U.S. patent application number 09/359909 was filed with the patent office on 2002-02-21 for electron beam exposure apparatus and device manufacturing method.
Invention is credited to MURAKI, MASATO.
Application Number | 20020020820 09/359909 |
Document ID | / |
Family ID | 16627899 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020020820 |
Kind Code |
A1 |
MURAKI, MASATO |
February 21, 2002 |
ELECTRON BEAM EXPOSURE APPARATUS AND DEVICE MANUFACTURING
METHOD
Abstract
An electron optical system for controlling an electron beam to
write a pattern detects the position of a stage reference mark on a
stage using the electron beam, and a wafer stage position detection
unit detects the position of the stage. Based on the detection
results, the relative position between the electron beam and stage
is specified, and pattern writing is controlled in accordance with
this relative position. The electron optical system has an electron
optical system reference mark. The electron optical system detects
the position of this electron optical system reference mark at
predetermined time intervals during pattern writing, and the
relative position is corrected on the basis of a variation of that
position.
Inventors: |
MURAKI, MASATO; (TOKYO,
JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Family ID: |
16627899 |
Appl. No.: |
09/359909 |
Filed: |
July 26, 1999 |
Current U.S.
Class: |
250/491.1 |
Current CPC
Class: |
H01J 2237/30455
20130101; H01J 37/3045 20130101; B82Y 10/00 20130101; H01J 37/3174
20130101; B82Y 40/00 20130101 |
Class at
Publication: |
250/491.1 |
International
Class: |
G03F 009/00; G01J
001/00; G01N 021/00; G01N 023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 28, 1998 |
JP |
10-212756 |
Claims
What is claimed is:
1. An electron beam exposure apparatus for writing a pattern on a
substrate using an electron beam, comprising: a stage which moves
while carrying the substrate; a first reference mark formed on said
stage; an electron optical system for writing a pattern on the
substrate by deflecting the electron beam, and detecting a position
of an object to be irradiated by irradiating the object with the
electron beam; a second reference mark which is formed on said
electron optical system to fall within a deflection range of the
electron beam by said electron optical system; control means for
specifying a relative position between said stage and the electron
beam on the basis of a position of said first reference mark
detected by said electron optical system, and controlling writing
of the pattern on the substrate on the basis of the relative
position; and correction means for detecting a position of said
second reference mark using said electron optical system, and
correcting the relative position on the basis of the detected
position.
2. The apparatus according to claim 1, further comprising: distance
measurement means for detecting a position of said stage, and
wherein said control means specifies the relative position on the
basis of the position of the first reference mark upon detecting
said first reference mark, and the position of said stage detected
by said distance measurement means.
3. The apparatus according to claim 1, wherein said correction
means corrects the relative position by adjusting at least one of
deflection of said electron optical system and driving of said
stage on the basis of a change in position of said second reference
mark along with an elapse of time, which is detected by said
electron optical system.
4. The apparatus according to claim 1, wherein a position detection
frequency of said first reference mark is lower than a position
detection frequency of said second reference mark by said
correction means.
5. The apparatus according to claim 1, wherein said correction
means measures the position of said second reference mark at a
predetermined time interval, calculates a difference between the
currently detected position and the previously detected position of
said second reference mark, and corrects the relative position on
the basis of the calculated difference during writing of the
pattern by said control means.
6. The apparatus according to claim 2, wherein said distance
measurement means detects a position of said stage relative to said
electron optical system.
7. The apparatus according to claim 6, wherein said distance
measurement means comprises a first mirror fixed to said stage, a
second mirror fixed to said electron optical system, and detection
means for irradiating said first and second mirrors with a laser
beam, bringing laser beams reflected by said first and second
mirrors to interference, and detecting a relative position between
said first and second mirrors.
8. A method of controlling an electron beam exposure apparatus
which comprises a stage which moves while carrying the substrate,
and an electron optical system for writing a pattern on the
substrate by deflecting an electron beam, and detecting a position
of an object to be irradiated by irradiating the object with the
electron beam, and writes a pattern on the substrate using the
electron beam, comprising: the specifying step of detecting a
position of a first reference mark formed on said stage using said
electron optical system, and specifying a relative position between
said stage and the electron beam on the basis of the detected
position; the control step of controlling writing of the pattern on
the substrate on the basis of the relative position specified in
the specifying step; and the correction step of detecting a
position of a second reference mark, which is formed on said
electron optical system to fall within a deflection range of the
electron beam, using said electron optical system, and correcting
the relative position on the basis of the detected position.
