U.S. patent application number 09/811719 was filed with the patent office on 2002-02-28 for electron microscope.
Invention is credited to Abe, Katsuaki, Komuro, Osamu, Nishigata, Kenichi.
Application Number | 20020024012 09/811719 |
Document ID | / |
Family ID | 18748818 |
Filed Date | 2002-02-28 |
United States Patent
Application |
20020024012 |
Kind Code |
A1 |
Abe, Katsuaki ; et
al. |
February 28, 2002 |
Electron microscope
Abstract
In order to provide an electron microscope which enables the
operator to position the field of view easily and accurately on a
target fault, the electron microscope for observing a surface or
inside of a semiconductor wafer or a mask for exposing a
semiconductor pattern for faults and/or foreign objects, is
provided comprising a function of loading measurement data of
coordinates or sizes of faults or objects which were observed by
another wafer or mask inspecting apparatus, moving the field of
view of the electron microscope to the area where said fault or
object exists, and displaying the coordinates of faults or objects
which were obtained by another wafer or mask inspecting apparatus,
the field of view of the electron microscope and its vicinity, a
function of a pointing device switch which moves the field of view
of the electron microscope to a position which is pointed to by a
pointer on said display, and a function of changing the display as
said field of view moves.
Inventors: |
Abe, Katsuaki;
(Hitachinaka-shi, JP) ; Komuro, Osamu;
(Hitachinaka-shi, JP) ; Nishigata, Kenichi;
(Hitachinaka-shi, JP) |
Correspondence
Address: |
Edward W. Greason
Kenyon & Kenyon
One Broadway
New York
NY
10004
US
|
Family ID: |
18748818 |
Appl. No.: |
09/811719 |
Filed: |
March 19, 2001 |
Current U.S.
Class: |
250/311 |
Current CPC
Class: |
H01J 2237/24585
20130101; H01J 37/265 20130101; G01N 23/2251 20130101; G06T 1/0007
20130101; G06T 2207/30148 20130101; H01J 2237/2817 20130101; H01J
2237/2487 20130101 |
Class at
Publication: |
250/311 |
International
Class: |
G21K 007/00; G01N
023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2000 |
JP |
2000-260877 |
Claims
What we claim is:
1. An electron microscope for observing a surface or inside of a
semiconductor wafer or a mask for exposing a semiconductor pattern
for faults and/or foreign objects, comprising a function of loading
measurement data of coordinates or sizes of faults or objects which
were observed by another wafer or mask inspecting apparatus, moving
the field of view of the electron microscope to the area where said
fault or object exists, and displaying the coordinates of faults or
objects which were obtained by another wafer or mask inspecting
apparatus, the field of view of the electron microscope and its
vicinity, a function of a pointing device switch which moves the
field of view of the electron microscope to a position which is
pointed to by a pointer on said display, and a function of changing
the display as said field of view moves.
2. An electron microscope in accordance with claim 1, wherein the
switch of said pointing device has a function to magnify or shrink
the field of view of the electron microscope and its vicinity at
any rate.
3. An electron microscope in accordance with claim 1, further
comprising a function which magnifies or shrinks said field of view
of the electron microscope and its vicinity as the field of view
moves on a screen displaying said field of view of the electron
microscope and its vicinity.
4. An electron microscope in accordance with claim 1, further
comprising a function which moves and displays the center
coordinates of the field of view and its vicinity as said field of
view moves.
5. An electron microscope in accordance with claim 1, further
comprising a function which displays shapes of faults on the screen
displaying said field of view and a function which changes the
display on the screen as the observing conditions of the electron
microscope change.
6. An electron microscope in accordance with claim 1, further
comprising a function which displays coordinates of faults or
objects obtained by said another wafer or mask inspecting apparatus
and distances of the field of view of the electron microscope, a
function which stores said distance values, and a function which
relatively moves the field of view of the electron microscope by
said stored distances.
7. An electron microscope in accordance with claim 1, further
comprising a function which displays an observed area and a
non-observed area separately on the screen displaying said field of
view and its vicinity, and a function which changes said display as
the observing conditions of the electron microscope change.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an electron microscope for
observing or detecting a surface or inside of a semiconductor wafer
or a mask for exposing a semiconductor pattern for faults and/or
foreign objects, particularly to an electron microscope for
observing or detecting a surface or inside using coordinates of
faults and/or faults which were measured by another wafer/mask
inspecting apparatus.
