JP2843424B2 - Mass production start-up in semiconductor manufacturing process and foreign matter inspection method and apparatus for mass production line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to mass production start-up and mass production line of a semiconductor production process for detecting, analyzing, and taking countermeasures against foreign substances generated in a mass production line and mass production line of a semiconductor production process. And a device for inspecting foreign matter.

[Conventional technology]

In the conventional semiconductor manufacturing process, the presence of foreign matter on a wafer causes defects such as wiring insulation failure and short-circuiting. In addition, when a semiconductor element is miniaturized and minute foreign matter is present in the wafer, the foreign matter can cause insulation of the capacitor. It also causes destruction of the film and the gate oxide film.

These foreign substances are generated from various parts such as those generated from the movable part of the transport device, those generated from the human body, those generated by reaction in the processing apparatus by process gas, and those mixed in chemicals and materials. It is mixed in various states depending on the cause.

From this, one of the major tasks of mass production start-up of LSI is to investigate the cause of these foreign substances and take countermeasures. It will be a great clue for investigating the cause.

A conventional technique for detecting and analyzing minute foreign matter on a wafer of this type has been developed and disclosed in Japanese Patent Application Laid-Open No. 63-135848. This technology irradiates a laser on the wafer and detects the scattered light from the foreign matter generated when the foreign matter adheres to the wafer. The detected foreign matter is subjected to laser photoluminescence or secondary X-ray analysis (XMR). The analysis is performed using such an analysis technique.

[Problems to be solved by the invention]

The above prior art is becoming insufficient to detect and analyze foreign matter generated in a mass production start-up line of a fine element as a semiconductor element is miniaturized, and to plan a countermeasure. There was a problem that required analysis.

Further, in order to detect and analyze the fine foreign matter, the detection and analysis equipment becomes extremely large, which requires cost and space, and also hinders reduction in mass production lines. This means that in order to detect minute foreign matter, it is necessary to scatter light more efficiently by the foreign matter and to collect the scattered light, and to analyze finer foreign matter, Auger electron spectroscopy or secondary ion mass analysis is required. This is because an expensive and large-sized apparatus such as an analysis apparatus (SIMS) is required, and this trend is expected to further increase in the future. In addition, since detection and analysis of such a minute foreign substance takes a long time, there is a problem that it is necessary to use a necessary device as efficiently as possible to reduce the production cost. Further, there is a problem that it is necessary to install a necessary and sufficient monitor at a necessary and sufficient place to reduce the mass production line.

Furthermore, among the above analysis techniques, the elemental analysis method using an electron beam (secondary X-ray analysis, etc.) is limited to the analysis of foreign matter up to about 0.5 μm from the electron beam focusing efficiency. However, it is necessary to increase the energy of the irradiated electrons in order to increase the beam condensing efficiency. As a result, there is a problem that foreign matter to be analyzed is scattered. Was. In a method using light such as infrared light emission spectroscopy and fluorescence spectroscopy, it is difficult to obtain a resolution smaller than a dimension d calculated from the wavelength λ of light by the following equation.

d = 1.22λ / sin θ (1) Here, θ is the angle of confinement of the detection optical system. Therefore, there is a problem that the spatial resolution needs to be increased in the above-described method for analyzing foreign matter.

The present invention clearly distinguishes between the two states of mass production start-up and mass production in the semiconductor manufacturing process, maximizes the function of detection, analysis and evaluation of foreign substances necessary for mass production start-up, and reduces production lines during mass production. It is another object of the present invention to provide a mass production start-up of a semiconductor production process and a method for inspecting foreign substances on a mass production line, which can reduce the production cost.

[Means for solving the problem]

In order to achieve the above object, a method and an apparatus for mass production start-up of a semiconductor manufacturing process and a foreign substance inspection method for a mass production line of the present invention use a sampling wafer at the time of mass production start-up of a semiconductor manufacturing process. In evaluating the foreign matter management situation such as the above, by separating the foreign matter detection / analysis / evaluation system from the mass production line, only a simple monitoring device is arranged in the mass production line.

The foreign matter detection, analysis, and evaluation system at the time of mass production start-up detects foreign matter on the sampling wafer and then determines the element type of the foreign matter using a scanning tunneling microscope / spectrometer (STM / ST).
The analysis is performed by S), and the analysis data by STM / STS is stored in advance as a database, and is compared with the data to be analyzed to identify the foreign element species to be analyzed.

