JP2005117063A - Electron beam proximity exposure system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron beam proximity exposure system, in which an imaging means used when a mask and a wafer are positioned relatively, is capable of not exerting bad effects on an electronic beam for performing a proximity exposure. <P>SOLUTION: The electron beam proximity exposure system uses a microscope imaging apparatus AX1 when the mask 32 and the wafer 44 are positioned relatively.A cover glass 91 is attached in the front face of a microscope objective lens 90 of the microscope imaging apparatus AX1. Moreover, a conductive thin film 91A is evaporated on the surface of the cover glass 91, and the conductive thin film 91A is grounded through a conductive retention member 92 and a cabinet of the microscope imaging apparatus AX1. Thereby, electrons or secondary electrons scattered at the time of transfer by an electron beam, is not charged on the surface of the cover glass 91, and the electron beam is not bent according to Coulomb force carelessly. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electron beam proximity exposure apparatus, and more particularly to an electron beam proximity exposure apparatus that uses an electron beam to transfer a mask pattern of a mask disposed close to a semiconductor wafer to a resist layer on the wafer at an equal magnification.

  Conventionally, this type of electron beam proximity exposure apparatus is disclosed in Patent Documents 1 and 2.

  FIG. 17 is a view showing a basic configuration of the electron beam proximity exposure apparatus. The electron beam proximity exposure apparatus 10 mainly includes an electron beam source 14 that generates an electron beam 15, an electron gun 12 that includes a lens 16 that makes the electron beam 15 a parallel beam, and a shaping aperture 18, main deflectors 22 and 24, and a secondary deflector. The scanning unit 20 includes deflectors 26 and 28 and scans an electron beam parallel to the optical axis, and a mask 30. The mask 30 is arranged so as to be close to the wafer 40 having a resist layer 42 formed on the surface (so that the gap is 50 μm). In this state, when the electron beam is irradiated perpendicularly to the mask 30, the electron beam that has passed through the mask pattern of the mask 30 is irradiated to the resist layer 42 on the wafer 40.

  Further, the scanning unit 20 controls the deflection of the electron beam so that the electron beam 15 scans the entire surface of the mask 30 as shown in FIG. As a result, the mask pattern of the mask 30 is transferred to the resist layer 42 on the wafer 40 at the same magnification.

The electron beam proximity exposure apparatus 10 is provided in a vacuum chamber 50 as shown in FIG. Further, in the vacuum chamber 50, an electrostatic chuck 60 for attracting the wafer 40 and the wafer 40 attracted to the electrostatic chuck 60 are moved in two horizontal orthogonal directions and rotated in a horizontal plane. A θXY stage 70 is provided. The θXY stage 70 moves the wafer 40 by a predetermined amount each time the mask pattern is transferred at an equal magnification, thereby allowing a plurality of mask patterns to be transferred onto one wafer 40. In FIG. 19, reference numeral 80 denotes a conduction pin pressed against the upper surface of the wafer 40 in order to conduct the wafer 40.
US Pat. No. 5,831,272 Japanese Patent No. 2951947

  By the way, a plurality of wafers are exposed using a plurality of masks having different mask patterns, thereby forming an integrated circuit. When exposing each mask pattern, it is necessary to relatively position the mask and the wafer so that the mask pattern to be exposed has a predetermined positional relationship with the already exposed mask pattern.

  The present invention provides an electron beam proximity exposure apparatus capable of preventing an adverse effect on an electron beam for proximity exposure when the imaging means is used to relatively position a mask and a wafer. The purpose is to provide.

  In order to achieve the above object, according to the first aspect of the present invention, a mask is arranged in proximity to a wafer, and the mask pattern formed on the mask is scanned on the resist layer on the wafer by scanning the mask with an electron beam. In the electron beam proximity exposure apparatus to be transferred, an image pickup means for simultaneously picking up an alignment mask mark provided on the mask and an alignment wafer mark provided on the wafer, and output from the image pickup means Detecting means for detecting a positional deviation between the mask mark and the wafer mark based on an image signal to be detected, and relatively aligning the mask and the wafer so that the positional deviation is zero based on a detection output of the detecting means. And an optical member of the imaging means, wherein a conductive thin film is deposited on a surface thereof, and the conductive thin film is It is characterized in that it is the earth.

