the element species constituting the ion beam Establishing a method that can easily and inexpensively remove contamination containing the element species that make up the deposition film, and a method that can easily remove the area where the FIB is embedded, and the development of a device that can realize it Was desired.

  In view of the above-mentioned problems, the first object of the present application is to perform a new inspection that does not waste a substrate for evaluation and does not cause a defect even if a wafer from which a sample for inspection is taken out is returned to the process. It is to provide an analysis method and an electronic component manufacturing method, and a second object is to provide a sample preparation apparatus for achieving the first object.

  The first object as described above is achieved by the following.

(1) A substrate is irradiated with a first ion beam, the substrate surface is processed, a processed portion is inspected or analyzed, or at least a part of the substrate is separated by a processing method using the first ion beam irradiation. In the substrate inspection / analysis method for inspecting / analyzing the separated microsample, the second ion beam is irradiated to a region including at least the region irradiated with the first ion beam on the substrate, The substrate inspection / analysis method is characterized in that at least a part of the sample surface containing the ion beam element species is removed.

  According to the inspection / analysis method of this means, the substrate is not wasted for evaluation, and no new defect is generated even if the substrate from which the sample for inspection is cut out is returned to the process.

(2) After an arbitrary processing step of the process of manufacturing the circuit pattern on the substrate, the step of irradiating the first ion beam to process the substrate surface and inspecting or analyzing the processing portion, or after the processing step, And a step of separating a part of the substrate using at least the first ion beam irradiation, and then irradiating the second ion beam to a region including at least the region irradiated with the first ion beam on the substrate. And, after passing through a step of removing at least a part of the sample surface containing the first ion beam element species, the substrate is returned to the process of manufacturing a circuit pattern and subjected to a second processing. An electronic component manufacturing method is provided.

  According to the electronic component manufacturing method of this means, the substrate is not wasted for evaluation, and a new defect is not generated even if the substrate from which the sample for inspection is cut out is returned to the process. As a result, the manufacturing yield of electronic components is improved.

(3) The substrate is irradiated with an ion beam, the substrate surface is processed, the processed portion is inspected or analyzed, or at least a part of the substrate is separated by a processing method using ion beam irradiation, and the microsample is separated. In a substrate inspection / analysis method for inspecting and analyzing the substrate, at least a part of the sample surface containing the ion beam element species is removed by irradiating the region including at least the region irradiated with the ion beam on the substrate with a laser beam. A substrate inspection / analysis method characterized by:

  According to the inspection / analysis method of this means, the substrate is not wasted for evaluation, and no new defect is generated even if the substrate from which the sample for inspection is cut out is returned to the process.

(4) After an arbitrary processing step of the process of manufacturing the circuit pattern on the substrate, the ion beam is irradiated to process the surface of the substrate and the processing portion is inspected or analyzed, or at least the ion beam after the processing step. A step of separating a part of the substrate using irradiation, and then irradiating the region including at least the region irradiated with the ion beam on the substrate with a laser beam, After passing through the process of removing at least a part, the substrate is returned to the process of manufacturing a circuit pattern, and second processing is performed.

  According to the inspection / analysis method of this means, the substrate is not wasted for evaluation, and a new defect does not occur even if the substrate from which the sample for inspection is cut out is returned to the process. As a result, the manufacturing yield of electronic components is improved.

(5) The substrate is irradiated with an ion beam, the substrate surface is processed, the processed portion is inspected or analyzed, or at least a part of the substrate is separated by a processing method using ion beam irradiation, and the separated micro A substrate inspection / analysis method for inspecting / analyzing a sample by a processing method including covering a substrate with a thin film before irradiating the substrate with an ion beam and then irradiating the ion beam from the thin film A substrate inspection / analysis method is characterized in that the substrate surface is processed and the thin film is removed after the processing.

  According to the electronic component manufacturing method of this means, the substrate does not need to be discarded for evaluation. In addition, even if the substrate from which the sample for inspection is cut out is returned to the process, no new defect is generated.

