JP4996206B2 - Shape observation apparatus and shape observation method - Google Patents

Description

  The present invention relates to a shape observation apparatus and a shape observation method for a shape of a sample.

In recent years, semiconductor devices have been miniaturized. In a semiconductor device, a fine pattern is formed as a three-dimensional shape. As an apparatus for observing the three-dimensional shape of this pattern, an apparatus for observing the cross section of a semiconductor device by rupturing the whole or a part of the semiconductor device, such as a cross section SEM, and a microscopic apparatus, such as an atomic force microscope (Atomic Force Microscope). An apparatus for observing a probe by scanning the surface of a semiconductor device has been proposed. When handling a semiconductor device, it has been proposed to form a mark in the semiconductor device in order to specify the position in the semiconductor device (see, for example, Patent Documents 1 to 3).
JP 2002-340756 A Japanese Patent Laid-Open No. 11-108810 Japanese Patent Laid-Open No. 10-92364

  However, in the cross-sectional SEM, since the semiconductor device is broken, a damaged region is large, and there is a problem that a broken semiconductor device or a semiconductor wafer on which a plurality of semiconductor devices are mounted cannot be used. In addition, since the atomic force microscope scans a minute probe, it takes time to scan, and there is a problem that a reverse taper of a three-dimensional shape cannot be detected. On the other hand, since the mark formed in the semiconductor device changes the surface shape of the semiconductor device or generates particles when the mark is formed, the mark is used for observing the three-dimensional shape of the semiconductor device. It never happened.

  Therefore, an object of the present invention is to provide a shape observation apparatus and a shape observation method that can observe the shape of a sample having a fine pattern, such as a semiconductor device, in a short time and that cause little damage to the sample.

According to a first aspect of the present invention that solves the above-described problems, a formation portion that forms an observation mark whose shape viewed from a reference direction is a reference shape on a surface of a sample, and the observation mark is formed in the reference direction after the formation of the observation mark. an observation image photographing unit that obtains an observation image taken from different viewing directions a, possess an observation image display unit for displaying the observation image, the observation marks, sputter processing of the sample, to the upper sample It is a shape observation device formed by deposition processing, physical change of the sample, chemical change of the sample, or surface modification of the sample .
In addition, a feature of the second aspect of the present invention is that the observation mark includes an element having an atomic number that is 5 or more away from an atomic number of an element constituting the sample.
The observation mark is a groove, and the groove is formed so as to reach the surface of the sample that becomes a blind spot from the reference direction.
According to a fourth aspect of the present invention, an etching unit that selectively etches the sample around the observation mark while leaving the observation mark after the formation of the observation mark.
The forming unit further includes a specifying unit that specifies a position on the sample where the observation mark is to be formed before the forming unit forms the observation mark, and the specifying unit photographs the sample from the reference direction. A reference image capturing unit for acquiring a reference image, a reference image display unit for displaying the reference image, and a reference mark having the reference shape on the reference image displayed on the reference image display unit. A feature of the fifth aspect of the present invention is that the forming unit forms the observation mark based on the position of the arranged reference mark and the reference shape. .
In addition, the forming unit uses the first charged particle beam source or the first light source that irradiates the sample with the charged particle beam or the light from the reference direction so that the irradiation shape becomes the reference shape. A mark is formed on the surface of the sample, and the first charged particle beam source or the first deflecting unit that deflects the charged particle beam or light irradiated by the first light source is used, and the sample becomes a blind spot from the reference direction. A feature of the sixth aspect of the present invention is that the observation mark is formed on the surface.
In addition, the forming unit uses the first charged particle beam source or the first light source that irradiates the sample with the charged particle beam or the light from the reference direction so that the irradiation shape becomes the reference shape. A mark is formed on the surface of the sample, and the charged particle beam or light irradiated by the first charged particle beam source or the first light source penetrates the sample and enters the surface of the sample that becomes a blind spot from the reference direction. A feature of the seventh aspect of the present invention is that the observation mark is formed on the surface of the sample that reaches the blind spot from the reference direction.
In addition, the forming unit uses the first charged particle beam source or the first light source that irradiates the sample with the charged particle beam or the light from the reference direction so that the irradiation shape becomes the reference shape. A mark is formed on the surface of the sample, and the observation image photographing unit uses a second charged particle beam source or a second light source that irradiates the sample with a charged particle beam or light from the observation direction, The first charged particle beam source or the first light source irradiates the sample with a charged particle beam or light from the reference direction, and then irradiates the sample with the charged particle beam or light from the observation direction. As described above, the first charged particle beam source or the first light source is used as the second charged particle beam source or the second light source by using a direction changing unit that changes the direction in which the charged particle beam or light is applied to the sample. That is also used for And features of the present invention 8.
In the ninth aspect of the present invention, an observation mark whose shape viewed from the reference direction is a reference shape is formed on the surface of the sample, and after the observation mark is formed, the observation mark is viewed from an observation direction different from the reference direction. Taking an observation image by photographing, displaying the observation image , the observation mark is sputter processing of the sample, deposition processing on the sample, physical change of the sample, chemical change of the sample, Alternatively, it is a shape observation method formed by surface modification of the sample .
In addition, a feature of the tenth aspect of the present invention is that the observation mark includes an element having an atomic number that is 5 or more away from an atomic number of an element constituting the sample.
The observation mark is a groove, and the groove is formed so as to reach the surface of the sample that becomes a blind spot from the reference direction.
In addition, a feature of the twelfth aspect of the present invention is that the sample around the observation mark is selectively etched after the observation mark is formed, leaving the observation mark.

