JP2007019246A - Electronic beam device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic beam device capable of immediately detecting the occurrence of an abnormality in characteristics such as a positional abnormality, and an irradiating amount of an electronic beam or the like which is generated during the drawing of a test piece, and to provide a device manufacturing method employing the electronic beam device. <P>SOLUTION: The electronic beam device has an opening 9 for passing an electronic beam 2 deflected to be irradiate on a test piece by a deflection control means; a shielding unit for shielding the electronic beam controlled so as to be deflected so that the beam is not irradiated on the test piece by the deflection control means; an aperture means having a light emitting substance on the lower surface of the shielding unit; a detecting means 11 for detecting light generated from the light emitting body by at least one of reflected electrons reflected by irradiating the electron beam on the test piece after passing through the opening, and a secondary electron 18; and a means 15 for obtaining an irradiating state on the test piece based on the detecting result 14 of the detecting means. Accordingly, the characteristics can be derived in the electron beam irradiated on the test piece. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electron beam apparatus that irradiates a sample with an electron beam, and in particular, an electron beam apparatus that can immediately detect an abnormality in electron beam characteristics such as an electron beam position abnormality and an electron beam irradiation amount that occur during writing, and the electron The present invention relates to a device manufacturing method using a beam apparatus.

In general, if any abnormality occurs in the apparatus during the electron beam irradiation, the irradiation beam is also affected. In particular, when such an abnormality occurs during drawing of a pattern on a mask blank or a semiconductor wafer using an electron beam drawing apparatus, it causes a pattern drawing failure. The following are possible causes of the abnormality in the electron beam drawing apparatus. One is due to the drawing system. Specifically, it is a timing shift between subsystems, noise mixing, and the like. For example, if an abnormality occurs in the blanking control system due to these causes, a drawing defect such as a shot position shift or an abnormal dose amount occurs. The other is due to physical disturbance to the electron beam. For example, the beam trajectory is disturbed due to charge-up of each part in the column, or the electric field in the apparatus is suddenly changed due to micro discharge, so-called vignetting occurs and the dose is insufficient. It causes drawing defects such as omission.
Such an abnormality is difficult to detect during drawing, and an actually drawn pattern or a semiconductor device formed on a wafer is inspected as a circuit. For this reason, abnormalities are found in the post-pattern drawing process. Therefore, even though abnormalities have occurred, they cannot be detected, so drawing must be continued, and more time-consuming inspections are required. Otherwise, there is a problem that the pass / fail judgment cannot be made.
If the occurrence of abnormality is immediately found, the subsequent drawing time and inspection time can be omitted. For this reason, conventionally, a method of checking the deflection data error of the drawing system, a method of measuring the amount of current flowing into the blanking aperture and comparing it with the deflection data, a reflection electron or secondary electron from the sample, etc. A method is used in which the amount is measured and compared with the deflection data.
For example, Japanese Patent Laid-Open No. 2-215033 (Patent Document 1) proposes an electron beam apparatus capable of measuring a beam current and the like with a simple configuration, and a conductive cylindrical body provided below the aperture. The electron beam axis was adjusted by detecting the electron beam incident on the light source.
Japanese Patent Laid-Open No. 2-215033

However, the method of checking the deflection data error of the drawing system has a problem that it is impossible to detect whether the beam is actually irradiated on the sample.
In the method of measuring the amount of current flowing through the blanking aperture and the method of measuring the amount of reflected electrons and secondary electrons, there is a problem that accurate measurement is difficult because the amount of electron beam current is small. Moreover, when performing blanking at high speed, measurement at high speed is required.
Accordingly, the present invention provides an electron beam apparatus that can immediately detect the occurrence of abnormalities in characteristics such as electron beam position abnormality and electron beam irradiation amount generated during drawing of a sample, and a device manufacturing method using the electron beam apparatus. The purpose is to do.