  The conductive thin film is a tin oxide film or an indium tin oxide film as described in claim 2 of the present application.

  According to a third aspect of the present invention, there is provided an electron beam proximity exposure apparatus for transferring a mask pattern formed on a mask onto a resist layer on the wafer by arranging the mask in proximity to the wafer and scanning the mask with an electron beam. In the above, an image pickup means for simultaneously picking up an alignment mask mark provided on the mask and an alignment wafer mark provided on the wafer, and an image signal output from the image pickup means Detecting means for detecting misalignment between the mask mark and the wafer mark, and means for relatively aligning the mask and the wafer so that the misalignment becomes zero based on the detection output of the detecting means; And the imaging means does not charge electrons or secondary electrons scattered during transfer by the electron beam to the optical member of the imaging means. It is characterized by having a shutter mechanism for shielding so.

  That is, in the first to third aspects, the optical member is conducted or shielded by the shutter mechanism so that electrons or secondary electrons scattered during transfer by the electron beam are not charged to the optical member of the imaging means. This prevents electrons from being charged on the optical member of the image pickup means arranged in the vicinity of the mask, and prevents the electron beam from being bent by the Coulomb force.

  According to the present invention, the surface of the optical member of the image pickup means used for relatively positioning the mask and the wafer is connected to be groundable, or the optical member is shielded by the shutter mechanism during transfer by the electron beam. Therefore, it is possible to prevent electrons or secondary electrons scattered during the transfer by the electron beam from being charged on the optical member of the image pickup means, thereby preventing the electron beam from being bent unexpectedly during the transfer. Can do.

  Preferred embodiments of an electron beam proximity exposure apparatus according to the present invention will be described below with reference to the accompanying drawings.

[First Embodiment]
1 and 2 are a top view and a side view, respectively, of a transfer portion of an electron beam proximity exposure apparatus according to the present invention.

  As shown in these drawings, this electron beam proximity exposure apparatus is provided with three microscope imaging devices AX1, AY1, and AX2 facing the mask 32. These microscope imaging devices AX1, AY1, and AX2 are arranged so that the photographing optical axis is inclined with respect to the mask surface so as not to block the electron beam during exposure with the electron beam. Note that the main configuration of the electron beam proximity exposure apparatus is the same as that shown in FIGS. 17 to 19, and a detailed description thereof will be omitted.

  FIG. 3 is an enlarged top view of the transfer portion of the electron beam proximity exposure apparatus.

  In the figure, reference numeral 44 denotes a wafer attracted by the electrostatic chuck 60 on the θXY stage 70.

  On this wafer 44, a wafer mark MWX for positioning each chip of the wafer 44 in the x-axis direction and a wafer mark MWY for positioning in the y-axis direction are provided outside the area where the chips are formed. ing.

  On the other hand, the mask 32 has a mask pattern formed in the area indicated by the broken line, and the x and y shifts between the mask 32 and the wafer 44 in relation to the wafer marks MWX and MWY outside the area indicated by the broken line. , And three mask marks MMX1, MMX2, and MMY for detecting a shift in the rotational direction of the xy plane.

  Details of the wafer mark and the mask mark will be described with reference to FIGS.

  4 is an enlarged view of a portion indicated by reference symbol A in FIG. 3, and FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. As shown in FIG. 4, a mask mark MMX1 is formed on the mask 32, and the lower wafer marks MWX and MWX can be seen through the mask 32.

  The mask mark MMX1 formed on the mask 32 is composed of 5 × 3 small openings, while the wafer mark MWX is composed of 14 × 3 convex portions (FIGS. 4 and 4). 5).

  Next, the microscope imaging apparatus AX1 will be described.

  FIG. 6 shows an outline of the microscope imaging apparatus AX1. As shown in the figure, the microscope imaging apparatus AX1 is arranged so that the incident angle of the optical axis is a predetermined angle α with respect to the mask 32 arranged horizontally.

  A cover glass 91 is attached to the front surface of the microscope objective lens 90. A conductive thin film 91A is deposited on the surface of the cover glass 91, and the conductive thin film 91A is grounded via the conductive holding member 92 and the housing of the microscope imaging apparatus AX1. This prevents electrons or secondary electrons scattered during transfer by the electron beam from being charged on the surface of the cover glass 91.

