JP2006071353A - Microscope device, appearance inspection device, semiconductor appearance inspection device, and sample illumination method in microscope device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microscope device capable of realizing with a simple constitution an illumination means for illuminating a sample which is an observation object and a space filter for removing a specific space frequency component of a pattern on the sample, and its illumination method. <P>SOLUTION: A light source 40 of the microscope device is provided on the pupil surface 8 of an objective lens 3 or on a plane 23 conjugated with the pupil surface, and a support means 40 for supporting the light source 40 on the surface/plane is used as the space filter. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to illumination of a sample observed with a microscope, and in particular, a microscope used in an appearance inspection apparatus that captures an image of a pattern formed on a sample such as a semiconductor wafer and detects a defective portion by processing an image signal. Related to lighting.

  A predetermined pattern is repeatedly formed on a semiconductor wafer, a semiconductor memory photomask, a liquid crystal display panel, or the like. In view of this, an optical image of a pattern is captured using an optical microscope and a pattern defect is detected by comparing adjacent patterns (for example, Patent Document 1 below). As a result of the comparison, if there is no difference between the two patterns, the pattern has no defect, and if there is a difference, it is determined that a defect exists in one of the patterns. In the following description, a semiconductor wafer appearance inspection apparatus that inspects a defect of a pattern formed on a semiconductor wafer will be described as an example. However, the present invention is not limited to this, and can also be applied to an appearance inspection apparatus for inspecting defects such as a semiconductor memory photomask and a liquid crystal display panel.

  FIG. 1 is a diagram showing a schematic configuration of a semiconductor wafer appearance inspection apparatus. As shown in FIG. 1, the semiconductor wafer appearance inspection apparatus includes a stage 1 that holds a semiconductor wafer 2, an objective lens 3 that projects an optical image of the surface of the semiconductor wafer 2, and a projected surface of the semiconductor wafer 2. An imaging device (image sensor) 4 that converts an optical image into an electrical image signal, lenses 21 and 22 that further project an image of the semiconductor wafer 2 projected by the objective lens 3 onto the image sensor 4, and the image sensor 4 The image signal processing circuit 5 that processes the analog image signal output from the digital image data and converts it into multi-value digital image data, and the digital image data processing that processes the digital image data and compares the same part of the pattern to detect defects The circuit 6 has an image data memory 7 for storing image data for data processing. The illumination optical system that illuminates the surface of the semiconductor wafer 2 includes a light source 11, illumination lenses 12 and 13, and a semi-transparent mirror (beam splitter) 15 provided in the projection optical path of the objective lens 3.

  A TV camera using a two-dimensional CCD element or the like can be used as the imaging device 4, but in order to obtain a high-definition image signal, a stage 1 is used by using a one-dimensional line sensor such as TDI. In many cases, the image signal processing circuit 5 captures the signal of the line sensor 4 and acquires an image in synchronization with the drive pulse signal for driving the stage 1. .

  The illumination optical system of the semiconductor wafer appearance inspection apparatus will be described. Illumination light from the light source 11 is guided through the lenses 12 and 13 and reflected toward the objective lens 3 by the semi-transparent mirror 15 provided in the projection path, and illuminates the surface of the sample (wafer) 2 through the objective lens 3. To do. The image of the light source 11 is projected at the position indicated by the pupil position 8 of the objective lens 3, and the surface of the wafer 2 is uniformly illuminated with no unevenness in the amount of light.

Next, a projection optical system (imaging optical system) of the appearance inspection apparatus will be described. The semiconductor wafer appearance inspection apparatus is provided with lenses 21 and 22 that are imaging optical systems for projecting the image of the sample 2 projected by the objective lens 3 onto the image sensor 4 at a desired magnification. Here, the imaging optical system has a plane conjugate with the pupil plane 8 of the objective lens 3 (for example, in the conceptual diagram shown in FIG. 1, the back focal position of the lens 22 is conjugate with the pupil plane 8 of the objective lens 3. On this surface 23, a frequency component intensity distribution image (Fourier transform image) of the image of the sample 2 to be observed is generated.
Accordingly, by providing a spatial filter (spatial frequency filter) on the pupil plane 8 or the plane 23 conjugate with the pupil plane 8, for example, the frequency component of the periodic pattern formed on the sample 2 is masked and the other components are masked. It is possible to increase the relative signal intensity of the diffracted light generated from the portion, that is, the defect (short-circuit) portion.