In order to achieve the above object, an electron beam apparatus of the present invention is an electron beam apparatus that irradiates a sample with an electron beam from an electron source.
Deflection control means for controlling deflection of the electron beam based on blanking data;
An opening for passing the electron beam whose deflection is controlled to be irradiated onto the sample by the deflection control means, and the electron beam whose deflection is controlled so as not to be irradiated on the sample by the deflection control means. An aperture means having a shielding part, and a light emitter having a luminescent material on the lower surface of the shielding part;
Detecting means for detecting light generated from the light emitter by at least one of reflected electrons and secondary electrons that are reflected by the electron beam passing through the opening and reflected by the sample;
Means for obtaining an irradiation state on the sample based on a detection result of the detection means.
Furthermore, the electron beam apparatus of the present invention is the second light emitter having a second opening instead of the light emitter and provided below the aperture means in the aperture means, and having a light emitting material on the lower surface. Have
The electron beam passes through the opening and the second opening, receives at least one of the reflected electrons and the secondary electrons reflected and reflected from the sample, and generates light generated from the second light emitter. The detection means detects.
Furthermore, in the electron beam apparatus according to the present invention, the light emitter is formed by applying a light emitting material to the lower surface of the shielding portion, or made of a light emitting material.
Furthermore, in the electron beam apparatus according to the present invention, the second light emitter is formed by applying a light emitting material on the lower surface, or made of a light emitting material.
Furthermore, the electron beam apparatus of the present invention further includes means for comparing the obtained irradiation state on the sample with the blanking data.
Furthermore, the electron beam apparatus of the present invention is characterized in that a conductive material is provided on at least one of the front surface and the back surface of the shielding portion.
Furthermore, the electron beam apparatus of the present invention is characterized in that the irradiation error of the electron beam is determined based on a result of comparing the irradiation state on the sample and the blanking data.
Furthermore, the electron beam apparatus of the present invention is characterized in that an irradiation amount of the electron beam is obtained based on an irradiation state on the sample.
Furthermore, the electron beam apparatus of the present invention is characterized in that the blanking data is corrected based on an irradiation state on the sample.
Further, the electron beam apparatus of the present invention is a drawing apparatus, and the means for determining the irradiation state on the sample is based on a pattern already drawn on the sample irradiated with the electron beam. Correct the irradiation characteristic data.
Furthermore, the device manufacturing method of the present invention includes a step of exposing a sample using the electron beam apparatus, and a step of developing the exposed sample.

According to the electron beam apparatus of the present invention, an opening through which the electron beam whose deflection is controlled so as to be irradiated onto the sample by the deflection control means, and the sample so as not to be irradiated by the deflection control means. A shielding unit that shields the deflection-controlled electron beam, aperture means having a light emitter having a luminescent material on the lower surface of the shielding unit, and the electron beam passes through the opening and is reflected by the sample. Detecting means for detecting light generated from the light emitter by at least one of reflected electrons and secondary electrons, and means for obtaining an irradiation state on the sample based on a detection result of the detecting means. The characteristics of the electron beam irradiated to the sample can be derived, and the occurrence of abnormalities in the characteristics of the electron beam, such as the position of the electron beam and the amount of electron beam irradiation, generated during the drawing of the sample It can be detected in the seat.
Further, according to the electron beam apparatus of the present invention, in place of the light emitter of the aperture means, a second opening is provided below the aperture means, and a second light emitting material is provided on the lower surface. A light emitter, and the electron beam passes through the opening and the second opening and receives and reflects at least one of the reflected electrons and the secondary electrons irradiated and reflected on the sample. Since the detection means detects the light generated from the sample, the characteristics of the electron beam irradiated to the sample can be derived, and abnormalities in the characteristics of the electron beam, such as the electron beam position and electron beam irradiation, generated during the drawing of the sample Can be detected immediately.
Furthermore, according to the electron beam apparatus of the present invention, since at least one of the front surface and the back surface of the shielding portion is provided with a conductive material, charging caused by irradiation of the electron beam to the blanking aperture is effective. Therefore, the drift of the irradiation position of the electron beam is reduced.
Furthermore, according to the electron beam apparatus of the present invention, the electron beam irradiation error is determined based on the result of comparing the irradiation state on the sample and the blanking data, and thus occurs during the drawing of the sample. The occurrence of an abnormal position of the electron beam can be detected immediately.
Furthermore, according to the electron beam apparatus of the present invention, since the electron beam irradiation amount is obtained based on the irradiation state on the sample, an abnormality in the electron beam irradiation amount that occurs during the drawing of the sample is immediately detected. Can be detected.
Furthermore, according to the electron beam apparatus of the present invention, since the blanking data is corrected based on the irradiation state on the sample, an abnormal position of the electron beam generated during the drawing of the sample, the electron beam irradiation amount, etc. It is possible to immediately detect the occurrence of an abnormality in the characteristics of the electron beam and to control the irradiation state of the electron beam to the sample.
Further, the electron beam apparatus of the present invention is a drawing apparatus, and the means for determining the irradiation state on the sample is based on a pattern already drawn on the sample irradiated with the electron beam. Since the irradiation characteristic data is corrected, more accurate data can be obtained. Particularly, in the electron beam drawing apparatus, the influence of the background can be canceled to obtain accurate irradiation characteristic data. The control accuracy of the irradiation state of the base electron beam can be improved.
Furthermore, according to the device manufacturing method of the present invention, the method includes: exposing the sample using the electron beam apparatus; and developing the exposed sample. It is possible to immediately detect the occurrence of abnormalities in the characteristics of the electron beam, such as the electron beam position and electron beam irradiation amount, which occur during the drawing of the sample by the apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