  As the conductive thin film 91A, a tin oxide film or an indium tin oxide film (ITO) is used. In this embodiment, the conductive thin film 91A is vapor-deposited on the surface of the cover glass 91. However, in the case of a microscope imaging apparatus in which the cover glass is not provided, the surface of the microscope objective lens 90 is electrically conductive. A conductive thin film is deposited so that the conductive thin film is grounded.

  In addition, a mechanical shutter mechanism may be provided instead of the conductive thin film 91A, and the shutter mechanism may be closed to shield the optical member of the microscope image pickup device during the transfer by the electron beam, and the shutter mechanism may be opened during the image pickup. . Needless to say, the shutter mechanism in this case is not charged with electrons.

  Illumination means is provided inside the microscope imaging apparatus AX1. That is, the illumination means is composed of a white light source 93, a lens 94, a reflection mirror 95, and a half mirror 96, and the white illumination light emitted from the white light source 93 is made into substantially parallel light by the lens 94 and is reflected by the reflection mirror 95. The mask 32 and the wafer 44 are illuminated through the half mirror 96, the objective lens 90, and the cover glass 91.

  The scattered light from the mask mark of the mask 32 and the wafer mark of the wafer 44 thus illuminated enters the imaging unit 97 through the objective lens 90 and the half mirror 96 and is imaged.

  The other microscope imaging devices AY1 and AX2 are configured similarly to the microscope imaging device AX1.

  As shown in FIG. 7A, the mask mark MMX and the wafer mark MWX have a length of each mark and an incident angle α of the photographing optical axis so that a part of the mark is positioned on the focal plane F of the microscope imaging apparatus. Has been determined. In FIG. 7A, P is the specularly reflected light of the white illumination light, Q and R are the scattered light of the white illumination light at the mask mark MMX and the wafer mark MWX, respectively, and G is the difference between the mask 32 and the wafer 44. It is an interval.

  FIG. 7B is an image showing a state where the scattered lights Q and R of the white illumination light are imaged by the microscope imaging device.

  Next, a method for detecting the deviation between the mask and the wafer based on the mask mark and wafer mark imaged as described above will be described.

  As shown in FIG. 8A, a focused portion (a portion surrounded by a frame) is continuously extracted in the x direction from the captured image of the mask mark and wafer mark. FIG. 8B shows the luminance level at each position in the x direction of the image extracted in this way.

Here, as shown in FIG. 8B, the peak position of the center of the three peaks is obtained for the luminance levels corresponding to the two mask marks MMX and one wafer mark MWX, and the distance between the peaks. Find x1 and x2. The positional deviation amount Δx in the x direction and the mask mark MMX and the wafer mark MWX are expressed by the following equation:
[Equation 1]
Δx = (x1 -x2) / 2
Can be obtained.

  The microscope image pickup devices AX1 and AX2 can detect two displacement amounts of the mask 32 and the wafer 44 in the x direction. The microscope image pickup device AY1 can detect one displacement amount of the mask 32 and the wafer 44 in the y direction. Can be detected.

  Next, a method for measuring the expansion / contraction rate in the x and y directions of the wafer will be described.

  As shown in FIG. 3, first, a chip in the upper left corner of the wafer 44 (hereinafter referred to as a first chip) and the mask 32 are positioned. In this positioning, the θXY stage 70 is moved in the x direction and the y direction so that the displacement amounts detected by the microscope imaging devices AX1, AY1, and AX2 become zero at the same time, and the θXY stage 70 is moved in the xy plane. This is done by rotating. In this embodiment, the θXY stage 70 is rotated. However, the mask 32 may be rotated. Instead of moving the wafer 44, the mask 32 is moved in the x and y directions. You may let them.

  When the positioning of the mask 32 and the first chip is completed as described above, the chip in the upper right corner of the wafer 44 (hereinafter referred to as the second chip) and the mask 32 are positioned. The positioning at this time is performed based on the amount of positional deviation detected by each microscope imaging device AX1, AY1, and the rotation direction is not adjusted.

