JPH09283582A - Apparatus and method for automatically analyzing composition of foreign matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically and rapidly analyze composition of foreign matters on a sample to be analyzed such as a semiconductor wafer by providing a means for automatically positioning the foreign matters at the center of observation of a foreign matter composition analyzer. SOLUTION: A wafer 19 waiting for inspection out is mounted on and fixed to a sample stage 18 provided in an electron beam radiation chamber 12 provided via a load lock device 13. Then an electron beam 16 emitted from an electron gun 15 by an instruction from an electron beam controller 14 is deflected by a deflector 17 to be shed to a predetermined region of the wafer 19. In this case the sample stage 18 is controlled with its movement amount by a controller 21 based on defect inspection data 31 which has been measured in advance by a defect inspector 29 and stored in an external storage 30. Characteristic X-rays generated by radiation of the electron beam 16 are detected by an X-ray detector 20, and its detection signal is analyzed by a data arithmetic device 26 via a signal processor 24 and a detection signal storage 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foreign matter composition automatic analysis apparatus and a foreign matter composition automatic analysis method, and in particular, to high-speed transmission of various information such as defects, contamination, or processing defects occurring during processing of semiconductor wafers. The present invention relates to a foreign matter composition automatic analysis device and a foreign matter composition automatic analysis method for performing automatic and automatic analysis.

[0002]

2. Description of the Related Art In recent years, the degree of integration of semiconductor devices has improved, and the minimum processing line width has become 1/3 to 1/4 μm (quarter submicron) or less. Contamination of semiconductor wafers, which is generated during the process, and processing defects due to adhesion of fine particles to semiconductor wafers are becoming more and more problems.

That is, the amount of fine particles generated depends on the size of the fine particles, and the smaller the fine particles, the larger the amount.
This is because the amount of fine particles that have an undesired effect on processing dramatically increases with the miniaturization of the minimum processing line width.

Therefore, in order to elucidate the cause of the occurrence of such a processing defect and reduce it, a semiconductor wafer or LCD
The number and position of minute defects and foreign matter that adhere to the substrate (liquid crystal display device substrate), and the rough size are inspected with a high-speed defect inspection device to check whether the process is operating normally. It is routinely done to constantly monitor and feed back the result to each process to maintain the manufacturing apparatus in the best condition.

However, no matter how careful the maintenance of the manufacturing apparatus is, in the plasma etching apparatus, CVD apparatus (chemical vapor deposition apparatus), sputtering apparatus, etc., when the predetermined process is performed, the mechanism inside the manufacturing apparatus becomes Abrasion powder, reaction products, or deposits in a manufacturing apparatus are often peeled off and scattered and adhere to semiconductor wafers or LCD substrates, which is the largest cause of lowering the product yield.

In order to investigate the cause of such deposits and reduce the deposits, it is necessary to know the elemental composition and distribution of the deposits and the state of their combination. Although it is possible to measure the presence or absence of a defect, the position of the defect, and the rough size of the defect at a speed, the elemental composition, distribution, and compound state of the defect cannot be measured.

Therefore, the measurement of the elemental composition and the compounding state of the foreign matter at the defective portion existing in such a semiconductor wafer is
This is performed using a foreign material composition analyzer such as a SEM-EDX apparatus (scanning electron microscope-energy dispersive X-ray analyzer) or Auger analyzer.

For example, based on the defect position data obtained by the defect inspection apparatus, the foreign matter is introduced into the visual field of the foreign matter composition analysis apparatus with a rough accuracy, and then a dedicated operator aligns the analyzed foreign matter, Characteristic X-rays emitted from the foreign matter element by irradiating the foreign matter with an electron beam having an acceleration energy sufficient to generate electron beam excited X-rays,
That is, the energy value and intensity of fluorescent X-rays or Auger electrons are measured to identify the foreign element and determine the existing amount of the foreign element.

[0009]

However, when the conventional foreign matter composition analyzer is used, it is possible to measure the elemental composition of the defect and the compounding state, but such measurement / analysis is automatically performed. Moreover, there is no high-speed device, and the operation is performed manually by a dedicated worker. For example, it takes 1 minute or more to align and measure a foreign matter on one point. It takes several hours to perform the measurement, and there is a disadvantage that if this operation is performed on a large number of semiconductor wafers, it takes a huge amount of time.