[0002] Faults or objects on a semiconductor wafer or a mask for
exposing a semiconductor pattern may give fatal problems to the
semiconductor performances and reduce the efficiency of production
of semiconductors.
[0003] Therefore, to increase the production efficiency of
semiconductors, it is required to remove unwanted objects from
wafers and masks and faults from semiconductor patterns or mask
patterns on the wafers as much as possible. Therefore, it is
thought to be very important to detect and observe wafers and masks
for faults and/or objects (hereinafter generically described as
faults) in the production of semiconductors and analyze the causes
of the faults.
[0004] Recently, semiconductors have become smaller and smaller and
their performance may be seriously damaged by even a fault of about
0.1 micron on a wafer. Conventionally an optical fault inspector or
an optical object inspector (hereinafter generically described as
an inspector) is used to locate faults on a wafer, move the field
of view of the electron microscope to the location where the faults
exist according to information on fault coordinates or the like
obtained by said inspector, observe and identify the fault.
[0005] However, a wafer/mask area to be observed at a time at a
magnification is limited although it is dependent upon the size of
a display screen of the electron microscope. Therefore, if fault
coordinates measured by another inspector contain errors, the fault
cannot be caught in the field of view of the electron
microscope.
[0006] Although various techniques have been supported to eliminate
coordinate errors between the electron microscope and another
inspector, such techniques cannot assure coordinate accuracies high
enough to capture all faults in the field of view of the electron
microscope.
[0007] To search faults, the operator gradually moves the field of
view of the electron microscope using a pointing device (such as a
mouse or a trackball) according to fault coordinates measured by
another inspector and the location of the field of view of the
electron microscope in reference to a wafer map, a die/chip diagram
or an optical microscope image which is displayed separately. The
conditions of observation of the electron microscope (such as a
magnification) is calculated and set from data obtained by another
inspector.
[0008] However, at a high magnification, for example, .times.10,000
of the electron microscope, said conventional techniques do not
have any means to show where the observation is made now and it is
very difficult to move the field of view of the electron microscope
to a position for observation.
[0009] Further, to detect target faults in the field of view of the
electron microscope or to set conditions of observation for the
field, the conventional technique must calculate observation
conditions such as a magnification for each fault from numeric data
obtained by another inspector.
[0010] Further, the conventional technique cannot use coordinate
errors obtained in search of a fault easily for search of other
faults, searching of the conventional technique is not
efficient.
[0011] Furthermore, in case both an area which was already observed
by an electron microscope and an area which has not been observed
are separately displayed on-screen, it sometimes happened that the
conventional technique could not change conditions of observation
of the electron microscope or involuntarily initialized
displays.
SUMMARY OF THE INVENTION
[0012] An object of the present invention is to solve the aforesaid
problems and to provide an electron microscope which enables the
operator to move and set the field of view onto an area having a
fault easily and accurately.
[0013] To attain the aforesaid object, the present invention is
characterized by the following.
[0014] In accordance with the present invention, an electron
microscope for observing a surface or inside of a semiconductor
wafer or a mask for exposing a semiconductor pattern for faults
and/or foreign objects comprises
[0015] a function of loading measurement data of coordinates or
sizes of faults or objects which were observed by another wafer or
mask inspecting apparatus, moving the field of view of the electron
microscope to the area where said fault or object exists, and
displaying the coordinates of faults or objects which were obtained
by another wafer or mask inspecting apparatus, the field of view of
the electron microscope and its vicinity,
[0016] a function of a pointing device switch which moves the field
of view of the electron microscope to a position which is pointed
to by a pointer on said display, and
[0017] a function of changing the display as said field of view
moves.
[0018] The electron microscope in accordance with the present
invention can display fault coordinates obtained by another
inspectors, the field of view of the electron microscope and its
vicinity, enlarge or shrink the views by operation of a pointing
device or according to the movement of the field of view of the
electron microscope or move the vicinity at a constant
magnification.
[0019] Further, the operator can move the field of view of the
electron microscope by pointing to a desired position on the view
with a pointing device.
