KR20010046460A - A system for carring wafer carriers - Google Patents

Abstract

PURPOSE: A transfer system for a wafer carrier is provided to actively input wafers while the process congestion of post process equipment occurs in a manufacture line of semiconductor devices and to prevent the pollution caused by the long time congestion of the wafers. CONSTITUTION: An automatic guided vehicle(40) transfers a wafer carrier to primary process equipment on the basis of a received command through a wireless transmitting device(45) and the moved wafer carrier is input to the primary process equipment. If the primary process is finished, a host server(30) is informed of the completion of the process through a network. Before inputting the wafer carrier containing the wafers to post process equipment, the host server confirms the existence of empty input ports in the secondary process equipment through the network. In case of no empty input port, the host server commands the movement of the wafer carrier to a wafer carrier temporary storage device(50) and the moved wafer carrier is temporarily stored in the wafer carrier temporary storage device. If the empty input port exists in the secondary process equipment, the host server confirms the wafer carrier in the wafer carrier temporary storage device. The host cover commands the carrying of the wafer carrier to the secondary process equipment. And the wafer carrier is input to the secondary process equipment.

Description

Wafer Carrier Carrier System {A system for carring wafer carriers}

TECHNICAL FIELD The present invention relates to a wafer carrier transport system, and more particularly, to a wafer carrier transport system equipped with a wafer carrier temporary storage device for allowing a plurality of facilities installed in a semiconductor manufacturing line to proceed continuously and quickly.

In general, semiconductor products are manufactured in highly clean environments. This is because fine dust, oil, sodium, etc. present in the air and very fatal damage to the wafer in which the semiconductor process is performed by the operator.

The biggest cause of the contamination of the wafer is an operator, and in recent years, an unmanned trolley transport system excluding an operator who is a source of contamination in a semiconductor manufacturing line has been introduced to contribute to the improvement of semiconductor yield.

However, unmanned trolley conveying systems have contributed a lot to improving the process environment in semiconductor manufacturing lines, but on the other hand, have caused many problems.

For example, assuming that there is a process facility that performs the preceding process A and a process facility that performs the subsequent process B, a process facility that processes A and a process facility that processes B is a Since the time required to proceed the process is mostly different, the wafers that have completed the A process are delayed or waited for the B process to proceed, and thus, the processes before the A process are inevitably affected by the process.

When such a case occurs, the unmanned vehicle transport system cannot find a place to transport the wafers that have completed the A process, and the A process equipment becomes stagnant, resulting in the interruption of the input into the A process equipment.

In this case, the operator changes the driverless transport system off-line, and then the operator directly enters the semiconductor manufacturing line to take out the delayed or waiting wafer and temporarily store it in another location.

After that, process A continues the process by hand, and when the process condition of the subsequent process equipment becomes normal, the process proceeds by injecting the temporarily stored wafer into the subsequent process equipment.

As described above, the loading and unloading of the wafer by the operator causes a mistake in the order of input of the wafer, and the contamination of the manufacturing line by the operator is increased.

In addition, the wafer transport by the operator is difficult to determine the systematic process input order, which hinders the smooth progress of the process and causes an increase in the waiting time of the wafer, thereby causing a surface contamination problem of the wafer.

As an example of the surface contamination of the wafer according to the increase in the waiting time, the preceding process is a process of cleaning the wafer on which the HSG (hemispherial grained) film is to be formed, and the subsequent process is a process of depositing the HSG film.

The wafer on which the HSG film is to be deposited must be added to the HSG deposition process within three hours after the cleaning process, which is a preliminary process, to prevent the growth of the native oxide film by the cleaning liquid, but the HSG within three hours after the cleaning process is performed. If the wafer cannot be added to the deposition process, there is a problem in that a defective process occurs due to a natural oxide film generated on the wafer. In order to remove the naturally occurring oxide film, a cleaning process before HSG deposition occurs. In this case, frequent cleaning puts stress on the wafer and increases overall process time.

An object of the present invention is to allow a wafer to be smoothly introduced into a process when a process congestion occurs in a subsequent process facility in a semiconductor manufacturing line.

Another object of the present invention is to prevent surface contamination due to long-term stagnation of the wafer.

The objects of the present invention will become more apparent from the following detailed description and the accompanying drawings.

1 is a block diagram of a wafer carrier delivery system according to the present invention.

2 is a plan view showing an embodiment of a wafer carrier transport system according to the present invention.

3 is a flow chart of a wafer carrier delivery system according to the present invention.