Therefore, an object of the present invention is to automatically analyze the composition of a foreign substance on a sample to be analyzed such as a semiconductor wafer at a high speed.

[0011]

FIG. 1 is an explanatory view of the principle configuration of the present invention, and means for solving the problems in the present invention will be described with reference to FIG. See FIG. 1. (1) In the automatic foreign matter composition analyzer, the present invention includes defect inspection data including at least the position of the foreign matter existing on the surface of the sample to be analyzed, which is previously measured by the defect inspecting apparatus, and the preset size data. Based on the above, a means for automatically aligning the position of the foreign matter with the observation center position of the foreign matter composition analyzer, a means for irradiating a predetermined region of the observation center position with an electron beam accelerated to a predetermined energy, generated from that region It is characterized by comprising means for detecting at least one of fluorescent X-rays and Auger electrons, and means for analyzing the detection result.

As described above, in the present invention, the defect inspection including at least the position of the foreign matter existing on the surface of the sample to be analyzed, which is preliminarily measured by the defect inspecting apparatus in the step of, and the number of the foreign matter of each preset size. The data is read, the foreign matter is aligned with the observation center position of the foreign matter composition analyzer in the process of, and the foreign matter composition is analyzed based on the X-ray fluorescence or Auger electron in the process of The foreign material composition analysis, which has been performed for a long time, can be automatically performed at a high speed.

Since the fluorescent X-rays and Auger electrons are simultaneously generated by the irradiation of the electron beam, the analysis is performed with fluorescent X-rays.
It is also possible to use both lines and Auger electrons, and the use of both lines improves the accuracy of analysis.

(2) Further, in the present invention according to the above (1), a two-dimensional data group relating to position measurement errors of various defect inspection devices, two-dimensional data relating to position setting errors of the foreign matter composition analyzer, and various defect inspections. Positioning error correction two-dimensional data correction unit between the apparatus and the foreign matter composition analyzer, and two-dimensional position measurement error correction of the defect inspection apparatus that inspects the sample when analyzing the composition of the foreign matter to be analyzed Data is searched from the position setting error correction two-dimensional data group so that the position setting error with the center of the foreign substance to be analyzed is minimized.
It is characterized in that it has means for correcting the feed amount of the sample stage at any time.

As described above, in the step, using the standard wafer provided with the position measurement marker, the two-dimensional data group relating to the position measurement error of various defect inspection devices and the two-dimensional data relating to the position setting error of the foreign matter composition analyzer are preliminarily used. Measure the data,
A two-dimensional position setting error correction data group between the defect inspection device and the foreign material composition analyzer for each defect inspection device obtained based on this result is read, and in the step of By correcting the feed amount of the stage as needed, the foreign matter to be analyzed can be accurately and automatically aligned.

(3) Further, in the present invention, in the above (2), residual position setting errors between various defect inspection devices and foreign matter composition analyzers existing after the position setting error correction is measured in advance. The residual position setting error two-dimensional data group is stored, and the residual position setting error two-dimensional data of the defect inspection apparatus inspecting the sample is analyzed when the composition of the foreign matter to be analyzed is analyzed. It is characterized in that the electron beam is diffused or scan-irradiated within the range of the residual position setting error at the desired position based on the two-dimensional data of the residual position setting error by searching from the data group.

Even if the position setting error correction as described in (2) above is performed, a residual position setting error still exists. Therefore, this residual position setting error is measured in advance, and the residual position setting at the desired position is performed in the step of. Irradiation accuracy is increased by performing diffuse irradiation or scanning irradiation with the electron beam within the error range.

(4) Further, the present invention is based on defect detection data including at least the position of a foreign substance existing on the surface of a sample to be analyzed, which has been measured in advance, and data on each preset size. After automatically adjusting the position of the foreign matter to the observation center position of, the predetermined area of the observation center position is irradiated with an electron beam accelerated to a predetermined energy, and fluorescent X-rays and Auger generated from the electron beam irradiation area are obtained. In the foreign matter composition automatic analysis method of detecting at least one of the electrons and then analyzing the detection result, the electron beam irradiation region is divided into a plurality of minute regions, and the divided minute regions are successively irradiated with an electron beam It is characterized in that the measurement result is stored for each minute area, and the analysis is performed using only the measurement result of the area where the data regarding the element to be analyzed set in advance is obtained.