  ADVANTAGE OF THE INVENTION According to this invention, the shape observation apparatus which can observe the shape of the sample which has a fine pattern like a semiconductor device in a short time, and has little damage to a sample, and a shape observation method can be provided.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
As shown in FIG. 1, the shape observation apparatus 1 according to the first embodiment of the present invention includes a first scanning electron microscope (lens barrel) 2 and a second scanning electron microscope (lens barrel) 6. is doing. The first scanning electron microscope (lens barrel) 2 includes a first charged particle beam source 3 and a first deflection unit 4. The second scanning electron microscope (lens barrel) 6 has a second charged particle beam source 7 and a deflection unit (not shown). The first scanning electron microscope (lens barrel) 2 is not limited to the scanning electron microscope, but may be an electron beam exposure apparatus, a focused ion beam exposure apparatus, or a laser beam irradiation apparatus. The first scanning electron microscope ( The lens barrel 2 is an example of a charged particle beam and light irradiation device. The second scanning electron microscope (lens barrel) 6 is not limited to an electron microscope, but may be a focused ion beam microscope or an optical microscope. The second scanning electron microscope (lens barrel) 6 includes charged particle beams and It is one example of the microscope using the light irradiation apparatus. Accordingly, the first charged particle beam source may be a first light source, and the second charged particle beam source 7 may be a second light source, which irradiates a charged particle beam or light beam of an electron beam or an ion beam, respectively. .

  The first scanning electron microscope (lens barrel) 2 is attached to a chamber 10 that can be depressurized, such as a semiconductor device placed on a sample stage 9 in the chamber 10 or a semiconductor product of a semiconductor wafer on which a plurality of semiconductor devices are mounted. The sample 11 having a fine pattern can be irradiated with the electron beam 47, and further, although not necessarily required, an image of the sample 11 can be taken by irradiation of the electron beam 47. The second scanning electron microscope (lens barrel) 6 is also attached to a chamber 10 that can be decompressed, and an image of the sample 11 can be taken by irradiating the sample 11 with an electron beam. The first scanning electron microscope (barrel) 2 irradiates the electron beam 47 from the reference direction 32, and the second scanning electron microscope (barrel) 6 irradiates the electron beam from an observation direction 33 different from the reference direction 32. Can be irradiated.

The source gas supply unit 5 supplies a source gas such as silane (SiH ₄ ) into the chamber 10. The source gas is decomposed by the electron beam 47 applied to the sample 11 from the first charged particle beam source 3 of the first scanning electron microscope (lens barrel) 2, and the elements contained in the source gas are irradiated by the electron beam 47. The sample 11 is fixed on the surface. An observation mark 31 is constituted by the fixed element. The observation mark 31 may be formed from the charged particles irradiated from the first charged particle beam source 3 and the sample 11 without using the source gas, and the observation mark 31 is an ion of charged particles of the sample 11. It may be formed by sputtering processing by, deposition processing by source gas or ions on the sample 11, physical or chemical change such as phase change of the sample 11, or surface modification of the sample 11.

  The observation mark 31 is formed on the surface of the sample 11, and the three-dimensional shape of the surface of the sample 11 is transferred to the observation mark 31. By observing the observation mark 31, the three-dimensional shape of the sample 11 can be grasped. The observation mark 31 is observed using the second scanning electron microscope 6.

The etching unit 8 supplies, for example, a chlorine (Cl) -based etching gas into the chamber 10, and after the formation of the observation mark 31, the observation mark 31 made of silicon oxide (SiO ₂ ) is left and the periphery of the observation mark 31. The sample 11 made of silicon (Si) is selectively etched. According to this etching, observation of the observation mark 31 can be facilitated.

  The first control unit 12 has a display screen and mainly controls the first scanning electron microscope 2. The second control unit 13 also has a display screen and mainly controls the second scanning electron microscope 6.

  As illustrated in FIG. 2, the first control unit 12 includes a CPU, an HDD, an output I / F, an input I / F, and a RAM. A display screen is connected to the output I / F. A pointing device such as a mouse is connected to the input I / F. In the RAM, a specifying unit 14 and a forming unit 19 that are read and worked by the CPU are stored as programs. The specifying unit 14 further includes a reference image photographing unit 15, a reference image display unit 16, and a GUI 17.

  As shown in FIG. 3, the second control unit 13 also includes a CPU, an HDD, an output I / F, an input I / F, and a RAM. A display screen is connected to the output I / F. A pointing device such as a mouse is connected to the input I / F. In the RAM, an observation image photographing unit 21, an observation image display unit 22, an observation image storage unit 23, an extraction unit 24, a cross-sectional shape calculation unit 28, and a measurement unit 29, which are read and operated by the CPU, are stored. Stored as a program. The extraction unit 24 further includes a contour extraction unit 26 and a thinning unit 27.

