JP3238487B2 - Electron beam equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam apparatus, and more particularly, to a pattern for inspecting a fine pattern defect formed on an exposure mask for a semiconductor device using a charged particle beam such as an electron beam. Inspection equipment, pattern drawing equipment for drawing a fine pattern on a wafer mask coated with a photosensitive resist, or pattern appearance inspection for observing the surface state of a wafer or mask using a charged particle beam such as an electron beam The present invention relates to an electron beam apparatus suitable for use in an apparatus or the like and performing high-density and high-speed processing.

BACKGROUND OF THE INVENTION In recent years, as semiconductor integrated circuits have become more sophisticated and higher in density, patterns such as, for example, exposure masks have tended to become increasingly finer. However, as the pattern becomes finer, the time required for drawing the pattern becomes longer, and the inspection of the finished product becomes more difficult.

[0003] Therefore, a high-speed drawing technique for a fine pattern, a technique for inspecting a fine pattern defect caused by a process error or the like, a technique for inspecting the appearance of a fine pattern, and the like are required.

[0004]

2. Description of the Related Art As an electron beam application apparatus, the present applicant has previously disclosed a "pattern inspection apparatus" (Japanese Patent Application No. 3-137692, June 10, 1991) suitable for defect inspection of fine patterns.
Japanese application). FIG. 15 is a configuration diagram of a main part of an embodiment of the apparatus.

In FIG. 15, reference numeral 1 denotes an electron beam generating means. The electron beam generating means 1
For example, a plurality of (two in this case) electron emitters 3 and 4 made of a metal such as silicon (Si) or tantalum (Ta), or hexavalent boron lanthanum are formed, and are formed under the electron emitters 3 and 4. Side, the extraction electrode 5, the focusing electrode 6,
The deflection electrode 7 and the detectors 8 and 9 are stacked.

Reference numeral 10 denotes an anode, reference numerals 11 and 12 denote ground electrodes, reference numeral 13 denotes a sample on which a fine pattern (not shown) is formed, and examples of the sample 13 include a sample to be inspected such as an exposure mask and a sample to be viewed. A sample to be exposed such as a wafer or a mask coated with a resist can be considered. In the above configuration, from the electron emitters 3,4, a charged particle beam having a beam current corresponding to the electrode voltage V ₅ of the lead electrode 5 (hereinafter, the electron beam that) 3a, 4a are pulled out, these electron beams 3a , 4a indicate the electrode voltage V of the focusing electrode 6.
After being converged at a convergence rate according to ₆ , the beam is deflected at a deflection angle according to the electrode voltage V ₇ of the deflection electrode 7 and spot-irradiated on the surface of the sample 13.

As shown by broken lines in FIG. 15, reflected electrons or secondary electrons are emitted from the surface of the sample 13, and these emitted electrons are captured by detectors 8 and 9 and converted into electric signals. You. Incidentally, for example, when the sample is an X-ray mask and used as an inspection device, for example, an electron beam absorber (pattern) is used more than a material made of an element having a small atomic weight such as silicon used for a mask substrate (membrane). For example, since a material made of an element having a large atomic weight such as gold (Au) or tantalum has a higher generation rate of reflected electrons and secondary electrons, the amount of electrons emitted from the mask substrate forming the sample 13 is used. The amount of electrons emitted from the electron beam absorber is larger than that.

That is, a plurality of electron beams 3a and 4a are simultaneously irradiated, and the detectors 8 and
9 are collectively processed, so that fine and large amount of pattern data formed on the surface of the sample 13 can be quickly and
And it is inspected accurately. When used as a drawing device, a plurality of electron beams 3a and 4a are simultaneously irradiated, so that fine and large-capacity pattern data can be drawn quickly and accurately.

[0009]

However, in the electron beam device according to the above-mentioned prior application, since a plurality of electron beams are provided with a common electrode, a mechanical system of an optical system for each electron beam is required. Due to manufacturing errors, there are problems such as slight differences in the spot diameter of the electron beam, misalignment of the axis of the electron beam, and mismatch of the deflection angle. There was a technical issue that needed to be improved in terms of alignment.