Further, as the foreign matter composition automatic analysis method,
In the process of step 2, the electron beam irradiation area is divided into a plurality of minute areas for measurement, and in the minute area data calculation processing step, analysis is performed using only the measurement results of the area where the data for the preset element to be analyzed is obtained. By doing so, it is possible to increase the S / N ratio by excluding the data of the region in which only the underlying element signals that are not analyzed, such as Si and Al, are detected, and performing analysis using only significant data.

(5) Further, according to the present invention, after the position setting error is corrected, the residual position setting error between the various defect inspecting apparatuses and the foreign matter composition analyzing apparatus which are present is measured in advance, and the residual position setting error 2 is detected. Stored as a dimensional data group, and when analyzing the composition of the foreign matter to be analyzed, the residual position setting error two-dimensional data of the defect inspection apparatus that inspected the analyzed sample is searched from the residual position setting error two-dimensional data group, In the foreign matter composition automatic analysis method of diffusing irradiation or scanning irradiation of the electron beam in the range of the residual position setting error at the desired position based on the residual position setting error two-dimensional data, the position of the foreign matter to be analyzed previously obtained by the defect inspection apparatus Based on the data
It is characterized in that the observation order of the foreign matter to be analyzed is rearranged so that at least one of the residual position setting error at each position or the total time required to move the sample stage is minimized.

The position data of the foreign matter to be analyzed are arranged along the scanning direction in the defect inspection apparatus, but when the electron beam irradiation is performed in the arranged order, the position data of the sample stage is moved. Because it takes time,
By rearranging the observation order in advance so that the total movement time of the sample stage is minimized in the process of 1, the analysis time can be shortened, and the residual position setting error is
In some cases, the observation order may be rearranged in consideration of this change because it changes depending on how the sample stage moves.

(6) According to the present invention, the residual position setting error between the various defect inspection devices and the foreign matter composition analyzer existing after the position setting error correction is measured in advance to detect the residual position setting error 2. Stored as a dimensional data group, and when analyzing the composition of the foreign matter to be analyzed, the residual position setting error two-dimensional data of the defect inspection apparatus that inspected the analyzed sample is searched from the residual position setting error two-dimensional data group, In the method for automatically analyzing the composition of a foreign material in which the range of the residual position setting error at a desired position is diffused or scanned and radiated based on the residual position setting error two-dimensional data, the analysis is performed using the position data previously obtained by the defect inspection apparatus. The residual position setting error range at the position of the foreign matter or a region slightly larger than this range is observed by the electron beam scanning means or the optical means to detect the foreign matter to be analyzed. Heart position, size, and the shape is measured, and determines the shape and the electron beam irradiation position based on the measurement results.

As described above, the electron beam irradiation accuracy is improved by measuring the center position, size, and shape of the foreign matter to be analyzed by the electron beam scanning means or the optical means such as the laser interferometer and feeding back the measurement result. It can be further increased.

(7) Further, according to the present invention, in any one of the above (4) to (6), only the energy range of fluorescent X-rays or Auger electrons caused by a preset element to be analyzed is counted and analyzed. Is characterized by.

Thus, by setting the element to be analyzed to a specific element other than the underlying element and measuring only the energy range of the fluorescent X-rays or Auger electrons resulting therefrom, the measurement time can be greatly shortened. You can

(8) Further, the present invention is characterized in that in any one of the above (4) to (7), the measurement region in the sample to be analyzed is limited to a region having an arbitrary shape.

Depending on the purpose of analysis, it is not necessary to measure the foreign matter on the entire surface of the semiconductor wafer, and as a result of the defect inspection, the measurement time is shortened by limiting a specific area such as an area having a high foreign matter distribution density as the measurement area. can do.

[0028]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described with reference to FIGS. First, with reference to FIG. 2, a schematic configuration of a foreign matter composition automatic analyzer used for carrying out the present invention will be described. See FIG. 2. The mechanical configuration of the foreign substance composition automatic analysis device according to the embodiment of the present invention is composed of an electron beam lens barrel 11, an electron beam irradiation chamber 12, and a load lock device 13 as in the conventional SEM-EDX device. The wafer 1 that is waiting for inspection outside the equipment
9 is mounted and fixed on a sample stage 18 provided in the electron beam irradiation chamber 12 via a load lock device 13.