[0020] This enables the operator to know the position or area which
is now observed and to move the field of view of the electron
microscope easily to an area near the fault coordinates obtained by
another inspector.
[0021] Further, fault sizes are displayed on a screen showing the
field of view and the display is changed according to the condition
of observation of the electron microscope.
[0022] Therefore, the operator can set conditions of fault
observation for the field of view of the electron microscope and
detect faults in the field of view according to the fault
shapes.
[0023] Furthermore, the electron microscope in accordance with the
present invention has a function of displaying fault coordinates
and distances of the field of view obtained by another inspector,
storing the values, and moving the field of view of the electron
microscope relatively by the stored distances.
[0024] This function enables a coordinate error in a fault
searching to be used for search of another faults and increase the
efficiency of searching.
[0025] Both an area which was already observed by an electron
microscope and an area which has not been observed are separately
displayed on-screen. These views are changed when the conditions of
observation of the electron microscope are changed.
[0026] This enables efficient observation of non-observed areas
only independently of condition of observation of the electron
microscope and prevents incomplete observation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] One embodiment of the present invention will be explained
below with reference to the accompanying drawings. This embodiment
uses a three-button mouse as a pointing device. However, it is not
intended as a definition of the limits of the present
invention.
[0028] FIG. 1 is a schematic view of a system configuration of a
scanning electron microscope which is an embodiment of the present
invention. Electron beams 2 emitted from an electron gun 2 are
condensed by an electron lens 3, scanned and deflected
2-dimensionally by a defector 4, and applied to a specimen 5. When
hit by the electron beams, the specimen generates secondary
particles such as reflected electrons and secondary electrons
according to the shape and material of the specimen. These
secondary electrons are detected by a detector 6 and amplified by
an amplifier 7.
[0029] A signal output from the amplifier 7 is A/D-converted into a
digital image data by an image processor 8 and the digital image
data is realtime-displayed on the CRT of a workstation or a
personal computer 9.
[0030] The workstation or the personal computer 9 is connected to a
computer for controlling the electron microscope by a transmission
medium (not visible in FIG. 1). The operator can submit various
commands from the workstation or the personal computer 9 to the
controlling computer 10 to move the specimen stage 11 of the
electron microscope. As the specimen stage 11 moves, the field of
view of a specimen 5 also moves on the CRT of the workstation or
the personal computer 9.
[0031] A semiconductor wafer or mask 12 is sent to an optical
inspecting apparatus 13 (another wafer/mask inspector) and
undergoes a fault inspection to detect faults 14 on the wafer or
mask 12. The optical inspecting apparatus 13 collects information
about coordinates and sizes of faults 14 on the wafer or mask and
outputs the result.
[0032] The wafer or mask 12 inspected by the optical inspecting
apparatus 13 is set on the specimen 11 of said electron microscope.
At the same time, the result of inspection made by the optical
inspecting apparatus 13 is sent in an information medium
(transmission, floppy disk, MO, etc.) to the workstation or the
personal computer 9 of the electron microscope.
[0033] The workstation or the personal computer 9 corrects the
coordinates of the wafer or mask on the specimen stage of the
electron microscope according to the coordinate information in said
inspection result. Next, the specimen stage 11 of the electron
microscope, that is the field of view is moved to the coordinates
on which a fault 14 exists and the obtained microscope image is
displayed on the CRT of the workstation or the personal computer
9.
[0034] FIG. 2 shows a schematic screen layout of the CRT of the
workstation or a personal computer 9. This screen shows detailed
information, the field of view, and its vicinity.
[0035] The CRT screen 21 which is the display screen of the present
invention shows an electron microscope image and the graphical user
interface (GUI) for the operator. The CRT screen comprises a field
for an electron microscope image 22, a field for a pointer 23 as a
pointing device, a field for a field-of-view 26 of the electron
microscope, a field for a vicinity 24 of the field of view of the
electron microscope, a field for the center coordinates 25, and a
field for a list 27 of inspection results of faults obtained by the
optical inspecting apparatus 13. The field-of-view 26 of the
electron microscope shows an observation area including the
electron microscope image 22.