FIG. 16 is a conceptual diagram of an example of a problem that occurs due to a variation in spot diameter when used as an inspection apparatus. In addition, the waveforms a and b described corresponding to the two spots indicate the detection intensity of reflected electrons or secondary electrons from the sample surface or transmitted electrons transmitted through the sample.

As shown in FIG. 16, a pattern defect that can be detected without any problem when the spot diameter is small is small, but when the spot diameter is large, the signal intensity corresponding to the defective portion is small. I can't recognize. That is, the size of the beam spot diameter determines the lower limit of the inspection sensitivity as an inspection device, and is a factor in determining the minimum pattern size for a writing device.

FIG. 17 is a conceptual diagram of an example of a problem caused by a variation in the deflection angle when the same is used as an inspection apparatus. That is, if the deflection angle is too large, the overlap area extends to the adjacent irradiation area, and the area becomes a multiple detection area. On the other hand, if the deflection angle is too small, the irradiation area may fall off with the adjacent irradiation area, and the area becomes a non-detection area.

[0013] These disadvantages also cause inconvenience when used as a drawing apparatus. For example, variations in the spot diameter cause the shape accuracy or deterioration of the drawing pattern, and variations in the deflection angle cause deterioration in the drawing position accuracy. In this case, it is difficult to obtain a normal appearance. In addition, not only the beam spot diameter and deflection angle, but also the spot shape becomes a problem,
Similar problems occur in the case of a shape close to an ideal circle and the case of a distorted ellipse.

The causes of the deterioration of the spot shape include non-axial symmetry of the lens system for converging the electron beam, and deviation of the electron beam axis from the lens axis. [Purpose] Accordingly, it is an object of the present invention to provide an electron beam apparatus that adjusts the characteristics of a plurality of electron beams, and makes the characteristics of each electron beam accurate.

[0015]

According to the present invention, a plurality of electron emitters 21 are provided on a common substrate 20 or individual substrates arranged on the same plane as shown in FIG. Each of the electron emitters 21 is provided with an extraction electrode 23 for extracting a charged particle beam 22 having a beam current corresponding to the electrode voltage from the electron emitter 21, and a convergence rate corresponding to the electrode voltage or the excitation current to the charged particle beam 22. A convergence electrode 24 or convergence coil to be applied, a deflection electrode 25 or deflecting coil to apply a deflection angle corresponding to an electrode voltage or an excitation current to the charged particle beam 22, and a sample 26 exposed to the converged and deflected charged particle beam 22 A detector 29 is provided for detecting, for each charged particle beam 22, secondary electrons 27 from the surface or reflected electrons or transmitted electrons 28 transmitted through the sample 26. Both are configured to include adjusting means 30 for adjusting all or a part of the respective electrode voltages or excitation currents applied to the extraction electrode 23, the converging electrode 24 or the converging coil and the deflecting electrode 25 or the deflecting coil. are doing.

Also, a plurality of electron emitters are formed on the same substrate or individual substrates arranged one-dimensionally or two-dimensionally on the same plane, and each of the plurality of electron emitters has a beam current corresponding to an electrode voltage. An extraction electrode for extracting a particle beam from the electron emitter; a converging electrode for providing a charged particle beam with a convergence rate corresponding to an electrode voltage or an excitation current; and a deflection electrode for providing a deflection angle to the charged particle beam according to the electrode voltage or the excitation current. A beam shape shaping electrode for correcting the deviation between the charged particle beam axis and the central axis of the focusing electrode, and shaping the beam shape of the charged particle beam; and A detector for detecting secondary electrons, reflected electrons, or transmitted electrons transmitted through the sample, the extraction electrode, the focusing electrode, the deflection electrode, and the beam shape component. It is configured with means for adjusting the electrode voltage applied to the electrodes.

In this case, it is preferable that the beam shape shaping electrode is an electrode having at least one or more stages of an electrostatic octaelectrode structure, and it is effective that the beam shaping electrode is formed in the ground electrode of the electrostatic lens. is there.