JP 2003-149169 A

  However, according to the conventional configuration, an optical system (that is, the illumination lenses 12 and 13 and the semi-transparent mirror 15) for guiding the light source to the objective lens 3 is required, and the microscope used for the semiconductor wafer appearance inspection apparatus is required. The configuration was complicated. In addition, in order to remove the periodic component of the periodic pattern formed on the sample, it is necessary to provide the above-described spatial filter or an insertion mechanism that allows the spatial filter to be taken in and out, which further complicates the configuration. It was.

  According to the conventional configuration, the illumination light from the light source 11 provides uniform illumination light on the surface of the wafer 2. Therefore, for example, in order to cut low-order diffracted light generated by the periodic pattern on the sample using a spatial filter, the incident angle of the diffracted light to the objective lens is changed by changing the incident angle of the illumination light to the sample. Or, the illumination light could not be controlled such as changing the azimuth angle of the illumination light according to the directionality of the pattern on the sample.

Accordingly, the present invention provides a microscope apparatus and an illumination method therefor that realize an illumination unit that illuminates a sample to be observed and a spatial filter that removes a specific spatial frequency component of a pattern on the sample with a simple configuration. With the goal.
In addition, an object of the present invention is to provide a microscope apparatus and a method for illuminating the same with a simple configuration of illumination means capable of changing the incident angle and azimuth angle of illumination light on a sample.

  In order to achieve the above object, according to the present invention, a light source is provided on a pupil plane of an objective lens or a plane conjugate with the pupil plane, and support means for supporting the light source on these planes is a spatial filter (spatial frequency). Used as a filter).

  That is, the microscope apparatus according to the first aspect of the present invention is provided on a pupil plane of an objective lens or a plane conjugate with the pupil plane, and a light source that illuminates a sample via the objective lens, and supports the light source and the objective. And a support means for blocking a predetermined portion of the sample image projected onto the pupil plane or a plane conjugate with the pupil plane by the lens.

  The sample illumination method in the microscope apparatus according to the second aspect of the present invention illuminates the sample via the objective lens with a light source provided on the pupil plane of the objective lens or a plane conjugate with the pupil plane. Then, a predetermined part of the image of the sample projected on the pupil plane or a plane conjugate with the pupil plane is blocked by the objective lens by the support means for supporting the light source.

The support means may block a predetermined portion of the Fourier transform image of the sample generated on the pupil plane of the objective lens or a plane conjugate with the pupil plane. The support means may include an opening or a transmission part for allowing a predetermined portion of the sample image and the Fourier transform image of the sample to pass therethrough.
Furthermore, the light source may be provided at a plurality of locations of the support means, and may be provided as a semiconductor light emitting element array at a plurality of locations of the support means.

  The illumination method for the microscope apparatus according to the first aspect of the present invention and the microscope apparatus according to the second aspect may be used for an appearance inspection apparatus that performs an appearance inspection of a sample by observing a pattern formed on the sample surface. The semiconductor wafer inspection apparatus may be used for inspecting the appearance of a semiconductor wafer or the like by observing a pattern formed on the surface of the semiconductor wafer, photomask, liquid crystal panel or the like.

In order to guide the light source to the objective lens 3 by providing the light source on the pupil plane of the objective lens or on a plane conjugate with the pupil plane, and using support means for supporting the light source on these planes as a spatial filter. The above optical system becomes unnecessary, and the above-described spatial filter or an insertion mechanism that allows the spatial filter to be taken in and out can be omitted. This realizes a simple configuration of the microscope. In particular, since a light source can be provided in the projection optical path of the objective lens 3, there is an advantage that the installation of the semi-transparent mirror 15 is unnecessary.
Furthermore, by providing light sources at a plurality of locations of the support means, it is possible to change the incident angle and azimuth angle of the illumination light to the sample with a simple configuration. Further, by using a semiconductor light emitting element as the light source, the light source has a long life and the light quantity adjustment is facilitated.
Further, the support means is provided with an opening or a transmission part for allowing a predetermined part of the sample image or the Fourier transform image of the sample to pass therethrough, and the sample projected onto the pupil plane of the objective lens or a plane conjugate with the pupil plane By allowing the spatial frequency component of the upper pattern to pass through appropriately, a stereomicroscope can be easily realized.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a diagram showing an optical system portion of the semiconductor wafer appearance inspection apparatus according to the first embodiment of the present invention. Other portions shown in FIG. 1 are omitted here. Further, in the following description, a semiconductor wafer appearance inspection apparatus for inspecting a defect of a pattern formed on a semiconductor wafer will be described as an example, but the present invention is not limited to this, and a photomask for a semiconductor memory, Further, it can be widely applied to an appearance inspection apparatus for inspecting semiconductor devices such as liquid crystal display panels.