[0036] Data obtained by the optical inspecting apparatus 13
contains the coordinates and size of each fault detected by the
optical inspecting apparatus. The field for a vicinity 24 of the
field of view of the electron microscope shows fault positions and
sizes according to these kinds of information. These kinds of
information obtained by the optical inspecting apparatus 13 are
stored in the storage means of the workstation or the personal
computer 9.
[0037] The pointing device to operate the GUI on the CRT screen 21
is a three-button mouse 28 having a left button 29, a center button
30, and a right button 31.
[0038] The operator takes a procedure explained below to search a
fault. The operator first selects a fault in the fault list 27,
clicks the left button 29 of the mouse on it. The field of view of
the electron microscope moves to the coordinates of the selected
fault.
[0039] The view of the area in which the field of view positions is
displayed in the electron microscope image field 22. At the same
time, the coordinates of the fault selected from the list is placed
in the center 25 of the vicinity field 24 and the field of view 26
is displayed in the vicinity field to indicate the position of the
field of view relative to the center coordinates.
[0040] In some cases, a selected fault is not found in the new
field of view at the coordinates of the fault selected from the
list which is obtained by the optical inspecting apparatus. This is
because of unreliable fault coordinates obtained by the optical
inspecting apparatus, errors of the specimen stage of the electron
microscope, or a difference between the magnification of the
optical microscope and the magnification of the electron
microscope. In this case, the operator moves the field of view 26
of the electron microscope to the vicinity of the fault, that is,
towards the center of coordinates 25 which indicate the coordinates
of the fault obtained by the optical inspecting apparatus.
[0041] With this, the operator can recognize the position or area
of the current field of view of the electron microscope relative to
the fault coordinates obtained by the optical inspecting apparatus
at a glance and easily move the field of view of the electron
microscope at a high magnification around the fault coordinates
obtained by the optical inspecting apparatus where a fault must
exist.
[0042] [Embodiment 1]
[0043] Below will be explained an embodiment of the present
invention which enlarges or shrinks the field of view of the
electron microscope and its vicinity.
[0044] FIG. 3 is an illustration for explaining a procedure of
enlarging or shrinking the field of view of the electron microscope
and its vicinity and FIG. 4 shows its flowchart.
[0045] The operator moves the field of view of the electron
microscope to the fault coordinates obtained by the optical
inspecting apparatus. The field for the field-of-view 26 of the
electron microscope, the vicinity field 24, the center of
coordinates 25, and the actual size 41 of the vicinity field are
displayed on-screen.
[0046] By clicking the center button 30 or the right button 31 of
the mouse anywhere in the vicinity field 24, the operator gets a
step value 42 to change the actual size 41 of the vicinity field
(S11). The operator can enter any step value.
[0047] When the operator clicks the center button 30 (S12), the
workstation or personal computer subtracts a step value from the
current actual size 41 of the vicinity field and gets a new
vicinity field size (S13).
[0048] Next, the workstation or personal computer calculates the
display size of the field of view 26 of the electron microscope
relative to the new vicinity field (S16) and displays the enlarged
field-of-view field and the enlarged vicinity field as shown in
FIG. 3 (b) (S17).
[0049] When the operator clicks the right button 31 (S14), the
workstation or personal computer adds a step value to the current
actual size 41 of the vicinity field and gets a new vicinity field
size (S15).
[0050] Next, the workstation or personal computer calculates the
display size of the field of view 26 of the electron microscope
relative to the new vicinity field (S16) and displays the shrunk
field-of-view field and the shrunk vicinity field as shown in FIG.
3 (c) (S17).
[0051] This function enables the operator to specify the rate of
enlargement or shrinkage of the vicinity field of the fault
coordinates obtained by another inspecting apparatus by numeric
values. Accordingly, in case the deviation of fault coordinates can
be estimated according to the types of optical inspecting apparatus
or in case the deviation of fault coordinates can be estimated for
each unit on a wafer, the operator can change sizes of the vicinity
field and search a target fault efficiently.
[0052] Further, the operator can recognize the size of the
field-of-view field relative to the vicinity field at a glance and
estimate the number of field-of-view fields required to observe
before searching the result. This can easily tell the quantity of
works required for searching.