[0018]

According to the present invention, the electrode voltage or the excitation current for each charged particle beam is individually adjusted. For example, the beam current changes by adjusting the electrode voltage of the focusing electrode or the electrode voltage of the extraction electrode. Then, the spot diameter is changed, and the beam axis of the charged particle beam is changed by adjusting the electrode voltage of the deflection electrode.

Further, the beam spot shape is adjusted to an ideal shape by the beam shape shaping electrode. That is,
The characteristics of each charged particle beam are precisely aligned.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 2 to 8 are views showing an embodiment of the electron beam apparatus according to the present invention, and are examples applied to a pattern inspection apparatus. First, the configuration will be described.

In FIG. 2, reference numeral 30 denotes one or many substrates composed of a plurality of layers. The substrate 30 has a plurality of (three in this case) composed of a metal such as silicon or tantalum, or hexavalent boron lanthanum. Electron emitters 31 to
33 are formed. The substrate 30 may be a substrate common to the plurality of electron emitters 31 to 33, an individual substrate for each electron emitter, or a stack of several substrates and holding them together. It may be the one that causes it. However, in the case of individual substrates, the substrates are arranged on the same plane, and the substrates are fixed and integrated.

The lower side of each electron emitter 31-33
, The extraction electrode E_ai(Less than, _iIs 31, 32, 3
3), the anode E_bi, First ground electrode E
_ci, Focusing electrode E_di, The second ground electrode E_ei, Deflection electrode E
_fiAnd detector S_iAre provided, and these electrodes are
Only for each electron emitter. Where the main electrode
explain about.

The extraction electrode E _ai is provided with a given electrode voltage V _ai.
The electron beam B _i having a magnitude of beam current corresponding to those drawn from the electron emitter 31 (32 or 33). Focusing electrode E _di is for converging the electron beam B _i to generate an electric field corresponding to a given electrode voltage V _di.

The deflection electrode E _fi has a given electrode voltage V _fi
The electric field corresponding to occur are those that provide a deflection angle to the electron beam B _i. The other electrodes (anode E _bi , first ground electrode E _ci , second ground electrode E _ei ) assist the function of the extraction electrode E _ai and form an electric field distribution that converges electrons with the focusing electrode. The other electrodes are supplied with the same electrode voltage Vg (ground potential).

The detector S _i provided for each electron beam B _i is used to detect the position of the surface of the sample 34 such as an X-ray exposure mask, the alignment mark of the sample to be exposed, or a unit pattern for correction described later in detail. is intended to convert it into an electric signal capturing reflected electrons or secondary electrons are emitted, the electrical signal taken out from the respective detectors S _i, (not shown) the electron beam absorbing member provided in the sample 34 , That is, information on the minute shape of the fine pattern or the position information of the sample to be exposed by the alignment mark.

Therefore, from all the electric signals, the sample 34
The two-dimensional information can be reproduced, and the location of a defect (for example, a white / black defect) or a drawing position in the fine pattern can be accurately specified. In this case, if the detector is arranged on the back side of the sample, the transmitted electrons transmitted through the sample can be captured and converted into an electric signal, and the two-dimensional information of the sample and the one-dimensional information in the transmission path can be reproduced. .

Here, the circuit C _i for each beam, which is formed on the upper surface of the substrate 30 by a fine processing technique, has a function as an adjusting means described in the gist of the invention, and a power supply supplied from an external power supply unit. The voltage V _o is adjusted to generate voltages (V _ai , V _di , V _fi , and V g) required for each beam, for example, by resistive voltage division. Figure 3 is a plan view and a detailed view of the main portion of the circuit C _i.

[0028] The circuit C _i the retracted the power supply voltage V _o is,
As shown in the detailed diagram (b), it is taken out as V _ai , V _di or V _fi through a parallel resistance network composed of several resistance elements (R ₁ , R ₂ , R ₃ , R ₄ ). In this case, the voltage can be adjusted by selectively cutting the resistance element.
The voltage adjustment method using the resistor network is not limited to such a parallel resistor network, but may be a series resistor network, or a parallel / series mixed resistor network.