Next, a distance Lx between the first chip and the second chip is obtained. This distance Lx is given by the following equation, where x2 is the movement amount in the x direction of the θXY stage 70 moved from the positioning of the first chip to the positioning of the second chip, and y2 is the movement amount in the y direction.
[Equation 2]
Lx = √ (x22 + y22)
Can be obtained. The movement amounts x2 and y2 are measured by two laser interferometers that detect the movement amounts of the θXY stage 70 in the x and y directions. That is, the reading values of the two laser interferometers when the first chip is positioned are (0, 0), and the reading values of the two laser interferometers when the second chip is positioned (x2). , Y2), the movement amounts x2 and y2 are measured.

On the other hand, when the reference distance between the first chip and the second chip is Lref, the expansion / contraction amount δx of the wafer 44 in the x direction is expressed by the following equation:
[Equation 3]
δx = Lx−Lref
The expansion / contraction ratio εx in the x direction is given by
[Equation 4]
εx = (Lx−Lref) / Lref
It becomes. The reference distance Lref is a length determined when the previous process or the wafer mark is formed or a design dimension.

  In addition, when there is a posture error (particularly an error in the yaw direction) due to the movement of the θXY stage 70, the laser interferometer is composed of three axes (for example, X, Y1, and Y2) and changed in the yaw direction. It is preferable to measure an angle and remove an error due to yaw from the value of Lx.

  Similarly, the expansion ratio εY of the wafer 44 in the y direction can be obtained. In this case, a chip in the lower left corner of the wafer 44 (hereinafter referred to as a third chip) and the mask 32 are positioned. This positioning is performed based on the amount of positional deviation detected by the microscope imaging devices AX1 and AY1, similarly to the positioning of the second chip, and the rotation direction is not adjusted. Then, the distance between the first chip and the third chip is measured from the reading values (x3, y3) of the two laser interferometers when the third chip is positioned.

  In the above embodiment, the movement distance between the chips when the three chips (first, second, and third chips) are positioned is measured, and the expansion and contraction rates of the wafer in the x and y directions are determined. As shown in FIG. 9, the movement distance between the chips when the four chips 1 to 4 are positioned is measured to obtain the expansion / contraction ratios in the x and y directions of the wafer. Also good.

  That is, as shown in FIG. 9, the movement distance Lx between the chips 1 and 2 when the chips 1 and 2 separated from each other in the x direction on the wafer 44 are measured to measure the wafer in the x direction. In the same manner, the expansion / contraction rate is obtained, and the movement distance Ly between the chips 3 and 4 when the chips 3 and 4 separated from each other in the y direction on the wafer 44 are measured, and the wafer in the y direction is measured. Obtain the expansion / contraction rate.

  The chips 1 and 3 are positioned by moving the θXY stage 70 in the x and y directions so that the displacement amounts detected by the microscope imaging devices AX1, AY1, and AX2 become zero at the same time, and at the same time, the xy plane. The chips 2 and 4 are positioned based on the amount of displacement detected by the microscope imaging devices AX1 and AY1, and the rotation direction is not adjusted.

  Further, at the time of positioning with the chips 1 and 3, the θXY stage 70 is rotated to adjust θ, but the adjustment of θ may be performed by rotating the mask side. In this case, when the chip 2 or the chip 4 is positioned, the alignment in the x direction and the y direction is performed without rotating the mask (that is, in a state where the rotational position of the mask adjusted for θ is maintained).

  FIG. 10 is a block diagram showing an embodiment of the controller of the electron beam proximity exposure apparatus according to the present invention.

  In the figure, a central processing unit (CPU) 100 performs overall control of the entire apparatus. As described above, the processing for obtaining the expansion and contraction rates in the x and y directions of the wafer, wafer positioning control, and exposure time are performed. Controls deflection of the electron beam. Each image signal obtained by imaging with the three microscope imaging devices AX1, AY1, and AX2 is applied to the signal processing circuit 102. The signal processing circuit 102 calculates three misregistration amounts between the mask mark and the wafer mark based on each input image signal.

  The CPU 100 moves the θXY stage 70 in the x and y directions via the stage drive circuit 104 so that the three positional shift amounts input from the signal processing circuit 102 become zero, and moves the θXY stage 70 in the xy plane. The wafer is rotated, thereby positioning the wafer with high precision (fine alignment).