Then, in accordance with a command from the electron beam control device 14, the electron gun 15 provided in the electron beam lens barrel 11
The electron beam 16 emitted from the electron beam is deflected by a deflector 17 which is also controlled by the electron beam controller 14, and is irradiated onto a predetermined area of the wafer.

In this case, the sample stage 18 is the controller 2
Although the movement amount is controlled by 1, the control is performed by the defect inspection device 29 in advance, and the defect inspection data 31 stored in the external storage device 30 such as a floppy disk is read into the arithmetic device 23. The position control distortion data 22 such as the two-dimensional data regarding the position setting error and the model / machine number data possessed by the foreign substance composition automatic analyzer are also read, and the defect inspection data 31 and the position control distortion data 22 are compared in the arithmetic unit 23. The position setting error correction two-dimensional data at each position is calculated by, and the result is stored in the storage device.

The defect inspection data 31 includes model / machine number data including a two-dimensional data group relating to position measurement errors of various defect inspection apparatuses in the factory, the number of the wafer to be analyzed, and its defects. It contains two-dimensional data on the position, and the model / machine number data of various defect inspection apparatuses is stored in advance in the foreign matter composition automatic analysis apparatus, and based on the wafer number of the wafer carried into the apparatus. Two-dimensional data relating to the position measurement error correction of the defect inspection apparatus used for the wafer defect inspection is read, and the sample stage 18 is corrected at any time based on this position setting error correction two-dimensional data.

Further, the characteristic X-ray generated by the irradiation of the electron beam is detected by the X-ray detector 20, and this detection signal is analyzed by the data arithmetic unit 26 via the signal processing unit 24 and the detection signal storage unit 25. The analysis result is displayed on the display device 28 as needed.

The central control unit 27 in the figure manages the process of the entire apparatus such as the arithmetic unit 23 and the data arithmetic unit 26, and is linked to various databases via a LAN or the like.

Next, details of the analysis method according to the embodiment of the present invention will be described with reference to FIGS. 3A and 3B. FIG. 3A shows a standard wafer 41 for preliminarily measuring the position measurement error of the defect inspection device and the position setting error of the foreign substance composition automatic analysis device. A position measuring marker 42 is drawn on a required portion of the standard wafer 41 by using an electron beam exposure apparatus with high accuracy.

Next, referring to FIG. 3B, in the defect inspection apparatus or the foreign substance composition automatic analysis apparatus, the measurement marker position 44 measured using the standard wafer 41 and the marker position 43 of the standard wafer 42 itself are compared, Errors Δx and Δy at each position
Is obtained as two-dimensional data, and this two-dimensional data is stored as the defect inspection data 31 and the position control strain data 22 in FIG.

Then, based on the two-dimensional data concerning the position measurement error of each defect inspection device and the two-dimensional data concerning the position setting error of the foreign substance composition automatic analyzer, the two-dimensional position setting error correction data between both devices are calculated. Then, the position setting error correction two-dimensional data group relating to each defect inspection apparatus is stored in the storage means in the foreign matter composition automatic analysis apparatus.

Then, the defect inspecting apparatus measures the center position and the rough size of the defect / foreign matter on the analyzed wafer. The rough size is arbitrarily set by the analyst and is, for example, 0.1 μm.
It is possible to classify each size by setting the following criteria: S size foreign matter, 0.1 to 0.3 μm M size foreign matter, and 0.3 μm or more L size foreign matter.

This measurement data is stored as defect inspection data 31 in the external storage device 30 shown in FIG. 2 together with the wafer number and the model / machine number data of the defect inspection device, and this defect inspection data 31 is supplied to the arithmetic unit 23. Then, the position setting error correction two-dimensional data for each wafer is read from the already stored position setting error correction two-dimensional data group, and the sample stage 18 is read based on the position setting error correction two-dimensional data.
To move the foreign matter to be analyzed to the electron beam irradiation area.

In this case, when the elemental composition of the minute foreign matter is analyzed, the signal from the base element, that is, noise is removed to remove S.
In order to improve the / N ratio, it is necessary to irradiate the electron beam only on the foreign matter as much as possible. However, when trying to irradiate the analyzed foreign matter of 0.1 to 0.3 μm with the electron beam, empirically, Positioning accuracy of about 1/2 of the size of the foreign matter to be analyzed is required.