First, an electron beam apparatus according to Embodiment 1 of the present invention will be described with reference to the schematic configuration diagram of FIG. 1 and FIGS. 2 and 3.
The electron gun 1 is a device that irradiates an electron beam 2. In the electron beam 2, an on-state electron beam 6 and an off-state deflected electron beam 7 are produced by the voltages of the two beam blanking electrodes 4 and 5 of the blanker 3. The on-state electron beam 6 passes through an electron beam aperture 9 provided in the blanking aperture 8. The electron beam 6 that has passed through the electron beam aperture 9 passes through an aperture 17 provided in the vicinity of the optical axis of the light-emitting plate 16 and reaches the sample 12. When the electron beam 6 enters the sample 12, reflected electrons 18 and secondary electrons are generated from the vicinity of the surface of the sample 12. When these reflected electrons 18 and secondary electrons reach the back surface of the light emitting plate 16, light emission 19 is generated from the light emitting material applied to the back surface of the light emitting plate 16. The detector 11 is a device that detects the light emission 19 and is provided on the sample 12 side in the vicinity of the light emitting plate 16.
Here, a light emitting material may be applied to the back surface of the blanking aperture 8 itself without providing the light emitting plate 16, or the light emitting material may be included.
On the other hand, the blanker 3 of the electron beam apparatus is connected to a control unit 13 that controls them, and the detector 11 is connected to a measurement circuit 14. The output signal of the control unit 13 and the measurement result of the measurement circuit 14 are input to the comparison unit 15, and the comparison result is output to the control unit 13.
The light emitting plate 16 contains a fluorescent material such as Y ₂ SiO ₅ : Tb having a property of emitting light when irradiated with an electron beam, or is coated on the surface. In addition, various fluorescent materials such as ZnS: Ag, ZnS: Cu, Al, Y ₂ O ₂ S: Eu, which are used as fluorescent materials for cathode ray tubes, can be used. Since many of these materials are insulating materials, it is known that they are charged by electron beam irradiation. As a countermeasure, the fluorescent material on the light-emitting plate 16 can be coated with a conductive material such as aluminum to effectively prevent charging, and the drift of the irradiation position of the electron beam can be reduced.
Here, the detector 11 may be one that senses the light emission intensity on the surface of the fluorescent material on the light emitting plate 16, or may be a camera or a CCD that observes the light emission state on the surface of the fluorescent material on the light emitting plate 16.
In the first embodiment, the shape of the detector 11 is a plate shape as shown in FIG. 1, but the shape may be arbitrarily selected in consideration of light collection efficiency and restrictions on mounting. In an apparatus that uses an electron beam that has been narrowed to some extent as in the present embodiment, it may have any shape that does not interfere with the on-state electron beam 6. It may be.