(6) After an arbitrary processing step of manufacturing the circuit pattern on the substrate, at least a part of the substrate is covered with a thin film, and then the substrate surface is processed by irradiating an ion beam from above the thin film. After the inspection or analysis step, or after the processing step, there is a step of separating at least a part of the substrate by a processing method including covering the substrate with a thin film and then irradiating an ion beam from the thin film. Then, after passing through the step of removing the thin film, the substrate is returned to the process of manufacturing a circuit pattern and second processing is performed.

  According to the electronic component manufacturing method of this means, the substrate does not need to be discarded for evaluation. In addition, even if the substrate from which the sample for inspection is cut out is returned to the process, no new defect is generated. As a result, the manufacturing yield of electronic components is improved.

In order to achieve the second object, (7) a part of the substrate is formed by a processing method using at least a sample stage that can hold and move the substrate and irradiating a desired location on the substrate with an ion beam containing gallium. In a sample preparation apparatus that separates and manufactures a microsample, a laser capable of irradiating a portion irradiated with an ion beam with a laser beam and removing at least a part of the sample surface containing the ion beam element species A sample preparation apparatus including a beam apparatus is provided.

  According to the sample preparation apparatus of this means, inspection / analysis methods and electronic components that do not waste a substrate for evaluation and do not cause a new defect even if a substrate from which a sample for inspection is cut out is returned to the process. A manufacturing method can be realized.

(8) A microsample is obtained by separating a part of the substrate by a processing method using at least a sample stage that can hold and move the substrate and irradiating a desired location on the substrate with the first ion beam containing gallium. In the sample preparation apparatus, the ion beam control device for recording the region irradiated with the gallium ion beam and the irradiation condition is recorded, and the ion beam control device based on the recording is arranged with argon, nitrogen, A sample preparation apparatus is characterized by being an ion beam control apparatus that controls to remove a sample surface containing gallium by irradiating a second ion beam containing at least one of oxygen.

  According to the sample preparation apparatus of this means, inspection / analysis methods and electronic components that do not waste a substrate for evaluation and do not cause a new defect even if a substrate from which a sample for inspection is cut out is returned to the process. A manufacturing method can be realized.

In any one of (1) to (8) above, (9) the sample is a silicon semiconductor wafer, an epitaxially grown silicon wafer, a wafer having a silicon thin film formed on a substrate, a compound semiconductor wafer, or a magnetic head integrated wafer. Or (10) the electronic component is any one of a silicon semiconductor device, a compound semiconductor device, a magnetic recording / reproducing head, and a magneto-optical recording / reproducing head. (11) The inspection uses at least one of a transmission electron microscope, a scanning transmission electron microscope, a scanning electron microscope, or a scanning probe microscope. (12) The analysis is performed by at least one of an electron beam, an ion beam, and an X-ray. Elemental analysis using Whether the quality is good or bad compared with at least any of the pure product concentrations, or (13) the above analysis is based on a predetermined reference shape, dimension, element distribution, element concentration, impurity distribution, The cause obtained by removing at least one of the impurity concentrations or (14) the data obtained in the step of performing at least one of the monitoring or the inspection or the analysis is stored in at least a computer.

  By using the inspection / analysis method according to the present application, the material is not wasted for evaluation, and a new defect is not generated even if the wafer from which the sample for inspection is cut out is returned to the process. Further, by using the electronic component manufacturing method according to the present application, the wafer can be evaluated without cleaving, no new defect is generated, and an expensive wafer is not wasted. As a result, the manufacturing yield of electronic components is improved. Furthermore, a sample preparation apparatus capable of realizing these inspection / analysis methods and electronic component manufacturing methods is provided.