[Action]

The mass production start-up in the semiconductor manufacturing process and the foreign matter inspection method and apparatus for mass production lines are expensive and high-performance evaluation equipment for evaluating and improving (debugging) materials, processes, devices, designs, etc. at the time of mass production start-up. In this way, each process, equipment, and the like are evaluated, and during mass production, the equipment on the production line is reduced as much as possible, and in particular, the items of inspection and evaluation are reduced to reduce the cost of the equipment and the time required for inspection and evaluation.

To do this, we use a foreign matter inspection and analysis system that uses sampling wafers to make the evaluation at the start of mass production smooth and quick, to investigate the cause of foreign matter generation, change the inspection specifications when obtaining materials, and generate dust from equipment. Source measures are taken, and the results are fed back to each material, process, equipment, etc., to change the specifications of processes that are easy to generate dust to specifications that are less likely to generate dust, or to design elements that are resistant to dust generation. At the same time, it is used to create specifications for inspection and evaluation of mass production lines, and installs a foreign matter (dust generation) monitor as necessary at a place where foreign matter is likely to occur, or monitors only the increase or decrease of a specific foreign matter at a specific place Or

By separating the mass production line from the mass production line as described above, the foreign substance detection, analysis, and evaluation equipment can be efficiently operated at the mass production start-up, and mass production start-up can be accelerated. The inspection and evaluation equipment for foreign substances (dust generation) used is made a simple and simple monitoring device to reduce the weight of the mass production line. In addition, by devising a sampling wafer at the start of mass production, the sampling interval can be shortened and the sampling time can be shortened to collect more accurate foreign matter generation data. The raising period can be shortened.

ST used for the analysis of foreign element species at the time of mass production start-up
Although M / STS technology has existed in the past, this technology was not used in LSI manufacturing because it was said that the element type of the sample could not be determined. Focusing on the fact that STM / STS technology can be applied when focusing on the limitations of, STM / STS spectra of elements that may generate dust on the production line are stored in a database and inspected. The system is capable of analyzing dust by comparing it with target data. This system can be used to fix the element type of foreign matter and evaluate the source and take countermeasures.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 15.

FIG. 1 is a block diagram showing an embodiment of a method and an apparatus for starting up mass production in a semiconductor manufacturing process and inspecting a foreign substance on a mass production line according to the present invention. In FIG. 1, the mass production start-up in the semiconductor manufacturing process and the foreign substance inspection device on the mass production line include an exposure device 101, an etching device 102, a cleaning device 103, an ion implantation device 104, a sputtering device 105, a CVD device 106 and the like. A semiconductor manufacturing apparatus group 100, a sensing unit 200 including a temperature sensor 201, a dust generation monitor 202, a pressure sensor 203, a vacuum dust generation motor 304, and the like, a sensing unit control system 205, a gas supply unit 301, and a water supply unit 302. Utility group 300 consisting of
01, a gas sampling wafer 402, an in-apparatus sampling wafer 403, a device wafer 404, a sampling unit 400 including an atmosphere sampling wafer 405, a detection unit 500 including a wafer foreign matter detection unit 501 and a pattern defect detection unit 502,
Scanning electron microscope (SEM) and secondary ion mass spectrometer (S
IMS) 602 and scanning tunneling microscope / spectrometer (STM / ST)
S) Analysis unit 600 including 603, infrared spectrometer 604, etc., foreign matter lethality determination system 701, and minute foreign matter cause investigation system 702
And a response system 700 comprising a pollution source countermeasure system 703. In addition, these components are divided into an online foreign substance inspection system 1001 for mass production lines and an offline foreign substance inspection system 1002 for mass production start-up lines. Make