FIG. 2 is a diagram showing details of the control unit 13 connected to the blanker 3, the measurement circuit 14 connected to the detector 11, and the comparison unit 15 in the electron beam apparatus of FIG. 1.
The data processing unit 25 generates a beam on / off signal pattern and comprehensively controls a desired irradiation time and irradiation timing, and the bank memory 26 stores irradiation data composed of multi-valued bitmaps. A component for buffering the irradiation data output from the bank memory 26; a pulse width modulation circuit 28 for converting the irradiation data output from the buffer memory 27 into a pulse width; The driver 29 is a component that sends the data output from the pulse width modulation circuit 28 to the blanker 3 as a drive signal. The amplifier 30 is a component for amplifying the signal detected by the detector 11, the AD converter 31 is a component for converting the signal amplified by the amplifier 30 into a digital value, and the derivation unit 32 is an AD converter 31. This is a constituent element for deriving the characteristics of the electron beam irradiated on the sample from the output of. The data signal 33 is a signal output from the buffer memory 27 to the pulse width modulation circuit 28, and the signal 34 is a signal obtained by processing the signal from the detector 11 by the measurement circuit 14. These signals 33 and 34 are compared by the comparison unit 15. The data processing unit 25 generates multi-valued bitmap data from the beam on / off signal pattern and stores it in the bank memory 26. The bitmap data stored in the bank memory 26 is transferred to the buffer memory 27 at a desired timing instructed by the data processing unit 25 and sequentially updated. The bit map data output from the buffer memory 27 is processed into a blanking signal having a pulse width corresponding to the size of each data by the pulse width modulation circuit 28 and output to the driver 29 to connect the blanking electrodes 4 and 5. To drive. Here, the pulse width modulation circuit 28 performs modulation so that the center of the pulse width overlaps the center of the time interval determined by the data output period. The data processing unit 25 controls the operation timing of the pulse width modulation circuit 28 and the operation timing of the measurement circuit 14 in addition to the timing at which the bank memory 26 and the buffer memory 27 output data.

FIG. 3 is an explanatory diagram of the comparison operation performed by the comparison unit 15, and the comparison operation regarding the amount of the electron beam 6 irradiated on the sample 12 will be described.
The irradiation signal 40 is a component output by the pulse width modulation circuit 28, and the output 41 is an output of the amplifier 30. The output of the pulse width modulation circuit 28 is a binary value of 0 and 1, with 0 corresponding to beam off and 1 corresponding to beam on. The on time and off time of the electron beam 2 are determined by the width of the pulse.
On the other hand, there is a correlation between the irradiation amount of the electron beam 6 irradiated to the sample 12 and the amount of reflected electrons and secondary electrons generated at that time. Therefore, the output obtained by detecting the light emission 19 by the light emitting plate 16 reflects the amount of the electron beam 6 irradiated on the sample 12. Therefore, the irradiation amount of the electron beam 6 that reaches the sample 12 can be derived from the output of the detector 11 through various calculations.
Next, by comparing the irradiation signal 40 with the output 41, the signal sent to the blanker 3 can be compared with the amount of electron beam irradiated on the sample. In the first embodiment, an irradiation error is detected based on the comparison result.
The signals actually input to the comparator 15 are signals 33 and 34. The signal 33 is data before being modulated to the pulse width, and the signal 34 is digitally converted data, but comparing the signal 33 with the signal 34 is comparing the irradiation signal 40 with the output 41. Is equivalent to
As a comparison method, for example, the signal 34 is measured at the center of the pulse according to the sampling frequency of the pulse width modulation circuit, and only the presence or absence of the pulse is compared from the result and the data of the signal 33. There is a method of obtaining actual waveform data by sampling and comparing the result with a logical waveform determined by the data of the signal 33. In addition to these methods, the signal 33 and the signal 34 can be compared and determined by a statistical processing method such as examining the correlation between an actual waveform obtained and a logical waveform.
The comparison result 35 obtained by the method as described above is output to the data processing unit 25 and used for various purposes such as device sequence and display.