The adjustment may be made not by disconnection but by connection, and each element of the resistor network may be a transistor. Apparatuses suitable for cutting or connecting such fine patterns include, for example, “Journal of Precision Engineering” (No. 5).
Vol. 3, No. 6, pp. 15-18 18 June 1987
A high-intensity FIB (Focused Ion Beam) having a beam diameter of 0.1 μm or less and 1 A / cm ² or more is generated by a metal ion source described in Japan Society of Precision Engineering. It is possible to use a mask repair apparatus that corrects a defect (black / white defect) (that is, cuts and removes a black defect or connects a white defect by depositing a source gas).

[0030] By selectively cutting each resistor element R ₁ to R ₄ of the circuit C _i, for example, as an example of which is shown in FIG. 4, the focusing electrode E _di changing the division ratio of the power supply voltage V _o The electrode voltage V _{di applied} to the converging electrode E can be appropriately adjusted.
it is possible to change the spot diameter individually by changing the convergence rate of the electron beam B _i converged by _di. Further, by adjusting the electrode voltage V _ai applied to the extraction electrode E _ai, can increase or decrease the beam current of the electron beam B _i, the correlation between the beam current and spot diameter, similarly changing the spot diameter individually be able to.

Further, the electrode voltage V applied to the deflection electrode E _fi
By adjusting the _fi, you can change the beam axis and the deflection angle of the electron beam B _i. Therefore, since the characteristics of the individual electron beams can be individually adjusted, the overall electron beam characteristics can be accurately aligned, and each electron beam generated due to a mechanical manufacturing error of the optical system for each electron beam can be adjusted. Problems such as a difference in beam spot diameter, a deviation of the axis of the electron beam, and a mismatch in deflection angle can be solved.

Next, a description will be given of the preferred embodiment for detecting the variations in characteristics of the electron beam B _i. FIG. 5A is a plan view of a table 35 movable in the X and Y directions while the sample 34 is placed. At a predetermined position of the table 35, a reference pattern portion 36 is fixedly attached, and by moving the table 35, the reference pattern portion 36 can be positioned in an irradiation area 37 by a plurality of electron beams. .

FIG. 5B is a side view showing a state in which the reference pattern section 36 is located in the irradiation area 37. The reference pattern portion 36 is exposed to a plurality of electron beams simultaneously irradiated from an electron beam generating means 38 including a plurality of electron emitters. As will be described in detail later, unit patterns (using elements having a high atomic weight) for exactly the number of beams, which are accurately designed, are regularly arranged in the reference pattern unit 36. Each unit pattern and a non-pattern portion around the unit pattern are used. transmission electron transmitted through the reflective electron or secondary electron or the unit pattern and the non-pattern portion of the periphery thereof, is released from is captured by the detector S _i described above.

FIG. 6A is a diagram showing the state of the electron beam when one unit pattern and its surrounding non-pattern portion are irradiated. By deflection scanning or table 3
It is considered that the relative positional relationship between the electron beam and the unit pattern has changed from the position A to the position B and then to the position C by the minute movement of No. 5. At the position A, all of the electron beam is applied to the non-pattern portion, and the amount of electrons passing through the non-pattern portion is the largest. At the position B, about half of the electron beam covers the non-pattern portion and the rest covers the unit pattern. At the position C, all of the electron beam covers the unit pattern, and the amount of passing electrons is the smallest.

FIG. 6B is a graph showing a change in the amount of passing electrons from the position A to the position C by a change in the beam current. Initially, a large current value is shown, but the current change curve La is obtained such that it sharply decreases before and after passing through the position B, and thereafter, the amount of passing electrons becomes zero. FIG. 6C is a graph showing a differential value of the current change curve La, and a differential curve Lb having both sides as zero values and the position B as a vertex is obtained. The width (generally, half width) of the differential curve Lb represents the beam width of the electron beam, that is, the spot diameter. Such a spot diameter measuring method is a technique called a knife edge.