9. The method according to claim 8, wherein the control step
includes the step of detecting a position of the first reference
mark, detecting a position of said stage at that time, and
specifying the relative position on the basis of the detected
position of the first reference mark and the detected stage
position.
10. The method according to claim 8, wherein the correction step
includes the step of correcting the relative position by adjusting
at least one of deflection of said electron optical system and
driving of said stage on the basis of a change in position of the
second reference mark along with an elapse of time, which is
detected by said electron optical system.
11. The method according to claim 8, wherein an execution frequency
of the specifying step is lower than an execution frequency of the
correction step.
12. The method according to claim 8, wherein the correction step
includes the step of measuring the position of the second reference
mark at a predetermined time interval, calculating a difference
between the currently detected position and the previously detected
position of the second reference mark, and correcting the relative
position on the basis of the calculated difference during writing
of the pattern in the control step.
13. The method according to claim 9, wherein a position of said
stage relative to said electron optical system is detected upon
detecting the position of said stage.
14. The method according to claim 13, wherein the position of said
stage is detected by irradiating a first mirror fixed to said stage
and a second mirror fixed to said electron optical system with a
laser beam, bringing laser beams reflected by said first and second
mirrors to interference, and detecting a relative position between
said first and second mirrors.
15. An electron beam exposure method for writing a pattern on a
substrate placed on a stage using an electron beam coming from an
electron optical system, comprising: the step of detecting a
position of a first reference mark fixed to the stage using the
electron beam, detecting a position of the stage at that time using
distance measurement means to obtain a positional relationship of
the stage relative to the electron beam, and pre-detecting a
position of a second reference mark, which is fixed to the electron
optical system to fall within a deflection range of the electron
beam, using the electron beam; and the step of detecting the
position of the second reference mark again using the electron
beam, calculating a difference between the currently detected
position and the pre-detected position of the second reference
mark, and correcting the relative positional relationship on the
basis of the calculated difference, upon writing the pattern on the
substrate using the electron beam on the basis of the obtained
positional relationship between the electron beam and the
stage.
16. The method according to claim 15, wherein the relative
positional relationship is corrected during writing of the pattern
on the substrate using the electron beam.
17. The method according to claim 15, wherein a position of the
stage relative to the electron optical system is detected upon
detecting the position of the stage using the distance measurement
means.
18. A device manufacturing method for manufacturing a device by a
manufacturing processing including an electron beam exposure method
of claim 15.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an electron beam exposure
apparatus and, more particularly, to an electron beam exposure
apparatus which can quickly and precisely measure and correct any
position variation of an electron beam with respect to a stage that
carries an object to be exposed, and a device manufacturing method
using the same.
[0002] In an electron beam exposure apparatus, the position
stability of an electron beam with respect to a stage that carries
the object to be exposed is an important factor that determines its
work precision. As factors that impair the position stability of an
electron beam, an electron beam position variation resulting from
charging of a contaminant such as a carbon compound that has become
attached inside an electron optical system, and an electron beam
position variation arising from a thermal or mechanical deformation
of a structure for supporting the electron optical system, the
stage, and an interferometer that detects the stage position are
known. When the electron beam position has varied, the relationship
between the writing coordinate position defined by the electron
beam and the coordinate position of the stage defined by the
interferometer deviates before or after writing, or during writing,
thus impairing the stitching precision and overwriting precision of
the patterns to be written.
[0003] Conventionally, a displacement between the writing
coordinate system and stage coordinate system due to an electron
beam position variation is corrected by the following method.
[0004] A reference mark is formed on a movable stage which carries
a sample such as a wafer or the like. The stage is then moved on
the basis of a stage coordinate system defined by the
interferometer to locate the reference mark at the design standard
irradiation position of an electron beam, and a mark coordinate
position (X0, Y0) of the reference mark is obtained by the electron
beam. Writing is temporarily stopped during writing, and the stage
is moved again to locate the reference mark at the standard
irradiation position of the electron beam. The coordinate position
of the standard position is detected by the electron beam to obtain
a mark coordinate position (X1, Y1) at that time. A difference
(.DELTA.X1, .DELTA.Y1) between the previous mark coordinate
position (X0, Y0) and the current mark coordinate position (X1, Y1)
is calculated to obtain the electron beam position variation. Then,
the deflection position of the electron beam or stage position is
corrected based on this difference (.DELTA.X1, .DELTA.Y1). The
aforementioned operation is repeated until the end of writing.