  An embodiment of an electronic component manufacturing method according to the present application is an electronic component manufacturing method in which a plurality of processing processes are performed on a sample to form an electronic component. In the processing process, a part including the substrate surface of the sample is extracted, The process of monitoring or inspecting or analyzing the progress of the processing in the above-described processing process on a part including the substrate surface, and removing the part including the substrate surface, and further processing the substrate There is a method of manufacturing a return circuit pattern.

<Embodiment 1>
The basic flow of the electronic component manufacturing method according to the present application will be described with reference to FIG.

First, a lot 13 composed of a plurality of wafers is input to an arbitrary Nth process 11. Next, the inspection wafer 14 is selected from the plurality of wafers, and the remaining wafers wait. The selected inspection wafer 14 is first introduced into the inspection electron microscope 15. If an abnormality is found here, the position is recorded and the information is sent to the sample preparation device 17. The micro sample 6 including a portion to be inspected from the inspection wafer 14 by the sample preparation device 17 is used by using the probe 3 attached to the tip of the gallium FIB 1 and the manipulator, and the deposition film produced by the deposition gas W (CO) 6. Extract. The inspection wafer 14 from which the microsample 6 has been extracted is again incorporated into the remaining lot 13 and is fed to the next (N + 1) th process 12. Here, the micro sample 6 is sent to the analysis device 18 and analyzed with respect to a predetermined inspection item. As described above, a major feature is that the microsample 6 for analysis is extracted from the Nth process to the N + 1th process. Further, the semiconductor device including the processing region in which the microsample 6 is extracted by the inspection does not become a product because the N + 1th and subsequent processes are invalidated, but the number of wafers is not reduced. That is, the number of wafers to be input to the Nth process is the same as the number of wafers to be input to the N + 1th process, and semiconductor devices manufactured outside the region from which the microsample 6 is taken out can be manufactured as a product if it is a non-defective product. To contribute.

  However, in this method, when separating a micro sample, since gallium FIB is used, contamination including gallium occurs in the processing region where the micro sample is taken out and its periphery. In addition, since a deposition film is used, contamination including tungsten, carbon and the like occurs.

  Therefore, in a sample preparation apparatus provided with a laser beam irradiation apparatus, a region irradiated with gallium on the wafer is irradiated with a laser beam, and the sample portion containing gallium is removed. The details of the sample preparation device 17 provided with the laser beam irradiation device will be described later.

  The laser used here may have an output sufficient to melt and evaporate the sample in a short time. For example, an excimer laser, a YAG laser, a carbon dioxide laser, and a dye laser can be used. In this example, a YAG laser was used. This laser beam has a very high intensity and can evaporate the sample surface. For example, a target laser beam is automatically irradiated to a fine semiconductor device manufactured on a silicon wafer by a laser beam control device that inputs microsample manufacturing conditions. As a result, regions that contain gallium are removed from the wafer surface. Note that the wavelength and energy of the laser may be adjusted depending on the material of the sample surface irradiated with the laser beam.

  Conventionally, when observing a sample, a laser microscope that irradiates the sample with a laser beam, detects light reflected from the sample, and observes the sample is attached to the ion beam device. The surface could hardly be removed and the object of the present invention could not be achieved.

  According to the electronic component manufacturing method of the present embodiment, it is not necessary to waste a board for evaluation. In addition, even if the substrate from which the sample for inspection is cut out is returned to the process, no new defect is generated. As a result, the manufacturing yield of electronic components is improved.

  In this embodiment, the sample preparation apparatus incorporating the laser device is used. However, after the sample preparation, the wafer is introduced into a laser processing apparatus having the same performance as the laser device, and the same removal operation is performed. May be. In this case, the processing position information is transferred from the sample preparation device 17 to the laser processing device 19 so that automatic laser irradiation can be performed on the processing position. However, in this case, the cost of the two apparatuses is necessary, and the working time becomes long. As a result, the economical cost for manufacturing the device increases.

<Embodiment 2>
FIG. 3 shows a schematic configuration diagram of a sample preparation apparatus provided with a laser beam irradiation apparatus which is an embodiment according to the present application.