FIG. 7 is a diagram showing another method. FIG.
In (a), when a basic pattern in which a light element such as silicon and a heavy metal such as tantalum is combined is irradiated with an electron beam in the same manner as described above, a difference in the generation efficiency of reflected electrons and secondary electrons due to the light and heavy atomic weight is caused. A difference occurs in the emission amount, and a current change curve Lc as shown in FIG. 7B is obtained from the position A to the position C. This curve also changes abruptly before and after the position B similarly to the curve Lb by the knife edge method, so that by taking its differential value, a differential curve similar to that shown in FIG. Can be measured.

The above specific measurement example is for one electron beam. However, to collectively measure a plurality of electron beams, for example, the method shown in FIG. 8 may be used.
FIG. 8A shows a preferred planar shape of the unit pattern. Here, a triangular unit pattern is used, and the electron beam is scanned in three directions F _{1 to} F ₃ orthogonally to each of the three sides. In this way, it is possible not only to accurately measure the diameter of a perfect circular spot of the electron beam, but also to measure the minor axis and the major axis of the elliptical spot diameter where astigmatism has occurred.

Now, it is assumed that electron beams B _{1 to} B ₅ having different spot diameters are applied to each of unit patterns P _{1 to} P ₅ constituting an arbitrary unit pattern sequence. Scanning direction is F _1. The differential curve of the beam current for each unit pattern is shown in FIG. L ₁ is a differential curve derivative curve, L ₂ is corresponding to the electron beam B ₂ corresponding to the electron beam B _1, below, L ₃ is B _3, L ₄ is B _4, L ₅ is a B _5.

When these curves L _{1 to} L ₅ are compared, the width of L ₅ corresponding to B ₅ having the smallest spot diameter is the smallest and has the highest peak, and conversely, B ₄ has the largest spot diameter. width to L ₄ corresponds to the maximum a and peak is observed for low. Curve L ₅ corresponding to minimum spot diameter
The difference between this and the other curves corresponds to the spot diameter difference. Therefore, by utilizing such a curve difference, a spot diameter correction value for each electron beam can be determined.

Further, according to FIG. 8 (b), B ₄ of the beam axis (spot center) is displaced slightly from the oblique center of the basic pattern, L ₄ corresponding to the B _4, only minute the deviation The peak position is shifted from the reference line of the beam axis indicated by the broken line. Therefore, the correction value of the beam axis deviation for each electron beam can be determined by using the deviation amount of the peak position.

It should be noted that a stencil-shaped perforated unit pattern can also be used. In this case, it is desirable to provide a current measuring device such as a Faraday cup below each hole. Further, as a circuit C _i described above, the digital - may be used analog converter (DAC), applied to the DAC correction value of the spot diameter correction value and the beam axis deviation calculated as described above as a digital amount, D
The electrode voltage may be generated as it is or by superimposing the analog output from the AC on a predetermined constant voltage. Since the DAC has a practical upper limit of the number of bits, if the resolution is made finer, the correction width is limited. Therefore, it is preferable to use the DAC together with the above-described resistance adjustment. Fine adjustment can be achieved while securing a large adjustment range.

[0042] Furthermore, as a circuit C _i described above, preferred use of the variable power supply such as a voltage regulator circuit and a programmable power supply. In the former case, the above-mentioned spot diameter correction value or beam axis deviation correction value may be given to the reference voltage, and in the latter case, the same correction value may be given to the program input. Furthermore, when the correction target of the electromagnetic type, configured as a current source circuit C _i described above, for example, by using a resistor divider, may be divided into a current from the current source appropriately.

Next, another embodiment of the present embodiment will be described.
In ordinary scanning electron microscopes and electron beam writing apparatuses, the beam shape is corrected by an octupole electromagnetic coil or an octupole electromagnet called a stigmator. In the above-described embodiment, the beam shape of each beam may be distorted due to some manufacturing error or the like.