[0005] However, when the required stitching precision or
overwriting precision becomes stricter, the allowable range of
electron beam position variations becomes narrower, and electron
beam position variations must be corrected more frequently. As a
result, a problem, i.e., low throughput of the electron beam
exposure apparatus, remains unsolved.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide an
excellent electron beam exposure apparatus which can solve the
above problems, and a device manufacturing method.
[0007] It is another object of the present invention to allow quick
correction of the positional relationship between the stage and
electron beam upon writing a pattern on a substrate by the electron
beam, and to attain both high writing precision and high
throughput.
[0008] According to one aspect of the present invention, there is
provided an electron beam exposure apparatus comprising: a stage
which moves while carrying a substrate; a first reference mark
fixed onto the stage; an electron optical system for writing a
pattern to be written by deflecting an electron beam on the
substrate by deflection means, irradiating an object to be
irradiated on the stage with the electron beam, detecting electrons
reflected by the object, and detecting a position of the object
with respect to the electron beam; a second reference mark fixed to
the electron optical system and located in a deflection range of
the electron beam; a distance measurement system for detecting a
position of the stage; and control means for detecting a position
of the first reference mark using the electron optical system,
detecting the position of the stage at that time using the distance
measurement system to obtain a positional relationship of the stage
with respect to the electron beam, pre-detecting a position of the
second reference mark using the electron optical system, detecting
the position of the second reference mark again using the electron
optical system upon writing a pattern to be written on the
substrate by the electron beam by making the stage and the
deflection means cooperate with each other on the basis of the
obtained positional relationship between the electron beam and the
stage, calculating a difference between the currently detected
position and the pre-detected position of the second reference
mark, and correcting a relative position between the electron beam
and stage using at least one of the deflection means and the stage
on the basis of the calculated difference.
[0009] Preferably, the control means detects the position of the
second reference mark using the electron optical system during
writing of the pattern to be written on the substrate by the
electron beam, calculates the currently detected position and the
pre-detected position of the second reference mark, and corrects
the relative position between the electron beam and stage using at
least one of the deflection means and the stage on the basis of the
calculated difference.
[0010] Preferably, the distance measurement system detects the
position of the stage relative to the electron optical system.
[0011] Preferably, the distance measurement system has a movable
mirror fixed to the stage, a reference mirror fixed to a position
detection system, and means for irradiating the movable mirror and
reference mirror with a laser beam, bringing laser beams reflected
by the movable mirror and reference mirror to interference, and
detecting that interference light.
[0012] According to another aspect of the present invention, there
is provided an electron beam exposure method for writing a pattern
to be written on a substrate, which is placed on a stage, with an
electron beam coming from an electron optical system, comprising
the step of detecting a position of a first reference mark fixed to
the stage using the electron beam, detecting a position of the
stage at that time using a distance measurement system to obtain a
positional relationship of the stage with respect to the electron
beam, and pre-detecting a position of a second reference mark,
which is fixed to the electron optical system and is located in a
deflection range of the electron beam, using the electron beam; and
the step of detecting the position of the second reference mark
again using the electron beam upon writing the pattern to be
written on the substrate using the electron beam on the basis of
the obtained positional relationship between the electron beam and
the stage, calculating a difference between the currently detected
position and the pre-detected position of the second reference
mark, and correcting a relative position between the electron beam
and the stage on the basis of the calculated difference.
[0013] The electron beam exposure method preferably further
comprises the step of detecting the position of the second
reference mark using the electron beam during writing of the
pattern to be written on the substrate using the electron beam,
calculating the difference between the currently detected position
and the pre-detected position of the second reference mark, and
correcting the relative position between the electron beam and the
stage on the basis of the calculated difference.
[0014] Preferably, the distance measurement system detects the
position of the stage relative to the electron optical system.
[0015] Preferably, the distance measurement system irradiates a
movable mirror fixed to the stage and a reference mirror fixed to
the electron optical system with a laser beam, brings laser beams
reflected by the movable mirror and reference mirror to
interference, and detects that interference light.
[0016] According to still another aspect of the present invention,
there is provided a device manufacturing method for manufacturing a
device using the aforementioned electron beam exposure apparatus or
method.
[0017] Other features and advantages of the present invention will
be apparent from the following description taken in conjunction
with the accompanying drawings, in which like reference characters
designate the same or similar parts throughout the figures
thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate embodiments of
the invention and, together with the description, serve to explain
the principles of the invention.