  Next, a method for observing the three-dimensional shape of the sample 11 using the shape observation apparatus 1 will be described.

  First, as shown in FIG. 1, the sample 11 is placed on the sample stage 9 using a transport unit (not shown), and the inside of the chamber 10 is decompressed using a decompression unit (not shown).

  The reference image capturing unit 15 of the specifying unit 14 captures the sample 11 from the reference direction 32 using the first scanning electron microscope 2 and acquires the reference image 34 shown in FIG.

  As shown in FIG. 4, the reference image display unit 16 displays the reference image 34 on the display screen of the first control unit 12. The captured reference direction 32 preferably coincides with the normal direction of the surface of the sample 11, and the top-down view of the sample 11 can be obtained as the reference image 34 by matching. It is assumed that the reference image 34 includes a line pattern 35 formed on the substrate 36 of the sample 11.

  The GUI 17 uses the reference image 34 to specify the position on the sample 11 where the observation mark 31 is formed and the reference shape. The GUI 17 supports the user of the shape observation apparatus 1 that places a reference mark having a reference shape on the reference image 34.

  Specifically, the GUI 17 displays a toolbar 37 on the display screen. On the toolbar 37, a line reference shape 41, a stripe reference shape 42, a mesh reference shape 43, a concentric reference shape 44, and a radial line reference shape 45 are displayed. The user can designate at least one of the reference shapes 41 to 45 by using the pointing device using the GUI 17.

  For example, a case where the user designates the reference shape 41 of the line using the GUI 17 will be described. First, the user designates the reference shape 41 of the line on the toolbar 37 using the GUI 17. The user further designates the position on the reference image 34 where the left end of the line is to be arranged using the GUI 17. Next, the user designates the position where the right end of the line is arranged on the reference image 34 by using the GUI 17. As described above, the user can use the GUI 17 to place the reference mark 46 having the reference shape 41 of an arbitrary size line at an arbitrary position on the reference image 34 as shown in FIG.

  Similarly, a case where the user designates the stripe reference shape 42 using the GUI 17 will be described. First, the user designates the stripe reference shape 42 on the tool bar 37 using the GUI 17. The user further designates a position on the reference image 34 where the upper left end of the entire stripe is to be arranged by the GUI 17. Next, the user designates the position at which the upper right end of the entire stripe is arranged on the reference image 34 using the GUI 17. Furthermore, the user designates the position on the reference image 34 where the lower left end of the entire stripe is to be arranged by the GUI 17. Further, the user designates a position on the reference image 34 where the lower right end of the entire stripe is to be arranged by the GUI 17. Finally, the user inputs the stripe pitch on the tool bar 37 using the GUI 17. As described above, the user can use the GUI 17 to place the reference mark 46 having the reference shape of the stripe having an arbitrary pitch at an arbitrary position on the reference image 34 as shown in FIG.

  A case where the user designates the mesh reference shape 43 using the GUI 17 will be described. First, the user designates the mesh reference shape 43 on the tool bar 37 using the GUI 17. The user further designates the position on the reference image 34 where the upper left corner of the entire mesh is to be arranged using the GUI 17. Next, the user designates the position on the reference image 34 where the upper right end of the entire mesh is to be arranged using the GUI 17. Furthermore, the user designates the position on the reference image 34 where the lower left corner of the entire mesh is to be arranged using the GUI 17. In addition, the user designates the position on the reference image 34 where the lower right end of the entire mesh is to be arranged using the GUI 17. Finally, the user inputs the pitch X in the horizontal direction and the pitch Y in the vertical direction on the toolbar 37 using the GUI 17. As described above, the user can place a reference mark having a mesh reference shape 43 having an arbitrary pitch X and pitch Y at an arbitrary position on the reference image 34 using the GUI 17.

  A case where the user designates the concentric reference shape 44 using the GUI 17 will be described. First, the user specifies a concentric reference shape 44 on the tool bar 37 using the GUI 17. The user further designates a position on the reference image 34 where the center of the concentric circle is to be arranged by the GUI 17. Next, the user designates a position on the reference image 34 where the outer circumference of the circle that is the outermost circumference of the concentric circles is to be arranged using the GUI 17. Finally, the user inputs the pitch of the radius of the concentric circle on the tool bar 37 using the GUI 17. As described above, the user can place the reference mark 46 having the concentric reference shape 44 having a pitch of an arbitrary radius at an arbitrary position on the reference image 34 by the GUI 17.

  A case where the user designates the reference shape 45 of the radial line using the GUI 17 will be described. First, the user designates the reference shape 45 of the radial line on the tool bar 37 using the GUI 17. The user further designates the position on the reference image 34 where the center of the radial line is to be arranged by the GUI 17. Next, the user designates the position where the end of the radial line is arranged on the reference image 34 by using the GUI 17. Finally, the user inputs the pitch of the angle formed by the adjacent lines of the radial lines on the tool bar 37 using the GUI 17. As described above, the user can place the reference mark 46 having the reference shape 45 of the radial line having the pitch of an arbitrary angle at an arbitrary position on the reference image 34 by the GUI 17.

