JP2728508B2 - Dust detection method and semiconductor manufacturing apparatus using the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust monitoring system for a device in which the generation of dust inside a semiconductor manufacturing device or the like greatly affects its performance, and particularly to a device for inspecting a device to be inspected. The present invention relates to a dust detection method capable of easily specifying a dust generation point.

[Conventional technology]

A dust monitoring system for a device in which the generation of dust inside a semiconductor manufacturing device or the like has a great effect on its performance is conventionally provided with a semiconductor manufacturing device as described in Japanese Patent Application Laid-Open No. 60-218845. The inspected wafer is put into the inspection apparatus, and the inspection of the dust adhesion state and the like are performed.

[Problems to be solved by the invention]

The data obtained by the above-mentioned conventional technology is the sum of all the dust conditions in the semiconductor manufacturing equipment, and almost information can be obtained from where in the semiconductor manufacturing equipment and when dust adheres to the wafer. Absent. Therefore, the management of dust in semiconductor manufacturing equipment is mainly based on numbers, and when the total number of dust detected from wafers or the number of dust having a specific particle size exceeds a certain number, the semiconductor manufacturing equipment is stopped and the internal disassembly is stopped. Perform cleaning to remove dust adhering inside the equipment. Since this operation takes a long time, the operation rate of the apparatus is significantly reduced. In addition, since it is not possible to specify a dust generation location, there is another problem that it is difficult to clean unnecessary portions or to take appropriate measures to suppress dust generation at the dust generation location.

[Means for solving the problem]

In order to achieve the above-mentioned purpose of specifying the dust generation point, a mechanism for knowing when dust is detected is provided, and by comparing this detection time information with the time chart of each step in the apparatus, dust is reduced in the apparatus. Where it occurred. In addition, by constantly monitoring the outputs of the detectors provided at various places, it is possible to specify a dust generating point in the apparatus. In addition, when dust is detected, a mark is made in the apparatus, and the location of the dust can be specified by checking this mark. Further, by comparing the information on the dust of the processing object processed by the apparatus immediately before the apparatus is input and the information on the dust on the object to be processed immediately after passing through the apparatus, it is possible to monitor the internal dust generation state. Furthermore, it can be achieved by specifying the dust generation location and changing the operating conditions of that location.

[Action]

When dust is generated in the apparatus and adheres to the sensor surface, the sensor introduced into the apparatus performs at least detection of the adhered dust and detection of the adhesion time by the sensor. In some cases, detection of the diameter of the attached particles and other information is also performed.
Information on the detection of the adhesion of dust obtained earlier and the adhesion time,
By comparing the time required for each step in the apparatus, it is possible to specify the place where dust adheres to the sensor. In addition, since the generation of dust at each location is constantly monitored by sensors provided at various locations inside the apparatus, the occurrence of dust is immediately detected, and thereby the location of dust generation can be specified. In addition, when dust generated in the apparatus adheres to the sensor surface, at least the sensor detects the attached dust and detects the adhesion time when the input sensor in the apparatus adheres to the sensor surface. At this time, the position of the sensor is marked in the apparatus. By confirming this mark, it is possible to specify the location where dust is generated.
Further, it is possible to monitor the state of generation of dust inside the apparatus based on a change in dust information immediately before insertion and immediately after unloading, which is detected by dust detection mechanisms provided immediately before the apparatus is input and immediately after the exit. Furthermore, since the dust sensor can identify a dust generating portion inside the apparatus, the dust generating amount can be controlled by changing the operating condition of this portion.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a flowchart of the embodiment. First, it has a mechanism to detect dust and a mechanism to detect the time when dust is detected,
A dust sensor provided with a mechanism for recording information on the dust detected by the detection mechanism is input to a device to be inspected for the internal dust generation status. Next, dust inside the apparatus is detected by the dust sensor. At this time, information on the time at which dust is detected is also recorded. In some cases, information on the particle size position of dust and the like are also recorded. When the recording of the dust information inside the device to be inspected is completed, a dust map is created based on the dust information recorded by the dust sensor. Using the map created after this, it is specified where the dust is generated in the device to be inspected. This is because the created map contains the time information at which dust was detected.Comparing this detection time with the chart of the required time of each step in the device under test, the time at which dust was detected It can be known where in the device the dust sensor was located. This makes it possible to specify a dust generation location.