  When determining the expansion / contraction ratios in the x direction and y direction of the wafer, the CPU 100 performs fine alignment of the first chip, the second chip, and the third chip of the wafer as described with reference to FIG. The distance between each chip is calculated from the reading values (x2, y2) and (x3, y3) of the laser interferometers LX and LY after fine alignment of the third chip and the third chip, and the measured distance and the reference distance Based on the above, the expansion and contraction rates in the x and y directions of the wafer are obtained.

  In addition, the CPU 100 supplies correction data corresponding to the expansion / contraction ratio of the wafer together with the deflection amount data when scanning the mask to the digital arithmetic circuit 106, and the digital arithmetic circuit 106 scans the mask based on the deflection amount data. A digital signal is output to the main DAC / AMP 108, and the transfer magnification in the x direction and the y direction is changed in proportion to the expansion ratio in the x direction and the y direction of the wafer based on the correction data. Is output to the sub DAC / AMP 110.

  The main DAC / AMP 108 converts the input digital signal into an analog signal, amplifies it, and outputs it to the main deflectors 22 and 24 shown in FIG. As a result, the electron beam 15 is deflected so as to scan the entire surface of the mask 30 as shown in FIG. 18 while maintaining a state parallel to the optical axis.

  The sub DAC / AMP 110 converts the input digital signal into an analog signal, amplifies it, and outputs it to the sub deflectors 26 and 28 shown in FIG. Thereby, the incident angle of the electron beam 15 on the mask 32 is controlled as shown in FIG.

As shown in FIG. 11, when the incident angle of the electron beam 15 on the mask 32 is α and the distance between the mask 32 and the wafer 44 is G, the shift amount δ of the transfer position of the mask pattern due to the incident angle α is formula,
[Equation 5]
δ = G ・ tan α
It is represented by In FIG. 11, the mask pattern is transferred to a position shifted from the normal position by the shift amount δ.

  Therefore, the transfer magnification can be changed by changing the incident angle α according to the scanning position of the electron beam. The incident angle α is set such that the incident angle α is 0 at the mask center, and the incident angle α is increased as the distance from the mask center increases.

  FIG. 12 is a flowchart showing the operation procedure of the electron beam proximity exposure method according to the present invention.

  As shown in the figure, a mask is first loaded on the electron beam proximity exposure apparatus (step S10), and then the wafer is positioned on the electrostatic chuck 60 on the θXY stage 70, and then attracted and fixed by the electrostatic chuck 60. Thus, the wafer is loaded (step SS12). Subsequently, the wafer is brought into conduction with conduction pins or the like so that electrons are not charged on the wafer (step S14).

  Next, the height is detected by the z sensor for detecting the height of the wafer, the wafer height is adjusted (step S16), and then the wafer is roughly aligned (course alignment) (step S18). .

  Subsequently, as described with reference to FIGS. 3 and 9, the expansion / contraction ratios εx and εY in the x and y directions of the wafer are measured (MAG measurement (global)) (step S30), and the measured expansion / contraction ratios εx and εY are measured. Is output to the correction arithmetic circuit 106A. Thereafter, the wafer is moved to the transfer position (step S20).

Next, the gap (GAP) between the mask and the wafer is adjusted (step S22). As shown in FIG. 7A, the gap G between the mask and the wafer is a photographed image of a line segment QR between the intersection point Q of the imaging surface of the microscope imaging apparatus and the mask mark MMX and the intersection point R of the wafer mark Mwx. From this line segment QR and the incident angle α of the photographic optical axis,
[Equation 6]
G = QR ・ sin α
Can be obtained. Details are disclosed in JP-A No. 2000-356511. The method for measuring the gap G is not limited to this embodiment.

  The interval G is adjusted so that the interval G measured as described above becomes a predetermined value (for example, 50 μm). The value of the interval G (interval value) is added to the correction arithmetic circuit 106A. The correction arithmetic circuit 106A corresponds to a circuit that performs deflection control of the sub deflectors 26 and 28 in the digital arithmetic circuit 106 shown in FIG.