2 (a) to 2 (d) show the sampling section 400 of FIG.
1 is a configuration perspective view showing one embodiment. Fig. 2 (a)-
In (d), the water sampling wafer of FIG. 2 (a)
401 is a buffer chamber in a unit consisting of pure water piping 406, sampling faucet 407, buffer chamber 408, and drainage means 409.
The foreign matter in the pure water of the water supply unit 302 shown in FIG. The gas sampling wafer 402 shown in FIG. 2B is similarly placed in a buffer chamber 412 in a unit including a gas pipe 410, a sampling valve 411, a buffer chamber 412, a rotary pump 413, and an exhaust unit 414. Foreign substances in the gas of the gas supply unit 301 in FIG. 1 are sampled. The sampling wafer 403 in the apparatus shown in the sectional view of FIG.
2) Inside loader room 403, treated water 417 and unloader room 4
The foreign matter generated in the processing device 415 after passing through the sampler 18 is sampled. In this sampling, both the case where the processing is actually performed in the processing chamber 417 and the case where the processing is not performed are considered. The device wafer 404 is a wafer that is actually processed by the processing apparatus 415 (such as the etching apparatus 102). The atmosphere sampling wafer 405 shown in FIG. 2D is placed on the sampling table 420 in the processing environment 419, and foreign substances in the processing environment 419 are sampled.

FIG. 3 is a block diagram showing a configuration of an embodiment of the detecting section 500 shown in FIG. In FIG. 3, the detection unit 500 includes a vacuum chamber 511, a high vacuum pump 512 such as an ion pump or a turbo molecular pump, a valve 513, a roughing pump 514 such as a rotary pump, windows 515, 516, 517, and a gate valve 51.
8, a vacuum chamber system 510 comprising a gate valve 520, a vacuum pump 521, a valve 522, and a gas spray nozzle 523, and a semiconductor laser.
531,532, condenser lenses 540,541, mirrors 533,534, condenser objective lenses 535,536, detection objective lens 537, detector 538, a detection optical system 530 composed of a cooler 539, a stage section 560 composed of an XYZ stage 561, and binarization. A signal processing system 570 including a circuit 571, a stage controller 572, a signal processing unit 573, and a coordinate data generating unit 574, an interface room 581, a load lock 582, a wafer mounting unit 583, a wafer transfer unit 584, a gas spray nozzle 585, and a valve 586. And trolley 5 with vacuum pump 587
And an interface unit 580 composed of 88.

FIG. 4 is a block diagram showing a configuration of an embodiment of the analyzing section 600 of FIG. In FIG. 4, the analysis unit 600 includes a vacuum chamber 611, a high vacuum pump 612 such as an ion pump or a turbo molecular pump, a roughing pump 614 such as a rotary pump, a gate valve 618, a preliminary vacuum chamber 619, a gate valve 620, and a vacuum. A vacuum chamber 610 comprising a pump 621, a valve 622, and a gas spray nozzle 623, and an atomic force microscope (AFM: At
omic Force Microscope) tip (AFM tip) 631
And weak force reaction lever 632, lever fixing part 634, and STM tip 6
33 and STMXYZ fine movement unit 635, AFM bias power supply 638 and STM
Bias power supply 637, current measuring means 639,640, and sample mounting table 64
1 and STM unit arm 636 and sample STM coarse drive unit 642
The signal processing unit 670 includes an STM unit 630, a STMXYZ fine movement unit controller 671, a sample STM coarse drive unit controller 672, an analysis data creation unit 674, an analysis data storage unit 675, an analysis data determination unit 676, and an information management unit 673.
And an interface unit 5 which is the same as that of the detection unit 500 in FIG.

Next, the sampling unit 400 shown in FIGS. 2, 3 and 4 which is the core of the off-line foreign matter inspection system 1002 shown in FIG.
The functions and operations of the detection unit 500 and the analysis unit 600 will be described.

The sampling unit 400 shown in FIGS. 2 (a) and 2 (b) is used, for example, in the unit shown in FIG. 2 (a) as an evaluation of pure water used in various manufacturing steps of the water supply unit 302 shown in FIG. Foreign matter in the pure water is caused to adhere to the sampling wafer 401 while pouring the pure water onto the sampling wafer 401. Alternatively, a processing apparatus 415 having a vacuum processing chamber or the like in FIG.
(For example, the etching wafer 102)
03, and adheres foreign matter generated in the processing device 415. Further, the sampling wafer 405 is left at an arbitrary position in the clean room of the processing environment 419 shown in FIG. 2D, and foreign substances in the atmosphere are attached to the wafer 405. Next, the details of the sampling wafers 401 to 405 used here will be described with reference to FIGS.