FIG. 2 is a diagram showing the operation of the dust sensor used in the dust sensor system. The dust sensor has a detection mechanism for detecting dust, a mechanism for detecting the time of dust detection, a mechanism for determining whether the detected signal is due to dust, a mechanism for transferring dust information to the inside or outside of the dust sensor body, and transfer. There is provided a mechanism for recording the obtained information. First, the dust sensor is started. Next, the information inside the sensor is deleted to initialize the sensor. The information erased at this time is information detected by the detection mechanism, such as dust adhesion time information, dust adhesion position information, and dust adhesion number information. In some cases, dust particle size distribution information and dust components. Information is also included. Next, measurement of the in-sensor time is started to obtain the time information. Then, the dust sensor is initialized. It consists of two steps. First, scanning on the sensor surface is performed to detect dust adhering on the sensor surface at this time. Next, the detected result is used as initial information of the sensor. The initial information is
The information detected by the detection mechanism is the initial information collection time, dust attachment position information, dust attachment number information, and in some cases, dust particle size distribution information, dust component information, and the like.
After the initialization of the dust sensor, a trigger signal for dust measurement in the device to be inspected is input. With this trigger, the dust sensor starts measuring the dust after the device to be inspected is put in. The dust sensor is supplied to the device under test after receiving the trigger signal. The input dust sensor starts scanning the sensor surface for dust detection. When dust generated in the device to be inspected adheres to the sensor surface, it is detected by a detection mechanism provided on the center surface. Dust information is extracted based on this detection signal. Since the detection signal may include a signal generated due to disturbance due to something other than dust, this is compared with information in the sensor to determine whether the signal is due to dust. If it is determined that the signal is due to dust, this is used as dust information. The contents of this information include dust detection time information, dust adhesion position information, dust adhesion number information, and in some cases, dust particle size distribution information, dust component information, and the like. Next, processing for transferring this information is performed. In this processing, the dust information obtained by this scan is compared with the dust information obtained by the immediately preceding scan, and the transition of the information is obtained. This transition is then transferred to a mechanism for storing dust information provided inside or outside the sensor. The transferred dust information is sequentially stored in a storage mechanism. Next, it is determined whether or not to continue the detection and measurement of dust. When the detection is continued, the operation from the scanning for detecting the dust to the accumulation of the dust is repeated again. When the detection is terminated, a process for creating a dust map is performed based on the accumulated dust information. This processing is performed either inside the sensor or outside the sensor. After this processing is completed, the measurement operation of the dust sensor is stopped. The dust sensor for which measurement has been completed is carried out of the processing apparatus to be inspected. FIG. 3 is a diagram showing the operation of the detection mechanism for detecting dust in the dust sensor of the dust sensor system. In the present embodiment, the dust detection mechanism uses a light receiving sensor that detects light and scattering of light and dust obscuration. First, light for dust detection is emitted. When light scattering due to dust generated in the device to be inspected is detected, the light is emitted in parallel with the light receiving sensor surface so that the light does not directly enter the light receiving sensor. When dust generated in the apparatus enters a space from which light is radiated, light is scattered by the dust. Dust can be detected by detecting the scattered light with the light receiving sensor. Further, when detecting light obscuration due to dust generated in the apparatus, the light is emitted so that light directly enters the light receiving sensor surface. When dust generated in the apparatus adheres to the light receiving sensor surface, light entering the light receiving sensor is covered by the dust, so that the dust can be detected. In any case, the detection signal of the light receiving sensor caused by the dust is determined by comparing the signal due to the dust or the signal due to other disturbance with the information in the sensor. If it is determined that the signal is due to dust, the signal is regarded as dust information. If it is determined that the disturbance is other than the dust detection, the detection is continued.

