JPH11186144A - Charged particle beam exposure system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce generation of troubles in a signal transmission line to an aperture of a BAA, by arranging a resistor between a signal transmission line from a driver to an electrode of the BAA(blanking aperture array) and a power source line of DC level like ground. SOLUTION: A signal transmission line is installed from a driver 65 of a blanking aperture array(BAA) driving circuit arranged on a substrate 63 to a blanking electrode via a cable 75, a wiring 91 of a connection substrate 62, a wiring 92 of a plurality of connectors and a probe card 60, a probe 61, an electrode pad of a BAA substrate 30, and wiring of the BAA substrate 30. On the substrate 63, a resistor 83 is connected between the signal transmission line and ground, in the vicinity of the connectors. On the connection substrate 62, a resistor 84 is connected between the signal transmission line and the ground, in the vicinity of the connectors. In the probe card 60, a resistor 85 is connected between the signal transmission line and the ground, in the vicinity of the probe. As a result, a trouble point can be easily detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a charged particle beam exposure apparatus, and more particularly to a blanking aperture array (B).
AA: A charged particle beam exposure apparatus using a blanking aperture array (AA).

[0002]

2. Description of the Related Art In recent years, semiconductor technology has been increasingly developed in recent years, and the degree of integration and functions of semiconductor integrated circuits (ICs) have been improved and played a role as a core technology of technological progress over a wide range of industries such as computer, communication, and machine control. Expected. ICs have achieved four times higher integration in two to three years. For example, a dynamic random access memory (DRAM: Dy:
In the case of a dynamic random access memory, its storage capacity has increased to 4M, 16M, 64M, 256M, and 1G. Such high integration of LSI largely depends on the progress of fine processing technology in semiconductor manufacturing technology.

At present, the limit of the fine processing technology is defined by the pattern exposure technology. As a technique for exposing a pattern, an optical exposure apparatus called a stepper is currently used. In an optical exposure apparatus, the minimum width of a pattern that can be formed due to the diffraction phenomenon is defined by the wavelength of an exposure light source. At present, a light source that emits ultraviolet light is used, but it is becoming more difficult to use light with a shorter wavelength, and in order to perform finer processing, a new exposure method other than an optical exposure device is used. Is being considered.

It is known that charged particle beam exposure has a very short wavelength, so that fine processing of 0.05 μm or less can be realized with an alignment accuracy of 0.02 μm or less. However, conventionally, this charged particle beam exposure
It has been considered that the throughput is lower than that of the stepper, so that it cannot be used for mass production of LSI. A problem of the throughput in the charged particle beam exposure is, for example, a discussion on a single-stroke electron beam exposure in which exposure is performed by continuously scanning one particle beam (electron beam).
It is not the result of elucidating the cause by focusing on the physical / technical bottleneck to increase the throughput and seriously examining it. That is, the fact that the charged particle beam exposure has a low throughput and cannot be used for mass production of LSIs is merely determined in view of the productivity of currently commercially available devices.

On the other hand, in recent years, by applying block exposure or multi-beam exposure using a blanking aperture array (BAA), for example, 1 cm
A charged particle beam exposure apparatus capable of achieving a throughput of about ² / sec has been expected. Especially,
The multi-beam exposure using BAA is slightly inferior to block exposure in terms of accuracy, but has the advantage of being able to perform high-throughput exposure irrespective of the shape and density of the pattern. The present invention relates to a multi-beam type charged particle beam exposure apparatus using the BAA. In addition,
In the following description, a multi-beam type charged particle beam exposure apparatus using a BAA may be simply referred to as a BAA exposure apparatus.

FIG. 1 is a block diagram schematically showing an example of the above BAA exposure apparatus, and shows an electron beam exposure apparatus using an electron beam. As shown in FIG. 1, a semiconductor wafer 10 as an exposure target (sample) is
The moving stage 12 is mounted on the moving stage 12.
Is controlled by the stage control circuit 14. Here, the position of the moving stage 12 is detected by the laser interferometer 16 and fed back to the stage control circuit 14 to control the movement of the stage 12. Further, a resist film is applied on the semiconductor wafer 10, and the resist film is irradiated with the electron beam EB2 passing through the circular opening of the aperture plate 18, so that the electron beam exposure is performed. It has become.

The electron beam E on the semiconductor wafer 10
The scanning of B2 is performed by moving stage 12 and moving stage 1
The operation is performed by an electromagnetic main deflector (Main Deflector) 20 and an electrostatic sub deflector (Sub Deflector) 22 arranged above the two. The order of the range that can be scanned with the required accuracy is as follows:
Moving stage 12, main deflector 20, and sub deflector 2
2, but the order of higher scanning speed is reversed.

The main control circuit 24 includes a stage control circuit 14
, A periodic sawtooth signal is supplied to the amplifier circuit 26, the stage detection position Y is received from the laser interferometer 16, and a signal proportional to the sub deflection distance is supplied to the amplifier circuit 28. The drive signals amplified by the current amplification and the voltage amplification by the amplifier circuits 26 and 28, respectively, are supplied to the main deflector 2
0 and to the sub deflector 22.

FIGS. 2 and 3 are diagrams for explaining the principle of the BAA exposure method. Referring to FIG.
The exposure method will be briefly described. The charged particle (electron) beam emitted from the electron gun 1 passes through a group of apertures of the blacking aperture array 30 and the electromagnetic main deflector 20.
The sample 10 is scanned in the direction of arrow F by an electrostatic sub deflector (not shown). Q1 to Q3 are
2 shows an electron beam flux moving on a sample 10.

On the other hand, the blacking aperture array 3
At 0, a plurality of apertures 33 are two-dimensionally arranged, and the electron beam is split into a plurality of beams by passing through the blacking aperture array 30.
Depending on whether or not a voltage is applied between the electrodes provided on both sides of each opening 33, the on / off control of the electron beam passing through each opening can be performed. Specifically, when a voltage is applied between the electrodes, the electron beam that has passed through the aperture is deflected and the trajectory of the electron beam changes, but when no voltage is applied between the electrodes, the electron beam has passed through the aperture. The electron beam goes on. Here, if the deflected electron beam whose trajectory has changed is shielded by the aperture, an electron beam flux that has passed through the opening where no voltage is applied between the electrodes can be obtained. In this way, the on / off control of the electron beam passing through each hole can be performed.