Referring to FIG. 4, a multi-beam electron beam drawing in which an electron beam emitted from an electron gun according to Embodiment 2 of the present invention is divided into a plurality of beams and arranged in a matrix, and a pattern is simultaneously drawn with each beam. The apparatus will be described.
Since this type of apparatus simultaneously draws a pattern in a wider field of view with a plurality of electron beams, it is considered that the throughput can be improved.
The electron gun 50 is a light source of the drawing apparatus. The electron beam 51 emitted from this light source is converted into a substantially parallel electron beam 51 a by the condenser lens 52. The substantially parallel electron beam 51a enters a multi-beam module 53 in which a plurality of element electron optical systems 54 are arranged. The element electron optical system 54 having a blanking electrode forms intermediate images 55 and 56 of a plurality of light sources in the vicinity of an aperture 57 of an aperture 57 that shields unnecessary beams due to scattering, etc., and simultaneously operates a plurality of blanking electrodes individually. Thus, a plurality of electron beams are shielded by a blanking aperture 61 located at the pupil position of the projection system described later.
Next, the magnetic lens 59 and the magnetic lens 60 constitute a projection system with a magnetic symmetric doublet. Here, the distance between the magnetic lens 59 and the magnetic lens 60 is equal to the sum of the focal lengths of the respective lenses, and the intermediate images 55 and 56 of the light source are in the vicinity of the focal position of the magnetic lens 59, and these images are magnetic fields. It is formed near the focal position of the lens 60. 63 is a magnetic field deflector, and 64 is an electrostatic deflector that deflects by an electric field. By using these two deflectors, the electron beams from the plurality of intermediate images 55 and 56 are deflected to form a plurality of intermediate image images. The sample 62 is moved in a plane. Here, the magnetic deflector 63 and the electrostatic deflector 64 are selectively used depending on the moving distance of the light source image. 65 is a dynamic focus coil for correcting a shift of the focus position due to deflection aberration generated when the deflector is operated, and 58 is a dynamic stig coil for correcting astigmatism generated in the same process. Reference numeral 66 denotes an XYZ stage for moving the sample 62 in the X, Y, and Z directions. At the time of drawing, based on the pattern data, a plurality of intermediate images are projected onto the sample 62 by the projection system, and the blanking electrodes of the plurality of element electron optical systems are operated to turn on the plurality of electron beams. While being turned off, the entire surface of the sample 62 is scanned using the magnetic deflector 63, the electrostatic deflector 64, and the XYZ stage 66 to obtain a desired exposure pattern.

Next, referring to FIG. 5, the blanking electrodes of the element electron optical system 54 mounted on the multi-beam module 53 in the electron beam drawing apparatus according to the second embodiment of the present invention, the driver for driving them, and the drive signal are shown. A transmission path for transmission will be described.
A drawing signal is converted into an on / off signal pattern for each beam, and a drive signal is output from a data processing system 67 that gives a desired exposure time to a driver 68. This output is connected to the interface connector 70 of the relay board 71 via the drive signal cable 69, passes through the electron optical column 78 by a wiring pattern, and is input to the terminator 72 which is a drive signal termination circuit. The drive signal that has passed through the terminator 72 passes through the vacuum seal 79 and is connected to the blanking module 74 via the contact unit 73. Further, on the blanking module 74, a pair of blanking electrodes 76 are provided in each blanking opening 77, and a drive signal is connected to the blanking electrodes 76 from the contact unit 73 through the wiring pattern 75.

Next, a method for detecting the characteristics of an electron beam in the apparatus described with reference to FIGS. 4 and 5 will be described with reference to FIG.
The electron beam 90 is a divided electron beam, the blanking module 74 is a component mounted on the relay substrate 71, and the lens groups 91 and 92 are lens groups that constitute a projection optical system that projects the divided electron beam 90 in a reduced scale. The blanking aperture 61 is the aforementioned component.
Here, the data processing system 67 converts the pattern data into a beam on / off signal pattern and provides a desired irradiation time and irradiation timing, and irradiation data composed of a multi-valued bitmap. Stored bank memories 95a, 95b, buffer memories 94a, 94b for temporarily storing irradiation data output from the bank memory, a pulse width modulation circuit 93a for converting irradiation data output from the buffer memory into a pulse width, 93b, a calculation unit 96 that adds the outputs of the buffer memory in time series and outputs an irradiation profile, a low-pass filter 99 that removes unnecessary high-frequency components of the detection signal, an AD converter 100 that digitizes the detection signal, an irradiation profile, A signal processing unit that performs processing such as analysis, comparison, and determination on the output of the AD converter 100 01, decision output 103 generated by the determination process of the data processing unit 102 from the output of the signal processing unit 101 is configured. Furthermore, 68a and 68b are drivers that send signals output from the pulse width modulation circuits 93a and 93b as drive signals to a blanker mounted on the blanking module 74, and a detector 97 is provided on a light emitting plate 105 to be described later. A detector / amplifier 98 for detecting the emitted light 107 of the phosphor is an amplifier for amplifying the signal detected by the detector 97.
The data processing unit 102 generates multi-valued bitmap data from pattern data to be drawn and stores it in the bank memory 95. A plurality of bank memories are prepared corresponding to the number of blankers for blanking the divided electron beams. In addition, the same number of subsequent processing parts are prepared. The bitmap data stored in the bank memory is transferred to the buffer memory 94 at a desired timing. In this example, the buffer memory is sequentially updated by a so-called FIFO according to a command from the data processing unit 102. The bitmap data output from the buffer memory is input to the pulse width modulation circuit 93, processed into a blanking signal having a pulse width corresponding to the size of each data, and output to the driver 68. The driver 68 is supplied to the blanking module 74. The arranged blanking electrodes are driven. Here, the pulse width modulation circuit 93 performs modulation so that the center of the pulse width overlaps the center of the time interval determined by the data output period.