  If the user designates dots on the toolbar 37 using the GUI 17, the user further inputs the dot pitch using the GUI 17, so that the GUI 17 has the reference shapes 41 to 45 arranged on the reference image 34. The reference mark 46 can be represented by a dot row that is not continuous like a line segment.

  Thus, the reference mark 46 may be a line segment having an arbitrary length as shown in FIG. 5 or a plurality of line segments as shown in FIG. Further, it may be a mesh, a concentric circle, or a radial line segment. A shape like an interference fringe in which the radiation intensity is changed in the scanning direction or the radiation direction may be used. A combination of these may also be used. When forming line segments or dots on the sample 11, a beam obtained by focusing the electron beam 47 may be used. However, when the shape is repeated like a stripe, mesh, concentric circle, or radial line, It is possible to use an interference pattern represented by

  In addition, although the data input by the user is performed by GUI17, it is not restricted to this, A pointing device may be used and the icon showing the mark position displayed on the display screen may be selected. Further, a horizontal line segment (reference mark) that divides the reference image 34 vertically into two is set on the reference image 34 in advance, and the line pattern 35 is photographed so as to be arranged at a desired position in the reference image 34. good.

  When the end of designation of the reference mark 46 is input by the user, the forming unit 19 controls the first scanning electron microscope 2 to irradiate the electron beam 47, and the shape viewed from the reference direction 32 is the reference shape 41 to 41. An observation mark 31 that is 45 is formed on the surface of the sample 11. At this time, the forming unit 19 forms the observation mark 31 based on the position of the reference mark 46 arranged on the reference image 34 and the reference shapes 41 to 45.

  It should be noted here that the first scanning electron microscope 2 irradiates the sample 11 with the electron beam 47 from the reference direction 32 so that the irradiation shape becomes the reference shapes 41 to 45, and the observation mark 31 is set to the sample 11. However, when the observation mark 31 is observed from a direction different from the reference direction 32, for example, the observation direction 33, the line pattern 35 causes the observation mark 31 to be observed. Is observed distorted. By observing this distortion, the unevenness of the line pattern 35 can be detected.

  When the observation mark 31 is formed on the sample 11, the beam intensity (voltage, current) of the electron beam 47 may be increased or the irradiation time may be longer than when the reference image 34 is captured. As a result, physical changes (including contamination), chemical changes, and electrical changes of the sample 11 that do not occur at the time of photographing can be caused, and these changes can be made into the observation mark 31.

  As shown in the bird's-eye view of the sample 11 in FIG. 7, if the shape of the line pattern 35 is a forward taper, the electron beam 47 is irradiated from the normal direction 48 of the substrate 36, so The line 47 can be irradiated, and the observation mark 31 can be formed on the side surface.

  As shown in the bird's-eye view of the sample 11 in FIG. 8A, if the shape of the line pattern 35 is a reverse taper, when the electron beam 47 is irradiated from the normal direction 48 of the substrate 36, the side surface of the line pattern 35 becomes an electron. It is considered that the observation mark 31 cannot be formed on the side surface due to the shadow of the line 47. Therefore, as shown in FIG. 8A, by irradiating a beam having a high intensity, specifically, an electron beam 47 with an increased acceleration voltage, the inside of the line pattern 35 is caused to penetrate the electron beam 47, so that the line pattern Observation marks 31 are formed on the side surfaces of 35. According to this, the electron beam 47 reaches the surface of the sample 11 that becomes the blind spot from the reference direction 32, and the observation mark 31 can be formed on the surface of the sample 11 that becomes the blind spot from the reference direction 32.

  Further, as shown in FIG. 8B, by irradiating the electron beam 47 while tilting the sample 11, the electron beam 47 reaches the surface of the sample 11 that becomes a blind spot from the reference direction 32. The observation mark 31 can be formed on the surface of the sample 11 that becomes a blind spot. The forming unit 19 can use the tiltable sample stage 9 shown in FIG. 1 in order to tilt the sample 11.

  Further, as shown in FIG. 8C, by irradiating the electron beam 47 while tilting it, the electron beam 47 reaches the surface of the sample 11 that becomes a blind spot from the reference direction 32. An observation mark 31 can be formed on the surface of the sample 11. The forming unit 19 can use the first deflecting unit 4 of FIG. 1 that deflects the electron beam 47 in order to tilt the electron beam 47.

  Further, a physical change of forming a groove as the observation mark 31 may be performed. This groove is formed so as to reach the surface of the sample 11 that becomes a blind spot from the reference direction 32, that is, to divide the line pattern 35 into two.

  After the observation mark 31 is formed on the sample 11, the observation image photographing unit 21 in FIG. 3 uses the second scanning electron microscope 6 to change the observation mark 31 from the reference direction 32 as shown in FIG. 1. Images are taken from different observation directions 33, and an observation image 51 in FIG. 9 is acquired. The observation image photographing unit 21 photographs the observation mark 31 using the second charged particle beam source 7 that irradiates the sample 11 with an electron beam from the observation direction 33. For imaging the observation mark 31, an energy dispersive X-ray analyzer (EDX) may be used. According to EDX, the mapping of a specific element can be made into the observation image 51. Therefore, if the elements that are not included in the sample 11 but are included only in the observation mark 31 are mapped by EDX, only the observation mark 31 can be extracted and photographed. However, in order to increase the sensitivity of EDX, it is better that the atomic numbers of the elements are separated, and only the observation mark 31 includes an element having an atomic number that is 5 or more away from the atomic number of the elements constituting the sample 11. It is desirable. And the extraction by the extraction part 24 mentioned later can be omitted.