Now, a pattern as shown in FIG. 2 (2) is formed by three columns (R1, R2, R3) as shown in FIG.
Consider a case in which exposure is performed using nine blacking aperture arrays 30 in three rows (L1, L2, L3).
As shown in (1) of FIG. 3, first, only the opening in the middle column R2 of the leftmost row L1 of the blacking aperture array 30 is turned on, and all other openings are set in the off state. On the other hand, in this state, the deflecting means 20 and 22 deflect and irradiate the electron beam to the position of Q1 on the sample 10. Therefore, the electron beam is applied only to the position P1 of the sample 10.

Next, as shown in FIG. 3 (2), the exposure pattern moves rightward by one row, and the middle row L 2 in the middle row R 2 in the blacking aperture array 30.
The aperture of No. 2 is turned on, the apertures of columns R1 and R3 of row L1 are turned on, and the other apertures are turned off. On the other hand, in this state, the deflecting means 20 and 22 deflect and irradiate the electron beam to the position of Q2 on the sample 10. for that reason,
The electron beam that has passed through the apertures (L2, R2) is again irradiated on the position P1 of the sample 10 exposed in the state shown in FIG. Further, the apertures (L1, R1) and (L1, R3)
The two electron beams that have passed through are newly irradiated at positions P2 and P3 on the sample 10.

Next, as shown in FIG. 3 (3),
The exposure pattern is further moved rightward by one row, and the opening in the middle column R2 of the rightmost row L3 in the blackening aperture array 30 is turned on, and the middle row L
The apertures in columns R1 and R3 of row 2 are turned on, and the leftmost row L
The apertures of the third row R1, R2, R3 are turned on, and the other apertures are turned off. On the other hand, the deflection means 20 and 22
In this state, the electron beam is deflected to the position of Q3 on the sample 10. Therefore, the electron beam that has passed through the apertures (L3, R2) is again irradiated on the position P1 of the sample 10 exposed in the states (1) and (2) of FIG. Furthermore, the two electron beams that have passed through the apertures (L2, R1) and (L2, R3) are again irradiated to positions P2 and P3 on the sample 10, and the apertures (L1, R1), (L1, R2) ), (L1, R
The three electron beams that have passed through 3) are newly irradiated at positions P4, P5, and P6 on the sample 10.

As described above, in the BAA exposure method, the exposure pattern and the deflection position in the blackening aperture array 30 are moved in synchronization with each other, so that a single point on the sample is exposed a plurality of times with different apertures.
In the BAA exposure method, the drawing speed can be increased by the number of columns compared to the case of single-stroke writing. Similarly, the drawing speed can be increased by the number of columns with a single-row blanking aperture array. However, in the case of a single-line drawing or a single-row blacking aperture array, the full aperture changes from the off state to the on state. However, when such a change occurs, a defocus phenomenon occurs in which the focus position of the electron beam shifts. When such a phenomenon occurs, the quality of the exposure pattern deteriorates, so it is necessary to correct the focus position, and although not shown in FIG.
Although the focus position can be adjusted by providing a refocus coil, delays in correction are unavoidable due to rapid changes, which limits the scanning speed and hinders the improvement of the drawing speed.

On the other hand, in the BAA exposure method, the ratio of the number of openings that change from the off state to the on state to the total number of openings is reduced to approximately one-half of the number of rows. It becomes smaller and the scanning speed can be improved. The area exposed by one aperture in the BAA exposure method is 0.128 μm square. For example, 3μm □
When compared with the variable rectangular method, the throughput is reduced in the case of the entire solid fill pattern unless the BAA exposure method is composed of about 550 or more beams. Therefore, in order to realize a practically high drawing speed, the number of apertures needs to be at least 550 or more, and desirably 1000 or more.

FIG. 4 is a diagram showing an example of a blacking aperture array having 512 holes, in which 64 columns perpendicular to scanning and 8 rows are arranged in the scanning direction. In the figure, 30A1, 30A2,...
The opening group of the row is shown. Openings that are arranged in a staggered grid with a shift of the length of one side of the opening are considered to be shifted in the X direction, and here, the shifted two rows are regarded as one row. Opening 3
3 is formed on a thin substrate 31, and for each opening 33,
A pair of common electrodes 34 and a blanking electrode 35 are formed on the substrate 31, respectively, so as to control the deflection of the electron beam passing through each opening 33. The pitch p of the opening 33 in the X direction is, for example, three times the length a of one side of the opening 33 in order to secure a region for the electrode and the wiring. Also, the aperture groups 30A and 30C having two rows as one group are shifted by half a side of the aperture in the Y direction with respect to 30B and 30D, and the pitch in the X direction between the groups 30B and 30C. Is 3.5 times the length a of one side of the opening 33.
As a result, the beams of the four groups are exposed so as to overlap each other by half, so that the dimension adjustment of the pattern edge portion and the proximity effect correction can be performed with a smaller value than the dot size. A detailed description of this will be omitted.

As described above, the order in which the range that can be scanned with the required accuracy is large is the moving stage 12, the main deflector 20, and the sub deflector 22, but the order in which the scanning speed is high is reversed. . In order to perform scanning efficiently using such properties, scanning as shown in FIG. 5 is performed. FIG. 5 is FIG.
FIG. 4 is a diagram for explaining beam scanning in the charged particle beam exposure apparatus of FIG.

The stage 12 continuously moves in the direction of D2 as shown in FIG. When the subfield A2 to be exposed comes within the deflectable range (set value) of the main deflector (main differential) 20, the main deflector jumps vectorwise to the center value. (Wanders in the scanning direction as shown in the figure.) In the subfield, there are a plurality of cell stripes A1 for performing raster scan, which are sub-deflectors (sub-defs) 2.
2 is scanned.