The divided electron beam 90 passes through a part 91 of the projection optical system and reaches the vicinity of the blanking aperture 61 while being deflected by the pulse width modulation signal applied to the blanking electrode of the blanking module 74. The blanking aperture 61 has an opening in the vicinity of the optical axis of the projection optical system, shields the electron beam deflected by the blanking module 74, and passes through the opening when the electron beam is not received, and further passes a part 92 of the projection optical system. After passing through and obtaining a predetermined reduction ratio, it passes through a central opening provided in the light-emitting plate 105 and is further irradiated to the sample 62 below. When the sample 62 is irradiated with the electron beam, reflected electrons 106 and secondary electrons are generated from the vicinity of the sample surface. These reflected electrons and secondary electrons are irradiated to the lower surface of the light-emitting plate 105 placed on the electron source side as viewed from the sample. Although not shown in FIG. 4, the light emitting plate 105 is installed below the magnetic lens 60.
Here, the light-emitting plate 105 has a truncated cone shape convex toward the sample 62, and is provided with an opening centered around the optical axis of the electron beam. Further, a light emitting material is applied to the sample surface side (the lower surface in the second embodiment) of the light emitting plate 105, and light emission 107 is generated when an electron beam composed of reflected electrons and secondary electrons is incident. The shape of the light-emitting plate 105 takes into account the efficient collection of reflected electrons and secondary electrons, ensuring a sufficient amount of light when receiving light by the detector 97, and considering the mounting space of the detector 97. Designed.
In the second embodiment, a fluorescent material is used as the luminescent material, and the same laying form and material as in the first embodiment of the present invention are selected.
For example, various detectors such as a photodiode, a phototransistor, a PIN, and a photomultiplier can be used as the detector 97 that detects the light emission 107. When selecting, use the optimum one according to the emission wavelength of the phosphor to be used. In the second embodiment, a so-called PIN diode is used. In order to give high speed response to the output of the PIN diode, the load resistance is kept small, and a gain of about 100 times is obtained by the amplifier 98 in the subsequent stage. The output of the amplifier passes through the low-pass filter 99, removes unnecessary high frequencies, and is digitized by the AD converter 100.
The signal processing unit 101 outputs characteristic data including the output of the arithmetic unit 96, the output of the AD converter 100, the reflectance of the pattern already formed on the sample from the base pattern characteristic data memory 104, the secondary electron generation rate, and the like. Waveform analysis is performed using methods such as waveform trace, integration, differentiation, second-order differentiation, centroid calculation, etc. In this case, when the mode for performing the base pattern correction is set, the output of the AD converter 100 is the reflectivity of the base pattern obtained from the data stored in advance in the base pattern characteristic data memory 104, and the generation of secondary electrons. Correction is made using values such as rate. The main mode of this correction is reflectivity correction in the evaluation of the electron beam dose. The reflectivity considering the shape and material of the base pattern and the resist characteristics is stored in the base pattern characteristic data memory 104 for each drawing shot. The reflectance data is read in synchronization with the output of the AD converter 100, and the output of the AD converter 100 is multiplied by the reciprocal of the reflectance at that portion. By this operation, the irradiation amount of the electron beam incident on the sample is calculated while eliminating the influence of the base.
After the above correction, comparison and statistical processing of the identity, similarity, correlation, etc. of the output of the arithmetic unit 96 and the AD converter 100 are performed, and at the same time, obtained by waveform analysis, comparison, and statistical processing. The abnormalities are also judged using the information. These waveform data, characteristic data, comparison, statistical information, and determination results are sent to the data processing unit 102, and the data processing unit corrects irradiation parameters based on the information and simultaneously evaluates the irradiation state. A determination output 103 is obtained.