  As shown in FIG. 9, the observation image display unit 22 (see FIG. 3) displays the observation image 51 on the display screen of the second control unit 13. Due to the unevenness of the line pattern 35, the observation mark shown in the observation image 51 is distorted. The image of the observation mark that is distorted is referred to as a deformation mark 52. The user can grasp the three-dimensional shape of the line pattern 35 by observing the deformation mark 52. Note that the observation image storage unit 23 stores an observation image 51 as necessary.

  Next, taking the observation image 51 and the observation mark 31 as an example will be described using the hole pattern 49 as shown in FIG.

  As shown in FIG. 10, if the shape of the hole pattern 49 is a forward taper, the electron beam 47 can be irradiated also to the side surface of the hole pattern 49 by irradiating the electron beam 47 from the normal direction 48 of the sample 11. The observation mark 31 can be formed on the side surface. However, if the observation mark 31 is photographed from an oblique direction, it may be considered that the observation mark 31 may not be photographed due to being blocked by the side surface of the hole pattern 49.

  Therefore, as shown in FIG. 11A, the sample 11 is tilted to the point where the observation mark 31 can be seen, and the electron beam 50 from the second scanning electron microscope 6 is irradiated, whereby the electron beam 50 is observed. An observation mark 31 that reaches the surface of the sample 11 that becomes a blind spot from the direction 33 and that becomes a blind spot from the observation direction 33 can also be photographed. The observation image photographing unit 21 can use the tiltable sample stage 9 in FIG. 1 in order to tilt the sample 11.

  Further, as shown in FIG. 11B, the electron beam 50 reaches the surface of the sample 11 that becomes a blind spot from the observation direction 33 by irradiating the electron beam 50 while tilting in the direction of the normal line of the substrate. The observation mark 31 that becomes a blind spot from the observation direction 33 can be photographed. The observation image photographing unit 21 can deflect the electron beam 50 by the second scanning electron microscope 6 in order to tilt the electron beam 50.

  As shown in FIG. 11C, the electron beam 50 can be transmitted through the side surface of the hole pattern 49 also by irradiating a strong beam, specifically, an electron beam 50 with an increased acceleration voltage. Therefore, the observation mark 31 in the hole pattern 49 can be photographed.

  As shown in FIG. 12, the sample 11 has a multilayer structure, and the intermediate layer 58 may be exposed on the side surface of the hole pattern 49. In such a case, when the observation mark 31 is formed, the observation mark 31 may not be formed only on the intermediate layer 58. Specifically, the source gas supplied from the source gas supply unit 5 in FIG. 1 reacts in a region other than the intermediate layer 58 to form the observation mark 31, but does not react with or reacts with the intermediate layer 58. In other cases, the reaction product volatilizes and does not accumulate, and the observation mark 31 is not formed. In addition, there may be a case where the observation mark 31 is not formed because the intermediate layer 58 is depressed. From this, the thickness of the intermediate layer can be indirectly measured by measuring the length of the gap between the observation marks 31.

  Next, the extraction unit 24 in FIG. 3 extracts a deformation mark 52 that is an image of the observation mark 31 from the observation image 51 in FIG. By this extraction, it is possible to observe, that is, restore, the three-dimensional shape corresponding to the observation mark 31 and the sample 11. As a method for extracting the deformation mark 52, there are a method in which the user traces with a pointing device, a method in which the contour extraction unit 26 uses the contour extraction processing of the image processing, and the like. Further, since the deformation mark 52 itself has a width, the thinning unit 27 performs a thinning process for generating a thin line passing through the center of the width as necessary.

  The cross-sectional shape calculation unit 28 calculates (restores) the cross-sectional shape of the deformation mark 52 in a cross section cut by a plane passing through the observation mark 31 of the sample 11 from the extracted deformation mark 52 and the observation direction 33. The cross-sectional shape of the deformation mark 52 is displayed on the display screen of the second control unit 13 as shown in FIG. The cross-sectional shape of the deformation mark 52 represents the cross-sectional shape of the sample and the line pattern. As a method for calculating the cross-sectional shape, there is a method of geometrically transforming the extracted deformation mark 52 according to the angle information of the observation direction 33. If there are not only one observation direction 33 but a plurality of deformation marks 52 for a plurality of observation directions 33, a more accurate restoration can be expected.

  As shown in FIG. 13, the measurement unit 29 measures the size or angle of the cross-sectional shape of the deformation mark 52 and displays it on the observation image 51. In FIG. 13, the distance corresponding to the height of the line pattern is measured as a dimension. As the angle, an angle corresponding to the taper angle of the line pattern is measured.