  As shown in FIG. 2, the defect inspection apparatus for a semiconductor wafer according to the present embodiment includes a stage 1 that holds a semiconductor wafer 2, an objective lens 3 that projects an optical image of the surface of the semiconductor wafer 2, and an objective lens 3. A light source 40 that illuminates the sample, a support means 30 that supports the light source 40 on the pupil plane 8 of the objective lens 3, and an image sensor 4 that converts the optical image of the projected surface of the semiconductor wafer 2 into an electrical image signal. And a projection lens 9 that projects the reflected light from the semiconductor wafer 2 passing through the objective lens 3 onto the image sensor 4. The support means 30 is fixed to a lens barrel (not shown) for holding the objective lens 3 and the projection lens 9.

  The image sensor 4 is preferably a one-dimensional line sensor such as TDI. Then, the stage 1 is moved relative to the semiconductor wafer 2 (scanned), and the image signal processing circuit 5 outputs the signal from the line sensor 4 in synchronization with the drive pulse signal from the stage controller 66 that drives the stage 1. Capture and acquire images. It is also possible to use a TV camera using a two-dimensional CCD element.

  FIG. 3A is a bottom view of the support means 30 and the light source 40 as viewed in the z direction from below. The support means 30 extends in a predetermined direction (x direction) to support the annular edge member 31 fixed to a lens barrel (not shown) for holding the objective lens 3 and the projection lens 9 and the light source 40. And the existing beam member 32. A region other than the beam member 32 in the annular edge member 31 (a region surrounded by the edge member 31 and the beam member 32 in FIG. 3A) is projected onto the pupil plane 8 by the objective lens 3. 2 is cut out so as not to block the reflected light, and the area is not provided with a shielding object, or the area is filled with a highly transmissive member.

FIG. 3B is a diagram showing a pattern on the semiconductor wafer 2 captured in the visual field 3 ′ of the objective lens 3, and FIG. 3C is projected onto the pupil plane 8 of the objective lens 3 at this time. FIG. When a repetitive pattern having a constant spatial frequency component in a predetermined direction (x direction in the figure) as shown in FIG. 3B is observed, the pupil plane of the objective lens 3 is shown in FIG. 8, a Fourier transform image representing a frequency component intensity distribution image having spot portions 51 corresponding to the spatial frequencies included in the repetitive pattern is generated.
The support means 30 blocks the projection optical path of the portion where the spot portion 51 corresponding to the spatial frequency included in the repetitive pattern in the Fourier transform image projected on the pupil plane 8 of the objective lens 3 is blocked by the beam member 32. Thus, an effect as a spatial filter (spatial frequency filter) for removing a predetermined spatial frequency component from the projection image of the observation object is exhibited.

As shown in FIG. 4A, a plurality of light sources 40 may be provided at different positions on the beam member 32, or may be provided at a position away from the optical axis instead of the optical axis position of the objective lens 3. By providing the light source 40 at a position away from the light source of the objective lens 3, the semiconductor wafer 2 is not illuminated vertically as in the conventional illumination device, but the incident angle is set to a desired angle and the semiconductor wafer is inclined. 2 can be illuminated. Thus, it is possible to set the frequency intensity signal that appears corresponding to the low-order diffracted light generated from the sample so that the position on the pupil plane 8 is a desired position.
For example, the signal intensity included in the low-order diffracted light is set such that the position on the pupil plane 8 of the frequency intensity signal that appears corresponding to the low-order diffracted light is the position where the beam member 32 that blocks this frequency intensity signal exists. The signal intensity of the diffracted light generated from the defect (short circuit) portion can be relatively increased.
In addition, by providing a plurality of light sources 40 at different positions on the beam member 32, the plurality of light sources 40 are selected and turned on, and incident according to the pattern on the semiconductor wafer 2 captured in the field of view of the objective lens 3. The angles may be changed sequentially.