However, the sample stage of the defect inspection device or the foreign substance composition automatic analysis device has individual strains such as linear strain, orthogonal strain, or feed strain, and is about ± 2 μm when controlling only the feed amount of the pulse motor or the like. Therefore, a residual position setting error of ± 0.5 μm will remain even with a thoroughly examined sample stage.

However, with respect to the residual position setting error, a preload in one direction is applied to the sample stage by a spring or the like to reduce the influence of play, or a preload in the lateral direction perpendicular to the moving direction of the sample stage is applied. Reducing the reproducibility of the position setting so that 3σ, which is three times the standard deviation of the normal distribution, is about ± 0.3 μm by suppressing swinging or feeding from one direction. can do.

Therefore, the feed amount of the sample stage is corrected based on the position setting error correction two-dimensional data at any time, and the electron beam is irradiated within the range of the residual position setting error of ± 0.3 μm, so that the image after the position setting is corrected. The foreign matter composition analysis can be performed accurately without using additional position measurement such as processing.

In the electron beam irradiation method in this case, the range of the residual position setting error of ± 0.3 μm, that is, the region of 0.6 μm × 0.6 μm may be scanned by the focused electron beam. , A circular electron beam with a radius of 0.3 μm may be irradiated, and the probability of normal analysis can be maintained at 99.7%, which is the definition of 3σ, by either method. Since the irradiation area is smaller by using, it is assumed that the irradiation density is the same, π ×
Since 0.3 × 0.3 / 0.6 × 0.6 = π / 4≈0.78, the analysis time can be shortened to 78%.

4A and 4B. FIG. 4 shows the observation order of the foreign matter 46 on the analyzed wafer 45. FIG. 4A shows the foreign matter 46 measured by a defect inspection apparatus. It shows the case where the position data is processed according to the order of the position data.

That is, the normal defect inspection apparatus has a method of sequentially scanning in the X-Y direction without a gap, and a method of sequentially scanning inward or outward while rotating like a mosquito coil. 4A shows the case based on the position data obtained by the method of scanning without gaps in the X-Y direction sequentially.

See FIG. 4B. However, when the electron beam irradiation is performed in the order of detection by the defect inspection apparatus as described above, the time required for moving the sample stage is not minimized. Prior to the irradiation, it is necessary to rearrange the irradiation order in advance so that the total moving time becomes the shortest based on the position data of the foreign matter, and perform the order as shown in FIG.

When the number of foreign matters is large, if all the possibilities are calculated, the time required for calculating the rearrangement of orders becomes huge, so it is not always necessary to calculate all the possibilities. Therefore, in some cases, it may not be the shortest time in the strict sense.

See FIG. 5A. FIG. 5A is a diagram showing a result of foreign matter analysis.
The α ray is 1.49 keV, and the Si Kα ray is 1.7.
4 keV, 3.69 keV which is Kα ray of Ca, and
Each fluorescent X-ray of 6.40 keV, which is Kα ray of Fe, was observed by combining an energy-dispersive Li-doped Si detector and a pulse peak value analyzer, and the element type was identified from the X-ray energy value. The measured intensity, that is,
The abundance of the element is determined from the count number.

Such identification and determination is performed by using the detection signal storage device 25 and the data operation device 26 shown in FIG. 2, but in reality, signals from other elements and noise from the outside are generated. Since it is mixed, it requires a fairly high-level arithmetic processing to determine the identification and the amount of the element, which requires a considerable amount of time and is not suitable for high-speed measurement.

Therefore, in the case of high-speed measurement, some main elements or some elements of interest are selected in advance by preliminary observation with another observation means or the present measuring device.
Only the energy range of the fluorescent X-ray emitted by the element needs to be counted and calculated.

See FIG. 5B. For example, C is formed on the surface of the Si wafer on which the Al wiring is provided.
When measuring whether or not there are fine particles of a and Fe, since Al and Si are naturally existing elements, there is no need to observe them again.
As shown in the figure, it is sufficient to count and calculate an energy range slightly wider than the energy spread of the measurement system, centering around 6.40 keV, and to shorten the analysis time by limiting the energy range in this way. You can

The analysis result thus obtained is arbitrarily displayed on the display device 28 in FIG. 2 according to the position information of the observation region which has been measured in advance, so that the generation source and the approach direction of the specific element are It is possible to investigate the cause of processing defects such as.