The sample preparation device 17 includes a vacuum container 41, and includes a liquid metal ion source 32 that emits gallium, a beam limiting aperture 33, an ion beam scanning electrode 34, an ion beam lens 31, and the like. FIB irradiation optical system 35, secondary particle detector 36 for detecting secondary electrons and secondary ions emitted from the sample by FIB irradiation, and source gas for forming a deposition film in the ion beam irradiation region are supplied. A deposition gas source 37, a probe 3 attached to the tip of a manipulator 42, a sample stage 39 on which a sample substrate 38 such as a semiconductor wafer or a semiconductor chip is placed, and a sample holder 40 for fixing a minute extracted sample obtained by extracting a part of the sample substrate. Etc. are arranged. In addition, a laser device 56 including a laser generation oscillator 51, a laser amplifier 52, a second harmonic generator 53, and the like, a laser reflecting mirror 54 that guides laser light to a sample processing position, a laser optical lens 55, and the like are mounted. Has been. The laser device 56, the laser reflecting mirror 54, the laser optical lens 55, and the like are collected as one component and fixed to a vacuum vessel. As other devices for controlling this device, a stage control device 61, a manipulator control device 62, a secondary electron detector amplifier 63, a deposition gas source control device 64, a FIB control device 65, a laser mainly composed of an electric circuit and an arithmetic device. A reflecting mirror position control device 71, a laser optical lens control device 72, a laser control device 73, a calculation processing device 74, and the like are arranged.

Next, the operation of the sample preparation apparatus will be described. First, the sample substrate 38 is irradiated with ions emitted from the liquid metal ion source 32 through the beam limiting aperture 33 and the ion beam lens 31. FIB 1 is bundled to a diameter of several nanometers to about 1 micrometer on the sample. When the sample substrate 38 is irradiated with the FIB 1, constituent atoms on the sample surface are released into the vacuum by a sputtering phenomenon. Therefore, by scanning the FIB 1 using the ion beam scanning electrode 34, processing from the micrometer level to the submicrometer level can be performed. Further, the deposition film can be formed by irradiating the sample substrate 38 with the FIB 1 while introducing the deposition gas into the sample chamber. In this way, the sample substrate 38 can be processed by skillfully using sputtering or deposition by the FIB 1. The deposition film formed by FIB 1 irradiation is used to connect the contact portion at the tip of the probe 3 and the sample, or to fix the extracted sample to the sample holder 40. Also, the FIB 1 is scanned, secondary electrons and secondary ions emitted from the sample are detected by the secondary particle detector 36, and the intensity is converted into the luminance of the image, thereby the sample substrate 38, the probe 3, etc. Can be observed.

  The processing operation for producing the microsample using gallium FIB1 is the same as the conventional method. Then, the micro sample 6 is sent to a transmission electron microscope to analyze the cross-sectional microstructure. Next, the laser beam irradiation operation after the microsample is manufactured will be described. Here, a YAG laser is used as the laser generator. First, the direction of the laser light 57 emitted from the laser generator 56 is changed by the laser reflecting mirror 53 and directed to the processing region through the laser optical lens 54 and guided into the vacuum container. The laser used here has sufficient power to melt and evaporate the sample in a short time. This laser was a pulsed laser and was set to a pulse width of about 6 nsec, a wavelength of 532 nm, and a pulse energy of about 5 mJ. When the sample is irradiated with the laser, constituent atoms on the sample surface are released into the vacuum due to melting and evaporation phenomena. Further, the laser beam irradiation trace is scanned in advance with FIB 1, the secondary electrons emitted from the sample are detected by the secondary particle detector 36, and the laser beam irradiation trace is observed, so that the laser beam irradiation region and the ions are observed. If the positional relationship of the beam irradiation region is clarified, for example, the laser beam 57 can be automatically irradiated to the processing region 42 based on the processing position information for a fine semiconductor device manufactured on a silicon wafer. In this example, the laser pulse was irradiated 10 times, and a region containing several tens of micrometers on one side could be removed several tens of micrometers deep. These controls are unified by the calculation processing device 74. Next, the sample substrate 38 is put into the next process, but gallium and deposition gas components can be removed by the laser irradiation process, and it does not cause a defect in the subsequent processes.