  As shown in FIG. 14, when the reference shape is a stripe composed of a plurality of lines, the cross section of the deformation mark 52 is a cross section obtained by cutting the sample 11 along a plane passing through the line for each of the plurality of lines as a restored three-dimensional shape. The shape is calculated.

  Furthermore, as shown in FIG. 15, the shape of the deformation mark 52 may be calculated when the direction of the viewpoint to be observed is changed to a direction that is not the observation direction 33 or the cross-sectional view. When the rotation angle in the direction of the viewpoint with the reference direction 32 as the rotation axis is input to the area 53 and the angle formed by the direction of the viewpoint and the reference direction 32 is input to the area 54, the second control unit 13 The shape of the deformation mark 52 viewed from the viewpoint direction is calculated and displayed.

  As shown in FIG. 1, the first control unit 12 and the second control unit 13 may be configured by separate computers or a single computer. If only the observation of the deformation mark 52 is required, the extraction unit 24, the cross-sectional shape calculation unit 28, and the measurement unit 29 illustrated in FIG. 3 may be omitted.

  As described above, according to the shape observation apparatus 1 of the first embodiment, since only the local observation mark 31 is attached to the sample 11, damage to the sample 11 is small, and an electron microscope, a focused ion beam microscope, or Since observation is performed using an optical microscope, the three-dimensional shape of the sample 11 with the observation mark 31 can be observed at high speed. In addition, the shape of a sample having a fine pattern such as a semiconductor device can be observed, and a three-dimensional shape with a reverse taper can be detected.

(Second Embodiment)
As shown in FIG. 16, the shape observation apparatus 1 according to the second embodiment of the present invention scans from two scanning electron microscopes 2 and 6 as compared with the shape observation apparatus 1 according to the first embodiment. The difference is that only one type electron microscope 2 is provided. Accordingly, the second control unit 13 is incorporated in the first control unit 12. The first charged particle beam source 3 of the scanning electron microscope 2 is used not only for forming the observation mark 31 but also for photographing the observation mark 31 of the second charged particle beam source 7 of the first embodiment. Is done. The first charged particle beam source 3 of the scanning electron microscope 2 irradiates the electron beam 47 from the oblique observation direction 33 to the observation mark 31 after irradiating the electron beam 47 from the reference direction 32 to form the observation mark 31. Irradiate and observe. At the time of this observation, the direction changing unit changes the direction in which the sample 11 of the electron beam 47 is irradiated. The direction changing unit includes an inclined unit 55 and a second deflecting unit 56, and tilts the sample 11 or the electron beam 47 to realize observation from an oblique direction.

  As shown in FIG. 17, the tilting part 55 tilts the sample 11 as the direction changing part. As a result, the observation mark 31 can be observed by irradiating the observation mark 31 with the electron beam 47 from the oblique observation direction 33.

  As shown in FIG. 18, the second deflecting unit 56 deflects the electron beam 47 as the direction changing unit. This also makes it possible to observe the observation mark 31 by irradiating the observation mark 31 with the electron beam 47 from the oblique observation direction 33.

(Third embodiment)
As shown in FIG. 19, the shape observation apparatus 1 according to the third embodiment of the present invention is different from the shape observation apparatus 1 of the first embodiment in that the scanning electron microscope 2 is a focused ion beam exposure apparatus. The difference is that the lens barrel is 57. By using the focused ion beam exposure apparatus (lens barrel) 57, the specimen 11 can be sputtered to form the observation mark 31. Further, if the source gas is supplied from the source gas supply unit 5 into the chamber 10, the observation mark 31 can be formed by ion beam evaporation.

  In the above-described embodiment, the shape observation apparatus 1 that forms and observes the observation mark 31 has the single chamber 10 as an integrated apparatus. However, the present invention is not limited to this, and the portion where the observation mark 31 is formed and the portion where the observation mark 31 is observed may be separated and separated. Further, the shape observation apparatus 1 may have a dedicated chamber for forming the observation mark 31 and a dedicated chamber for observing the observation mark 31.