  A semiconductor light emitting device such as a light emitting diode (LED) or a laser diode (LD) is preferably used for the light source 40, but other light emitting devices may be used. When a plurality of light sources 40 are provided on the beam member 32, a semiconductor light emitting element array may be used.

5A to 5E show various modifications of the support means 30 and the light source 40. FIG.
The beam member 32 of the support means 30 shown in FIG. 5 (A) has the effect of removing the frequency component of the frequency component intensity distribution image generated on the pupil plane 8 by a repetitive pattern having spatial frequency components in the x and y directions. It has a function as a filter. The white circles in the figure all indicate the light source 40. However, for simplicity, only one of them is given the reference numeral 40 and the others are omitted. The same applies to FIGS. 5B to 5E and FIGS. 7A and 7B.

The beam member 32 of the support means 30 shown in FIG. 5B has a frequency component intensity distribution image frequency generated on the pupil plane 8 by a repetitive pattern having spatial frequency components at the azimuth angles of 45 ° and 135 ° with respect to the x-axis direction. It has a function as a spatial filter that has the effect of removing components.
The beam member shown in FIG. 5 (C) is a mode in which the beam member 32 shown in FIGS. 5 (A) and 5 (B) is combined, and the x-axis direction and the y-axis direction, and the x-axis direction and 45 ° It has a function as a spatial filter that has an effect of removing the frequency component of the frequency component intensity distribution image generated on the pupil plane 8 by the repetitive pattern having the spatial frequency component at the azimuth angle of the 135 ° direction.

As shown in FIG. 5D, the support means 30 may be provided with beam members 32 and 33 in a lattice shape.
When the observation pattern is a repetitive pattern, a relatively large diameter is formed on the pupil plane 8 along a straight line that passes through the intersection of the pupil plane 8 and the optical axis of the objective lens 3 and extends in the repetition direction of the observation pattern. A spot portion having a line is formed side by side. Therefore, the beam member 32 passing through the intersection of the pupil plane 8 and the optical axis of the objective lens 3 and extending in the observation pattern repeating direction is formed relatively wide, and the other beam member 33 is formed relatively narrow. . This prevents the projection image from being blocked more than necessary. The light source 40 may not be provided in the beam member 33 having a relatively narrow width. FIG. 5E shows a mode in which a beam member 33 having a relatively narrow width is provided on the support means 30 shown in FIG.

  Further, by providing a mechanism for moving the beam member 33 in the plane on the pupil plane 8, the beam member 33 is caused to receive the most of the reflected diffracted light from this pattern according to the repeated pattern formed on the semiconductor wafer 2. It is good also as positioning control to the optimal position which can filter efficiently. FIG. 6A shows a top view of a support means having a mechanism for moving the beam member 33 in the plane of the pupil plane 8, and FIG. 6B shows a cross-sectional view taken along line AA ′ of FIG. Show.

As shown in the figure, the support means 30 includes a plurality of beam members 33x extending in the x direction and a plurality of beam members 33y extending in the y direction. The plurality of beam members 33x are connected by a connecting member 35x that penetrates the beam member 33x and the link member 34x so as to be rotatably connected to form a parallel link mechanism. Similarly, the plurality of beam members 33y, the link member 34y, and the connecting member 35y also constitute a parallel link mechanism.
The link member 34x and the protrusion portion 36x of the support means are also penetrated by the connecting member 35x and rotatably connected thereto, so that the link member 34x is rotatably supported by using the connecting portion with the protrusion portion 36x as a fulcrum. . Similarly, the link member 34y is rotatably supported with a connection point with the projection 36y as a fulcrum.

  The parallel link mechanism including each beam member 33x, link member 34x, and connecting member 35x moves the pupil plane 8 in the plane by the operation of each drive unit 37x according to a control signal from the light source control unit 65, and thereby the light source control unit 65. It is possible to change the position in the y direction of the plurality of beam members 33x and the interval between them. Similarly, the light source controller 65 can change the x-direction positions of the plurality of beam members 33y and the intervals between them by operating the drive unit 37y. In this way, for example, the light source control unit 65 corresponds to the spatial frequency of the repetitive pattern formed on the semiconductor wafer 2, and the interval between the spot light appearing on the pupil plane 8 corresponding to this spatial frequency and the plurality of beam members It is possible to control the positions of the beam members 33x and 33y so as to cut the spot light by combining the positions of 33x and 33y and the interval (pitch) between them.