Although the time for exposing one subfield is very short, the amount of movement of the stage during that time is fed back to the sub differential deflector 22 in real time. When exposing the next frame, the stage moving direction is reversed, and the meandering direction of the main differential is also reversed. In FIG.
The chip regions C1 to C11 on the semiconductor wafer 10 are exposed to the same pattern. The frame A4 in one chip, which is indicated by oblique lines, is sequentially exposed in the direction of the arrow,
The movement of the moving stage 12 is controlled, and the exposure dot data of the frame A4 is repeatedly used. The main control circuit 24 in FIG. 1 generates an on / off signal indicating whether or not to apply a voltage to the electrode of each blacking aperture according to the movement of the exposure pattern, and outputs each electrode via a driver of the BAA drive circuit 40. Is applied with a voltage signal.

As described above, a pair of common electrodes 34 and blanking electrodes 35 are formed for each of the openings 33. For example, all of the common electrodes 34 are connected to a DC-level power line such as a ground, A signal for turning on / off the electron beam passing through the opening is applied to the ranking electrode 35.
FIG. 6 is a diagram showing an example of wiring in BAA.
FIG. 2 is a diagram viewed from the surface of A. As shown, the wiring to each blanking electrode 35 is provided on the back surface, and the wiring to the common electrode 34 is provided on the front surface. In the BAA sequence of FIG.
A DC level power supply line 51 is provided in the center between the groups of 0B and 30C, and a wiring 5 from the power supply line 51 to each common electrode 34 is provided.
2 are provided. The wiring to each blanking electrode 35 is provided from one peripheral side for the group of 30A and 30B, and from the other peripheral side for the group of 30C and 30D.
It is provided to face the center.

BAA is formed on a thin substrate (membrane) by a semiconductor process. As shown in FIG. 7, an electrode pad 54 is provided on the substrate, and each blanking electrode 3 is provided.
5 and the wiring to the DC level power supply line 51 are connected to each electrode pad. The wiring on the back surface is connected to the electrode pads on the front surface by through holes or the like. As described above, the aperture 33
Are more than 500, and the electrode pads are DC
It is necessary to add the number of electrode pads connected to the power supply line 51 of the level.

FIG. 8 is a diagram showing an example of a transmission line for supplying a power supply and a drive signal for each hole to the electrode pad 54 of the BAA substrate. The BAA substrate is fixed and held in the case 3 of the electron beam exposure apparatus, and is arranged so that the electron beam from the electron gun 1 is shaped by the shaper 2 and is incident on the blanking aperture array (BAA) of the BAA substrate. Have been. The substrate indicated by reference numeral 60 is a probe card provided with a probe 61 which is in contact with the electrode pad of the BAA substrate.
1 are provided. Since the inside of the electron beam exposure apparatus is evacuated, the case 3 is provided with a connection board for wiring to the outside while maintaining the inside vacuum. This connection board is divided into four parts 62a to 62d, the inner connector of the connection boards 62a to 62d is connected to the connector of the probe card 60, and the outer connector is connected to the boards 63a and 63b on which the BAA drive circuit 40 is mounted. Connected. A board 63a on which the BAA drive circuit 40 is mounted,
63 b is connected to the substrate 64 on which the main control circuit 24 is mounted, and the BAA drive circuit 40 outputs a BAA drive signal according to a signal supplied from the main control circuit 24. Since the BAA drive circuit 40 is a driver circuit and consumes considerable power, it is necessary to provide cooling means and the like. In addition, since electromagnetic waves are generated due to the consumption of large electric power, if they are arranged near the electron beam exposure apparatus, the exposure apparatus will be adversely affected by noise. In consideration of cooling means and noise, the substrates 63a and 63b on which the BAA drive circuit 40 is mounted need to be provided separately from the electron beam exposure apparatus.

FIG. 9 shows a circuit board 6 on which the main control circuit 24 is mounted.
FIG. 4 is a diagram showing an outline of a signal transmission path from No. 4 to a BAA board 30 in an easy-to-understand manner. As shown, the BAA substrate 30
The probe card 60 and the probe card 60 are connected by a probe, and the probe card 60 and the connection board 62 (62a to 62d are shown collectively; the same applies to the board 63). The connector 71 of the connection board 62 and the connector 73 of the connection board 62 are connected by pins 72. Between the connection board 62 and the board 63 on which the BAA drive circuit 40 is mounted, the connector 74 of the connection board 62 and the connector 76 of the board 63 are connected by a cable 75. The connector 77 of the board 63 and the connector 79 of the board 64 are connected by a cable 78 between the board 63 and the board 64 on which the main control circuit 24 is mounted. The signal sent from the main control circuit 24 to the BAA driving circuit 40 is a serial signal,
Since the signal is converted into a parallel signal by a shift register or the like provided at 0, the number of signal lines between the substrates 63 and 64 may be relatively small.
Since the signals applied to the blanking electrodes 35 are output in parallel, at least the number of signal transmission paths from the substrate 63 to the BAA substrate is required, and a very large number of signal transmission paths such as 500 or more are required. It is necessary to provide.

[0024]

The BAA substrate 30 is irradiated with an electron beam from the electron gun 1. The electron beam is, as it were, a flow of charges of high voltage (voltage of the electron gun). Thereby, the signal transmission path to each blanking electrode is charged to a high voltage. The current generated by this electron beam irradiation is as small as several μA, but the voltage sometimes becomes as high as several tens of KV. Therefore, when the driver of the BAA drive circuit 40 applies a voltage to the signal transmission line, the voltage is maintained. However, when the driver is off or the signal transmission line is open halfway and the driver connects. If not, between the signal transmission lines that are close to each other due to the high voltage of the signal transmission line or between the signal transmission line and the DC level power line connected to the common electrode,
Over time, charge migration (migration) may occur, and eventually dielectric breakdown may occur. As shown in FIG. 9, at present, there is a circuit board in the signal transmission path from the driver to the blanking electrode, and the signal transmission path is closest to the circuit board. This has been a factor in increasing costs.