[0053] [Embodiment 2]
[0054] Below will be explained a second embodiment of the present
invention which enlarges or shrinks the field of view of the
electron microscope and its vicinity. FIG. 5 is an illustration for
explaining a procedure of enlarging or shrinking the field of view
of the electron microscope and its vicinity and FIG. 6 shows its
flowchart.
[0055] The operator moves the field of view of the electron
microscope to the fault coordinates obtained by the optical
inspecting apparatus. Referring to FIG. 5 (a), the field for the
field-of-view 26 of the electron microscope, the vicinity field 24,
the center of coordinates 25, and the actual size 41 of the
vicinity field are displayed on-screen.
[0056] In some cases, a selected fault is not found in the new
field of view at the coordinates of the fault selected from the
list which is obtained by the optical inspecting apparatus 13. This
is because of unreliable fault coordinates obtained by the optical
inspecting apparatus, errors of the specimen stage of the electron
microscope, or a difference between the magnification of the
optical microscope and the magnification of the electron
microscope.
[0057] In such a case, to observe a target fault as an electron
microscope image, the electron microscope of this embodiment
enlarges or shrinks the vicinity field 24 as the field-of-view
field 26 moves without changing the field-of-view field 26 in the
vicinity field 24.
[0058] The operator moves the field of view by operating the
pointing device and gets a step value to enlarge or shrink the
vicinity field (S21). The operator can enter any step value.
[0059] Next, the workstation or personal computer checks whether
the new field of view (after movement) is in the vicinity field. As
shown in FIG. 5 (b), if the field of view 26 is not in the vicinity
field, the entered step value 42 is added to the actual size of the
current vicinity field size (S23). As shown in FIG. 5 (c), the
result is used as the actual size 42 of a new vicinity field (S24).
With this, the new shrunk field-of-view field and the new shrunk
vicinity field are displayed (S25).
[0060] When the field of view is in the vicinity field, the entered
step value 42 is subtracted from the actual size 41 of the current
vicinity field (S26).
[0061] Next, the workstation or personal computer checks whether
the new field of view (after movement) is in the vicinity field
(S27). If the field of view 26 is in the vicinity field as shown in
FIG. 5 (d), the new enlarged field-of-view field and the new
enlarged vicinity field are displayed (S25) with the result of
calculation as the actual size 41 of a new vicinity field (S24) as
shown in FIG. 5 (e).
[0062] In the other cases, the actual size 41 of the vicinity field
is not changed and the field-of-view field and the vicinity field
will be neither enlarged nor shrunk.
[0063] Each time the operator moves the field of view to detect a
fault in the field of view, the above steps are repeated.
[0064] With this, the field around the fault coordinates is
enlarged or shrunk with the field-of-view field displayed on-screen
even when the field of view of the electron microscope is moved to
anywhere. Therefore, even when a deviation from the fault
coordinate cannot be estimated in advance, the operator can
recognize the positional relationship between the field of view of
the electron microscope and the fault coordinates obtained by
another inspecting apparatus just by moving the field of view and
can search faults easily.
[0065] [Embodiment 3]
[0066] Below will be explained a third embodiment of the present
invention which moves the vicinity field without changing the
magnitude of the field of view of the electron microscope and the
magnitude of the vicinity field. FIG. 7 is an illustration for
explaining a procedure of moving the vicinity field according to
the movement of the field of view and FIG. 8 shows its
flowchart.
[0067] The operator moves the field of view of the electron
microscope to the fault coordinates obtained by the optical
inspecting apparatus. Referring to FIG. 7 (a), the field for the
field-of-view 26 of the electron microscope, the vicinity field 24,
the center of coordinates 25, and the actual size 41 of the
vicinity field are displayed on-screen.
[0068] Similarly in the above embodiments, a selected fault is not
found in the new field of view at the coordinates of the fault
obtained by the optical inspecting apparatus and the deviation
cannot be estimated.
[0069] To get an electron microscope image of a target fault in
such a case, this embodiment moves the center coordinates 25 in the
vicinity field 24 as the field of view 26 of the electron
microscope moves while keeping the field of view displayed in the
vicinity field 24.
[0070] After the operator moves the field of view by operating the
pointing device, the workstation or personal computer checks
whether the new field of view (after the movement) is in the
vicinity field (S31). If the field of view 26 is not in the
vicinity field as shown in FIG. 7 (b), the current center
coordinates is moved by the actual size 41 of the vicinity field
along the movement of the field of view as shown in FIG. 7 (c)
(S32).