[0019] FIG. 1 is a diagram showing an electron beam exposure
apparatus according to an embodiment of the present invention;
[0020] FIG. 2 is a plan view showing the electron beam exposure
apparatus according to the embodiment of the present invention;
[0021] FIG. 3 is a flow chart for explaining the exposure processes
according to the embodiment of the present invention;
[0022] FIG. 4 is a flow chart for explaining the manufacturing flow
of a microdevice; and
[0023] FIG. 5 is a flow chart for explaining the wafer process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Preferred embodiments of the present invention will now be
described in detail in accordance with the accompanying
drawings.
[0025] Arrangement of Electron Beam Exposure Apparatus
[0026] FIG. 1 shows an electron beam exposure apparatus according
to an embodiment of the present invention. This mainly has a main
structure 1, electron optical system 2, wafer stage 4, X-stage
position distance measurement system 5X, and Y-stage position
distance measurement system 5Y (not shown in FIG. 1). The electron
optical system 2, wafer stage 4, and X- and Y-stage position
distance measurement systems 5X and 5Y are held by the main
structure 1.
[0027] The electron optical system 2 is built by an electron gun 21
for radiating an electron beam, an electron lens system 22 for
converging an electron beam EB coming from the electron gun 21, a
deflector 23 for deflecting the electron beam EB, an electron
detection system 24 for detecting electrons reflected by the object
irradiated with the electron beam EB, and a reference plate 25
formed with an electron optical system reference mark ESM. The
respective building components are controlled by an electron
optical system controller 7. Upon exposing a wafer 6 by the
electron beam EB, the electron optical system controller makes the
deflector 23 scan the electron beam EB, and controls irradiation of
the electron beam EB in correspondence with each pattern to be
written. Upon detecting the position of the object irradiated using
the electron beam EB, the electron optical system controller 7
makes the deflector 23 scan the electron beam EB on the object, and
makes the electron detection system 24 detect electrons reflected
by the object, thus detecting its position. Note that the electron
optical system reference mark ESM is located within the deflection
range of the electron beam EB, and its position can be detected by
the electron beam EB. As also shown in FIG. 2 as a plan view of the
electron beam exposure apparatus of this embodiment, X- and
Y-reference mirrors 26X and 26Y are fixed to an electron optical
system structure that hold the respective components of the
electron optical system 2.
[0028] The wafer stage 4 is constructed by placing an X-stage 42 on
a Y-stage 41, and the wafer 6 applied with a photosensitive
material is held on the X-stage 42. Furthermore, a reference plate
43 formed with a stage reference mark SSM is placed at a position
on the X-stage 42 different from that of the wafer 6, and an
X-movable mirror 44X and Y-movable mirror 44Y (not shown in FIG. 1)
are respectively placed at one end of the X- and Y-directions on
the X-stage 42. The Y-stage 41 aligns the wafer 6 in the
Y-direction perpendicular to the page of FIG. 1 in a plane
perpendicular to an optical axis AX1 of the electron lens system
22, and the X-stage 42 aligns the wafer 6 in the X-direction
perpendicular to the Y-axis in the plane perpendicular to the
optical axis AX1 of the electron lens system 22. Note that a
Z-stage and the like (not shown) for aligning the wafer in the
Z-direction parallel to the optical axis AX1 of the electron
optical system 22 are also placed on the X-stage 42. The Y-stage 41
and X-stage 42 are controlled by a wafer stage controller 9.
[0029] In the X-stage position distance measurement system 5X, a
laser beam emerging from an interferometer main body 51X is split
by a beam splitter 52X into a distance measurement beam SB and
reference beam RB. The distance measurement beam SB travels toward
the X-movable mirror 44X, is reflected by the mirror 44X, and then
returns to the beam splitter 52X again. The reference beam RB
travels toward the X-reference mirror 26X via an X-reflecting prism
53X, is reflected by the mirror 26X, and returns to the beam
splitter 52X again via the X-reflecting prism 53X, as shown in
FIGS. 1 and 2. The two beams SB and RB which have returned to the
beam splitter 52X enter a receiver included in the interferometer
main body 51X. Upon leaving the beam splitter 52X, the distance
measurement beam SB and reference beam RB have frequencies
different by a small amount .DELTA.f, and the receiver outputs a
beat signal whose frequency has changed from .DELTA.f in
correspondence with the moving speed of the X-movable mirror 44X in
the X-direction. When this beat signal is processed by a wafer
stage position detection unit 10, the change amount of the optical
path length of the distance measurement beam RB with reference to
the optical path length of the reference beam RB, i.e., the
X-coordinate value of the X-movable mirror 44X fixed to the wafer
stage with reference to the X-reference mirror 26X fixed to the
electron optical system, can be measured with high resolution and
precision. Likewise, the Y-stage position distance measurement
system 5Y shown in FIG. 2 measures the Y-coordinate value of a
Y-movable mirror 44Y fixed to the wafer stage with reference to the
Y-reference mirror 26Y fixed to the electron optical system 2 with
high resolution and precision.