From the viewpoint of the life of each electron emitter, it is conceivable to prepare more electron emitters than the electron lens barrel and make the mechanism selectable in a timely manner.
There is a possibility that an axis deviation between each electron emitter and the electron lens barrel occurs, which also causes a distortion of the beam shape.
Therefore, in this embodiment, by disposing a plurality of electrostatic eight electrodes in each electron beam optical system, the deviation between the central axis of the electrostatic lens and the beam axis is corrected, and the beam shape is changed to an ideal circular shape. It is to be molded.

The principle of the present embodiment will be described with reference to FIGS. In FIG. 11, reference numeral 51 denotes an electron emitter;
Is an accelerating electrode, 53 is a two-stage electrostatic eight electrode, 54 is an electrostatic Einzel lens, and 55 is a sample. Electrostatic eight electrodes 5
By applying a voltage as shown in FIG.
A deflection electric field can be generated, and a stigmator function for correcting the beam shape can be performed by employing a voltage distribution as shown in FIG. 9B.

That is, by applying these two superimposed voltages to the respective electrodes, the axis shift correction and the stig correction can be performed simultaneously, and furthermore, the parallel movement of the beam axis,
If it is desired to change the angle or the like at the same time, a plurality of electrostatic eight electrodes may be provided. An appropriate voltage can be supplied to each electrode of the electrostatic eight electrodes of each electron beam optical system through a correction circuit unit finely formed in the electron beam generation unit, as in the above-described embodiment.

In this case, using the pattern shown in FIG.
The scanning direction of the electron beam, in FIG. 8, as shown in F ₁ to F _3, by the length, width, and diagonal directions, not only the spot diameter of each electron beam, knowing the spot shape in two dimensions Therefore, the voltage applied to each of the eight electrostatic electrodes of each electron beam optical system may be adjusted based on the spot shape.

Considering the matching of the structure of the electrostatic eight electrodes with the conventional microfabrication technology, as shown in FIG. 10, first, a conductive thin film is formed on an insulating substrate, and a normal IC (Integrat) is formed.
ed Circuit) It can be made by patterning in the same process as wiring processing. Here, when correcting the deviation between the electron beam axis and the electrostatic lens axis, as shown in FIG. 11, it is necessary to dispose an electrostatic eight electrode on the electron emitter side of the electrostatic lens.

When the correction of the axis deviation is not regarded as important, that is, when the main purpose is to form the spot shape,
Since it is possible to use both the electrostatic eight electrode and the electrostatic lens, as shown in FIG. 12, one electrode of the Einzel lens may be divided into eight, and a stigmator voltage may be applied to each of them. . Normally, in the Einzel lens, a voltage is applied to the intermediate electrode, and the electrodes on both sides are ground electrodes.

The effect of the thickness of each electrode of the electrostatic lens on the convergence effect is large as the center electrode is large, and the convergence force is increased as the thickness is increased. As shown in FIG. 12, manufacturing is easier if the electrostatic eight electrodes are formed on the ground-side electrodes located on both sides of the center electrode. The deflection ability, that is, how much voltage can be applied and how much deflection can be performed depends on the length of the deflection electrode in the beam axis direction.

The same applies to the forming ability of stigmatol, and the thin film as shown in FIG. 12 has relatively small deflection ability and forming ability. By the way, how much thickness is required depends on the acceleration energy of the electron beam and the required degree of misalignment or the required degree of beam shaping. When it becomes necessary, forming a conductive film having a considerable thickness in the process of finely forming an electron optical system requires a long time and is not practical.

Therefore, as shown in FIG. 13 (a), first, a conductive material is vapor-deposited obliquely from above on the holed insulating substrate. In this state, the insulating substrate is rotated to form an electrode pattern. It is formed. Next, as shown in FIG. 13B, the formed electrode pattern is wired on the upper surface, and the inner wall portion of the hole is cut for each electrode by a focused ion beam or the like, so that the hole is cut in the beam axis direction. An electrode having a certain length can be manufactured.