  As shown in FIGS. 5A to 5E and FIG. 6A, the beam member 32 extends in a plurality of different directions on the pupil plane 8, and a plurality of light sources 40 are provided on the beam member. Thus, the plurality of light sources 40 can be selected and turned on, and the semiconductor wafer 2 can be illuminated with illumination light having different azimuth angles. Thereby, for example, by applying illumination light along the direction of the pattern formed on the semiconductor wafer 2, the reflected light scattered at the edge portion of the pattern is weakened, and the scattered light signal generated from the defective portion existing between the patterns. The strength can be relatively increased.

Further, similar to the change of the incident angle of the illumination light described above with reference to FIGS. 4A and 4B, the plurality of light sources 40 are selected and turned on, and the semiconductor captured in the field of view of the objective lens 3 The azimuth angle of the illumination light may be sequentially changed according to the pattern on the wafer 2.
Thus, in order to select and light the light source 40 according to the pattern of the surface of the semiconductor 2 in the field of view of the objective lens 3, the appearance inspection apparatus of the present embodiment is realized by a computer or the like as shown in FIG. A possible calculator 61, an input / output unit 63 for inputting pattern data indicating the type of pattern formed at each position on the semiconductor wafer 2, and a storage unit 64 for storing pattern data input from the input / output unit 63. Based on the position information of the stage 1 output from the stage control unit 66, the type of pattern formed at each position on the semiconductor wafer 2 placed on the stage 1 is determined from the pattern data stored in the storage unit 64. A light source control unit 65 that reads and selects a plurality of light sources 40 according to the type of the read pattern is provided.

  Since the position of the semiconductor wafer 2 placed on the stage 1 is known, the light source controller 65 determines that the field of view of the objective lens 3 is based on the position information of the stage 1 output from the stage controller 66. It is possible to detect the position on the semiconductor wafer 2 placed on the semiconductor wafer 2. Then, the light source control unit 65 reads out the type of the pattern formed at the detected position on the semiconductor wafer 2 from the pattern data stored in the storage unit 64, and according to the read pattern type in the pattern data. The light source 40 is selected and turned on.

For example, when the pattern data includes information on the directionality of the pattern formed at the position on the semiconductor wafer 2, the light source control unit 65 sets information on the directionality of the pattern in the field of view of the objective lens 3. The light source 40 which reads out from the memory | storage part 64 and gives the illumination light along the direction is selected and lighted.
Further, for example, when the pattern data includes information on the pitch (spatial frequency) of the pattern formed at the position on the semiconductor wafer 2, the light source controller 65 determines the pitch of the pattern within the field of the objective lens 3. Information about the low-order diffracted light generated from the pattern based on the pitch, the distance between the objective lens 3 and the semiconductor wafer 2 (known), and the emission wavelength 40 (known) of the light source 40. Find the angle. Then, the light source 40 that provides illumination light at an incident angle such that the frequency component intensity signal corresponding to the low-order diffracted light is generated at a desired position on the pupil plane 8 is selected and turned on.

  The light source control unit 65 reads out the pattern type of the semiconductor wafer 2 in the field of view of the objective lens 3 from the storage unit 64 based on the sequentially output position information of the stage 1 output from the stage control unit 66, and this pattern The light source 40 to be turned on according to the type may be changed dynamically and freely during scanning of the objective lens 3 for visual inspection.

  Further, each spatial frequency of the pattern formed in each region on the semiconductor wafer 2 is included in the pattern data, and the light source control unit 65 is based on the position information of the stage 1 output sequentially from the stage control unit 66. Then, the spatial frequency of the pattern of the semiconductor wafer 2 in the field of view of the objective lens 3 is read from the storage unit 64, and the beam members 33x and 33y shown in FIGS. 6A and 6B are parallel according to this spatial frequency. The distance between the beam members 33x and 33y may be changed dynamically and freely by moving the link mechanism.