With reference to FIG. 7, a description will be given of a mode in which background pattern correction is not performed in the dose processing of the second embodiment.
FIG. 7 is a graph of the output of the pulse width modulation circuit, the output image of the arithmetic unit, and the output of the amplifier over time.
Signals Pa and Pb are outputs of pulse width modulation circuits 93a and 93b. Here, signals Pc and Pd are added in order to explain on the assumption that there are four divided electron beams, that is, four blankers. For this reason, signals Pa, Pb, Pc, Pd, and four signals are output to each driver, and the four blankers connected to the driver are driven.
Actually, it is necessary to simultaneously process 1024 signals. Here, the broken line on the vertical axis represents the time center position of each pulse, and the position is modulated so that this position is the center of the pulse. The interval between the broken lines represents the pulse transmission cycle, and in this example, the transmission cycle is 100 MHz. Therefore, the pulse interval is 10 nsec, and on / off control of all the beams is performed at each interval. The signal Ps is a time series sum of the signals Pa, Pb, Pc, and Pd. Actually, not the output of the pulse width modulation circuit but the output of the buffers 94a and 94b in the previous stage is digitally added in time series by the arithmetic unit 96.
On the other hand, the signal Ds is a signal obtained by multiplying the signal obtained by the detector 97 by the amplifier 98 and passing through the LPF. As can be seen from FIG. 7, the waveform of the signal Ps and the signal Ds are similar, and it can be seen that normal drawing has been performed. There are several methods for processing the dose. In this embodiment, the integration method and the second-order differentiation method are used. The integration method is a method in which the signals Ps and Ds are integrated within an integration window for each pulse, and the difference between the results is used as a parameter for determination. The second-order differentiation method focuses on the waveforms of the signals Ps and Ds, converts each waveform increase / decrease as a sign change of the slope by two differential operations, and evaluates the degree of coincidence of the data obtained from each waveform. This is a method used for determination.
The reason why the two different methods are used at the same time when the dose amount is compared in the second embodiment is to improve the determination accuracy. Further, in the embodiment, center value determination for complementing them is also used. The center value determination is literally a method of paying attention to the center value, that is, the data of the center position of the pulse, and the presence / absence of the pulse is determined from the data of the intersection of the signals Ps and Ds and each broken line in FIG. . Since this method can be easily discriminated and the burden on the circuit constituting the signal processing unit is light, it is always used for monitoring for the purpose of rough check. As described above, the signal Ds is digitized by the AD converter 100 and then subjected to signal processing.
The dose evaluation results obtained in this way are output to the data processing unit and fed back to both real-time correction and static correction. The real-time portion is the basic dose amount, which is determined by the drawing conditions, and has the meaning of correcting the variation. The static portion is a so-called offset, and is an amount that is corrected at an appropriate interval.
Returning to FIG. 5, the data processing unit 102 makes a comprehensive judgment from the information thus obtained and outputs a judgment output 103. This output is used by a host controller (not shown) or a display device. For example, it is used for starting operations such as device sequence change or stop, error display, alert output, error log registration, error recovery, retry sequence startup, and the like.
In the second embodiment, no particular consideration was given to the shape design of the detector 97, but various forms and configurations are conceivable as in the first embodiment of the present invention for the purpose of improving detection sensitivity and SN ratio.

Next, with reference to FIG. 8, a device manufacturing method according to a third embodiment of the present invention in which a semiconductor device is manufactured using the electron beam apparatus according to the first embodiment of the present invention will be described.
FIG. 8 shows the flow of manufacturing a microdevice (semiconductor chip such as IC or LSI, liquid crystal panel, CCD, thin film magnetic head, micromachine, etc.).
In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (exposure control data creation), exposure control data for the exposure apparatus is created based on the designed circuit pattern. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the wafer and the exposure apparatus to which the prepared exposure control data is input. The next step 5 (assembly) is referred to as a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), and the like. including. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).