  Thereafter, the mask and the chip on the wafer are accurately positioned (fine alignment) using the three microscope imaging devices AX1, AY1, and AX2 (step S24), and then the mask pattern is transferred to the wafer by the electron beam (step S24). S26).

  During this transfer, the correction arithmetic circuit 106A changes the transfer magnification based on the expansion / contraction ratios εx and εY of the wafer and controls (incline correction) the incident angle of the electron beam to the mask pattern so as to correct the mask distortion. It should be noted that data indicating the mask distortion measured in advance in step S32 is input to the correction arithmetic circuit 106A, and the correction arithmetic circuit 106A receives the mask distortion as shown in FIG. 13A, for example. The tilt correction of the electron beam is performed so that the mask pattern without the mask distortion as shown in FIG. 13B is transferred.

  When the transfer of the mask pattern to the wafer is completed, the wafer is unloaded (step S28).

[Second Embodiment]
FIG. 14 is an enlarged top view of the transfer portion of the second embodiment of the electron beam proximity exposure apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the part which is common in 1st Embodiment shown in FIG. 3, and the detailed description is abbreviate | omitted.

  As shown in FIG. 14, this electron beam proximity exposure apparatus is provided with four microscope imaging devices AX1, AY1, AX2, and AY2. Further, on the wafer 44 ', chips are formed with four sets of wafer marks MWX1, MWX2, MWY1, MWY2 (see FIG. 15) for positioning each chip of the wafer 44' and measuring the expansion / contraction rate of each chip. Provided outside the area.

  On the other hand, a mask pattern is formed in the area indicated by the broken line on the mask 32 '. There are provided four mask marks MMX1, MMX2, MMY1, MMY2 for detecting the deviation in the x direction, the y direction, and the deviation in the rotation direction of the xy plane, and the expansion / contraction rate in the x direction and the y direction of the chip. .

  Next, a method for measuring the expansion / contraction rate of each chip of the wafer in the x direction and the y direction will be described.

  When measuring the expansion / contraction ratio of the chip, the chip to be measured and the mask 32 'are positioned. When measuring the expansion / contraction ratio of the chip in the y direction, the three microscope imaging devices AX1, AY1, AX2 are positioned. The θXY stage 70 is moved in the x direction and the y direction so that the amount of positional deviation detected at the same time becomes zero, and the θXY stage 70 is rotated in the xy plane. In this embodiment, a positioning mark is formed to match the center of the chip with the center of the mask.

Then, a positional deviation amount Δy detected by the remaining microscope imaging device AY2 is obtained. This positional deviation amount Δy is expressed by the following equation when the distances between the two wafer marks MWY2 and the mask mark MMY2 are y1 and y2 as shown in FIG.
[Equation 7]
Δy = (y1−y2) / 2
It can be expressed as By dividing the positional deviation amount Δy thus determined by the reference length in the y direction from the center of the chip to the center of the two wafer marks MWY2, the expansion / contraction ratio of the chip in the y direction can be obtained. .

Similarly, when measuring the expansion / contraction ratio of the chip in the x direction, the θXY stage 70 is moved in the x direction so that the amount of displacement detected by the three microscope imaging devices AX1, AY1, and AY2 becomes zero simultaneously. While moving in the y direction, the θXY stage 70 is rotated in the xy plane, and a positional deviation amount Δx detected by the remaining microscope imaging device AX2 is obtained. This positional deviation amount Δx is expressed by the following equation when the distances between the two wafer marks MWX2 and the mask mark MMX2 are x1 and x2 as shown in FIG.
[Equation 8]
Δx = (x1 -x2) / 2
It can be expressed as By dividing the positional deviation amount Δx thus obtained by the reference length in the x direction from the center of the chip to the center of the two wafer marks MWX2, the expansion / contraction ratio of the chip in the x direction can be obtained. .

  FIG. 16 is a flowchart showing the operation procedure of the electron beam proximity exposure method according to the present invention. In addition, the same code | symbol is attached | subjected to the part which is common in FIG. 12, and the detailed description is abbreviate | omitted.