The embodiment of FIG. 4 is an operation diagram of another detection mechanism for detecting dust by the dust sensor of the dust sensor system. In the present embodiment, the dust detection mechanism includes an AT plate crystal oscillator, a transmission circuit of the oscillator, and a frequency detection circuit. First, the AT plate crystal oscillator is oscillated by an oscillation circuit. If dust generated in the device to be inspected adheres to the surface of the oscillator, the thickness of the oscillator changes. The frequency decreases by an amount. The amount of decrease is detected. Next, it is determined whether the detection signal is due to dust or other disturbance by comparing it with information in the sensor. If it is determined that the signal is due to dust, the signal is regarded as dust information. If it is determined that the disturbance is other than dust, the detection is continued.

The embodiment of FIG. 5 is an operation diagram of another detection mechanism for detecting dust by the dust sensor of the dust sensor system. In this embodiment, the dust detection mechanism includes a detector for detecting a minute electric charge and a detector for detecting a minute electric current caused by a change in the minute electric charge. When dust generated in the device to be inspected adheres to the minute-charge detector, the dust is usually charged, and the adhesion is detected by the minute-charge detector. Also, at this time, a small current is generated due to a change in charge. This current is detected by a minute ammeter. Next, it is determined whether the detection signal is due to dust or other disturbance by comparing the information with the information in the sensor. If it is determined that the signal is due to dust, the signal is regarded as dust information. If it is determined that the disturbance is other than dust, the detection is continued.

The embodiment of FIG. 6 is an operation diagram of another detection mechanism for detecting dust by the dust sensor of the dust sensor system. In this embodiment, the dust detection mechanism uses a photochemical reaction. As the photochemical reaction, a type in which the photochemical reaction progresses due to the adhesion of dust and a type in which the photochemical reaction is stopped by the adhesion of dust are used. In the type in which the photochemical reaction progresses due to the attachment of dust, light for suppressing the photochemical reaction is periodically emitted. This reaction progresses in the absence of light and the chemical reaction progresses, and is proportional to the passage of time. Therefore, when dust adheres to the dust sensor, a corresponding portion of the sensor surface is covered by light, and a chemical reaction proceeds. The time at which dust adheres can be determined based on the degree of progress of the chemical reaction. In the type in which the photochemical reaction is stopped by the attachment of dust, light for promoting the photochemical reaction is periodically emitted. This reaction stops when no light is applied. This chemical reaction is proportional to the passage of time over the light. Therefore, the chemical reaction stops because the corresponding portion of the sensor surface where dust adheres to the dust sensor is covered with light. The time at which dust adheres can be determined based on the degree of progress of the chemical reaction.

FIG. 7 is an operation diagram of a detection mechanism for detecting dust in a dust sensor of a dust sensor system. In this embodiment, the dust detection mechanism uses a photochemical reaction, and has a structure in which a substance whose chemical reaction is promoted by light of a specific wavelength is applied to the sensor surface so as to react to various wavelengths. At the time of measurement for detecting dust by the dust sensor, the first light is emitted. At this time, if dust adheres to the sensor surface, the first light is obscured, and the chemical substance reacting to the first light in that portion does not perform a chemical reaction.
The second light is emitted a certain time after the first light is emitted. At this time, if dust adheres to the sensor surface, the second light is obscured as in the case of the first light, and the second light of that portion is covered.
Chemicals that react to light do not undergo a chemical reaction. This is repeated for a number of wavelengths one after another. This makes it possible to determine when dust has adhered by examining which light is not responding.

FIG. 8 is an operation diagram of a detection mechanism for detecting other dust in the dust sensor of the dust sensor system. In the present embodiment, the dust detection mechanism is composed of an accelerometer and a signal processing system generated by the impact of dust on the sensor surface. First, the accelerometer is activated. When dust collides with the sensor surface, it is detected by the accelerometer. At this time, it is possible to detect at which position dust adheres and at which position by a plurality of accelerometers provided in the sensor surface. In addition, a signal processing system for eliminating an excessive input signal from the sensor is operated so as not to confuse a signal of an impact when the dust sensor moves with a dust adhesion signal.