FIG. 5 is a perspective view showing a mirror wafer of the sampling wafers 401 to 405 in FIGS. 1 and 2 (a) to (d). The mirror-surface wafer shown in FIG. 5 has a mirror-polished wafer surface, and has the advantage of being least affected by the wafer surface in detecting and analyzing foreign matter.

FIGS. 6 (a), (b) and (c) show the formation of Si ₃ N ₄ , Poly-Si and Al films on the sampling wafers 401 to 405 of FIGS. 1 and 2 (a) to (d), respectively. FIG. 3 is a perspective view showing a wafer that has been cut. 6 (a), (b), and (c) have the same material as the wafer to be cleaned in evaluating the cleaning tank (cleaning device 103 and the like), for example. It is possible to evaluate the septic tank with higher accuracy. Each of these wafers can be passed through a film forming apparatus or the like in the next step of the formed film to evaluate the state of foreign matter generation in the film forming apparatus or the like.

FIGS. 7 (a), (b), (c) and (d) show sampling wafers 401 to 405 of FIGS. 1 and 2 (a) to (d).
7 (a) and 7 (b) are perspective views showing a wafer on which the pattern shown in FIG.
The pattern shown in the partial enlarged view of (d) is formed, and the pattern shape of each of these wafers is a model of the pattern of an actual device. FIG. 7 (a)
The wafers (d) to (d) take into account the fact that the adhesion of foreign matter depends on the pattern shape, and these wafers can accurately reproduce the state of adhesion of foreign matter on an actual device. Further, in detecting foreign matter, in the case of regularly formed patterns such as these wafers, a diffraction filter from the pattern can be shielded with high accuracy by a spatial filter or the like, so that foreign matter can be detected with high accuracy. Specifically, in the case of the wafer pattern shown in FIGS. 7A and 7C, the longitudinal direction of the pattern is set to the XYZ stage 561 of the detection unit 500 shown in FIG.
When the wafer 401 is placed in the illustrated y direction, the diffracted light from the pattern does not enter the detection objective lens 537 of the detection optical system. In the case of the wafer pattern shown in FIGS. 7B and 7D, the direction of the pattern is changed to the detection unit 500 shown in FIG.
The XYZ stage 561 may be placed in a direction rotated by 45 ° with respect to the illustrated y direction. In this case, since there is scattered light from the intersection 406 of the pattern in FIG. Although the foreign matter detection cannot be performed with higher accuracy than the pattern shown in FIG. 7C, the actual device is modeled more faithfully than the pattern shown in FIG. Can be achieved.

8 (a), (b), (c) and (d) show FIGS. 1 and 2 (a) to (d) show sampling wafers 401 to 405.
FIG. 3 is a perspective view showing a lapping direction at the time of manufacturing the device and a scanning direction at the time of inspection. Normally, a mirror surface is polished on the wafer surface as a final finish when the wafer is manufactured, and the polishing direction at this time is the rotation direction around the central axis of the wafer as shown by an arrow in FIG. 8 (a). This is considered to be the case, the case in the y direction of the wafer as shown by the arrow in FIG. 8B, and the case of combining these FIGS. 8A and 8B. Therefore, a large number of small flaws parallel to the polishing direction of the wafers of FIGS. 8A and 8B are formed on the wafer surface, and the wafers of FIGS. 8A and 8B are combined in the polishing direction. Also, there are flaws in the direction mainly formed by the synthesis of these, but these flaws hinder detection of minute foreign particles on the wafer. Therefore, as shown by arrows in FIGS. 8 (c) and 8 (d), foreign substances are inspected on the wafer surface by scanning in the r, θ and x, y directions, respectively. The direction of the flaw can be kept constant with respect to the detection direction 802, and light mainly diffracted by the flaw direction can be cut.

1 and 2 (a) to (d), the sampling unit 401 to which the foreign matter is adhered by the sampling unit 400.
405 is sent to the detection unit 500. At this time, if it is not desired to put the wafer into the atmosphere using a vacuum processing apparatus or the like, the sampling wafers 401 to 40 are used by using the interface unit 580 shown in FIG.
5 can be carried into the vacuum chamber 511. Further, an alignment mark is attached to the sampling wafers 401 to 405 later as a coordinate standard for coupling between the detection unit 500 and the analysis unit 600. This alignment mark may be a cross mark or a # mark. Also, since x, y, and θ are required for coordinate matching, it is necessary to attach at least two or more places.

