JPH0693477B2 - Ion implanter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a substrate transfer system monitoring device for an ion implantation apparatus,
In particular, the present invention relates to an ion implantation apparatus equipped with a plurality of substrate transfer system monitoring mechanisms.

(Prior Art) In recent years, an ion implantation apparatus that implants impurity atoms such as B, P, and As into a substrate to be processed such as a semiconductor wafer to process the semiconductor substrate has become widespread.

In this ion implantation apparatus, a substrate to be processed, such as a semiconductor wafer, is transferred from the atmosphere into the vacuum processing chamber via the preliminary vacuum chamber, and after the ion implantation process, the semiconductor wafer is again exposed to the atmosphere via the preliminary vacuum chamber. Since the structure is such that the semiconductor wafer is unloaded, a wafer transfer system for transferring the semiconductor wafer is provided.

By the way, in this wafer transfer system, a wafer transfer system monitoring device is provided so as to promptly detect a trouble in the transfer mechanism so as not to affect a subsequent process. This wafer transfer system monitoring device is composed of a transfer system monitoring control device and a detection unit composed of a large number of detection devices provided at various places in the wafer transfer system, and inputs information from the detection unit to the transfer system monitoring device. The operation / state of the wafer transfer system is constantly monitored.

(Problems to be Solved by the Invention) However, only one conventional wafer transfer system monitoring device is provided for one wafer transfer system, and when the transfer system monitoring control device has an abnormality, There is a problem that even if the next abnormal signal is input, it will be overlooked, which has been a cause of a decrease in the requestability of the ion implantation apparatus as a whole.

The present invention has been made to solve the above problems, and an object thereof is to provide a highly reliable ion implantation apparatus.

[Structure of the Invention] (Means for Solving the Problems) The ion implantation apparatus according to the present invention provides an operation / state of a substrate transfer system for transferring a substrate to be processed between an ion implantation position and a substrate storage container to be processed. At least one system of detection means for detecting,
At least two transfer system monitoring means for monitoring the operation / state of the substrate transfer system by inputting information from the detection means, and controlling the operation / status of the substrate transfer system by signals from these transfer system monitoring means. Control means for controlling the number of processed substrates, and means for displaying the number of processed substrates for displaying the number of processed substrates.

(Operation) According to the present invention, a plurality of wafer transfer system monitoring units are provided, and the plurality of wafer transfer system monitoring units monitor the wafer transfer system. It is possible to perform highly reliable ion implantation work that can be controlled by the control section.

(Example) An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of the wafer transfer system monitoring apparatus of the embodiment. The semiconductor wafer 2 shown in FIG. 3 is taken out from the wafer cassette 1 provided outside the vacuum chamber and is transferred to the ion implantation processing chamber which is the vacuum chamber. A wafer transfer system is configured in which the wafer is transferred, mounted on a platen in the processing chamber, and after the ion implantation work is completed, the wafer is transferred back to the wafer cassette 1. At various points of this transfer system, a large number of transfer system detection devices, for example, a detection mechanism 10a for confirming the open / closed state of a valve that opens / closes when a wafer is loaded / unloaded in a vacuum chamber, and a lift for a pick that holds the semiconductor wafer during transfer Pick up / down detection mechanism to detect the condition
10b, a plurality of wafer position detection mechanisms 10c for confirming the transfer position of the semiconductor wafer in each process, and the like are provided to configure the detection unit 10 of the wafer transfer system monitoring system. As specific examples of these mechanisms, a photocoupler, a piezoelectric sensor, a door switch, etc. can be used.

The operation state detection signals of the wafer transfer system detected by the detection unit 10 are input to the transfer system monitoring control unit 11 and the auxiliary transfer system monitoring control unit 12, respectively.

The auxiliary transfer system monitoring control unit 12 monitors the operation state of the wafer transfer system by the detection signal input from the detection unit 10, and when a signal is input, sends a detection unit abnormality signal to the transfer system monitoring control unit 11. Output: For example, the abnormal signal is output and displayed together with the detection unit information that has been output. On the other hand, the transport system monitoring control unit 11 also has a detection unit.
The detection signals from the respective detection units are supplied from 10, and the operation state is of course monitored and the conveyance of the abnormal unit is stopped and controlled according to the content of the abnormality signal. That is, two systems are used for monitoring. Further, at the end of wafer processing, a wafer processing end signal is output to display the wafer processing end number on the wafer processing number display section 13. As the wafer processing number display unit 13, for example, a panel for displaying the number of processed wafers one by one by an LED may be provided and displayed on the panel.

Further, the transfer system monitoring control unit 11 monitors the operating state of the wafer transfer system by the detection signal input from the detection unit 10, and detects not only an abnormal signal from the detection unit 10 but also the running position, normal running, etc. Information is output from the auxiliary transport system monitoring control unit 12 to the transport system monitoring control unit 11. When an abnormality signal is input, a conveyance system abnormality signal is output to notify the wafer conveyance system abnormality. For example, the abnormal portion and the abnormality are displayed from the detection unit that has output the abnormality. Further, at the same time, control is performed so that the transport operation of at least the relevant portion is stopped according to the content of the abnormality.

In this way, if the transfer system monitor / control unit is composed of a plurality of systems, for example, two systems, the auxiliary transfer system monitor / control unit even if a failure occurs in the transfer system monitor / control unit 11 of one monitor control unit and an abnormality of the wafer transfer system is overlooked. 12 can be found and controlled, improving the reliability of the entire device.

In the above embodiment, the detection signal from the detection unit 10 of one system is set to 2
Although it was divided into systems and input to the transport system monitoring control unit,
The present invention is not limited to this, and a configuration may be adopted in which detection signals are input from independent detection units for each transport system monitoring control unit.