Further, when the signal transmission path becomes high voltage by irradiating the electron beam as described above, a high voltage is applied to the driver, and there is a problem that the driver is destroyed. The same applies to a case where the signal transmission path is opened again due to a poor connection of a connector or the like and a contact is made again. As described above, the BA that arranges the BAA in the path of the charged particle (electron) beam
In the A charged particle beam exposure apparatus, the charged particle beam BA
By irradiating A, a high voltage is applied to the signal transmission path to the opening of the BAA, and there is a problem that the signal transmission path and the driver are destroyed.

In the electron beam exposure apparatus of the BAA system, it is absolutely necessary that the individual apertures operate accurately in order to obtain an accurate exposure pattern. However, the BAA driving circuit 4
Connection board 6 from the board 63 on which the
2 and the probe card 60 are provided, and the boards are connected by a connector, a cable, or the like. Therefore, a problem such as an open signal transmission path easily occurs, and the failure rate is considerably high. Further, as described above, B
Since the number of signal transmission paths to the AA substrate is equal to the number of holes in the BAA, the number is very large, and the failure probability is multiplied by the number of channels. Therefore, in order to improve the operation rate of the equipment, it is necessary to regularly check whether such a failure has occurred and, if a failure has occurred, find out which part of the failure has occurred and repair it. is important.

As a method of finding such a fault,
Although it is conceivable to directly detect the voltage signal at the electrodes or electrode pads of the BAA substrate, it is very difficult to directly detect the voltage signal by directly contacting the electrodes etc. since the BAA substrate exists inside the evacuated device. It was difficult. In particular, during the exposure operation, it is not possible to contact the electrodes of the BAA substrate. Therefore, in order to detect the occurrence of a failure by this method, it is necessary to temporarily stop the apparatus, and the working efficiency is very poor. Further, when the measurement is performed in direct contact with the electrode, the influence of the direct contact with the electrode is included, which is different from the state at the time of exposure, and accurate measurement cannot be performed.

As a method of detecting the voltage of the electrode without directly contacting the electrode, there is a method of using an electron beam probe. However, it is difficult to directly detect the voltage of the electrode with the electron beam probe because the BAA is fine. This method also requires that the apparatus be temporarily stopped. Therefore, conventionally, a probe having an electrode is arranged in place of the sample, and the electron beam is selectively turned on one by one to detect a current flowing through the probe,
A failed signal transmission line was detected by detecting beams having different current amounts. However, in this method, it is difficult to specify a faulty transmission line with sufficient accuracy because the current amount of one beam is small.

For the reasons described above, the actual fault location was found by checking the continuity and the like by actually contacting each point of the signal transmission line with a measuring instrument. However, since the number of signal transmission lines is large,
It was a very complicated task. Further, the signal transmission path to the opening of the BAA is long, and the number of the signal transmission paths is large, so that a failure easily occurs. However, it is difficult to find such a failure and to find the location of the failure. It was difficult to detect.

The present invention relates to a BAA exposure apparatus,
It is an object of the present invention to reduce the occurrence of a failure in a signal transmission path to the opening of A, and to easily detect the occurrence of a failure and a failure location.

[0031]

In order to solve the above problem, a BAA charged particle beam exposure apparatus according to the present invention comprises a signal transmission path from a driver to an electrode of a BAA and a DC level power line such as a ground. A resistor is placed between them. By arranging such a resistor, the charge of the signal transmission line generated by the irradiation of the BAA with the charged particle beam can be released to the DC level power supply line, so that the signal transmission line does not have a high voltage.

That is, the charged particle beam exposure apparatus of the present invention is a charged particle beam exposure apparatus that forms a predetermined exposure pattern on a sample using a charged particle beam, and generates a charged particle beam. Means and a set of apertures arranged in the optical path of the charged particle beam from the charged particle beam generation means, for shaping the charged particle beam, and electrodes provided around the aperture are two-dimensionally arranged, A blackening aperture array for shaping a charged particle beam by applying or not applying a voltage signal to the electrodes; a blacking aperture array drive circuit for outputting a voltage signal to be applied to the electrodes of each aperture according to an exposure pattern; and a blackening aperture A black jack comprising a plurality of channels for applying the voltage signal output from the array drive circuit to the electrodes of each aperture. Characterized in that it comprises a resistor provided between the power supply line of the Guapacha signal transmission path and a predetermined DC level.

The resistance value of the resistor is determined according to the potential generated in the signal transmission line by the charged particle beam irradiated on the electrode and a part of the signal transmission line, and the withstand voltage with respect to the periphery of the signal transmission line. Furthermore, if the resistance is opened (opened) or short-circuited (short-circuited) at a voltage lower than the potential at which insulation breakdown occurs, depending on the dielectric strength voltage with the periphery of the signal transmission path,
Operates as a protection circuit.

When a driver applies a voltage to the signal transmission line, a current flows through the power supply line at the DC level through the resistor. A current monitor for detecting the current is provided.
If the area up to the point of the signal transmission path to which the resistor is connected is open, no DC current flows. If open before the point, a DC current flows. Can be detected by detecting the DC current with a current monitor by driving the DC.

In particular, if a plurality of resistors are connected between a DC level power supply line and a plurality of locations on the signal transmission line, the DC current detected by the current monitor differs depending on the location of the open circuit. Can be identified more precisely. In this case, if the resistor is set to be open at a potential lower than the potential at which the signal transmission path causes dielectric breakdown as described above, it becomes impossible to determine whether the signal transmission path is open or the resistance is open. Therefore, the current values are different when the resistors are open due to the different resistance values of the plurality of resistors, and the failure status can be determined from the difference between the current values. Further, when the signal transmission path includes a plurality of substrates and connection means between the substrates, it is desirable that the resistor be provided for each of the plurality of substrates. This is because there are many defects caused by connectors.