  According to the present embodiment, sample preparation that can realize an electronic component manufacturing method that does not waste a substrate for evaluation and does not generate a new defect even if a wafer from which a sample for inspection is cut out is returned to the process. An apparatus is provided.

FIG. 4 shows a sample preparation apparatus which is another embodiment similar to the present embodiment. In this sample preparation apparatus, laser beam irradiation is performed after the microsample is manufactured. Here, unlike the above embodiment, the laser generator 56 is not fixed to the vacuum vessel. In this apparatus, a relatively large excimer laser can be used as the laser. Similarly, in this apparatus, the laser beam 57 emitted from the laser generator 56 is changed in its direction by a laser reflecting mirror 53 placed in the atmosphere, and is further processed through a laser optical lens 54 placed in the atmosphere. Toward this, it is guided into the vacuum vessel. When the sample is irradiated with a laser, the sample upper layer including the processing region can be removed by melting, evaporation phenomenon, or the like. This control is similarly performed by the calculation processing device 74. Also in this embodiment, gallium and deposition gas components can be removed by the laser irradiation process, and there is no cause for defects in the subsequent processes.

<Embodiment 3>
FIG. 5 shows a schematic configuration diagram of a sample preparation apparatus including a second ion beam irradiation apparatus which is an embodiment according to the present application.

  The sample preparation device 17 includes a vacuum container 41, and the configuration of the FIB irradiation optical system 35, the secondary particle detector 36, the deposition gas source 37, the probe 3, the sample stage 39, and the like are included in the vacuum container. This is the same as the sample preparation apparatus of the second embodiment. In this apparatus, a second ion beam irradiation system including a duoplasmatron 81 that emits gas ions such as argon, oxygen, and nitrogen, an ion beam lens 82, an abeam limiting aperture 83, and an ion beam scanning electrode 84 is installed. is doing. In addition to the stage control device 61, the manipulator control device 62, the secondary electron detector amplifier 63, the deposition gas source control device 64, the FIB control device 65, the duoplasmatron control device 91, the optical system, and the like are controlled. A control device 92, an ion scanning control device 93, a calculation processing device 74, and the like are arranged.

  The operation of the FIB irradiation optical system 35 is the same as that of the second embodiment, and the processing operation for manufacturing the microsample using the gallium FIB 1 is the same as the conventional method. And the micro sample 6 extracted from this apparatus is analyzed by the test | inspection apparatus.

Next, the second ion beam irradiation operation after the microsample is manufactured will be described. The ion source of the second ion beam irradiation apparatus is a duoplasmatron 81, which irradiates argon ions here. The acceleration voltage of the ion beam 85 was 5 kV, the ion current was adjusted to 2 microamperes, and the beam diameter was adjusted to about 10 micrometers. Further, the beam scanning electrode 84 can aim at an arbitrary place of the substrate sample 38, and the processing region 42 irradiated with gallium can be scanned and irradiated. For this purpose, the following preparations are made in advance. First, the argon ion beam 85 is focused in a spot shape and irradiated onto the sample. Then scan the irradiation signatures of the spot shape in FIB1, by detecting secondary electrons, by Judging watch spot-like irradiation signatures, it should reveal an argon ion beam irradiation position and FIB1 irradiation position relationship. The ion beam scanning control device 93 of this apparatus stores the processing position of the microsample 6 and gallium FIB irradiation condition information. The processing position is called from the stored information, the argon ion beam irradiation system is controlled, and the processing is performed. The position is automatically irradiated with an argon ion beam 85. Furthermore, the amount of gallium irradiation can be calculated from the gallium FIB irradiation conditions, the conditions for removing almost all of the gallium can be set, and the argon ion beam 85 can be automatically irradiated. These controls are performed uniformly by the calculation processing device 74.