It is a block diagram of the shape observation apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram of the 1st control part of a shape observation apparatus. It is a block diagram of the 2nd control part of a shape observation apparatus. It is the screen display of the 1st control part on which the reference image and the tool bar were displayed. It is the screen display of the 1st control part on which the reference image by which the reference mark of a line is arranged is displayed. It is the screen display of the 1st control part on which the reference image by which the reference mark of a stripe is arranged is displayed. It is a bird's-eye view of a sample in which an observation mark is formed and has a forward tapered line pattern. (A) is a bird's-eye view of a sample in which an observation mark is formed by penetrating a reverse-tapered line pattern of the charged particle beam, and (b) is an observation mark formed by tilting the sample and irradiating the charged particle beam. It is a bird's-eye view of a sample, and (c) is a bird's-eye view of a sample having a reverse taper line pattern formed by irradiating an inclined charged particle beam to form an observation mark. It is the screen display of the 2nd control part on which the observation image on which the deformation mark of the line was copied was displayed. It is a bird's-eye view of the sample which has an observation mark and has a forward taper hole pattern. (A) is a bird's-eye view of a sample in which a sample is tilted and irradiated with a charged particle beam to photograph an observation mark, and (b) is an observation mark irradiated with a charged particle beam tilted from a predetermined observation direction. 2C is a bird's-eye view of a sample in which a charged particle beam passes through a hole pattern and images an observation mark. It is a bird's-eye view of the sample which has the forward taper hole pattern in which the observation mark is formed and the intermediate layer is exposed on the side wall. It is the screen display of the 2nd control part on which the deformation | transformation mark of the line was copied and the observation image on which the measured value was displayed was displayed. It is the screen display of the 2nd control part on which the observation image on which the deformation mark of the stripe was copied was displayed. It is the screen display of the 2nd control part on which the observation image which changed the direction of the viewpoint and displayed the deformation mark of a stripe was displayed. It is a block diagram of the shape observation apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram of the state in which the sample 11 of the shape observation apparatus which concerns on the 2nd Embodiment of this invention inclines. It is a block diagram of the state in which the charged particle beam of the shape observation apparatus which concerns on the 2nd Embodiment of this invention is deflecting. It is a block diagram of the shape observation apparatus which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shape observation apparatus 2 1st scanning electron microscope (barrel)
3 First charged particle beam source or first light source 4 First deflection unit 5 Source gas supply unit 6 Second scanning electron microscope (barrel)
7 Second charged particle beam source or second light source 8 Etching unit 10 Chamber 11 Sample 12 First control unit 13 Second control unit 14 Identification unit 15 Reference image photographing unit 16 Reference image display unit 17 GUI
DESCRIPTION OF SYMBOLS 19 Formation part 21 Observation image imaging part 22 Observation image display part 23 Observation image memory | storage part 24 Extraction part 28 Cross-sectional shape calculation part 29 Measurement part 31 Observation mark 32 Reference direction 33 Observation direction 34 Reference image 37 Toolbar 41 thru | or 45 Reference shape 46 Reference Mark 51 Observation image 52 Deformation mark 55 Inclination part 56 Second deflection part 57 Focused ion beam exposure apparatus (lens tube)

Claims (24)

