JPH10199945A - Dust monitor apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automate measurements for obtaining dust accumulation data and history per stocker by measuring the amt. of dust deposited onto a test wafer and transferring carried test wafers to a dust-measuring means. SOLUTION: A carrier 10 mounted on a truck 7 which moves a rail 8 houses wafers 9, and a stocker rail transfer machine 6 operates to take in the carrier 10, while the carrier 10 entered from a conveyer 2 in front of a stocker 1 is taken in the stocker 1. The carrier 10 is automatically set on a wafer dust meter 5 by a robot 4 to measure the amt. of dust deposited to the wafer 9. The wafer 9 is then housed in the carrier again and mounted on the truck 7 by the movement of the rail transfer machine 6 to go to the next stocker 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust monitor device, and more particularly to a dust monitor device for evaluating the degree of dust adhesion, that is, the degree of cleanness, in transport equipment in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art As the density of semiconductor devices increases,
The problem of foreign matter (hereinafter referred to as dust) has become more and more important, and has become an important issue both in terms of process technology and manufacturing processes. In particular, in recent manufacturing processes for high-density LSIs and the like, it is said that dust is associated with 80% of the defects in some form. At present, the technology for measuring dust in the air and the technology for measuring the number of dust adhering to wafers have already been established as laser application technologies such as the light scattering method. The former is 0.1 μm and the latter is 0.15 μm.
It is possible to measure reliably up to about μm and further up to about 0.05 μm. Further, a method using an SEM (scanning electron microscope) has been widely used for finer dusts, and has already been applied in an inline manner.

Conventionally, as a method of evaluating the cleanliness of the transfer equipment between each process in a semiconductor factory, a method of directly determining the amount of dust adhering to a test wafer has been adopted. The method shown in FIG. 6 for transporting and measuring the test wafer between the steps has been adopted.

[0004] This method is carried out as follows. 1) First, the measurement operator sets the wafer 31 for dust evaluation.
Is set in a carrier 32 on which a plurality of wafers are placed, and the wafer stocker A (33)
-1). 2) Further, the measurement operator sequentially transports the wafer 31 for dust evaluation stored in the carrier 32 between the plurality of stockers (33-1 to 33-3). 3) Then, after transporting the carrier 32 to the final stocker C (33-3), the final stocker C (33-33)
Remove the carrier 32 from 3). 4) The carrier 32 taken out is carried to a wafer measuring device 35 by a cart 34 or the like, and the dust attached to the wafer 31 for dust evaluation is measured.

By the way, in such a conventional method, a) since only the final dust data at the time when the transport between the stockers is completed is known, the state of dust adhesion at the time when the transport between the stockers is difficult to see. There is a problem. For this reason, it takes time to find out the stocker and the transport path that are the dust sources. b) The measurement operator needs to enter the stocker into the first stocker and leave the stocker from the last stocker, and move from the last stocker to the measuring device with the carrier and perform measurement in front of the measuring device. is there. c) When the measuring instrument is shared with other workers, the measuring instrument may be on standby because it is in use. There is a problem that measurement requires time and labor, and is uneconomic.

[0006]

As described above, in the conventional dust monitor device, during the measurement operation, the measurement operator has to enter the stocker into the first stocker, take out the stocker from the last stocker, and carry it. Measuring work also had to be performed on the measuring instrument side, resulting in poor workability. further,
The data obtained was only the data of the final dust accumulation, and data for each stocker could not be obtained, and it took time to find out the dust source.

In view of this point, in the present invention, once the test wafer is set, the measurement is automatically performed, the burden on the operator is small, the measurement work time is short, the dust accumulation data for each stocker and the dust accumulation data. It is an object to realize a dust monitor device capable of obtaining a history.

[0008]

In order to achieve the above-mentioned object, the present invention provides a semiconductor wafer storage / transport means comprising a plurality of semiconductor wafer storage means and a transport means for transporting semiconductor wafers between the storage means. In the dust monitoring device for monitoring dust contamination of the above, provided in each of the storage means, the dust measurement means for measuring the amount of dust adhered on the test wafer to reach the individual storage means, and transported by the transport means Sample transfer means for transferring the test wafer to the dust measurement means, and collecting dust amount measurement data measured by the dust measurement means, calculating, recording,
It is characterized by comprising arithmetic control means for displaying and communication means between the arithmetic control means and the dust measuring means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a dust monitor according to the present invention will be described in detail with reference to the accompanying drawings. This method is for evaluating the cleanliness of the transport equipment between each process in a semiconductor factory. FIG. 1 is a configuration diagram of a single stocker used in the dust monitor device of the present invention. In FIG. 1, 1 is a stocker, 2 is a conveyor, 3
Reference numeral denotes a stocker controller, 4 denotes a robot, 5 denotes a wafer dust measuring device, 6 denotes a stocker / rail transfer machine, 7 denotes a carrier, 8 denotes rails, 9 denotes wafers, and 10 denotes a carrier.