Even if the current monitor is provided for each signal transmission line, it is provided for each of a plurality of signal transmission lines, and the signal transmission line is selectively connected to the current monitor by a relay provided for each signal transmission line. It may be. Further, a fault detection that detects a current value detected by each of the current monitors while scanning temporally, and outputs a signal indicating a fault occurrence and a channel in which the fault has occurred when the detected current value differs from a predetermined value. It is desirable to provide a circuit.

[0037]

FIG. 10 is a block diagram showing the overall configuration of a charged particle beam (electron beam) exposure system apparatus according to an embodiment of the present invention. As shown, this device
A data operation computer 49 for operating the design data,
Exposure control computer 43 for controlling the exposure operation of the apparatus
And an autoloader (AL) control computer 6 for controlling the supply and discharge of semiconductor wafers, and these computers are mutually connected by a local area network (LAN) 45. The data operation computer 49 is connected to the bitmap creation unit 48 and the data transfer control unit 46 by a bus, and the exposure control computer 43 is connected to the deflection control unit 25 and the BAAF / G control unit 41 by a bus.

The pattern data created from the design data is stored in a disk device (not shown), and the data operation computer 49 reads the pattern data stored in the disk device 47,
The data is read into the data expansion unit 8 and expanded into bit data. At the same time, from the generated bit data, refocusing data for correcting expansion and contraction of the focal position of the beam depending on the number of turning on the beam is also created.

The exposure control computer 43, the deflection control unit 25 and the BAAF / G control unit 41 realize a function corresponding to the main control circuit 24 in FIG. The developed bit data is stored in the dedicated bit base disk 47 via the data transfer control unit 46 for each cell stripe or a plurality of cell stripes. These developing operations are performed before the exposure operation. Therefore, the exposure speed is not affected by the development of the bit data, and the data developed once can be used again when exposing the same data. Bit data is stored in the dedicated bit base disk 47
Is held. Further, since the data is retained, it is possible to verify later when a failure occurs at the time of exposure.

The bit data held on the dedicated bit base disk 47 is stored in the BAAF before the exposure operation is started.
The data is transferred to a shooting memory (high-through buffer) provided in the / G control unit 41. This shooting memory has a capacity to store data of about two 20 mm square chips. If the chip size to be exposed is smaller than 20 mm square, the shooting memory is divided into two parts to store data from one side and from the other side. Can be simultaneously output, so that the data of the chip to be exposed next can be transferred during the exposure of the previous chip. If the chip size is larger than 20 mm square, all the memory capacity is used for exposure of one chip.

The bit data output from the shooting memory is parallel-to-serial converted and supplied to the BAA driving circuit 40 while controlling the timing.
A voltage signal to be applied to the electrodes is generated by the driver of the A drive circuit 40 and applied to a signal transmission path to the BAA 30.
When a mark is detected for improving the accuracy of an exposure pattern, data for that is applied to a signal transmission path.

After the continuous movement of the stage is started, the deflection control unit 25 outputs a signal indicating the deflection position of the main differential and the sub differential to the analog control circuit 8, and the deflection position of the main differential and the sub differential is determined accordingly. The sub-definition scan is started. At the same time, the deflection control unit 25 generates a signal for starting the above-described cell stripe exposure, and in response to this signal, the BAAF / G control unit 41 sends bit data to the BAA drive circuit 40 to send the BAA for one cell stripe. ON / OFF control is performed.

The detailed operation of the above-mentioned parts is the same as that of the conventional one described with reference to FIG. 1, so that further description is omitted here. In the present embodiment, the signal transmission path from the BAA drive circuit 40 to the BAA board 30 is different from the conventional one, and a failure detection circuit 80 is provided to be attached to the BAA drive circuit 40.

FIG. 11 is a diagram showing a configuration of a signal transmission path from the BAA drive circuit 40 to the BAA board 30 in the present embodiment. As described above, this signal transmission path is
From the driver 65 of the BAA drive circuit 40 provided in the 3, the cable 75, the wiring 91 of the connection board 62, the connectors 73, 72, 71, the wiring 92 of the probe card 60, the probe 61, the electrode pad 54 of the BAA board 30, and B
The wiring reaches the blanking electrode via the wiring of the AA substrate 30. Such transmission paths are provided for the number of openings of the BAA, that is, 500 or more. In the board 63, the connector 76
, A resistor 83 is connected between the signal transmission line and the ground, and in the connection board 62, a resistor 84 is connected between the signal transmission line and the ground near the connector 73,
In the probe card 60, a resistor 85 is connected between the signal transmission line and the ground near the probe. The grounds of the substrates are connected to each other and to the ground of the device via a path not shown.

Therefore, as shown in FIG. 11, in the electron beam exposure apparatus of this embodiment, when the driver 65 does not apply a voltage, the electron beam is applied to the blanking electrode 35 of the BAA and the wiring portion to the blanking electrode 35. Then, a charge is applied to the signal transmission line to generate a voltage, but the voltage escapes to the ground by the resistors 83 to 85, so that migration occurs as in the conventional case, and the signal transmission line is broken down or the driver 65 breaks down. You will not do it.

In the substrate 63, each driver 6
A current monitor 82 for detecting the current flowing through the signal transmission path by the driver 65 is provided at the output portion of the control circuit 5. The board 63 is further provided with a failure detection circuit 80.
The failure detection circuit 80 has a monitor control circuit 81 that outputs a signal for sequentially activating each of the current monitors 82, and the current value detected by the current monitor that has been activated by the signal of the monitor control circuit 81 is a predetermined value. Check sequentially for values. Note that, since current is generated in the signal transmission line by the irradiation of the electron beam, it is desirable not to perform the irradiation of the electron beam when detecting the current value.

As shown in FIG. 11, when resistors 85, 84, and 83 are provided on the substrates 60, 62, and 63, respectively, the current Imon detected by the current monitor 82 is normal when the signal transmission path is not disconnected. And the output voltage of the driver 65 is V
Assuming that drv is Rrv and the resistance values of the resistors 83, 84 and 85 are R1, R2 and R3, respectively, Imon = Vdrv (R1 * R2 + R2 * R3 + R3 * R1) / (R1 * R2 * R3) (1) Becomes Therefore, if this current is detected, the signal transmission path is normal. When a current is detected in a state where the electron beam is irradiated, a current due to the electron beam is added to the above equation. The change of the current due to this is almost constant, and the current by the driver can be detected by subtracting the current by the electron beam from the detected current value, but considering the detection accuracy,
It is desirable not to irradiate the electron beam when detecting the current value.