Although the residual position setting error of the electron beam is set to ± 0.3 μm of 3σ in the above embodiment, the composition of a large number of foreign substances is analyzed as in the analysis of the present invention. However, when the result is statistically processed and the result is obtained, even if there is an observation error of several%, that is, some of 100 observations cannot be observed because the foreign matter position is displaced from the analysis area. However, since it is not a big problem, the residual position setting error may be set to ± 0.2 μm of 2σ, and in the case of 2σ, normal analysis can be performed with a probability of 95%.
Further, even with 1σ, normal analysis can be performed with a probability of 68%, and the irradiation region of the electron beam may be determined in consideration of the balance between the target analysis accuracy and the measurement time.

In this way, if irradiation is performed with a circular electron beam in which the range of the residual position setting error of ± 0.2 μm of 2σ is blurred, π × 0.2 × 0.2 / 0.6 × 0.6 = π / 9 ≒
Since it is 0.35, it is possible to reduce the analysis time per point to 35% while maintaining the probability of normal analysis at 95% or more.

In addition, as in the above embodiment, 0.1
When irradiating an area of ± 0.3 with a particle of μm by an electron beam, an unnecessary area as many as 8 times the originally necessary analysis area will be analyzed at the same time. When a Si wafer is irradiated with an electron beam accelerated to a sufficient energy, for example, 20 keV, the incident electron beam collides with and scatters on Si atoms, and there are many reflected electrons or secondary electrons that jump out from the wafer surface. Characteristic X-rays are also generated from foreign elements on the surface by electrons.

From Si atoms, Kα rays peculiar to Si,
Characteristic X of 1.74 keV and 1.84 keV from Kβ ray
An element having a characteristic X-ray that is generated with a high intensity and has a lower energy than the characteristic X-ray, such as Al, Mg, Na,
Secondary excited X-rays are generated from F, O, C, B and the like.

The excited region of the reflected electrons, secondary electrons, or characteristic X-rays due to the underlying atoms sharply decreases with distance from the center of the incident electron beam, and depends greatly on the element, but the center of the incident electron beam is about 0.1 μm. Sufficient excitation intensity can be obtained even if it is separated from.

Therefore, considering the excitation distance of 0.1 μm, within the range of the residual position setting error, the inside of the residual distance setting error, that is, when the residual position setting error is ± 0.3 μm, ± 0.2 μm By irradiating the region, fluorescent X-rays from the foreign element can be observed with sufficient intensity.

In this case, when the ± 0.2 μm rectangular area is scanned with the electron beam, 0.2 × 0.2 / 0.3 is obtained as compared with the case where the ± 0.3 μm rectangular area is scanned with the electron beam.
× 0.3 = 4 / 9≈0.44, that is, the analysis time can be shortened to 44%.

From another point of view, when a region of ± 0.3 is irradiated with a 0.1 μm foreign matter by an electron beam,
Simultaneous analysis of 8 times as much unnecessary area as originally necessary is performed simultaneously. From the unnecessary area, Si from the underlying Si wafer is analyzed.
Si fluorescent X-rays due to the elements are strongly emitted, which deteriorates the S / N ratio of the foreign matter to be analyzed.

In this case, the electron beam irradiation area of ± 0.3 μm is divided into nine minute areas each side of which is 0.2 μm square, and each minute area is divided by 1/9 of the conventional irradiation time. The same result can be obtained by irradiating the electron beam and integrating the obtained detection signals.

Therefore, the analysis signals for each minute region are separately stored, and only the analysis signals of the minute region in which the elemental signal of interest is detected are integrated to obtain the base element signal intensity from the unnecessary region. The S / N ratio of the detection signal can be improved.

In this case, it is not necessary to integrate all the signals in the minute regions, even if the signals from the target element are slightly detected, and it is possible to select the signals in the respective minute regions so as to maximize the S / N ratio. Good, further, the S / N ratio is further improved by performing the arithmetic processing in consideration of the analysis signal strength and the S / N ratio of each minute area and the distance from the minute area where the maximum signal strength is obtained.

In this case, the arithmetic processing of the detection signal data of each minute area may be performed in real time, or the arithmetic processing may be collectively performed after a series of measurement is completed. is there.