[0071] Next, the workstation or personal computer calculates the
position of the field of view relative to the center coordinates 25
(S33) and checks whether the center coordinates 25 are equal to the
fault coordinates obtained by another inspecting apparatus (S34).
If the center coordinates are not equal to the fault coordinates,
the workstation or personal computer deletes the center coordinates
25 as shown in FIG. 7 (d) (S36), displays an arrow 45 oriented to
the fault coordinates obtained by the optical inspecting apparatus
(S36), and updates the display of the field of view 26 (S37).
[0072] If the field of view moves out of the vicinity field as
shown in FIG. 7 (e), the center coordinates 25 is moved by the
actual size 41 of the vicinity field as shown in FIG. 7 (f)
(S32).
[0073] When the new center coordinates 25 (after this movement)
match with the fault coordinates obtained by another optical
inspecting apparatus, the workstation or personal computer displays
the center coordinates 25 as shown in FIG. 7 (g) (S38), deletes the
arrow 45 which is oriented to the fault coordinates obtained by the
optical inspecting apparatus (S39), and updates the display of the
field of view 26 (S37).
[0074] Each time the operator moves the field of view to detect a
fault in the field of view, the above steps are repeated.
[0075] With this, the center coordinates are moved by the actual
size of the vicinity field without changing the display size of the
field of view of the electron microscope while the field of view is
moved anywhere. Further this embodiment indicates a direction in
which the fault coordinates obtained by the optical microscope
exist. This enables the operator to search faults in each field of
an accessible size without a fail.
[0076] [Embodiment 4]
[0077] FIG. 9 shows an example of displaying a fault in the
field-of-view field in accordance with the present invention.
[0078] The workstation or the personal computer calculates the size
of a fault in the field-of-view field 26 within the vicinity field
24 from X and Y coordinates of a fault obtained by an optical
inspecting apparatus and displays the shape 51 (e.g. an ellipse) of
the fault in the field-of-view field 26. The fault can have any
shape (e.g. a rectangle).
[0079] If information about fault shapes and compositions are
available from the optical inspecting apparatus 13, it is also
possible to simulate so that the composition information can be
recognized.
[0080] When the magnification of the electron microscope image is
reduced, the actual size 41 of the vicinity field is increased in
inverse proportion to the magnification and the shape 51 of the
fault is reduced with the display ratio of the field-of-view field
26 to the vicinity field 24 unchanged.
[0081] When the magnification of the electron microscope image is
increased, the actual size 41 of the vicinity field is decreased in
inverse proportion to the magnification and the shape 51 of the
fault is increased with the display ratio of the field-of-view
field 26 to the vicinity field 24 unchanged.
[0082] With this, the operator can get the relative size of a fault
in the field-of-view field at a selected magnification of the
electron microscope. Therefore, even when a fault is not actually
in the field of view, the operator can set a magnification of the
electron microscope fit for searching or observation.
[0083] As the shape of a fault is displayed in the field-of-view
field of the electron microscope, the operator can easily recognize
a target fault when the fault is hard to be distinguished from a
pattern or a plurality of faults exist in the field-of-view
field.
[0084] [Embodiment 5]
[0085] FIG. 10 shows an example of moving the field of view of the
electron microscope and displaying a distance between the center of
the field of view and the fault coordinates.
[0086] The operator moves the field-of-view field of the electron
microscope toward the fault coordinates obtained by the optical
inspecting apparatus 13.
[0087] The field for the field-of-view 26 of the electron
microscope, the vicinity field 24, the center of coordinates 25,
and the distance 61 between the center of the field of view and the
fault coordinates are displayed on-screen.
[0088] In this status, the center coordinates 25 of the
field-of-view field matches with the center coordinates 25 of the
vicinity field 24. Therefore, the distance between the center of
the field of view and the fault coordinates is X=0 and Y=0.
[0089] When the operator moves the pointer 23 (of the pointing
device) to a position in the vicinity field 24 to which the
operator wants to move the field of view of the electron microscope
and click the left button 29 of the mouse, the field of view of the
electron microscope moves to the selected position. The workstation
or the personal computer calculates the distance between the center
coordinates 25 of the vicinity field 24 and the center coordinates
62 of the field-of-view field and displays the result in the
"Distance between the region of interest and the coordinates of the
fault" field 61.