FIG. 9 is an operation diagram of another mechanism for detecting dust in the dust sensor of the dust sensor system. In the present embodiment, microorganisms provided on the sensor surface are stimulated by the adhesion of dust to stimulate or suppress the growth of microorganisms. When the adhesion of dust stimulates the growth of microorganisms, when the dust adheres to the sensor surface, the growth is promoted by the stimulation of microorganisms in the portion where the dust adheres. The growth of microorganisms is proportional to the time since the stimulus, so that it is possible to know when dust has adhered. In addition, when the adhesion of dust is a stimulus and the growth of microorganisms is stopped, when the dust adheres to the sensor surface, the microorganisms in the portion where the dust is attached are stimulated and the growth stops. The microorganisms in the portion to which dust adheres continue to grow until the growth stops, and since this growth is proportional to the passage of time, it is possible to know when dust adheres.

The embodiment of FIG. 10 is another system flow diagram. A detection mechanism for detecting dust is provided in each part of the apparatus to be inspected, and the generation of dust in each part in the apparatus is monitored. As soon as dust is generated and detected by the detection mechanism, it is possible to specify which detection mechanism the dust detection is based on the information, and it is possible to specify the dust generation location.

The embodiment of FIG. 11 is still another system flow diagram.
A device is provided for inspecting the state of attachment of dust to the object to be processed immediately before the inlet of the object to be processed and immediately after the outlet of the object to be processed in the processing apparatus for monitoring the state of dust generation therein. The state of adhesion of dust is inspected by a device for inspecting the state of adhesion of dust, which is provided immediately before an inlet for introducing an object to be processed into the device to be monitored. Thereafter, the object to be processed is processed by the monitored device. After the treatment, the object to be processed is carried out, and the state of dust adhesion is inspected by an apparatus for inspecting the state of dust adhesion provided immediately after the exit. The dust generation status inside the monitored object processing apparatus can be monitored based on the dust adhesion information of the object to be monitored immediately before input to the processing apparatus and the dust adhesion information immediately after the processing.

The embodiment of FIG. 12 is a flowchart of yet another system. First, a mechanism for detecting dust, a mechanism for detecting the time at which dust is detected, a mechanism for recording information of the dust detected by this detection mechanism, and a position of the dust sensor in a device to be inspected when dust is detected. A dust sensor equipped with a mechanism is put into a device to be inspected for the inside dust generation status. Next, the dust inside the device is detected by the dust sensor. At this time, information on the time at which dust is detected is also recorded.
In some cases, information on the particle size position of dust and the like are also recorded. In addition, when dust detection is performed, a mark indicating the current position of the dust sensor is placed in the device to be inspected.
The material of this mark is a substance that is hard to cause dust and that can be easily removed after confirmation of the mark. When the recording of the dust information inside the device to be inspected is completed, a dust map is created based on the dust information recorded by the dust sensor. Thereafter, the location where dust is generated can be specified by the map created and the mark attached in the apparatus.

The embodiment of FIG. 13 is still another system flow diagram.
First, a semiconductor sensor for inspecting the state of dust generation inside a dust sensor provided with a mechanism for detecting dust, a mechanism for detecting the time at which dust is detected, and a mechanism for recording information of the dust detected by this detection mechanism. To Next, dust inside the apparatus is detected by the dust sensor. At this time, information on the time at which dust is detected is also recorded. In some cases, information such as the position of the particle size of dust is also recorded. When the recording of the dust information inside the semiconductor manufacturing apparatus to be inspected is completed, then a dust map is created based on the dust information recorded by the dust sensor. Using the map created thereafter, it is specified where the dust is generated in the semiconductor manufacturing apparatus to be inspected. This is because the created map contains the time information at which dust was detected.Comparing this detection time with the chart of the required time of each step in the device under test, the time at which dust was detected It can be known where in the device the dust sensor was located. As a result, it is possible to specify a dust generation location.

FIG. 14 is an external view of a dust sensor. The same diameter as the wafer used for processing in normal semiconductor manufacturing equipment, so that it is easy to inspect the state of dust generation inside the semiconductor manufacturing equipment,
It has the same thickness. A dust detection mechanism 11 is provided on a side corresponding to a surface to be processed of a wafer which is usually processed in a semiconductor manufacturing apparatus. A peripheral mechanism 12 containing a mechanism for detecting the time at which dust is detected and a mechanism for recording information on the detected dust is provided below the dust detection mechanism 11.