  The ion beam can irradiate the target position with higher accuracy than the laser device described in the second embodiment, and the ion beam is superior to the laser beam in focusing. Suitable for removing. On the other hand, since the sample can evaporate the sample in a short time, the laser beam is suitable for increasing the throughput and processing a wide area at a time.

  In this example, the argon ion beam 85 was irradiated for 1 minute, and the side including the processing region could remove a region of several tens of micrometers and a depth of 2 microns. Next, the sample substrate 38 is put into the next process, but the gallium and deposition gas components can be removed by the argon ion irradiation treatment, and it does not cause a defect in the subsequent processes.

  According to the present embodiment, sample preparation that can realize an electronic component manufacturing method that does not waste a substrate for evaluation and does not generate a new defect even if a wafer from which a sample for inspection is cut out is returned to the process. An apparatus is provided.

  In this device, the second ion beam device is incorporated in the FIB ion beam device, but the removal work is performed with the second ion beam irradiation device having the same performance as the second ion beam irradiation device. Also good. In this case, the processing position information is transferred from the FIB ion beam apparatus to the argon ion beam irradiation apparatus so that the processing position can be automatically irradiated with the laser. However, in this case, the cost of the two apparatuses is necessary, and the working time becomes long. As a result, the economical cost for manufacturing the device increases.

<Embodiment example 4>
Next, an example of reducing contamination by ion beam element species, that is, gallium, using a method of covering at least a part of the substrate with a thin film will be described.

  In this method, before processing the micro sample, first, a thin film is formed on the wafer so as to cover the processing region. As a method for forming the thin film, (1) a metal thin film such as gold or platinum prepared in advance or an organic thin film such as an epoxy resin thin film or a polyimide thin film is placed on the wafer. (2) A thin film is formed by applying a liquid material on the wafer and heating the wafer. (3) A thin film is formed in a vacuum apparatus by vapor deposition of metal or carbon, various thin film formation by sputtering, or chemical vapor deposition utilizing synthesis of chemical gas.

  The liquid material used in the above (2) is a coating solution for forming a silicon oxide film called spin-on glass (abbreviated as SOG) (for example, a silicon oxide system manufactured by Tokyo Ohka Kogyo Co., Ltd.). Coating solution for forming a film, or a metal complex solution such as Cr or Ti), an epoxy resin solution, or a polyimide precursor solution, which can be applied using a spinner or various pipettes. The protective film is formed by baking using a heating means such as various atmospheric furnaces, hot plates, lasers, or photocuring using an ultraviolet irradiation means for irradiating an ultraviolet lamp or an ultraviolet laser.