Here, assuming that the signal transmission line is opened for some reason between the connection points of the resistors R1 and R2, the current value Imon detected by the current monitor is Imon = Vdrv / R1 (2) Assuming that an open state is established between the connection points of the resistors R2 and R3, the current value Imon becomes Imon = Vdrv * R1 * R2 / (R1 + R2) (3). If it is open up to 30 blanking electrodes 35,
The current value Imon is the same as the above equation (1).

Therefore, by accurately detecting the current value with the current monitor 82, an open portion can be estimated. Resistance values R1, R of resistors 83, 84, 85
2, R3 is determined in consideration of the driving ability of the driver 65, but there is no problem if it is several KΩ, for example. It is necessary to detect that a failure has occurred during the exposure operation,
As described above, if the irradiation of the electron beam is performed at the time of detecting the current value, the detection accuracy of the current value is reduced accordingly. Therefore, during the exposure operation, the failure detection circuit 80
Are sequentially operated, and the driver 6 of the corresponding channel is
The current value detected by each current monitor 82 is read in accordance with the turning on of 5 to detect whether there is a difference in the current value between the channels. If a different channel is found, a failure may have occurred.
A request to stop the exposure is issued to the exposure control computer 43, and after stopping the irradiation of the electron beam, the value of the current monitor 82 of the channel is read to detect an accurate current value. Find out where is. In this way, by comparing with the current values of the other channels, the effect of the electron beam irradiation is canceled,
The occurrence of a failure can be accurately detected.

As described above, by connecting a plurality of resistors and accurately detecting the current value, an open portion of the signal transmission path can be specified. May occur. Therefore, even if a high voltage is applied to the signal transmission line by making the withstand voltage of the resistor different, a certain resistor is easily broken, so that it can be used as a protection circuit or a faulty part can be easily specified. There is also a resistor that short-circuits (short-circuits) when a high voltage is applied, and such a resistor can be used as a protection circuit. However, when the resistor is short-circuited, the voltage output from the driver is not applied to the blanking electrode.

Further, since the current value changes in the same manner as when the resistor is opened, it is difficult to determine whether the signal path is open or the resistor is open. For example, when the resistor 85 is opened, the detected current value Imon becomes the same as the above equation (3). Therefore, it cannot be determined whether the circuit board 60 and 62 are open or the resistor 85 is open.

However, when the resistor 84 is opened, the current value Imon becomes Imon = Vdrv * R1 * R3 / (R1 + R3) (4), and when the resistor 83 is opened, The current value Imon is given by: Imon = Vdrv * R2 * R3 / (R2 + R3) (5) Therefore, by setting the resistance values R1, R2, and R3 to appropriate different values, the resistance 85 Except for determining whether the signal transmission path is open or between the substrates 60 and 62, it is possible to determine where the signal transmission path has been opened and which resistor has been opened.

In the configuration shown in FIG. 11, a current monitor 82 is provided for each signal transmission line, and the failure detection circuit 80 sequentially activates each current monitor 82 in response to a signal from the monitor control circuit 81 to change the current value of each channel. Are sequentially read, but in this configuration, it is necessary to provide the current monitor 82 for each channel. Therefore, as shown in FIG.
Is provided only in the failure detection circuit 80, a relay 87 is provided for connecting each signal transmission line to the current monitor 86, and the monitor control circuit 81 controls each relay 87 so as to be sequentially connected to the current monitor 86 and May be detected. In this case, the current monitor can be used in common. The signal transmission path may be divided into a plurality of groups, and each group may be provided with one current monitor.

In the above description of the embodiment, the resistance of the signal transmission line has been described as being sufficiently smaller than the resistance. However, when the resistance of the signal transmission line is so large that it cannot be ignored, What is necessary is just to add a resistance value according to the length of the transmission path.

[0055]

As described above, according to the blanking aperture array (BAA) type charged particle beam exposure apparatus of the present invention, the failure detection of the blanking electrode of the BAA can be performed at high speed for each control channel. The reliability of the multiple beams, which was a problem of the method, can be easily guaranteed. Furthermore, since the system for detecting a failure is closed in the control channel, measurement can be performed by itself and the configuration is simple. Therefore, a device with high accuracy, high throughput, and high reliability can be easily realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a charged particle beam exposure apparatus according to the present invention.

FIG. 2 is a diagram illustrating an exposure principle of a charged particle beam exposure apparatus of a blanking aperture array (BAA) type. (Part 1)

FIG. 3 is a diagram illustrating an exposure principle of a blanking aperture array (BAA) type charged particle beam exposure apparatus. (Part 2)

FIG. 4 is a diagram showing an example of a blanking aperture array.

5 is a diagram illustrating beam scanning in the charged particle beam exposure apparatus of FIG.

FIG. 6 is a diagram showing an example of wiring on a blanking aperture array substrate.

FIG. 7 is a diagram showing an example of wiring on a blanking aperture array substrate.

FIG. 8 is a perspective view showing a signal transmission path from a BAA drive circuit to a blanking electrode of the BAA.

FIG. 9 is a diagram illustrating a schematic configuration of a signal transmission path from a BAA driving circuit to a blanking electrode of the BAA.

FIG. 10 is a diagram illustrating an overall configuration of an electron beam exposure apparatus according to an embodiment of the present invention.

FIG. 11 is a diagram illustrating a schematic configuration of a signal transmission path from a BAA driving circuit to a blanking electrode of the BAA in the embodiment.