In the detection unit 500 shown in FIG. 3, the sampling wafer 401 loaded by the wafer foreign matter detection unit 501 is placed on the XYZ stage 561, and the light from the semiconductor lasers 531 and 532 is irradiated by the condensing objective lens of the irradiation optical system with 535 and 536. The measurement point 803 on 401 is illuminated. The scattered light from the foreign matter on the measurement point 803 is imaged on the detector 538 by the detection objective lens 537 of the detection optical system. The signal photoelectrically converted by the detector 538 is binarized by the binarization circuit 571 and sent to the signal processing unit 573. On the other hand, the XYZ stage 561 is controlled so that the Z stage is driven during the inspection so that the measurement point 803 comes to the focal position of the detection objective lens 537 of the detection optical system. The entire surface is inspected. If a foreign substance is present, the signal processing unit 573 fetches the coordinates of the XY stage from the stage controller 572, creates coordinate data in the coordinate data creation unit 574, and sends it to the analysis unit 600.

Next, the analysis using the STM / STS 603 in the detection unit 600 shown in FIG. 4 will be described. Analysis using STM (STS: Scanning
Tonneling Spectroscopy is “Surface” Vol.26 No.6 (198
8) pp.384-391 “Scanning Tunneling Microscope / Spectroscopy (STM /
Application of STS) to Research on Catalyst Surface ”etc. In this document, it is described that STM / STS can measure with high spatial resolution, but has a disadvantage that element types cannot be identified. According to this document, the information that can be collected by the STM is only the bias voltage V, the tunnel current i, and the change ΔZ in the distance between the needle tip and the sample.
By calculating / dz, the work function φ of the sample surface can be calculated. Although the above document does not clarify the reason why the element species cannot be identified, it is considered that the element species cannot be identified for the following reasons. That is, since the work function φ is a function of the bonding state between the element species and the element, there can be considered many element types having one work function φ and the bonding state of the elements. Therefore, even if the work function φ can be determined, the element type and the element Cannot be determined. However, the present inventors have noticed that there is a limit to the elements that can be mixed in the semiconductor production line, and based on the work function φ obtained by STM / STS, We focused on the fact that it is possible to select from limited elements as follows.

The tunnel current i _T that can be detected by the ammeter 640 of the analysis unit 600 in FIG. 4 is, for example, “Applied Physics” Vol. 56, No. 9, pp. 1126-1.
According to 137 "scanning tunnel microscope", it is calculated by the following equation.

Here, J _T is the tunnel current density, e is the charge of the electron, h is the Planck constant, m is the mass of the electron, and φ is the work function.
In this equation (2), V _T is the bias voltage of the bias power supply 638, and the tunnel current i _T can be measured.
Since only the unknown value is unknown, the work function φ can be calculated by measuring the distances Z and Z + ΔZ between the needle tip and the sample and the tunnel current i _T.

FIG. 9 shows the work function xy of the sample 401 of the analyzer 600 of FIG.
It is a distribution map. The work function φ is calculated from the equation (2) by measuring the tunnel current i _T of the sample 401 by the analysis unit 600 in FIG. 4, and the distribution of the work function φ on the xy plane as shown in FIG. The distribution of the material of the sample 401 can be understood in the atomic order.

FIG. 10 is a cross-sectional view of the sample 401 of the analysis section 600 of FIG. The value of the work function φ of the sample 401 of the analysis unit 600 in FIG.
In the structure of the thin film 821 and the foreign matter 822 of the sample 401 as shown in FIG. 10, the work function of the entire system formed by the thin film 821 and the foreign matter 822 becomes the work function φ of the sample 401 shown in FIG. Since the database differs depending on the material of the base, it is necessary to measure various samples of the base. Conversely, if these data are taken for various bases, the material of the sample 401 can be inferred.