FIG. 15 is an external view of a wafer provided with a dust sensor. A dust sensor 1 is provided on a side corresponding to a surface to be processed of a wafer 2 which is usually processed in a semiconductor manufacturing apparatus.

The embodiment of FIG. 16 is a system flow diagram of a semiconductor manufacturing apparatus using a dust sensor system. First, a dust sensor equipped with a mechanism for detecting dust, a mechanism for detecting the time at which dust is detected, and a mechanism for recording information of the dust detected by this detection is provided inside a semiconductor manufacturing apparatus for controlling the internal dust generation situation. To Next, the dust inside the device is detected by the dust sensor. At this time, information on the time at which dust is detected is also recorded. In some cases, information such as the particle size and position of dust is also recorded. When the recording of the dust information inside the controlled device is completed, a dust map is created based on the dust information recorded by the dust sensor. Using the map created thereafter, where the dust is generated in the controlled device is specified. This changes the operating conditions of the dusting point. Thus, the amount of dust generated inside the controlled device can be controlled.

〔The invention's effect〕

According to the present invention, as described above, since the dust sensor can detect when dust adheres to the sensor, it is possible to specify from which part of the apparatus the dust is generated. In addition, since the inside of the apparatus is constantly monitored by the sensor provided in the apparatus, a dust generation point can be immediately specified. In addition, by confirming the mark attached to the inside of the apparatus, the dust generation point can be specified. Further, it is possible to monitor the state of dust generation in the apparatus based on a change in dust information immediately before insertion and immediately after unloading detected by dust detection mechanisms provided immediately before the entrance of the apparatus and immediately after the exit. Furthermore, since a dust generation point inside can be specified by the dust sensor, it is possible to control the amount of generated dust by changing the operating conditions at this point.

[Brief description of the drawings]

FIG. 1 is a system flow diagram of one embodiment of the present invention, FIG. 2 is a diagram of the operation of a dust sensor used in a dust sensor system in another embodiment, and FIG. 3 is dust of the dust sensor in still another embodiment. FIG. 4 is an operation diagram of a detection mechanism for detection, FIG. 4 is an operation diagram of another dust detection mechanism of a dust sensor in still another embodiment, and FIG. 5 is another dust detection mechanism of a dust sensor in still another embodiment. FIG. 6 is an operation diagram of another dust detection mechanism of a dust sensor in still another embodiment, and FIG. 7 is an operation diagram of a dust detection mechanism of a dust sensor in still another embodiment.
FIG. 8 is an operation diagram of another dust detection mechanism of the dust sensor in still another embodiment, and FIG. 9 is an operation diagram of another dust detection mechanism of the dust sensor in still another embodiment.
10 is another system flow diagram in still another embodiment, FIG. 11 is another system flow diagram in still another embodiment, FIG. 12 is another system flow diagram in still another embodiment, FIG. FIG. 14 is another system flow diagram in still another embodiment, FIG. 14 is an external view of a dust sensor in still another embodiment, FIG. 15 is an external view of a wafer provided with a dust sensor in still another embodiment, FIG. 16 is a system flow diagram of a semiconductor manufacturing apparatus using a dust sensor system in still another embodiment. 1 ... Dust sensor, 2 ... Wafer, 11 ... Dust detection mechanism, 12 ... Peripheral mechanism.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoko Ichikawa 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref.Hitachi, Ltd.Mechanical Laboratory Co., Ltd. In the laboratory (72) Inventor Toshio Akatsu 502 Kandachi-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Kimio Muramatsu 111, Nishiyokote-cho, Takasaki-shi, Gunma Pref.