It is explanatory drawing of Example 1 of this invention. It is a schematic block diagram of the control apparatus which comprises Example 1 of this invention. It is explanatory drawing of the signal waveform of Example 1 of this invention. It is explanatory drawing of Example 2 of this invention. It is explanatory drawing of the blanking module of Example 2 of this invention. It is explanatory drawing of the blanking module of Example 2 of this invention, and its peripheral circuit. It is explanatory drawing of the signal waveform of Example 2 of this invention. It is explanatory drawing of the flow of the device manufacturing method of Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electron gun 2 Electron beam 3 Blanker 4 Blanking electrode 5 Blanking electrode 6 Electron beam of ON state 7 Electron beam of OFF state 8 Blanking aperture 9 Electron beam aperture 11 Detector 12 Sample 13 Control unit 14 Measurement circuit 15 Comparison unit 16 Light Emitting Plate 17 Aperture 18 Reflected Electron and Secondary Electron 19 Light Emission 25 Data Processing Unit 26 Bank Memory 27 Buffer Memory 28 Pulse Width Modulation Circuit 29 Driver 30 Amplifier 31 AD Converter 32 Deriving Unit 33, 34 Signal 35 Comparison Result 40 Irradiation Signal 41 output 50 electron gun 51 electron beam 52 condenser lens 53 multi-beam module 54 element optical system 55, 56 intermediate image 57 aperture 58 dynamic stig coil 59, 60 magnetic lens 61 blanking aperture 62 sample 63 magnetic field Direction device 64 Electrostatic deflector 65 Dynamic focus coil 66 XYZ stage 67 Data processing system 68 Driver 69 Drive signal cable 70 Interface connector 71 Relay board 72 Terminator 73 Contact unit 74 Blanking module 75 Wiring pattern 76 Blanking electrode 77 Blanking opening 78 Electro-optical column 79 Vacuum seal 90 Electron beam
91, 92 Projection optical system 93a, 93b Pulse width modulation circuit 94a, 94b Buffer memory 95a, 95b Bank memory 96 Operation unit 97 Detector 98 Amplifier 99 Low pass filter 101 AD converter 101 Signal processing unit 102 Data processing unit 103 Determination output
104 Ground pattern characteristic data memory 105 Light emitting plate 106 Reflected electrons and secondary electrons 107 Light emission

Claims (11)

In an electron beam apparatus that irradiates a sample with an electron beam from an electron source,
Deflection control means for controlling deflection of the electron beam based on blanking data;
An opening for passing the electron beam whose deflection is controlled to be irradiated onto the sample by the deflection control means, and the electron beam whose deflection is controlled so as not to be irradiated on the sample by the deflection control means. An aperture means having a shielding part, and a light emitter having a luminescent material on the lower surface of the shielding part;
Detecting means for detecting light generated from the light emitter by at least one of reflected electrons and secondary electrons that are reflected by the electron beam passing through the opening and reflected by the sample;
An electron beam apparatus comprising: means for obtaining an irradiation state on the sample based on a detection result of the detection means. In the aperture means, a second light emitter having a second opening instead of the light emitter and provided below the aperture means, and having a light emitting material on the lower surface,
The electron beam passes through the opening and the second opening, receives at least one of the reflected electrons and the secondary electrons reflected and reflected from the sample, and generates light generated from the second light emitter. The electron beam apparatus according to claim 1, wherein the detection means detects.   The electron beam apparatus according to claim 1, wherein the illuminant is formed by applying a luminescent material on a lower surface of the shielding portion, or made of a luminescent material.   3. The electron beam apparatus according to claim 2, wherein the second illuminant has a lower surface coated with a luminescent material or is made of a luminescent material.   5. The electron beam apparatus according to claim 1, further comprising means for comparing the obtained irradiation state on the sample with the blanking data.   The electron beam apparatus according to claim 1, wherein a conductive material is provided on at least one of the front surface and the back surface of the shielding portion.   The electron beam apparatus according to any one of claims 1 to 6, wherein an irradiation error of the electron beam is determined based on a result of comparing the irradiation state on the sample and the blanking data.   The electron beam apparatus according to claim 1, wherein an irradiation amount of the electron beam is obtained based on an irradiation state on the sample.   9. The electron beam apparatus according to claim 1, wherein the blanking data is corrected based on an irradiation state on the sample. The electron beam device is a drawing device;
The means for obtaining an irradiation state on the sample corrects irradiation characteristic data of the electron beam based on a pattern already drawn on the sample irradiated with the electron beam. The electron beam apparatus as described.   A device manufacturing method comprising: exposing a sample using the electron beam apparatus according to any one of claims 1 to 10; and developing the exposed sample.

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