  As apparent from the flowchart shown in FIG. 16, in the second embodiment, instead of step 30 for measuring the expansion / contraction ratio of the entire wafer (global) shown in FIG. 12, as described in FIG. The difference is that it has a step 40 of measuring the expansion / contraction rate for each chip (MAG measurement (chip)). The positioning marks formed on the wafer or mask are not limited to this embodiment.

The top view of the transfer part of the electron beam proximity exposure apparatus which concerns on this invention Side view of transfer portion of electron beam proximity exposure apparatus according to the present invention 1 is an enlarged top view of the transfer portion of the electron beam proximity exposure apparatus shown in FIG. 3 is an enlarged view of the main part of FIG. Sectional view along line 5-5 in FIG. Schematic configuration diagram of a microscope imaging apparatus applied to the present invention The figure used in order to explain the method of detecting the amount of displacement of a mask mark and a wafer mark with a microscope imaging device The figure used in order to explain the method of detecting the amount of displacement of a mask mark and a wafer mark with a microscope imaging device The figure used in order to explain other embodiments of the measuring method of the expansion-contraction rate of a wafer The block diagram which shows embodiment of the control part of the electron beam proximity exposure apparatus which concerns on this invention The figure which shows a mode that the transfer position of an electron beam shifts by a sub deflector. The flowchart which shows the operation | movement procedure of the electron beam proximity exposure method which concerns on this invention. Diagram used to explain correction of mask distortion The top view which expanded the transfer part of 2nd Embodiment of the electron beam proximity exposure apparatus which concerns on this invention Diagram used to explain how to calculate the expansion / contraction rate for each chip The flowchart which shows the operation | movement procedure of 2nd Embodiment of the electron beam proximity exposure method. Basic configuration diagram of an electron beam proximity exposure apparatus to which the present invention is applied Diagram used to explain scanning of mask by electron beam 1 is an overall configuration diagram of an electron beam proximity exposure apparatus to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 15 ... Electron beam 22, 24 ... Main deflector, 26, 28 ... Sub deflector, 32, 32 '... Mask, 44, 44' ... Wafer, 60 ... Electrostatic chuck, 70 ... θXY stage, 90 ... Microscope objective Lens, 91 ... Cover glass, 91A ... Conductive thin film, 92 ... Conductive holding member, 93 ... White light source, 97 ... Imaging unit, 100 ... Central processing unit (CPU), 102 ... Signal processing circuit, 104 ... Stage Driving circuit 106 ... Digital arithmetic circuit 106A ... Correction arithmetic circuit AX1, AY1, AX2, AY2 ... Microscope imaging device, MWX, MWY, MWX1, MWX2, MWY1, MWY2 ... Wafer mark, MMX, MMY, MMX1, MMX2, MMY1, MMY2 ... Mask mark, LX, LY ... Laser interferometer

Claims (3)

In an electron beam proximity exposure apparatus that transfers a mask pattern formed on the mask to a resist layer on the wafer by placing the mask close to the wafer and scanning the mask with an electron beam.
Imaging means for simultaneously imaging a mask mark for alignment provided on the mask and a wafer mark for alignment provided on the wafer;
Detecting means for detecting a positional deviation between the mask mark and the wafer mark based on an image signal output from the imaging means;
Means for relatively aligning the mask and the wafer so that the displacement is zero based on the detection output of the detection means;
With
An electron beam proximity exposure apparatus characterized in that a conductive thin film is deposited on a surface of the optical member of the imaging means, and the conductive thin film is grounded.   3. The electron beam proximity exposure apparatus according to claim 2, wherein the conductive thin film is a tin oxide film or an indium tin oxide film. In an electron beam proximity exposure apparatus that transfers a mask pattern formed on the mask to a resist layer on the wafer by placing the mask close to the wafer and scanning the mask with an electron beam.
Imaging means for simultaneously imaging a mask mark for alignment provided on the mask and a wafer mark for alignment provided on the wafer;
Detecting means for detecting a positional deviation between the mask mark and the wafer mark based on an image signal output from the imaging means;
Means for relatively aligning the mask and the wafer so that the displacement is zero based on the detection output of the detection means,
The electron beam proximity exposure apparatus, wherein the image pickup means has a shutter mechanism that shields electrons or secondary electrons scattered during transfer by the electron beam so as not to charge the optical member of the image pickup means.

Images