In this case, a material having a relatively high resistivity is selected as a conductive material to be deposited around the hole, and the wiring is processed by using a material having a low resistivity.
As shown in (1), the connection between the electrode pattern and the wiring becomes the wiring potential, and a slight current flows between the adjacent connection parts to create a potential gradient. With this configuration, a necessary deflection and shaping electric field is created inside the hole without electrically disconnecting the electrodes.

The correction circuit may be an external ordinary electronic circuit independently of the electron beam generator, as in the above-described embodiment. However, the electron beam generator is provided on a silicon substrate. Since the electron emitter, the focusing electrode, the deflection electrode, and the like are formed by fine processing technology, it is possible to form a correction circuit as a fine integrated circuit on any one of the substrates. In this case, as the correction circuit, for example, A resistor division circuit, a digital-analog conversion circuit, a voltage regulator circuit and the like can be considered.

Therefore, in the present embodiment, the distortion of the beam spot shape in the plurality of electron optical systems is suppressed, and the accuracy of wafer mask defect detection is improved, or high-resolution drawing is performed at high speed. In the above-described embodiment, typical examples of the number of electrodes, the arrangement of the electrodes, the distribution of applied voltages, and the like are shown, and the present invention is not limited thereto.

In the above embodiment, the case of electrostatic convergence and electrostatic deflection has been described as an example. However, the present invention is not limited to this.
For example, electromagnetic convergence or electromagnetic deflection may be used, or an electrostatic type and an electromagnetic type may be mixed. However, in the case of the electromagnetic type, the above-mentioned focusing electrode (or deflection electrode) is replaced with a focusing coil (or deflection coil), and the electrode voltage applied to the electrode is used as the excitation current.

[0057]

According to the present invention, the electrode voltage or the excitation current of each charged particle beam can be individually adjusted for each of a plurality of charged particle beams, and the beam spot shape can be adjusted to an ideal shape by the beam shape shaping electrode. Therefore, the characteristics of each charged particle beam can be precisely aligned.

Therefore, it is possible to suppress, for example, a difference in spot diameter, a deviation of the beam axis, a variation in deflection angle, and a distortion in spot shape.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a main part configuration diagram of one embodiment.

3 is a plan view and a main part detailed diagram of the circuit C _i includes a circuit C _i of an embodiment.

FIG. 4 is a connection diagram for adjusting an electrode voltage V _di of a focusing electrode E _{di according to} one embodiment.

FIG. 5 is a layout diagram of a basic pattern section according to one embodiment.

FIG. 6 is a conceptual diagram of spot diameter measurement by a knife edge method according to one embodiment.

FIG. 7 is a conceptual diagram of spot diameter measurement using a light element and a heavy metal according to one embodiment.

FIG. 8 is a conceptual diagram for collectively measuring a plurality of electron beam characteristics according to one embodiment.

FIG. 9 is a principle diagram of another embodiment.

FIG. 10 is a view showing an electrostatic eight electrode.

FIG. 11 is a diagram for explaining an arrangement position of electrostatic eight electrodes.

FIG. 12 is a diagram for explaining formation of an electrostatic eight electrode.

FIG. 13 is a view for explaining a method of forming an electrostatic eight electrode.

FIG. 14 is a diagram for explaining another method of forming the electrostatic eight electrode.

FIG. 15 is a configuration diagram of a main part of a conventional example.

FIG. 16 is a conceptual diagram of a defect caused by a variation in spot diameter in a conventional example.

FIG. 17 is a conceptual diagram of a defect caused by variation in deflection angle in the conventional example.