FIG. 11 shows the sample 401 and the AFM chip 631 of the analysis section 600 shown in FIG.
FIG. 6 is a function diagram of a distance Z and an atomic force f. When the Z direction of the STM chip 633 is controlled while keeping the current i _A constant in the analysis 600 of FIG. 4, the distribution of the force f between the sample 401 and the AFM chip 631 can be measured by the AFM chip 631, and FIG. The atomic force f between the sample 401 and the AFM chip 631 as shown in FIG.
The relationship between 01 and the distance Z between the AFM chips 631 is obtained. According to Kittel, "Introduction to Solid State Physics, First Volume," Vol. 4, pp. 114-122, published by Maruzen Co., Ltd., this fz waveform is the sum of the cloning force and the repulsive energy, and therefore has two parameters. The two parameters are f-
Determine the z waveform. Assuming that these two parameters are α and β, the force f between the sample 401 and the AFM chip 631, the force between the sample 401 and the AFM
The following relationship is established with the distance Z between the chips 631.

Also, from the equation (3), the force f at two distances Z, that is, AF
By measuring the Z coordinate of the M-chip drive unit 635, the parameters α and β can be calculated.

FIG. 12 shows the sample 401 and the AFM chip 631 of the analysis section 600 shown in FIG.
FIG. 7 is a relational diagram of parameters α and β of a relational expression (3) between a distance Z and a nuclear force f and a work function φ of a sample 401.
From the measured values of f at two Z positions from the above equation (3), α,
When the result of calculating β and the value of the work function φ calculated from the measured value of i _T from the above equation (2) are plotted in three dimensions as shown in FIG. The plot position 811 or position 812 in is determined. That is, if the data of α, β, and φ are measured for a known foreign substance, the type of abnormality can be identified from the three-dimensional plot position of α, β, and φ of the measurement target.

FIG. 13 is a diagram showing the relationship between the tunnel current i and the atomic force f of the sample 401 of the analysis unit 600 shown in FIG. 4, and shows the relationship between the tunnel current and the change ΔZ of the distance Z while keeping the bias voltage V constant. It is a database obtained by measuring i _T and the interelectron force f of the above equation (3) and can be used as a database. At the current STM-related research level, the exact correlation between the tunnel current i and the atomic force f and the relationship between the elemental species are not fully understood, but this tunnel current i-atomic force f spectrum is By measuring many substances related to materials and foreign substances, it can be used for identification of a measurement object. The spatial distribution of the work function φ is also a powerful clue for element identification.

The sampling unit 400, the detection unit 500, and the analysis unit 600 of the off-line inspection system 1002 for mass production start-up of the semiconductor manufacturing process shown in FIG. By doing so, it is possible to classify the element type of the foreign substance by comparing the measurement result with the measurement result of the measurement object. This concept ignores the exact meaning of the work function and the reasons for the occurrence of other phenomena, and is inadequately useful for the purpose of identifying foreign elements and "estimating" the source. .

In addition, since the units of the sampling unit 400, the detection unit 500, and the analysis unit 600 of the inspection system can be operated at all times by connecting the units by coordinate management, the conventional system is disclosed in Japanese Patent Application Laid-Open No. 60-218845. The operation rate of each unit can be increased as compared with the technology in which each unit is connected and used as a mechanism. In addition, the performance of each unit can be easily improved.However, this is because the vibration of the whole system is increased by combining the conventional units mechanically, and the vibration of the whole system is increased. This is because an increase in the number of electrical nozzles due to a loss of balance can be eliminated.

The system 700 of the offline inspection system 1002 for mass production start-up of the semiconductor manufacturing process shown in FIG. 1 is based on the information on the foreign matter on the sample detected and analyzed by the sampling unit 400, the detection unit 500, and the analysis unit 600. The source of foreign matter is estimated, and one of the measures is taken to eliminate dust on the mass production line, which is considered to be the source. Be evaluated.
On the other hand, there is a monitor of the sensig unit 200 that can easily manage the process and equipment of the online foreign substance inspection system 1001 corresponding to mass production lines that have been found to be a dust source of foreign substance generation, and the material or atmosphere in real time. By installing this, this work will be carried out when starting mass production of LSI. The sensing unit 200 also corresponds to a sampling wafer, but normally monitors the product wafer 406. Further, during mass production, the device, process, and the like are constantly monitored by the monitor of the sensing unit 200 installed in the online foreign substance inspection system 1001, and the cause is investigated by the offline inspection system 1002 when an abnormality occurs.