The operation of each stocker 1 will be described. The carrier 10 containing the wafers 9 mounted on the carrier 7 moving on the rails 8 reaches the stocker 1 by the movement of the carrier 7 and moves to the stocker 1. -It is taken into the stocker 1 by the operation of the rail transfer machine 6. On the other hand, the carrier 1 received from the conveyor 2 in front of the stocker 1
0 is also taken into the stocker 1. The carrier 10 taken into such a stocker 1 is automatically set on the wafer dust measuring device 5 by the robot 4, and the amount of dust deposited on the wafer 9 in the taken carrier 10 is measured. .

After the dust measurement of the wafer 9 is performed in the stocker 1, the wafer 9 after the measurement is again transferred to the carrier 10.
, And is again mounted on the transport trolley 7 by the action of the stocker / rail transfer machine 6, and heads for the next stocker 1. The dust measurement may be performed on all the wafers 9 in the carrier 10 or may be performed on a specific one or several wafers 9.

The equipment control system in each stocker 1 is configured as shown in FIG. That is, a stocker controller 11 for controlling the stocker 1, a robot controller 12 for controlling a robot 4 for transferring a wafer into and out of the wafer dust measuring device 5, and a conveyor controller 13 for loading and unloading wafers from the front of the stocker 1.
The control is performed by a joint control operation of each controller mainly including the stocker controller 11, such as the wafer dust measuring device controller 14 that controls the wafer dust measuring device 5.

The data measured by the wafer dust measuring device 5 is once collected by the stocker controller 11 and then collected.
Transferred to wafer dust monitor terminal. The line between the controllers is, for example, RS458, RS
The connection is made using 232C or the like, but the connection type is not limited to this.

FIG. 3 is an explanatory diagram showing a working method of measurement in the present invention. FIG. 4 shows each wafer dust measuring device 5.
FIG. 3 is an explanatory diagram showing a state in which measurement data is communicated to a wafer dust monitor terminal 21 via each stocker controller 11.

An embodiment of measurement by the dust monitor of the present invention for measuring wafer dust by transferring between a plurality of stockers 1 will be described with reference to FIGS. 1, 2, 3 and 4. FIG. 1) First, as shown in FIG. 4, a carrier 10 carrying a wafer 9 to be measured is put on the conveyor 2 of the stocker A (1-1). 2) The robot 4 of the stocker A (1-1) automatically sends the stored carrier 10 to the wafer dust measuring device 5, and sets the wafer 9 in the measuring device. The wafer dust measuring device 5 measures the amount of dust deposited on the set wafer 9. During the measurement, the robot 4 can perform another transfer operation.

3) After the measurement is completed, the robot 4 automatically collects the wafer 9 and puts it in the carrier 10, and the stocker A
The carrier 10 carrying the wafer 9 to be measured carried out from (1-1) is placed on the carrier 7. 4) The carrier 10 transports the carrier 10 on the rail 8 to the next stocker B (1-2).

5) The data measured in 2) is transferred from the wafer dust measuring device 5 to the stocker controller 11 via the wafer dust measuring device controller 14. 6) Repeat steps 1) to 5) above in the final stocker C (1-
Repeat until 3).

7) As shown in FIG. 4, the data obtained by each stocker 1 is transferred from the stocker controller 11 to the wafer dust monitor terminal 21 via a network cable. 8) The wafer dust monitor terminal 21 arranges the data obtained by the individual stockers 1 and displays the data on the display device of the wafer dust monitor terminal 21. At this time,
You may make it output sequentially from the data of the stocker 1 in which the measurement was completed.

The format of the data display is, for example, as shown in FIG.
May be displayed as the dust adhesion history, or the difference between the measured values may be used to indicate the amount of dust adhered from the previous stocker to the stocker for each individual stocker 1. May be. This makes it possible to clarify the transition of dust adhesion on the test wafer 9 and the history of dust adhesion for each stocker 1.

Here, the measurement operation performed by the measurement operator simply involves placing the carrier 10 on which the test wafer 9 is mounted on the conveyor 2 in front of the stocker A (1-1) and performing the measurement procedure. From then on, if the observation is performed by the wafer dust monitor terminal 21, necessary data can be obtained.

As described above, according to the present invention, the stocker 1 is provided with the wafer dust measuring device 5, and the test wafer 9 is automatically transferred between the stockers 1. The data from each wafer dust measuring device 5 is And the wafer dust monitor terminal 21 for centralized management.

According to the above-described method, it becomes easy to narrow down the stocker and the transport path that are the source of dust.
Therefore, a process for minimizing the influence on the product can be performed by using this. Further, since the tendency can be managed on a stocker basis on a daily basis, it is possible to detect and prevent a problem caused by dust in advance. Further, the number of man-hours for the operator can be reduced both in man-hours for dealing with troubles and in the daily measurement work itself, and the running cost can be reduced accordingly.

Although not particularly mentioned in the above description, the cleanness of the stocker 1 can be evaluated by distinguishing the cleanliness of only the transfer equipment from the stocker 1 by forming the inside of the stocker 1 as a clean room. It is possible to prevent a difference in data indicating the amount of attached dust due to a change in the staying time inside 1.