FIG. 12 is a diagram illustrating a configuration of a modification of a portion related to current detection and failure detection in a signal transmission path.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Semiconductor wafer 12 ... Moving stage 30 ... Blanking aperture array (BAA) 33 ... Opening 34 ... Common electrode 35 ... Blanking electrode 40 ... BAA drive circuit 60, 62, 63 ... Substrate 83, 84, 85 ... Resistance

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[Procedure amendment]

[Submission date] December 15, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

FIGS. 2 and 3 are diagrams for explaining the principle of the BAA exposure method. Referring to FIG.
The exposure method will be briefly described. The charged particles (electrons) beam emitted from the electron gun 1, an electromagnetic type main deflector through an aperture group bra down King aperture array 30 20
The sample 10 is scanned in the direction of arrow F by an electrostatic sub deflector (not shown). Q1 to Q3 are
2 shows an electron beam flux moving on a sample 10.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] On the other hand, bra down King aperture array 3
In 0, a plurality of apertures 33 are two-dimensionally arranged, the electron beam is divided into a plurality of beams by passing through the bra down King aperture array 30.
Depending on whether or not a voltage is applied between the electrodes provided on both sides of each opening 33, the on / off control of the electron beam passing through each opening can be performed. Specifically, when a voltage is applied between the electrodes, the electron beam that has passed through the aperture is deflected and the trajectory of the electron beam changes, but when no voltage is applied between the electrodes, the electron beam has passed through the aperture. The electron beam goes on. Here, if the deflected electron beam whose trajectory has changed is shielded by the aperture, an electron beam flux that has passed through the opening where no voltage is applied between the electrodes can be obtained. In this way, the on / off control of the electron beam passing through each hole can be performed.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

Now, a pattern as shown in FIG. 2 (2) is formed by three columns (R1, R2, R3) as shown in FIG.
Horizontal Consider the case of exposure using a nine bra down King aperture array 30 of three rows (L1, L2, L3).
As shown in (1) in FIG. 3, only opening of the bra down King aperture columns in the middle of the left end of the line L1 of the array 30 R2 is turned on, and sets all other apertures OFF state. On the other hand, in this state, the deflecting means 20 and 22 deflect and irradiate the electron beam to the position of Q1 on the sample 10. Therefore, the electron beam is applied only to the position P1 of the sample 10.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

[0012] Next, as shown in (2) in FIG. 3, the exposure pattern is moved in one line rightward, the middle column of row L2 of the middle in the bra down King aperture array 30 R
The aperture of No. 2 is turned on, the apertures of columns R1 and R3 of row L1 are turned on, and the other apertures are turned off. On the other hand, in this state, the deflecting means 20 and 22 deflect and irradiate the electron beam to the position of Q2 on the sample 10. for that reason,
The electron beam that has passed through the apertures (L2, R2) is again irradiated on the position P1 of the sample 10 exposed in the state shown in FIG. Further, the apertures (L1, R1) and (L1, R3)
The two electron beams that have passed through are newly irradiated at positions P2 and P3 on the sample 10.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

Next, as shown in FIG. 3 (3),
Exposure pattern is moved further in the one row rightward opening in the column R2 of the middle of the right edge of the row L3 in bra emissions Kin <br/> grayed aperture array 30 is turned on, the middle lines L
The apertures in columns R1 and R3 of row 2 are turned on, and the leftmost row L
The apertures of the third row R1, R2, R3 are turned on, and the other apertures are turned off. On the other hand, the deflection means 20 and 22
In this state, the electron beam is deflected to the position of Q3 on the sample 10. Therefore, the electron beam that has passed through the apertures (L3, R2) is again irradiated on the position P1 of the sample 10 exposed in the states (1) and (2) of FIG. Furthermore, the two electron beams that have passed through the apertures (L2, R1) and (L2, R3) are again irradiated to positions P2 and P3 on the sample 10, and the apertures (L1, R1), (L1, R2) ), (L1, R
The three electron beams that have passed through 3) are newly irradiated at positions P4, P5, and P6 on the sample 10.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

[0014] Thus, in the BAA exposure method, bra down <br/> by moving to synchronize the deflection position and the exposure pattern in King aperture array 30, a plurality of times by apertures different for one point on the sample Perform exposure.
In the BAA exposure method, the drawing speed can be increased by the number of columns compared to the case of single-stroke writing. Similarly, in one row blanking aperture array, can be quickly several minutes drawing speed train, if the one or one column bra down <br/> King aperture array to perform a single stroke, fully open holes are off Changes to the on state, and such a change causes a defocus phenomenon in which the focus position of the electron beam shifts. When such a phenomenon occurs, the quality of the exposure pattern deteriorates, so it is necessary to correct the focus position, and although not shown in FIG.
Although the focus position can be adjusted by providing a refocus coil, delays in correction are unavoidable due to rapid changes, which limits the scanning speed and hinders the improvement of the drawing speed.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

[0016] Figure 4 is a diagram showing an example of a bra down key <br/> ring aperture array having 512 apertures, vertical 64 rows in the scan, an example in which eight rows arranged in the scanning direction. In the figure, 30A1, 30A2,...
The opening group of the row is shown. Openings that are arranged in a staggered grid with a shift of the length of one side of the opening are considered to be shifted in the X direction, and here, the shifted two rows are regarded as one row. Opening 3
3 is formed on a thin substrate 31, and for each opening 33,
A pair of common electrodes 34 and a blanking electrode 35 are formed on the substrate 31, respectively, so as to control the deflection of the electron beam passing through each opening 33. The pitch p of the opening 33 in the X direction is, for example, three times the length a of one side of the opening 33 in order to secure a region for the electrode and the wiring. Also, the aperture groups 30A and 30C having two rows as one group are shifted by half a side of the aperture in the Y direction with respect to 30B and 30D, and the pitch in the X direction between the groups 30B and 30C. Is 3.5 times the length a of one side of the opening 33.
As a result, the beams of the four groups are exposed so as to overlap each other by half, so that the dimension adjustment of the pattern edge portion and the proximity effect correction can be performed with a smaller value than the dot size. A detailed description of this will be omitted.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