Another embodiment of the present invention will be described with reference to FIG. 2 in which a detection signal is input from each of a plurality of independent detectors to the transport system monitoring controller. Detection unit
The detection signal output from the auxiliary detection unit 14 provided independently of 10 is adapted to be input to the auxiliary transport system monitoring control unit 12, where the detection signal from the auxiliary detection unit 14 is used as the basis. First, it is determined whether the wafer transfer system is operating normally. The numerous detection mechanisms that make up the auxiliary detection unit 14 are
A detection mechanism different from the detection mechanism constituting the unit 10, for example, a wafer detection mechanism in a cassette installed near the wafer cassette for detecting whether or not the pick holds the semiconductor wafer
14a and a sound detection mechanism 14b that detects a dropping sound of a semiconductor wafer during wafer transfer or a damage sound due to a crack of the wafer.
Etc.

As a specific example of the detection mechanism that constitutes the detection unit 14, the in-cassette wafer detection device 14a will be described as an example with reference to FIG. A large number of semiconductor wafers 2 are housed in a box-shaped wafer cassette 1 having an opening on the lower surface, and a scooping-shaped wafer transfer pick 3 arranged below the wafer cassette 1 is indicated by an arrow Y in the figure. The semiconductor wafers 2 are lifted and held by the arc-shaped grooves 3a provided on the upper end of the pick 3, and are vertically transferred one by one to an ion implantation processing chamber (not shown) above the wafer cassette 1.

The wafer cassette 1 is stepped in the direction of the arrow X in the drawing by a wafer cassette drive mechanism (not shown). The wafer cassette 1 is stepped in sequence and the semiconductor wafer to be processed next is placed on the pick 3. .

A lateral L-shaped photosensor type in-cassette wafer detection mechanism 14a is provided near the contact portion between the pick 3 and the semiconductor wafer 2, and can detect whether or not the semiconductor wafer 2 is present on the pick 3. it can. The in-cassette wafer detection mechanism 14a is attached to the in-cassette wafer detection mechanism fixing mount 5 mounted on the wafer cassette drive mechanism fixing base 4 so that the position can be adjusted. In this example, the in-cassette wafer detection device 14a uses a photosensor type, but is not limited to this.

In the wafer transfer system monitoring system having such a configuration, the semiconductor wafer 2 is not on the pick 3 due to a failure of the wafer placement detection mechanism 10c of the detection unit 10 even though the wafer 2 is held on the pick 3. Even if a signal, that is, a signal indicating that there is no semiconductor wafer 2 in the wafer transfer system is input to the transfer system monitoring controller 11, the in-cassette wafer detection mechanism 14a indicates that there is no semiconductor wafer 2 in the wafer cassette 1, that is, the wafer transfer system. Since the signal that the semiconductor wafer 2 is present is input to the auxiliary transfer system monitoring controller 12, the auxiliary transfer system monitoring controller 12 determines that the wafer transfer system is abnormal due to the contradiction between these two signals, and outputs an error signal to the transfer system. It can be output to the monitoring control unit 11 to detect an abnormality. Further, if the auxiliary detection unit 14 is provided with the sound detection mechanism 14b, a crack in the semiconductor wafer that cannot be detected by the detection unit 10 can be found.

As a further embodiment of the present invention, as shown in FIG. 2, the detection mechanism forming the auxiliary detection unit 14 is equivalent to the detection mechanism forming the detection unit 10, for example, the valve opening / closing detection mechanism 10a and the pick up / down detection mechanism 10b. For example, the detection unit may be configured to have double safety.

By providing a plurality of transport system monitoring control units in this way, an abnormality can be detected even if a failure occurs in one of the transport system monitoring control units, and reliability is greatly improved. Further, if the wafer processing number display unit 13 is provided as in this example, the operator can easily know how many semiconductor wafers have been processed.

[Effects of the Invention] As described above, according to the ion implantation apparatus of the present invention,
The reliability of the substrate transfer system monitoring system can be significantly improved, and the operator can easily know how many substrates have been processed.

[Brief description of drawings]

FIG. 1 is a diagram showing the structure of a wafer transfer system monitoring system of an ion implantation apparatus according to an embodiment of the present invention, FIG. 2 is a view showing the structure of another embodiment, and FIG. 3 is a wafer detection mechanism in a cassette. It is a perspective view which shows an example of a mounting position. 2 ... Semiconductor wafer, 3 ... Pick, 10 ... Detector, 11
…… Transport system monitoring control unit, 12 …… Auxiliary transport system monitoring control unit,
13 ... Wafer processing number display section, 14 ... Auxiliary detection section, 14a ...
... cassette wafer detection mechanism, 14b ... sound detection mechanism.

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Claims (5)

[Claims] Claim: What is claimed is: 1. At least one detecting means for detecting an operation / state of a substrate transfer system for transferring a substrate to be processed between an ion implantation position and a container for receiving a substrate to be processed, and information from the detecting means is inputted. And at least two transfer system monitoring means for monitoring the operation and status of the substrate transfer system, control means for controlling the operation and status of the substrate transfer system based on signals from these transfer system monitoring means, and ion implantation processing An ion implantation apparatus comprising: a substrate processing number display means for displaying the number of processed substrates. 2. The ion implantation apparatus according to claim 1, wherein the transport system monitoring means includes a substrate processing number display means for displaying the number of substrates that have undergone ion implantation processing. 3. The ion implanter according to claim 1, wherein the carrier system monitoring means is provided with an independent detecting means. 4. The ion implantation apparatus according to claim 1, wherein the detection means includes a detection means for detecting the presence of the substrate to be processed in the substrate storage container to be processed. 5. The ion implantation apparatus according to claim 1, wherein the detection means includes a sound detection means for detecting abnormal noise during the transportation of the substrate to be processed.