Although the present invention has been described with reference to one embodiment, the present invention is not limited to this embodiment without departing from the gist of the present invention. In particular, various modifications are conceivable for the semiconductor wafer transfer format, the measurement data communication system, and the like.

[0025]

As described above, according to the first aspect of the present invention, there is provided a semiconductor wafer storage / transporting means comprising a plurality of semiconductor wafer storage means and a transport means for transporting a semiconductor wafer between the storage means. In a dust monitoring device that monitors dust contamination, a dust measuring unit provided for each storage unit and measuring the amount of dust adhering to the test wafer up to each storage unit, and a test wafer transported by the transport unit are provided. And a sample transfer means for transferring to the dust measuring means. As a result, the test wafer can be automatically transferred between a plurality of storage means (stockers), and the amount of dust adhering to the test wafer can be measured each time the transfer is performed, thereby becoming a dust source. This makes it easier to narrow down the stockers and transport routes that are in use, and to perform processing to minimize the effects of dust on products. Further, it is possible to manage dust tendency on a stocker basis on a daily basis, and to detect and prevent problems caused by dust in advance. In addition, the man-hours of the worker can be reduced both in man-hours for dealing with troubles and in daily measurement work itself, and the running cost can be reduced accordingly.

According to a second aspect of the present invention, there is provided an arithmetic control means for collecting dust amount measurement data measured by each of the dust measuring means, and calculating, recording and displaying the data. And communication means between them. This allows the measurement operator to first set the test wafer in the first stocker, and the measurement is performed. Thereafter, only by observing with the wafer dust monitor terminal, the necessary data indicating the amount of dust attached is obtained. And the labor of measurement can be greatly reduced.

According to a third aspect of the present invention, there is provided a wafer container for accommodating a plurality of semiconductor wafers, wherein the semiconductor wafer is stored in the storage means in a state of being accommodated in the wafer container, and is accommodated in the wafer container. The sample transfer means transfers the test wafer from the wafer container and transfers it to the dust measurement means. This facilitates test wafer processing, so that the measurement operator simply sets the wafer container containing the test wafer in the first stocker, and the measurement is performed. As a result, necessary data indicating the amount of dust attached can be obtained, and the labor for measurement can be greatly reduced.

The invention according to a fourth aspect of the present invention is characterized in that the inside of the storage means including the dust measuring means has a clean room configuration. As a result, it is possible to evaluate the cleanliness of only the transfer equipment separately from the stocker, and to prevent a difference in data indicating the amount of dust attached due to a change in the stay time of the wafer inside the stocker. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a single stocker used in an embodiment of a dust monitor device of the present invention.

FIG. 2 is a block diagram showing a device control system in the stocker shown in FIG.

FIG. 3 is an explanatory view showing a working method of measurement in the embodiment shown in FIG.

FIG. 4 is an explanatory diagram showing a state where each wafer dust measuring device communicates measurement data to a wafer dust monitor terminal via each stocker controller in the embodiment shown in FIG. 1;

FIG. 5 is an example of output data indicating a history of dust data when each stocker is transported in the embodiment shown in FIG. 1;

FIG. 6 is an explanatory diagram showing a conventional measurement operation method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stocker, 2 ... Conveyor, 3 ... Stocker controller, 4 ... Robot, 5 ... Wafer dust measuring device, 6 ... Stocker / rail transfer machine, 7 ... Transportation trolley, 8 ... Rail, 9 ... wafer for dust evaluation,
10 ... Carrier, 11 ... Stocker controller,
12: Robot controller, 13: Conveyor controller, 14: Wafer dust measuring device controller, 21: Wafer dust monitor terminal, 31: Wafer for dust evaluation, 32: Carrier, 33: Wafer stocker, 34 ...... Dolly, 35 ... Wafer measuring device.

Claims (4)

[Claims] 1. A dust monitoring apparatus for monitoring dust contamination in a semiconductor wafer storage / transport unit comprising a plurality of semiconductor wafer storage units and a transport unit for transporting semiconductor wafers between the plurality of storage units. A dust measuring means for measuring the amount of dust attached to the test wafer before reaching the individual storage means; and a sample transfer for transferring the test wafer carried by the carrying means to the dust measuring means. And a dust monitor. 2. An arithmetic control means for collecting dust amount measurement data measured by each of said dust measuring means, and performing calculation, recording and display, and a communication means between said arithmetic control means and said dust measuring means. 2. The method according to claim 1, further comprising:
A dust monitor device according to item 1. 3. A wafer container for accommodating a plurality of semiconductor wafers, wherein the semiconductor wafer is stored in the storage means in a state of being accommodated in the wafer container, and is transferred in a state of being accommodated in the wafer container. 3. The dust monitor device according to claim 1, wherein the sample transfer unit takes out the test wafer from the wafer container and transfers the test wafer to the dust measurement unit. 4. 4. The dust monitoring device according to claim 1, wherein the inside of the storage unit including the dust measurement unit is configured as a clean room.