[0030] A main controller 11 processes data output from the electron
optical system controller 7, wafer stage position detection unit
10, and wafer stage controller 9, and supplies commands and the
like to these controllers.
[0031] Exposure Operation
[0032] The exposure operation of the electron beam exposure
apparatus of this embodiment will be explained below with the aid
of FIG. 3.
[0033] Prior to the description, a coordinate system will be
explained. The exposure apparatus of this embodiment has a stage
coordinate system defined by the wafer stage controller 9, and a
writing coordinate system defined by the electron optical system
controller 7. The X- and Y-axes of the stage coordinate system XY
represent the moving directions of the X-stage 42 and Y-stage 41
(or coordinate measurement directions by the X- and Y-stage
position distance measurement systems 5X and 5Y), and the x- and
y-axes of the writing coordinate system xy represent the deflection
directions of the electron beam. Note that the origins of these two
coordinate systems are defined to match the reference position
(optical axis AX1) of the electron beam.
[0034] Upon starting exposure, the main controller 11 executes the
following steps (see FIG. 3).
[0035] (Step S101)
[0036] The main controller 11 directs the wafer stage controller 9
to move the X-stage 42 so as to locate the stage reference mark SSM
on the optical axis AX1 of the electron optical system 2 (movement
of the X-stage 42 means to move the X-stage 42 by making the wafer
stage controller 9 and wafer stage position detection unit 10
cooperate with each other; the same applies to the following
description). The same applies to driving of the Y-stage 41.
[0037] (Step S102)
[0038] The main controller 11 directs the electron optical system
controller 7 to scan the stage reference mark SSM with the electron
beam coming from the electron optical system 2, and directs the
electron detection system 24 to detect electrons reflected by the
stage reference mark SSM, thereby detecting the position of the
stage reference mark SSM. In this way, the position displacement of
the stage reference mark SSM from the electron beam reference
position is detected. Also, the main controller 11 directs the
electron optical system controller 7 to scan the electron optical
system reference mark ESM with the electron beam coming from the
electron optical system 2, and directs the electron detection
system 24 to detect electrons reflected by the electron optical
system reference mark ESM, thereby detecting the position of the
electron optical system reference mark ESM. In this manner, the
coordinate position (x0, y0) of the electron optical system
reference mark ESM with respect to the electron beam reference
position is detected.
[0039] (Step S103)
[0040] The main controller 11 re-sets the stage coordinate system
defined by the wafer stage position detection unit 10 or the
writing coordinate system defined by the electron optical system
controller 7 on the basis of the position displacement of the stage
reference mark SSM with respect to the electron beam reference
position, which is detected in step S102. As a result, the
positional relationship (relative position) between the electron
beam EB and X-stage 42 is determined.
[0041] (Step S104)
[0042] A wafer is placed on the wafer stage 4.
[0043] (Step S105)
[0044] A pattern is written on the wafer 6 while deflecting the
electron beam EB and moving the X-stage on the basis of the
positional relationship between the electron beam EB and X-stage
42.
[0045] (Step S106)
[0046] If the writing time in step S105 has exceeded a first
predetermined time, writing is stopped.
[0047] (Step S107)
[0048] If all areas to be written on the wafer 6 have been written,
exposure of the wafer is completed. Then, the wafer 6 is removed
from the wafer stage 4. The flow returns to step S104 to process
the next, new wafer. If a second predetermined time longer than the
first predetermined time has elapsed, the flow returns to step S101
to re-set the relative positional relationship between the electron
beam and wafer stage 4 using the stage reference mark SSM. If all
areas to be written on the wafer 6 have not been written, the flow
advances to step S8.
[0049] (Step S108)
[0050] The electron optical system reference mark ESM is scanned
with the electron beam EB coming from the electron optical system
2, and electrons reflected by the electron optical system reference
mark ESM are detected by the electron detection system 24, thereby
obtaining a coordinate position (x1, y1) of the electron optical
system reference mark ESM at that time.