Further, by calculating the foreign substance composition element signal intensity distribution between each minute region, a rough shape of the foreign substance center and the foreign substance is obtained, and based on the obtained result, the electron beam is irradiated again to this region. Then, reanalysis may be performed and the same applies to the detection of Auger electrons.

In this case, when the positional accuracy of the foreign matter to be analyzed is further required, the center position, size, shape, etc. of the foreign matter to be analyzed are determined by using an electron beam scanning means or an optical means such as a laser interferometer. By measuring and determining the irradiation position and irradiation shape of the electron beam, more accurate analysis becomes possible.

See FIGS. 6A and 6B. Further, when there are several hundreds of defects on the semiconductor substrate, it is not always necessary to measure the total number, and as shown in FIG. On the surface of the analysis wafer 45, L-size foreign matter 4
7. When the M-size foreign matter 48 and the S-size foreign matter 49 are measured in a dispersed form, for example, the measurement area 50 is limited by appropriately selecting a high-density area of the M-size foreign matter 48. Can shorten the analysis time.

The measurement area 50 in this case is usually limited manually by an operator, but separate software is prepared and automatically determined based on the foreign matter position data and size data. You may set it.

As shown in FIG. 6C, as another limiting method, only foreign matter of a specific size may be measured, and the size data of the foreign matter obtained by the defect inspection apparatus may be used. It is possible to automatically measure based on this, and in the figure, only the L-size foreign matter 47 is measured.

Further, in the above description of the embodiment, the energy dispersive Li-doped S is used for the detection of fluorescent X-rays.
Although the i detector and the pulse crest value analyzer are combined, it is also possible to use a plurality of wavelength dispersive detectors.

Further, in the above description of the embodiment, the composition analysis of the foreign matter is carried out by measuring the fluorescent X-rays, but it is possible to measure the light atoms such as Na and C and the fine defects. Since it is not suitable for the measurement of light atoms such as Na and C and the measurement of fine defects, it is desirable to analyze the composition of the foreign matter by measuring Auger electrons.

Further, the irradiation of the electron beam causes fluorescence X
Since the line and Auger electrons are generated at the same time, it is possible to measure both at the same time, and by compensating for the different characteristics of both, it is possible to perform highly accurate analysis on all elements.

[0073]

According to the present invention, the position setting error correction data between the position setting error of the foreign substance composition analyzer and the position measuring error of each defect detecting device, and the residual position setting error data are analyzed in advance by the foreign substance composition analysis. By storing in the device,
The foreign matter composition analysis of each wafer can be performed automatically and at high speed, which greatly contributes to the improvement of product yield.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a principle configuration of the present invention.

FIG. 2 is an explanatory diagram of a schematic configuration of an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a position measurement error according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a foreign matter analysis order.

FIG. 5 is an explanatory diagram of a foreign matter analysis result.

FIG. 6 is an explanatory diagram of a measurement area limiting method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Foreign matter composition analyzer 11 Electron beam column 12 Electron beam irradiation chamber 13 Load lock device 14 Electron beam controller 15 Electron gun 16 Electron beam 17 Deflector 18 Sample stage 19 Wafer 20 X-ray detector 21 Controller 22 Position control distortion Data 23 Calculation device 24 Signal processing device 25 Detection signal storage device 26 Data calculation device 27 Central control device 28 Display device 29 Defect detection device 30 External storage device 31 Defect inspection data 41 Standard wafer 42 Position measurement marker 43 Marker position 44 Measurement marker Position 45 Wafer to be analyzed 46 Foreign matter 47 L size foreign matter 48 M size foreign matter 49 S size foreign matter 50 Measurement area

Claims (8)