7A and 7B show other modifications of the support means 30 and the light source 40. FIG. In the supporting means 30 shown in FIG. 7A, the edge member 31 is provided with a light source 40, whereby the light source 40 illuminates the semiconductor wafer 2 obliquely from a peripheral range excluding the periphery of the optical axis of the objective lens 3. Give illumination light.
When each light source 40 is arranged in this way, each directly reflected light reflected by the semiconductor wafer 2 by each illumination light from each light source 40 rotates with each light source 40 on the pupil plane 8 with respect to the optical axis of the objective lens 3. It will return to a symmetrical position and will be blocked by the edge 42 present at this position. Thus, dark field illumination can be realized by blocking each direct reflected light from the semiconductor wafer 2.

In the support means 30 shown in FIG. 7B, the edge member 31 is provided with an opening 34 through which the image of the semiconductor wafer 2 generated on the pupil plane 8 partially passes. The circles indicated by the pear ground in the figure all show such openings 34, but for the sake of simplicity, only one of them is given the reference numeral 34 and the others are omitted. By providing such an opening 34 and allowing the directly reflected light to partially pass therethrough, it is possible to realize a stereomicroscope device that projects an image generated by the directly reflected light on the image sensor 4.
Further, a transparent member may be embedded in such an opening 34 to form a transmission portion.

8A and 9A to 9C show still another embodiment of the support means 30 and the light sources 40, 43 and 44. FIG. The light sources 43 and 44 shown in FIG. 8A are light source elements that supply deflected emission light. The light source 43 emits radially deflected light in the radial direction of the annular edge member 31, and the light source 44 is annular. This is a circumferential deflection light source that emits circumferential deflection light of the edge member 31. As a light source that provides such deflection illumination light, a laser diode having a deflection direction may be used, or may be realized by providing a deflection filter in a light source that provides non-deflection illumination light.
In FIG. 8A, the light source 43 and the arrow shown in the light source 44 indicate the deflection direction, and the white circles to which the radial arrow of the annular edge member 31 is attached all indicate the radial deflection light source 43. The white circles to which the circumferential arrows of the member 31 are attached all indicate the circumferential deflection light source 44. However, for simplicity of the drawing, only one reference numeral is assigned to each one, and the others are omitted.

  The light source controller 65 selects only the radial deflection light source 43 to emit light according to the shape type of the pattern formed on the semiconductor wafer 2 within the field of view of the objective lens 3 (see FIG. 8B). Alternatively, only the circumferential deflection light source 44 is selected to emit light (see FIG. 8C), and the change direction of the illumination light that illuminates the semiconductor wafer 2 is switched. For example, when a dot pattern is formed on the semiconductor wafer 2 within the field of view of the objective lens 3, the light source controller 65 selects only the radial deflection light source 43 to emit light, thereby forming a linear pattern. In such a case, only the circumferential deflection light source 44 is selected to emit light. By changing the deflection direction of the illumination light in accordance with the pattern shape type, it is possible to improve the imaging resolution for the pattern having a specific shape.

  Further, information regarding the shape type of the pattern formed in each region on the semiconductor wafer 2 is included in the pattern data, and the light source control unit 65 outputs the position information of the stage 1 that is output sequentially from the stage control unit 66. The pattern type of the semiconductor wafer 2 in the field of view of the objective lens 3 is read from the storage unit 64 based on the above, and the radial direction deflection light source 43 or the circumferential direction deflection light source 44 is selected to emit light according to this type. As good as

Moreover, it is good also as providing such a radial direction deflection light source 43 and the circumferential direction deflection light source 44, and the non-deflection light source 40 together. As described above, by using the deflecting light sources 43 and 44 and the non-deflecting light source 40 together, the light amount of the light source is increased and the imaging resolution of the image signal obtained by imaging the pattern portion of the specific shape is enhanced, while the other part of the imaging pattern (Background image) can be captured to some extent.
9A shows an arrangement example in which the radial deflection light source 43 and the non-deflection light source 40 are combined, and FIG. 9A shows an arrangement example in which the circumferential deflection light source 44 and the non-deflection light source 40 are combined. (C) shows an arrangement example in which the radial deflection light source 43, the circumferential deflection light source 44, and the non-deflection light source 40 are combined.