Next, a description will be given of an in-vacuum dust monitor 204 as an embodiment of the sensor of the sensing unit 200 of the online inspection system 1001 for mass production start-up in the semiconductor manufacturing process of FIG.
The air dust monitor cannot be used because there is no medium for conveying dust in the vacuum, but the embodiment of the present invention utilizes the fact that there is no medium for conveying dust in this vacuum. In other words, when there is no medium to transport the dust in the vacuum, it falls down by dust or gravity, or is pulled by electrostatic force or moves randomly by ground motion. Power dominates. Therefore, a technique for counting the number of dust particles in a vacuum using these two forces has been devised.

FIG. 14 is a block diagram showing a configuration of an embodiment of the vacuum dust generation monitor 204 of the sensing unit 200 of FIG. 14, the in-vacuum dust generation monitor 204 is a vacuum processing device 107.
A port 221, a negative grid electrode 222, and a positive grid electrode
223, a positive plate electrode 225, a negative plate electrode 224, an applied power source 229, ammeters 226, 227 and a current counter 228,
A DC voltage is applied between the negative grid electrode 222 and the positive plate electrode 225 and between the positive grid electrode 223 and the negative plate electrode 224 by an applied power supply 229, and the ammeters 226 and 227 each have a high sensitivity capable of measuring even a single charge. It consists of.

The operation of the above configuration will be described with an example in which a foreign substance 811 or a foreign substance 812 is generated and jumps to the positive grid electrode 223 or the negative grid electrode 222. Now, when the foreign matter 811 passes through the positive grid electrode 223 and there are electrons excited in the foreign matter 811, the positive grid electrode 223 receives the electrons.At this time, the foreign matter 811 is positively charged and is applied to the negative plate electrode 224. Reach. As a result, the applied power 229
A current flows between the positive grid electrode 223 and the positive grid electrode 223. This current can be detected by the ammeter 226, and the number of times the current has flowed can be counted by the current counter 228 to count the number of foreign particles 811 that have flown. When the foreign matter 812 is likely to emit electrons when passing through the negative grid electrode 222, the foreign matter 812 receives the electron from the negative grid electrode 222, is negatively charged, and reaches the positive plate electrode 225. At this time, a current flows and is detected by the ammeter 227, and the number of times the current has flowed is counted by the current counter 228, so that the number of flying foreign substances 812 can be counted.

In FIG. 14, the in-vacuum dust generation monitor 204 has both the negative grid electrode type and the positive grid electrode type. However, depending on the application, one having only one of them is sufficiently useful. For the sake of explanation, the foreign substances 811, 812 are apt to receive electrons or emit electrons easily. However, in the present embodiment, this is not necessarily the case, and any particles are forcibly applied with a voltage. Can be counted. However, it is considered that the counting can be reliably performed because the foreign matter described above does not get hindered by the respective voltages when flying.

FIG. 15 is a configuration perspective view showing another embodiment of the in-vacuum dust monitor 204 of the sensing unit 200 of FIG. FIG. 15 shows an example in which the in-vacuum dust generation monitor 204 is installed in the piping system of the vacuum processing apparatus instead of in the vacuum processing apparatus 107 of FIG. In the in-vacuum dust generation monitor 204, the current flowing between the negative grid electrode 222 and the positive grid electrode 225 disposed in the pipe 107 is detected by the ammeter 227, so that foreign substances moving on the gas flowing in the pipe 109 are removed. The number can be counted with a current counter.