Although the time for exposing one subfield is very short, the amount of movement of the stage during that time is fed back to the sub differential deflector 22 in real time. When exposing the next frame, the stage moving direction is reversed, and the meandering direction of the main differential is also reversed. In FIG.
The chip regions C1 to C11 on the semiconductor wafer 10 are exposed to the same pattern. The frame A4 in one chip, which is indicated by oblique lines, is sequentially exposed in the direction of the arrow,
The movement of the moving stage 12 is controlled, and the exposure dot data of the frame A4 is repeatedly used. The main control circuit 24 of FIG. 1, and generates an on / off signal of whether or not to apply a voltage to the electrodes of each bra down King aperture in response to movement of the exposure pattern, each via drivers BAA drive circuit 40 A voltage signal is applied to the electrodes.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

FIG. 9 shows a circuit board 6 on which the main control circuit 24 is mounted.
FIG. 4 is a diagram showing an outline of a signal transmission path from No. 4 to a BAA board 30 in an easy-to-understand manner. As shown, the BAA substrate 30
And between the probe card 60 is connected with the probe, between the probe card 60 and the connection substrate 62 (shown as a summary of 62a to 62d. The same applies to the substrate 63.) Includes a connector 71 of the probe card 60 A connector 73 of the connection board 62 is connected by pins 72, and a connector 75 of the connection board 62 and a connector 76 of the board 63 are connected by a cable 75 between the connection board 62 and the board 63 on which the BAA drive circuit 40 is mounted. 63 and main control circuit 2
4 between the boards 64 on which the connectors 77 of the board 63 are mounted.
And the connector 79 of the board 64 are connected by a cable 78. The signal sent from the main control circuit 24 to the BAA drive circuit 40 is a serial signal, and is converted into a parallel signal by a shift register or the like provided in the BAA drive circuit 40. Therefore, the number of signal lines between the substrates 63 and 64 The signal applied to each of the blanking electrodes 35 of the BAA is output in parallel from the BAA drive circuit 40, so that the signal transmission path from the substrate 63 to the BAA substrate has at least the number of holes. It is necessary to provide a very large number of signal transmission paths such as 500 or more.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

That is, the charged particle beam exposure apparatus of the present invention is a charged particle beam exposure apparatus that forms a predetermined exposure pattern on a sample using a charged particle beam, and generates a charged particle beam. Means and a set of apertures arranged in the optical path of the charged particle beam from the charged particle beam generation means, for shaping the charged particle beam, and electrodes provided around the aperture are two-dimensionally arranged, Bed <br/> run-King aperture array for outputting the bra down King aperture array for shaping the charged particle beam by whether or not to apply a voltage signal to the electrodes, the voltage signals applied to the electrodes of each aperture according to the exposure pattern a drive circuit configured the voltage signal output from the bra down King aperture array driver circuit with a plurality of channels for application to the electrodes of each aperture bra Characterized in that it comprises a resistor provided between the King aperture signal transmission line and the power supply line of a predetermined DC level.

Claims (11)

[Claims] 1. A charged particle beam exposure apparatus for forming a predetermined exposure pattern on a sample using a charged particle beam, comprising: a charged particle beam generating means for generating a charged particle beam; Are arranged in the optical path of the charged particle beam, and two-dimensionally arrange a set of apertures for shaping the charged particle beam and electrodes provided around the apertures, and apply a voltage signal to each electrode. A blackening aperture array for shaping the charged particle beam depending on whether or not it is provided; a blackening aperture array driving circuit for outputting a voltage signal to be applied to the electrode of each aperture according to the exposure pattern; and a blacking aperture array driving circuit. Transmission of a blackening aperture signal composed of a plurality of channels for applying the output voltage signal to the electrode of each opening A charged particle beam exposure device, characterized in that it comprises a resistor and provided between the power supply line of a predetermined DC level. 2. The charged particle beam exposure apparatus according to claim 1, wherein the resistance value of the resistor is determined by the charged particle beam irradiated on the electrode and a part of the blackening aperture signal transmission path. A charged particle beam exposure apparatus which is determined in accordance with a potential generated in a blackening aperture signal transmission path and a withstand voltage between the periphery of the blackening aperture signal transmission path. 3. The charged particle beam exposure apparatus according to claim 1, wherein the resistance is lower than a potential at which dielectric breakdown occurs in accordance with a withstand voltage with respect to a periphery of the blackening aperture signal transmission path. Charged particle beam exposure equipment that opens (opens) or short-circuits (shorts). 4. The charged particle beam exposure apparatus according to claim 1, further comprising: a current monitor that detects a current flowing through each of the blacking aperture signal transmission paths. 5. The charged particle beam exposure apparatus according to claim 4, wherein a plurality of the resistors are provided at different positions on the blacking aperture signal transmission path. 6. The charged particle beam exposure apparatus according to claim 5, wherein the blackening aperture signal transmission path connects a signal line provided on a plurality of substrates and the signal line between the plurality of substrates. A charged particle beam exposure apparatus, wherein the plurality of resistors are provided for each of the plurality of substrates. 7. The charged particle beam exposure apparatus according to claim 5, wherein at least some of the plurality of resistors have different resistance values. 8. The charged particle beam exposure apparatus according to claim 4, wherein the current monitor is provided in each of the blacking aperture signal transmission paths. 9. The charged particle beam exposure apparatus according to claim 4, wherein the current monitor is provided for each of the plurality of blacking aperture signal transmission paths, and for each of the blacking aperture signal transmission paths. Established,
A charged particle beam exposure apparatus comprising a relay for selectively connecting the blackening aperture signal transmission path to the current monitor. 10. The charged particle beam exposure apparatus according to claim 4, wherein the current value detected by each of the current monitors is detected as needed while temporally scanning. A charged particle beam exposure apparatus including a failure detection circuit that outputs a signal indicating a failure occurrence and a channel in which the failure has occurred when the current value is different from a predetermined value. 11. The charged particle beam exposure apparatus according to claim 5, wherein the blackening aperture signal transmission path is opened based on a current value detected by each of the current monitors. )
A charged particle beam exposure apparatus including a failure detection circuit for detecting a damaged position.