In the wafer carrier transport system according to the present invention, when congestion occurs between process facilities, the unmanned transport cart conveys the stagnant wafer carriers and temporarily stores them in the wafer carrier unmanned temporary storage device. Among the wafer carriers, the wafer carrier has a wafer carrier temporary storage device configured to take out the first stored carrier carrier for processing.

Hereinafter, according to FIG. 1, the embodiment according to the present invention comprises a host server 30, an unmanned transfer truck 40, a wafer carrier temporary storage device 50, and process equipment groups I, II, and III. The equipment group refers to a plurality of process equipments that perform the process II, which is a subsequent process of the process I, and the process group III means a plurality of process equipments that perform the process III, which is a subsequent process of the process II, and the host server 30 ), The wafer carrier temporary storage device 50, and process equipment groups I, II, and III are connected by a network, and are configured to transmit and receive data necessary for process control and wafer carrier conveyance.

The host server 30 grasps the process progress of each process facility, determines the order of input of wafers to be processed by a series of algorithms, and when a certain process facility is congested, the wafer carrier staying in the stagnant process facility. To store in the wafer carrier temporary storage device 50.

In order to enable the wafer carrier to be stored in the wafer carrier temporary storage device 50 as described above, the embodiment requires an unmanned transfer truck 40 and a wireless transmission device 35 connected to the host server 30. The transfer command and the transfer result data are transmitted in both directions between the wireless transmission device 45 connected to the unmanned transfer truck 40.

In addition, the embodiment includes the L process equipment for proceeding the process as shown in Figure 1, the process equipment to proceed the first process, the process equipment group II proceeds to the second process proceeds the corresponding process M process equipments for this purpose are included, and N process equipments are included in the process equipment group III for carrying out the third process.

Each of the above-described process facilities has a loading port, an unloading port, and a process progression unit, and the loading port is a port through which the wafer carrier containing the wafer to be processed is supplied to the process facility by the unmanned transfer truck 40. The loading port is a port for unloading the wafer carrier containing the wafer, which has been processed, by the unmanned transport cart 40, and the wafer input from the loading port is processed and output to the output port.

In addition, each process facility is instructed by the host server 30 to perform the process through the network, the process progress is transmitted to the host server 30 via the network.

The unmanned conveyance trolley 40 is composed of moving means capable of reciprocating on a guide rail formed between process progress facilities, has a receiving portion for receiving a wafer carrier, and a robot arm configured to receive the wafer carrier. do.

In addition, the unmanned transfer truck 40 receives a command from the host server 30 via the wireless transmission device 45 or reports the current position data.

As briefly described above, the wafer carrier temporary storage device 50 is preferably installed at a place where the respective processes can be well connected between the respective process facilities.

Specifically, the wafer carrier temporary storage device 50 includes a wafer carrier accommodating part for storing the wafer carrier and a wafer carrier detecting part, and the wafer carrier accommodated in the wafer carrier accommodating part is placed at the time of loading and unloading by the wafer carrier detecting part. Information including a unique number of is detected, the information is often transmitted to the host server 30 through communication.

The wafer carrier temporary storage device 50 having such a configuration temporarily stores the wafer which is stagnant when a process congestion occurs, and thus, from the longest stored wafer to the subsequent process facility when the process progress condition of the subsequent process facility becomes normal. It also provides information on where wafers are being placed and on which wafers are stagnant.

The embodiment having the system configuration of FIG. 1 is arranged and operated as shown in FIG. 2, and the operation thereof is described in detail with reference to FIG. 3.

Among the first process equipments carrying out the first process shown in FIGS. 11 and 12, the wafer carrier 80 containing the wafer having completed the first process progress in the unloading port of the process equipment of FIG. It shows the situation before entering into one of the process equipments 13 and 14 which progresses a 2nd process. 15 and 16 are 3rd process equipment which performs a 3rd process.

For the sake of understanding, the first step and the second step are described as the first step and the second step, respectively.

The host server 30 first checks whether there is an empty input port in the first process facility through the network (S10).

First, when it is confirmed that there is an empty input port in the first process facility, the host server 30 instructs the unmanned transfer truck 40 to move the wafer carrier to the first process facility through the wireless transmission device 35.

The unmanned conveyance trolley 40 moves the wafer carrier to the first process facility according to a command received through the wireless transmission device 45, and the transferred wafer carrier is fed to the first process facility, and the wafer fed to the first process facility. The wafer stored in the carrier undergoes a first step (S20).

When the first process is completed, the host server 30 receives a process completion report of the first process facility through the network (S30).

Before injecting the wafer carrier 80 containing the wafer having completed the first process into the subsequent process facility, the host server 30 checks whether there is an empty input port in the second process facility through the network (S40).