〔The invention's effect〕

Since the present invention is configured as described above, the purpose of the present invention is to separate the foreign substance inspection system at the start of mass production in the semiconductor manufacturing process from the foreign substance inspection system at the mass production line. Since functions can be maximized, feedback to the mass production line can be smoothly advanced, and the mass production start-up period can be shortened.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a method and an apparatus for starting up a mass production in a semiconductor manufacturing process and a mass production line according to the present invention, and FIGS. 2 (a) to 2 (d) are sampling diagrams of FIG. FIG. 3 is a configuration block diagram showing one embodiment of the detection unit of FIG. 1, and FIG. 4 is a configuration block diagram showing one embodiment of the analysis unit of FIG. FIG. 5 is a perspective view showing a mirror-surface wafer of the sampling wear of FIG. 1, and FIGS. 6 (a), (b) and (c) are Si ₃ N ₄ , Poly-Si, FIGS. 7 (a) to 7 (d) are perspective views showing an Al film forming wafer, FIGS. 7 (a) to 7 (d) are perspective views showing a pattern forming wafer of the sampling wafer of FIG. 1, and FIGS. 8 (a) to 8 (d) are FIGS. FIG. 9 is a perspective view showing the lapping direction and the scanning direction of the sampling wafer. FIG. 9 is an xy distribution diagram of the work function of the sample shown in FIG. FIG. 10 is a cross-sectional view of the sample of FIG. 4, FIG. 11 is a diagram showing a relationship between an AFM chip sample distance and an atomic force in FIG. 4, and FIG. 12 is a diagram showing a relationship between α, β, and φ in FIG. , Thirteenth
FIG. 4 is a diagram showing the relationship between tunneling current and electron force in FIG. 4, FIG. 14 is a block diagram showing an embodiment of a vacuum dust generation monitor of the sensing unit in FIG. 1, and FIG. FIG. 9 is a configuration perspective view showing another embodiment of a dust generation monitor in a vacuum of a sensing unit. 100: Semiconductor manufacturing equipment group, 200: Sensing unit, 204
…… Dust generation monitor in vacuum, 300 …… Utility group, 400
…… Sampling unit, 401 to 405 …… Sampling wafer, 500 …… Detection unit, 600 …… Analysis unit, 603 …… STM / STS,
700… Corresponding system, 1000… Mass production start-up and mass production line foreign substance inspection system for semiconductor manufacturing process, 1001… Online foreign substance inspection system, 1002… Offline foreign substance inspection system, 531 532… Semiconductor laser, 535,536… Focusing Objective lens, 537… Inspection objective lens, 538 …… Detector, 571 …… Binarization circuit, 572 …… Stage controller, 581 …… Interface room, 631 …… AFM chip, 633 …… STM chip, 635 …… STMXYZ fine movement unit, 6
42 ... Sample STM coarse drive unit.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Yamaguchi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Hitachi, Ltd.Production Technology Research Laboratories (72) Inventor Makiko Kono 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock (72) Inventor Yoshimasa Oshima 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture In-house Hitachi, Ltd. Production Technology Laboratory (58) Fields investigated (Int.Cl. ⁶ , DB name) H01L 21 / 66 G01R 31/26 H01L 21/02 B23Q 41/02

Claims (7)

(57) [Claims] 1. A system for detecting, analyzing, and evaluating foreign substances at the start of mass production when evaluating the foreign substance management status of materials, processes, equipment, and the environment using a sampling wafer at the start of mass production in a semiconductor manufacturing process. Separate from the mass production line, feed back the result of the system to the mass production line,
A method for starting up mass production in a semiconductor manufacturing process and inspecting foreign substances in the mass production line, wherein the monitoring is performed only with a simple monitoring device in the mass production line. 2. The semiconductor manufacturing process according to claim 1, wherein the foreign matter detection / analysis / evaluation system detects foreign matter on the sampling wafer and then analyzes the element type of the foreign matter by STM / STS. Mass production start-up and mass production line foreign material inspection method. 3. The semiconductor manufacturing process according to claim 2, wherein the analysis data by STM / STS is stored in advance as a database, and the element type of the foreign substance is identified by comparing the data with the data to be analyzed. Mass production start-up and foreign material inspection method for mass production line. 4. A system for evaluating foreign material management status of materials, processes, equipment, and environment using a sampling wafer at the start of mass production in a semiconductor manufacturing process, wherein the foreign material detection / analysis / evaluation system at mass production start is mass-produced. The system is separated from the line, the result of the system is fed back to the mass production line, and the mass production line is configured to monitor only with a simple monitoring device. . 5. The semiconductor according to claim 4, wherein the foreign matter detection / analysis / evaluation system is configured to detect foreign matter on the sampling wafer and analyze an element type of the foreign matter by STM / STS. Mass production start-up in the manufacturing process and foreign material inspection equipment on the mass production line. 6. The structure according to claim 5, wherein the analysis data by STM / STS is stored in advance as a database, and the element type of the foreign matter is identified by comparing the analysis data with the data to be analyzed. Mass production start-up for semiconductor manufacturing process and foreign material inspection equipment for mass production line. 7. The apparatus according to claim 4, wherein the monitoring apparatus has a monitor for generating dust in a vacuum using gravity and / or electrostatic force.