FIG. 10 is a diagram showing an optical system portion of the semiconductor wafer appearance inspection apparatus according to the second embodiment of the present invention. The appearance inspection apparatus for a semiconductor wafer according to this embodiment includes lenses 21 and 22 (relay lenses) for further projecting an image of the semiconductor wafer 2 projected by the objective lens 3 onto the image sensor 4.
Then, a surface 23 (hereinafter referred to as a conjugate plane) that is conjugate with the pupil plane 8 of the objective lens 3 is generated at the rear focal position of the lens 21. An image of the light source provided on the conjugate plane 23 is formed on the pupil plane 8 of the objective lens 3, and a Fourier transform image of an inspection pattern generated on the pupil plane 8 of the objective lens 3 is formed on the conjugate plane 23. Produces the same image.
Therefore, in the semiconductor wafer appearance inspection apparatus according to the present embodiment, the surface 23 conjugate with the pupil plane 8 of the objective lens 3 in the projection optical path of the objective lens 3 has been described with reference to FIGS. By providing the light sources 40, 43, 44 and the support means 30, the same effects as those of the semiconductor wafer visual inspection apparatus according to the first embodiment of the present invention can be obtained.

  The present invention is applicable to an appearance inspection apparatus for inspecting a semiconductor device such as a microscope device, a semiconductor wafer, a semiconductor memory photomask, and a liquid crystal display panel.

It is a schematic block diagram of the conventional defect inspection apparatus for semiconductor wafers. It is a figure which shows the optical system part of the external appearance inspection apparatus for semiconductor wafers which concerns on 1st Example of this invention. (A) is a bottom view of the light source and the supporting means, (B) is a diagram showing a pattern on the semiconductor wafer captured in the field of view of the objective lens, and (C) is a Fourier generated on the pupil plane of the objective lens. It is a figure which shows a conversion image. (A) And (B) is a figure which shows the modification of a light source and a support means, respectively. (A)-(E) are the figures which show the modification of a light source and a support means, respectively. (A) is a top view of the support means which comprises a beam member so that a movement is possible, (B) is the A-A 'side view. (A) And (B) is a figure which shows the modification of a light source and a support means, respectively. (A) is a bottom view of the light source and supporting means for supplying deflected illumination light, and (B) is a light source of illumination light deflected in the radial direction among the light sources shown in (A). It is a figure which shows a case, (C) is a figure which shows the case where only the light source of the illumination light deflected in the circumferential direction among the light sources shown to (A) is turned on. (A) is a bottom view of a light source and a support means for supplying illumination light deflected in the radial direction and non-deflection illumination, and (B) is a light source for supplying illumination light deflected in the circumferential direction and non-deflection illumination. And (C) is a bottom view of the light source and the support means for supplying the illumination light deflected in the circumferential direction and the radial direction and the non-deflection illumination. It is a figure which shows the optical system part of the external appearance inspection apparatus for semiconductor wafers concerning 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stage 2 Wafer 3 Objective lens 4 Image sensor 8 Pupil plane of objective lens 30 Support means 40 Light source

Claims (8)

  A light source provided on a pupil plane of the objective lens or a plane conjugate with the pupil plane and illuminating the sample through the objective lens, and supporting the light source and conjugate with the pupil plane or the pupil plane by the objective lens And a support means for blocking a predetermined portion of the image of the sample projected on the plane to be a microscope apparatus.   The microscope apparatus according to claim 1, wherein the support unit blocks a predetermined portion of a Fourier transform image of the sample.   The microscope apparatus according to claim 1, wherein the light source is provided at a plurality of locations of the support means.   The microscope apparatus according to claim 1, wherein the support unit includes an opening or a transmission unit that allows a predetermined portion of the image of the sample to pass therethrough.   The microscope apparatus according to any one of claims 1 to 4, wherein the light source is a semiconductor light emitting element array provided at a plurality of locations of the support means.   An appearance inspection apparatus characterized by observing a pattern formed on the surface of the sample and performing an appearance inspection of the pattern with the microscope apparatus according to claim 1.   6. A semiconductor appearance inspection apparatus, wherein a pattern formed on the surface of a semiconductor wafer is observed by the microscope apparatus according to claim 1 to perform an appearance inspection of the pattern.   The sample is illuminated through the objective lens by a light source provided on a pupil plane of the objective lens of the microscope or a plane conjugate with the pupil plane, and the pupil is supported by the objective lens by a support unit that supports the light source. A sample illumination method in a microscope apparatus, wherein a predetermined portion of an image of the sample projected on a plane or a plane conjugate with the pupil plane is blocked.

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