[0051] (Step S109)
[0052] A difference (.DELTA.x1, .DELTA.y1) between the previous
coordinate position (x0, y0) and the current coordinate position
(x1, y1) of the electron optical system reference mark ESM is
considered as an electron beam position variation value (drift
value) during writing, and the deflection position of the electron
beam or wafer stage position is corrected on the basis of the
position displacement (.DELTA.x1, .DELTA.y1). The flow then returns
to step S105.
[0053] The characteristic features of this embodiment described
above will be explained below.
[0054] In the conventional electron beam exposure apparatus, the
following two variations are added, and their sum appears as a
position variation of the electron beam with respect to the
stage.
[0055] (1) The position of the electron beam varies with respect to
the electron optical system 2 due to charging of a contaminant such
as a carbon compound or the like that has become attached inside
the electron optical system.
[0056] (2) The position of the electron optical system 2 varies
with respect to the drive origin of the wafer stage 4 due to
thermal or mechanical deformations of the main structure 1 and the
like.
[0057] The time variation of (2) is smaller than that of (1). For
this reason, in this embodiment, the correction process that uses
the electron optical system reference mark ESM and does not require
any stage movement is executed for a variation of type (1) at short
time intervals (first predetermined time), and the correction
process that uses the electron optical system reference mark ESM
and requires stage movement is executed for a variation of type (2)
at long time intervals (second predetermined time). That is, since
correction which must be done frequently is executed at short time
intervals, a decrease in throughput due to correction can be
minimized. Furthermore, since the X- and Y-reference mirrors 26X
and 26Y are fixed to the electron optical system 2, the position of
the wafer stage 4 is measured with reference to the electron
optical system 2, thus always correcting a variation of type
(2).
[0058] Device Manufacturing Method
[0059] An embodiment of a device producing method using the
above-described exposure apparatus will be described below.
[0060] FIG. 4 shows the flow in the manufacture of a microdevice
(semiconductor chips such as LSIs, ICs, or the like, liquid crystal
panels, CCDs, thin film magnetic heads, micromachines, and the
like). In step 1 (circuit design), the circuit design of a
semiconductor device is made. In step 2 (exposure control data
generation), exposure control data of an exposure apparatus is
generated based on the designed circuit pattern. In step 3
(fabricate wafer), a wafer is fabricated using materials such as
silicon and the like. Step 4 (wafer process) is called a
pre-process, and an actual circuit is formed by lithography using
the exposure apparatus with exposure control data, and a wafer. The
next step 5 (assembly) is called a post-process, in which
semiconductor chips are assembled using the wafer obtained in step
4, and includes an assembly process (dicing, bonding), a packaging
(encapsulating chips), and the like. In step 6 (inspection),
inspections such as operation confirmation tests, durability tests,
and the like of semiconductor devices assembled in step 5 are run.
Semiconductor devices are completed via these processes, and are
delivered (step 7).
[0061] FIG. 5 shows the detailed flow of the wafer process. In step
11 (oxidation), the surface of the wafer is oxidized. In step 12
(CVD), an insulating film is formed on the wafer surface. In step
13 (electrode formation), electrodes are formed by deposition on
the wafer. In step 14 (ion implantation), ions are implanted into
the wafer. In step 15 (resist process), a photosensitive agent is
applied on the wafer. In step 16 (exposure), the circuit pattern on
the mask is printed on the wafer by exposure using the electron
beam exposure apparatus. In step 17 (development), the exposed
wafer is developed. In step 18 (etching), a portion other than the
developed resist image is removed by etching. In step 19 (remove
resist), the resist film which has become unnecessary after etching
is removed. By repeating these steps, multiple circuit patterns are
formed on the wafer.
[0062] Using the manufacturing method of this embodiment, highly
integrated semiconductor devices, which are hard to manufacture by
the conventional method, can be manufactured with low cost.
[0063] According to the present invention, the position variations
of the electron beam with respect to the stage are classified into
two variation factors, and correction processes suitable for the
individual variation factors are done, thus minimizing a decrease
in throughput due to correction in the electron beam exposure
apparatus. When a device is manufactured using such method, a
device with higher precision than the conventional one can be
manufactured.
[0064] As many apparently widely different embodiments of the
present invention can be made without departing from the spirit and
scope thereof, it is to be understood that the invention is not
limited to the specific embodiments thereof except as defined in
the appended claims.
* * * * *