[Claims] 1. An observation center of a foreign substance composition analyzer based on defect inspection data including at least the position of a foreign substance existing on the surface of a sample to be analyzed previously measured by the defect inspection device and data on each preset size. Means for automatically aligning the position of the foreign matter with the position, means for irradiating a predetermined region of the observation center position with an electron beam accelerated to a predetermined energy, and at least one of fluorescent X-rays and Auger electrons generated from the region. A foreign matter composition automatic analyzer, comprising: a detecting means; and a means for analyzing a detection result of the detecting means. 2. A two-dimensional data group relating to position measurement errors of the various defect inspection apparatuses, two-dimensional data relating to position setting errors of the foreign matter composition analyzer, and positions between the various defect inspecting apparatuses and the foreign matter composition analyzer. Setting error correction Two-dimensional data group is stored, and when measuring the composition of the foreign substance to be analyzed, the position measurement error correction two-dimensional data of the position inspection error correction of the defect inspection apparatus that inspected the sample to be analyzed is corrected to the position setting error correction. The foreign matter composition according to claim 1, further comprising means for retrieving from the two-dimensional data group and correcting the feed amount of the sample stage as needed so that the position setting error with respect to the center of the foreign matter to be analyzed is minimized. Automatic analyzer. 3. A means for storing a residual position setting error two-dimensional data group in which residual position setting errors between various defect inspection devices and a foreign matter composition analyzer existing after the position setting error correction are measured in advance are stored. When analyzing the composition of the foreign matter to be analyzed, the residual position setting error two-dimensional data of the defect inspection apparatus that inspects the sample to be analyzed is searched from the residual position setting error two-dimensional data group, and the residual position setting error two-dimensional data is searched. 3. The automatic foreign matter composition analyzer according to claim 2, wherein the range of the residual position setting error at a desired position is subjected to diffusion irradiation or scanning irradiation based on the position setting error two-dimensional data. 4. The foreign matter at the observation center position of the foreign matter composition analyzer based on the previously measured position of the foreign matter existing on the surface of the sample to be analyzed and the defect inspection data including at least data on each preset size. After automatically adjusting the position of the electron beam, a predetermined region of the observation center position is irradiated with an electron beam accelerated to a predetermined energy, and at least one of fluorescent X-rays and Auger electrons generated from the electron beam irradiation region is irradiated. In the foreign substance composition automatic analysis method of detecting and then analyzing the detection result, the electron beam irradiation region is divided into a plurality of minute regions, and the divided minute regions are sequentially irradiated with an electron beam, and the obtained measurement result is obtained. Is stored for each of the minute regions, and analysis is performed using only the measurement result of the region in which the data regarding the predetermined element to be analyzed is obtained. Foreign substance composition automatic analysis method. 5. A residual position setting error between various defect inspection apparatuses and a foreign matter composition analyzer existing after the position setting error correction is measured in advance and stored as a residual position setting error two-dimensional data group, When analyzing the composition of the foreign substance to be analyzed,
The residual position setting error two-dimensional data of the defect inspection apparatus that inspected the sample to be analyzed is searched from the residual position setting error two-dimensional data group, and the residual position at a desired position is determined based on the residual position setting error two-dimensional data. In a method for automatically analyzing the composition of a foreign matter in which an electron beam is diffusely irradiated or scanning-irradiated in a range of a setting error, a residual position setting error at each position or a sample stage is detected based on position data of the foreign matter to be analyzed previously obtained by the defect inspection apparatus. The method for automatically analyzing the composition of foreign matter, characterized in that the order of observing the foreign matter to be analyzed is rearranged so that at least one of the total time required to move the foreign matter is minimized. 6. A residual position setting error between various defect inspection apparatuses and a foreign matter composition analyzer existing after the position setting error correction is measured and stored as a residual position setting error two-dimensional data group, When analyzing the composition of the foreign substance to be analyzed,
The residual position setting error two-dimensional data of the defect inspection apparatus that inspected the sample to be analyzed is searched from the residual position setting error two-dimensional data group, and the residual position at a desired position is determined based on the residual position setting error two-dimensional data. In a foreign matter composition automatic analysis method of irradiating an electron beam by diffusion irradiation or scanning irradiation within a range of setting error, a residual position setting error range at the position of the foreign matter to be analyzed based on position data previously obtained by the defect inspection apparatus or somewhat from the range. Observing a large area with an electron beam scanning means or an optical means, measuring the center position, size, and shape of the foreign matter to be analyzed, and determining the shape and irradiation position of the electron beam based on the measurement result. A method for automatically analyzing the composition of a foreign substance. 7. The automatic foreign matter composition analysis method according to claim 4, wherein only the energy range of the fluorescent X-rays or Auger electrons resulting from the preset element to be analyzed is counted and analyzed. 8. The foreign matter composition automatic analysis method according to claim 4, wherein the measurement region of the sample to be analyzed is limited to a region having an arbitrary shape.