[0090] When the operator clicks the SAVE button 63, the values set
in the "Distance between the region of interest and the coordinates
of the fault" field 61 are saved. Next, the operator moves the
field of view to another fault coordinates and click the MOVE
button 64. The field of view of the electron microscope is
relatively moved by a distance which was saved latest.
[0091] As explained above, the operator can easily move the field
of view of the electron microscope to any place near the fault
coordinates. Therefore, this embodiment is very effective to move
the field of view of the electron microscope directly and easily to
any place near the fault coordinates in case a deviation of a fault
is estimated.
[0092] With this, when a fault is detected in the field of view,
the operator can get the distance between the fault coordinates
obtained by the optical inspecting apparatus 13 and the
actually-observed fault coordinates easily from the content in the
"Distance between the region of interest and the coordinates of the
fault" field 61. This is very effective when the fault coordinates
obtained by the optical inspecting apparatus 13 are not reliable or
affected by a stage error. This embodiment can correct such overall
coordinate errors between the optical inspecting apparatus 13 and
the electron microscope in accordance with the present
invention.
[0093] Further, if it is assumed that the other fault has almost
the same error, the operator can search the fault efficiently by
moving the field of view of the electron microscope to the same
deviated position by simple button operations.
[0094] [Embodiment 6]
[0095] FIG. 11 shows an example of separately displaying areas
which are already observed and areas which have not been observed
yet in accordance with the present invention.
[0096] The field-of-view field 26 moves in the vicinity field 24 as
the field of view of the electron microscope moves. In this case,
the areas 71 which were already observed are displayed in different
colors. This is also true when the field of view of the electron
microscope is rotated.
[0097] Further, when the vicinity field including the field of view
of the electron microscope is enlarged or shrunk, the areas 71
which were already observed are enlarged or shrunk according to the
size of the vicinity field.
[0098] This prevents re-observation of the already-observed areas
or skipping of observation of areas which have not been observed as
the areas which were already observed are clearly distinguished
from areas which have not been observed even when the field of view
of the electron microscope is moved or rotated or the vicinity
field including the field-of-view field is enlarged or shrunk.
[0099] The present invention can provide an electron microscope for
reviewing faults which are detected by an optical inspecting
apparatus, wherein said electron microscope can position its field
of view easily and accurately on a target fault regardless of
positional errors between different kinds of microscopes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0100] FIG. 1 is a schematic view of a system configuration of a
scanning electron microscope which is an embodiment of the present
invention.
[0101] FIG. 2 shows a schematic screen layout of the CRT of the
workstation or a personal computer to operate the electron
microscope of the present invention, including a field-of-view
field and a vicinity field.
[0102] FIG. 3 is an illustration explaining a procedure of
enlarging or shrinking the field of view and its vicinity of the
electron microscope of Embodiment 1.
[0103] FIG. 4 is a flowchart explaining a procedure of enlarging or
shrinking the field of view and its vicinity of the electron
microscope of Embodiment 1.
[0104] FIG. 5 is an illustration explaining a procedure of
enlarging or shrinking the field of view and its vicinity of the
electron microscope of Embodiment 2.
[0105] FIG. 6 is a flowchart explaining a procedure of enlarging or
shrinking the field of view and its vicinity of the electron
microscope of Embodiment 2.
[0106] FIG. 7 is an illustration explaining a procedure of moving
the vicinity field according to the movement of the field-of-view
field in Embodiment 3.
[0107] FIG. 8 is a flowchart explaining a procedure of moving the
vicinity field according to the movement of the field-of-view field
in Embodiment 3.
[0108] FIG. 9 is a schematic diagram explaining a procedure of
displaying a fault in the field-of-view field of Embodiment 4.
[0109] FIG. 10 is a schematic diagram explaining a movement of the
field-of-view field of the electron microscope of Embodiment 5 and
a procedure of displaying a distance between the fault coordinates
and the center of the field-of-view field.
[0110] FIG. 11 shows an example of separately displaying areas
which are already observed and areas which have not been observed
in Embodiment 6.
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