If there is no empty input port in the second process facility, the host server 30 instructs the unmanned transfer truck 40 to move the wafer carrier 80 containing the wafer having completed the first process to the wafer carrier temporary storage device 50. Instructed, the wafer carrier 80 transferred by the unmanned transfer truck 40 is temporarily stored in the wafer carrier temporary storage device 50. (S50)

If there is an empty input port in the second process facility in step S40, the host server 30 checks whether the wafer carrier 90 in the wafer carrier temporary storage device 50 is waiting for the second process (S60).

If there is a wafer carrier 90 waiting in the wafer carrier temporary storage device 50 in step S60, the host server 30 preferentially transfers the wafer carrier 90 waiting to the unmanned transfer truck 40 to the second process facility. Command to return. The wafer carrier 90 conveyed to the second process facility by the unmanned conveyance truck 40 is put into the second process facility. (S70)

At this time, when there are many wafer carriers waiting in the wafer carrier temporary storage device 50, the wafer carrier with the longest waiting time is conveyed preferentially.

If there is no wafer carrier waiting in the wafer carrier temporary storage device 50 in step S60, the host server 30 instructs the unmanned transfer truck 40 to convey the wafer carrier 80 to the second process progress facility. The second process proceeds to the wafer accommodated in the wafer carrier 80 conveyed to the second process facility by the unmanned conveyance trolley 40. (S80)

The host server 30 feeds back to step S10 to resume process input of the new wafer carrier.

This process is equally applicable to the process which is put into the third process after the second process.

According to the present invention, the automatic control according to the flowchart is repeatedly performed at each step from the step to the next step, and the process proceeds after being temporarily stored in the wafer carrier temporary storage device even when a process congestion occurs in the semiconductor manufacturing line.

The present invention having the above-described structure and function can be any embodiment in which a plurality of wafer carrier temporary storage devices are installed between different process facilities instead of one wafer carrier buffer in a semiconductor manufacturing line.

In addition, it is also possible to implement any number of systems in which the wafer carrier subjected to the preceding process is necessarily transferred to the wafer carrier temporary storage device.

Although the preferred embodiments of the present invention have been described in detail above, it will be understood by those skilled in the art that the present invention may be modified or modified in various ways. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

As described above, the wafer carrier transport system having the wafer carrier temporary storage device according to the present invention temporarily stores a wafer carrier in which the wafers subjected to the preceding process are stored in the wafer carrier temporary storage device when process congestion occurs in a subsequent process facility. By storing, there is an effect of preventing congestion of the preceding process equipment due to the process congestion of the subsequent process equipment.

In addition, when the process congestion of the subsequent process equipment is eliminated, the process waiting time is reduced due to the efficient process input by the storage order, thereby reducing the surface contamination of the wafer.

Claims (3)

Process equipment including a loading port for loading a wafer carrier, a process progression unit for processing a wafer housed in a wafer carrier, and an unloading port for unloading a wafer carrier in which a wafer having completed the process progresses is formed in a sequence of steps. A plurality of process equipment groups arranged; An unmanned conveyance trolley having a predetermined moving device capable of reciprocating between the plurality of process equipment groups, a predetermined area for accommodating a wafer carrier, and a wireless transmission device for transmitting and receiving data; The plurality of process equipment groups transmit and receive data through a predetermined network, and the unmanned transfer truck transmits and receives data by a wireless transmission device, and the process control and the wafer carrier are used as the transmitted and received data. A host server performing an algorithm for return; And A wafer carrier temporary for forming a predetermined area capable of accommodating the wafer carrier and a wafer identification device for identifying the wafer carrier is formed in the predetermined area to transfer data by the wafer carrier identification device to the host server through a network. The unmanned conveyance truck is equipped with a storage device, and the wafer for which the end of the immediately preceding process of the subsequent process is completed when the unmanned transfer truck is not ready for process input of a subsequent process equipment group among the plurality of equipment groups is accommodated by the algorithm of the host server. The wafer carrier is transferred to the wafer carrier temporary storage device, and stored in the wafer carrier temporary storage device. When the wafer carrier can be added to the subsequent process equipment group, the wafer carrier stored in the wafer carrier temporary storage device is provided to the unmanned transfer truck to be loaded into the subsequent process. Could be The wafer carrier transport system, characterized in that the. The wafer carrier transport system of claim 1, wherein the wafer carriers stored in the wafer carrier temporary storage device are first introduced into an order in which wafer carriers are introduced into a subsequent process progress facility. The wafer carrier transport system of claim 1, wherein the wafer carriers are sequentially removed from the wafer carriers stored first among the wafer carriers temporarily stored in the wafer carrier temporary storage device.