Next, the sample preparation process by this method will be described with reference to FIG. FIG. 6A is a diagram in which after the thin film 202 is formed on the silicon wafer 201, the micro sample is started to be manufactured by the FIB 1 in the sample preparation device. Prior to this step, a silicon oxide-based coating liquid thin film called spin-on glass (abbreviated as SOG), which is a liquid material, was applied on the wafer 201 so as to cover at least the region to be processed. Next, the wafer was baked by heating the spin-on glass on a hot plate. Then, it introduced into the sample preparation apparatus. Then, as already described, the microsample is extracted from the wafer by using the FIB 1 and the probe attached to the manipulator tip, ion beam gas assist deposition, and the like. FIG. 6B shows a sample cross section. This sample was prepared for development of a wiring process of a semiconductor device. A silicon oxide film 203 was formed on a silicon wafer 201, and a Cu wiring 204 was provided on the chain. However, the chain is broken within the circle 205. The purpose of analysis of this sample is to elucidate the cause of this disconnection. The silicon oxide film 203 is a thin film produced by baking spin-on glass. At the start of sample preparation, FIB 1 is irradiated from above the thin film, but sputtering causes a hole in the thin film and the ion beam reaches the sample. FIG. 6 (c) shows a state in which holes are drilled by FIB 1 from both sides while leaving the target disconnection. As shown in this figure, a deposit 206 containing gallium and a part of the sample exists on the upper surface of the sample around the processing region. In addition to gallium and some fragments of the sample, a part of the substance generated from the deposition gas or fine particles generated from the component parts of the sample apparatus may fall on the thin film. All of these are contaminants that can cause defects in the semiconductor manufacturing process. However, they will stay on the thin film without reaching the substrate. The subsequent microsample production procedure is the same as that of the conventional method. In the next step, after extracting the microsample, the substrate is taken out and the thin film is removed. As a method for removing the thin film, an etching apparatus using plasma was used. As a result, at least the substances generated from the gallium and the deposition gas and the fine particles generated from the component parts of the sample apparatus can be removed at a stroke by ion beam processing. Note that the ion beam remaining in the processing region, that is, gallium, can be removed by the method described in the first embodiment or the second embodiment of the invention, that is, the second ion beam irradiation or the laser beam.

  The thin film removal method differs depending on the type of thin film formed on the wafer. For example, (1) when the film is placed on the substrate, the thin film may be removed. When a thin film is formed on the substrate as in (2) and (3), it is removed by an ashing device, removed by dry etching using plasma or the like, or dissolved by an organic solvent and removed.

  According to the electronic component manufacturing method of the present embodiment, it is not necessary to waste a board for evaluation. In addition, even if the substrate from which the sample for inspection is cut out is returned to the process, no new defect is generated. As a result, the manufacturing yield of electronic components is improved. Note that in the example of the embodiment described above, an example in which a method of taking out a microsample with a sample preparation apparatus is described, but the shape of the microsample is processed with the sample preparation apparatus, and the substrate is removed from the sample preparation apparatus. The microsample may be taken out by another mechanism. For example, as shown in FIG. 7 (a), a thin film 208 is formed on a wafer, and both sides of the target position are processed stepwise with FIB1 to produce a cross-sectional sample thin film 207, as shown in FIG. 7 (b). In this manner, the periphery of the sample thin film is cut with FIB1 and the sample thin film 207 is cut from the wafer. Then, the wafer is taken out from the sample preparation apparatus, and the sample thin film 207 is moved from the wafer to the TEM sample holder 209 using the static electricity of the glass rod in the atmosphere. As described above, an apparatus that processes most of the outer shape of the microsample with the ion beam without taking out the microsample in the apparatus is also included in the sample preparation apparatus shown in the present application. In addition to the sample preparation device for taking out micro samples for analysis from the wafer as described above, holes are formed in the wafer by FIB and emitted from the FIB or electron beam irradiation device attached to the device. A sample preparation apparatus that performs device analysis by observing the inside of a device such as a cross-section with an electron beam is also included in the sample preparation apparatus shown in the present application.

The figure for demonstrating the flow of the wafer in the process in connection with the electronic component manufacturing method by this application. The figure for demonstrating the flow which isolate | separates a micro sample from the conventional sample. The figure which shows one Embodiment of the sample preparation apparatus by this application. The figure which shows one Embodiment of the sample preparation apparatus by this application. The figure which shows one Embodiment of the sample preparation apparatus by this application. The figure for demonstrating the sample preparation procedure in connection with the electronic component manufacturing method by this application. The figure for demonstrating the sample preparation method in connection with the electronic component manufacturing method by this application.