A forming part for forming an observation mark on the surface of the sample whose shape viewed from the reference direction is a reference shape;
After forming the observation mark, an observation image photographing unit that photographs the observation mark from an observation direction different from the reference direction and obtains an observation image;
An observation image display unit for displaying the observation image;
The observation mark is formed by sputter processing of the sample, deposition processing on the sample, physical change of the sample, chemical change of the sample, or surface modification of the sample. shape observation device shall be the features. A forming part for forming an observation mark on the surface of the sample whose shape viewed from the reference direction is a reference shape;
After forming the observation mark, an observation image photographing unit that photographs the observation mark from an observation direction different from the reference direction and obtains an observation image;
An observation image display unit for displaying the observation image;
Wherein the observation mark, than the atomic number of the elements constituting the sample, shape observation apparatus you characterized by the inclusion of elements 5 or more distant atomic number. A forming part for forming an observation mark on the surface of the sample whose shape viewed from the reference direction is a reference shape;
After forming the observation mark, an observation image photographing unit that photographs the observation mark from an observation direction different from the reference direction and obtains an observation image;
An observation image display unit for displaying the observation image;
The observation mark is a groove,
Shape observation apparatus you and forming the groove to reach the surface of the sample to be blind from the reference direction. A forming part for forming an observation mark on the surface of the sample whose shape viewed from the reference direction is a reference shape;
After forming the observation mark, an observation image photographing unit that photographs the observation mark from an observation direction different from the reference direction and obtains an observation image;
An observation image display unit for displaying the observation image;
Wherein after formation of the observed marks, shape observation apparatus it characterized as having an etch portion to selectively etch the sample near the observation marks leaving the observation mark. A forming part for forming an observation mark on the surface of the sample whose shape viewed from the reference direction is a reference shape;
Before the formation part forms the observation mark, a specifying part for specifying a position on the sample where the observation mark is formed;
After forming the observation mark, an observation image photographing unit that photographs the observation mark from an observation direction different from the reference direction and obtains an observation image;
An observation image display unit for displaying the observation image;
The specific part is:
A reference image photographing unit that obtains a reference image by photographing the sample from the reference direction;
A reference image display unit for displaying the reference image;
A GUI for assisting a user to place a reference mark having the reference shape on the reference image displayed on the reference image display unit;
The forming part, based on the reference shape and placement position of the reference mark, shape observation apparatus you and forming the observation mark. The specific part is:
Wherein prior to forming unit forms the observation mark, the shape observation apparatus according to claim 5, wherein the benzalkonium to identify the previous SL reference shape. A forming part for forming an observation mark on the surface of the sample whose shape viewed from the reference direction is a reference shape;
After forming the observation mark, an observation image photographing unit that photographs the observation mark from an observation direction different from the reference direction and obtains an observation image;
An observation image display unit for displaying the observation image;
The forming part is
Using the first charged particle beam source or the first light source that irradiates the sample with a charged particle beam or light from the reference direction so that the irradiation shape becomes the reference shape, the observation mark is placed on the surface of the sample. Forming,
Using a first deflecting unit that deflects a charged particle beam or light irradiated by the first charged particle beam source or the first light source;
Shape observation apparatus you and forming the observation marks on the surface of the sample to be blind from the reference direction. A forming part for forming an observation mark on the surface of the sample whose shape viewed from the reference direction is a reference shape;
After forming the observation mark, an observation image photographing unit that photographs the observation mark from an observation direction different from the reference direction and obtains an observation image;
An observation image display unit for displaying the observation image;
The forming part is
Using the first charged particle beam source or the first light source that irradiates the sample with a charged particle beam or light from the reference direction so that the irradiation shape becomes the reference shape, the observation mark is placed on the surface of the sample. Forming,
The charged particle beam or light irradiated by the first charged particle beam source or the first light source passes through the sample, reaches the surface of the sample that becomes a blind spot from the reference direction, and becomes a blind spot from the reference direction. shape observation apparatus you and forming the observation marks on the surface of the sample. A forming part for forming an observation mark on the surface of the sample whose shape viewed from the reference direction is a reference shape;
After forming the observation mark, an observation image photographing unit that photographs the observation mark from an observation direction different from the reference direction and obtains an observation image;
An observation image display unit for displaying the observation image;
The forming part is
Using the first charged particle beam source or the first light source that irradiates the sample with a charged particle beam or light from the reference direction so that the irradiation shape becomes the reference shape, the observation mark is placed on the surface of the sample. Forming,
The observation image photographing unit is
Using the second charged particle beam source or the second light source that irradiates the sample with the charged particle beam or light from the observation direction, the observation mark is photographed,
The first charged particle beam source or the first light source;
After irradiating the sample with a charged particle beam or light from the reference direction,
In order to irradiate the sample with a charged particle beam or light from the observation direction,
Utilizing a direction changing unit that changes the direction of irradiation of the charged particle beam or light to the sample,
The first charged particle beam source or the first light source is:
It said second charged particle beam source or shape observation apparatus you characterized in that it also serves a second light source. The shape observing apparatus according to claim 9 , wherein the direction changing unit includes an inclined unit that inclines the sample. The direction changing section, the shape of claim 9 or claim 10 wherein the first charged particle beam source or the first light source and having a second deflecting unit for deflecting the charged particle beam or light irradiation Observation device. The observation image photographing unit is
Using the second charged particle beam source or the second light source for irradiating a charged particle beam or light to the sample from the viewing direction, one of the claims 1 to 8, characterized in that photographs the observation mark The shape observation apparatus according to claim 1. Wherein the formation of the observed marks, the beam focused charged particle beam or light or, according to any one of claims 1 to 12, characterized in that use an interference pattern of the charged particle beam or light Shape observation device. The forming unit, an electron beam exposure apparatus, a focused ion beam exposure apparatus and the shape observation apparatus according to any one of claims 1 to 13, characterized in that to utilize at least one laser beam irradiator . The observation image photographing unit, an electron microscope, the shape observation apparatus according to any one of claims 1 to 14, characterized in that utilizes at least one of the focused ion beam microscope and an optical microscope. The shape observation apparatus according to any one of claims 1 to 15 , wherein the reference shape is a shape including at least one of a line, a stripe, a mesh, a concentric circle, and a radial line. The shape observation apparatus according to any one of claims 1 to 16 , further comprising an extraction unit that extracts a deformation mark that is an image of the observation mark from the observation image. The shape observation apparatus according to claim 17 , further comprising a cross-sectional shape calculation unit that calculates a cross-sectional shape of the sample from the deformation mark and the observation direction. The shape observation apparatus according to claim 18 , further comprising a measurement unit that measures a dimension or an angle of the cross-sectional shape. Shape observation apparatus according to any one of claims 1 to 19, wherein the sample is a semiconductor product. An observation mark whose shape viewed from the reference direction is the reference shape is formed on the surface of the sample,
After forming the observation mark, the observation mark is taken from an observation direction different from the reference direction to obtain an observation image,
Displaying the observed image ;
The observation mark is formed by sputter processing of the sample, deposition processing on the sample, physical change of the sample, chemical change of the sample, or surface modification of the sample. Shape observation method. An observation mark whose shape viewed from the reference direction is the reference shape is formed on the surface of the sample,
After forming the observation mark, the observation mark is taken from an observation direction different from the reference direction to obtain an observation image,
Displaying the observed image ;
The shape observation method , wherein the observation mark includes an element having an atomic number of 5 or more away from an atomic number of an element constituting the sample . An observation mark whose shape viewed from the reference direction is the reference shape is formed on the surface of the sample,
After forming the observation mark, the observation mark is taken from an observation direction different from the reference direction to obtain an observation image,
Displaying the observed image ;
The observation mark is a groove,
The shape observation method , wherein the groove is formed so as to reach a surface of the sample that becomes a blind spot from the reference direction . An observation mark whose shape viewed from the reference direction is the reference shape is formed on the surface of the sample,
After the formation of the observation mark, selectively etching the sample around the observation mark leaving the observation mark ,
After forming the observation mark, the observation mark is taken from an observation direction different from the reference direction to obtain an observation image,
Shape observation how to and displaying the observation image.