[Explanation of symbols]

 Reference Signs List 20 common substrate 21 electron emitter 22 charged particle beam 23 extraction electrode 24 focusing electrode 25 deflection electrode 26 sample 27 secondary electron 28 transmitted electron 29 detector 30 adjusting means 51 electron emitter 52 acceleration electrode 53 electrostatic eight electrode 54 electrostatic Einzel lens 55 samples

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H01L 21/66 H01L 21/30 541B G01R 31/28 L (56) References JP-A-63-269445 (JP, A) JP-A-63-269445 JP-A-2062019 (JP, A) JP-A-2-42714 (JP, A) JP-A-2-54855 (JP, A) JP-A-62-292434 (JP, A) JP-A-61-42130 (JP, A) , A) JP-A-4-361544 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/027

Claims (9)

(57) [Claims] A plurality of electron emitters (21) are formed on a common substrate (20) or individual substrates arranged on the same plane, and each of the electron emitters (21) has a charge having a beam current corresponding to an electrode voltage. Particle beam (2
2) from the electron emitter (21), an extraction electrode (23), a convergence electrode (24) or a convergence coil for giving a convergence rate corresponding to an electrode voltage or an excitation current to the charged particle beam (22), an electrode voltage or A deflecting electrode (25) or a deflecting coil for applying a deflection angle corresponding to the exciting current to the charged particle beam (22); a secondary beam from the surface of the sample (26) exposed to the converged and deflected charged particle beam (22) All or a part of a detector (29) for detecting, for each charged particle beam (22), an electron (27) or a reflected electron or a transmitted electron (28) transmitted through a sample (26) is provided, and the extraction electrode ( 23), all or all of the respective electrode voltages or excitation currents applied to the converging electrode (24) or the converging coil and the deflecting electrode (25) or the deflecting coil. An electron beam device comprising an adjusting means (30) for adjusting a part thereof. The adjusting means adjusts an electrode voltage or an exciting current by selectively cutting or connecting each element of the resistance network itself or a wiring portion connected to each element, and adjusts an electron emitter and an electron emitter. 2. The electron beam apparatus according to claim 1, wherein the electron beam apparatus is formed on the same substrate. 3. An electron beam apparatus according to claim 2, wherein each element of said resistance network is constituted by a transistor. 4. The method according to claim 1, wherein a variation in spot diameter or deflection angle of each charged particle beam after convergence and deflection is measured based on a signal from the detector. 2. An arithmetic unit for calculating a correction amount for correcting all or a part of each electrode voltage or excitation current applied to the electrode or the focusing coil and the deflection electrode or the deflection coil. An electron beam apparatus according to claim 1. 5. A plurality of electron emitters are formed on the same substrate or individual substrates arranged one-dimensionally or two-dimensionally on the same plane, and each of the plurality of electron emitters has a charged current having a beam current corresponding to an electrode voltage. An extraction electrode (extraction coil) for extracting a particle beam from the electron emitter; a focusing electrode (convergence coil) for providing a charged particle beam with a convergence rate corresponding to the electrode voltage or excitation current; and a deflection angle corresponding to the electrode voltage or excitation current. Electrode (deflection coil) for applying a beam to a charged particle beam, and a beam shape shaping electrode (beam shape shaping coil) for correcting the deviation between the charged particle beam axis and the central axis of the focusing electrode and shaping the beam shape of the charged particle beam ), And detection of secondary or reflected electrons from the sample surface exposed to the converged / deflected charged particle beam, or transmitted electrons transmitted through the sample. And an electrode voltage (excitation current) to be applied to the extraction electrode (extraction coil), the focusing electrode (convergence coil), the deflection electrode (deflection coil), and the beam shape shaping electrode (beam shape shaping coil). An electron beam device comprising an adjusting means for adjusting. 6. The electron beam apparatus according to claim 5, wherein said beam shape shaping electrode (beam shape shaping coil) is an electrode (coil) having at least one or more stages of electrostatic eight-electrode structure. 7. The electron beam apparatus according to claim 6, wherein said beam shape shaping electrode (beam shape shaping coil) is formed in a ground electrode of an electrostatic lens. 8. An electron beam apparatus according to claim 5, wherein said adjusting means is formed as an integrated circuit or a resistor network on the same substrate as said electron emitter. 9. A beam shape is detected based on a preset reference pattern and applied to the focusing electrode (focusing coil), the deflection electrode (deflection coil), and the beam shape shaping electrode (beam shape shaping coil). 7. The image processing apparatus according to claim 5, further comprising a calculating unit configured to calculate a correction amount of the voltage.
Or the electron beam device according to 8.