Explanation of symbols

1 ... FIB, 2 ... sample, 3 ... probe, 4 ... depot source, 5 ... madepogas, 6 ... micro sample, 11 ... Nth process, 12 ... N + 1th process, 13 ...
Lot, 14 ... inspection wafer, 15 ... inspection electron microscope, 17 ... sample preparation device,
18 ... Analyzer, 31 ... Ion beam lens, 32 ... Liquid metal ion source, 33 ...
Beam limiting aperture, 34 ... ion beam scanning electrode, 35 ... FIB irradiation optical system,
38 ... Secondary particle detector, 37 ... Depot source, 38 ... Sample substrate, 39 ... Sample stage,
DESCRIPTION OF SYMBOLS 41 ... Vacuum container, 42 ... Manipulator, 40 ... Sample holder, 51 ... Laser generator oscillator, 52 ... Laser amplifier, 54 ... Laser reflector, 55 ... Laser optical lens, 56 ... Laser generator, 61 ... Stage controller, 62 ... manipulator control device, 63 ... amplifier, 64 ... deposit gas source control device, 65 ... FIB control device, 71
DESCRIPTION OF SYMBOLS ... Laser reflecting mirror control apparatus, 72 ... Laser optical source control apparatus, 73 ... Laser apparatus control apparatus, 74 ... Calculation processing apparatus, 81 ... Duoplasmatron, 82 ... Ion beam lens, 83 ... Beam limiting aperture, 84 ... Ion beam Scan electrode, 91 ... Duoplasmatron controller, 92 ... Ion beam lens controller, 93 ... Ion beam scan controller, 201 ... Silicon wafer, 202 ... Thin film, 76 ... Sample holder, 77 ... Holder cassette, 78 ... Transfer means , 80 ... stage control device, 2
03 ... silicon oxide film, 204 ... Cu wiring, 205 ... circle, 206 ... deposit, 2
07: Sample thin film, 208: Thin film, 209: TEM sample holder.

Claims (8)

A sample stage that can hold and move the sample; and a first ion beam irradiation optical system that irradiates the sample with ions emitted from the liquid metal ion source, and is irradiated from the first ion beam irradiation optical system A sample preparation apparatus for manufacturing a micro sample by processing the sample with an ion beam,
A second ion beam irradiation optical system that irradiates the sample with gas ions such as argon, oxygen, and nitrogen, and a control device that controls the second ion beam irradiation optical system ;
An irradiation mark formed by irradiating the sample with the ion beam of the first ion beam irradiation optical system is observed with the ion beam of the first ion beam irradiation optical system, and an irradiation position by the first ion beam irradiation optical system is determined. Maintaining the relationship of the irradiation position of the second ion beam irradiation optical system,
The control device applies a second ion beam having a predetermined irradiation amount from the second ion beam irradiation optical system to the processing position based on the processing position of the sample and the ion beam irradiation amount of the first ion beam irradiation optical system. A sample preparation apparatus characterized by irradiation . The sample preparation apparatus according to claim 1,
A sample preparation apparatus comprising a deposition gas source for supplying a source material gas for a deposition film. In the sample preparation device according to any one of claims 1 and 2,
The sample preparation apparatus, wherein the first ion beam irradiation optical system irradiates a gallium ion beam. In the sample preparation device according to claim 3,
The sample preparation apparatus, wherein the second ion beam irradiation optical system irradiates an argon ion beam. In the sample preparation device according to claim 4,
A calculation processing device for storing the irradiation conditions of the gallium ion beam, wherein the calculation processing device controls the second ion beam irradiation optical system based on the irradiation conditions of the gallium ion beam; A sample preparation apparatus that irradiates a region irradiated with the argon ion beam. In the sample preparation device according to claim 5,
The calculation processing device calculates the irradiation amount of the gallium ion beam from the irradiation condition of the gallium ion beam, and controls the irradiation amount of the argon ion beam based on the irradiation amount of the gallium ion beam. Production device. In the sample preparation device according to any one of claims 1 to 6,
A sample preparation device comprising a probe for extracting a prepared microsample. In the sample preparation device according to any one of claims 1 to 7,
A sample preparation device comprising a sample holder for fixing an extracted microsample.

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