Claims (15)

(57) [Claims] A dust sensor having a detection mechanism for detecting dust and a mechanism for detecting a time at which the dust is detected, and a mechanism for recording information of the dust detected by the detection mechanism is provided. The occurrence situation is introduced and passed into the device to be inspected, and based on the information obtained by this dust sensor,
A dust detection method, comprising: creating a diagram of the state of dust generation in a device to be inspected, and enabling the location of dust generation in the device to be inspected to be identified using the chart. 2. The dust detecting method according to claim 1, wherein the dust sensor includes a detecting mechanism for detecting the dust, a detecting mechanism for detecting the time of the dust detection, a determining mechanism for determining whether or not the detected signal is due to the dust, Equipped with a mechanism to transfer information to the inside or outside of the dust sensor body and a mechanism to record the transferred information, erase the information inside the sensor immediately after starting the dust sensor, and then detect the initially attached dust on the sensor surface This is used as initial dust information, and then inspection / detection for detection of dust in the device to be inspected is performed by a trigger signal for performing inspection in the device to be inspected for the state of internal dust generation. Determine whether the detection signal is dust or not,
After transferring the obtained dust information to the inside of the sensor main body or to the outside of the sensor, recording and storing the transferred information, and repeating the operation from scanning for detection to recording and storage of information for a predetermined time, And processing the recorded / accumulated information as information for creating a chart of the status of dust generation in the device to be inspected. 3. The dust detection method according to claim 2, wherein the dust sensor detects the dust by using light for dust detection and:
A dust detection method using an element for detecting scattering and obscuration of the light by dust. 4. The dust detection method according to claim 2, wherein an AT plate quartz oscillator, a transmission circuit of this oscillator, and a frequency detection circuit are used for dust detection of the dust sensor. 5. The dust detection method according to claim 2, wherein a detector for detecting a minute electric charge and a detector for detecting a minute electric current caused by a change in the minute electric charge are used for detecting the dust of the dust sensor. . 6. The dust detection method according to claim 2, wherein a chemical reaction is used for detecting the dust by the dust sensor.
A dust detection method using the fact that the reaction of an adhering portion is started or stopped by the adhering of dust. 7. The dust detection method according to claim 2, wherein an accelerometer for detecting the collision of the dust with the sensor surface is used for detecting the dust of the dust sensor. 8. The dust detection method according to claim 2, wherein the detection of the dust by the dust sensor uses microorganisms, and utilizes the fact that the growth of the microorganisms is started or stopped by the adhesion of dust. Characteristic dust detection method. 9. A dust detection method according to claim 1, wherein a mechanism for detecting dust is installed in each part of the apparatus for inspecting the state of dust generation inside and constantly monitors dust information in each part. A dust detection method, comprising: identifying a dusting point in a device to be inspected. 10. The dust detection method according to claim 1, wherein
A mechanism for detecting dust is provided immediately before a workpiece input port and immediately after a workpiece outlet of a processing apparatus to be inspected for the state of internal dust generation, and monitors the state of dust generation inside the apparatus to be inspected. A dust detection method, comprising: 11. The dust detecting method according to claim 1, wherein
It has a detection mechanism for detecting dust and a mechanism for detecting the time at which dust is detected. A mechanism for recording information on the dust detected by this detection mechanism. When a dust sensor equipped with a positioning mechanism is inserted into or passed through a device to be inspected for dust generation inside, when the dust sensor detects dust, a mark identifying the position of the dust sensor is placed in the device. A dust detection method characterized in that it is possible to specify the location of occurrence in the inspection target device by using the mark. 12. The dust detecting method according to claim 1, wherein
A dust detection method, wherein a semiconductor manufacturing device is used as a device for inspecting the state of generation of dust inside. 13. The dust detecting method according to claim 1, wherein
A dust detection method, wherein the shape of a dust sensor is similar to that of a wafer that can be put into a semiconductor manufacturing apparatus. 14. The dust detection method according to claim 1, wherein
Dust sensor for wafer 1 put into semiconductor manufacturing equipment
A dust detection method comprising forming a portion. 15. A dust sensor having a detection mechanism for detecting dust and a mechanism for detecting the time at which the dust is detected, and a mechanism for recording information of the dust detected by the detection mechanism is provided. The dust generation status is input and passed into the semiconductor manufacturing equipment to be inspected, and based on the information obtained by this dust sensor, a chart of the dust generation status in the device to be inspected is created. A semiconductor manufacturing apparatus characterized in that a dust generation point in an apparatus is specified, and an operation condition of the dust generation point in a device to be inspected is changed based on the identified dust generation point to control a dust generation amount.