JPH0228948A - Wafer transfer apparatus - Google Patents

Abstract

PURPOSE:To make it possible to solve the problem of the contamination of a semiconductor wafer in transfer working by providing a wafer lifting mechanism by which the semiconductor wafer is put into and taken out of a wafer carrier, and providing a cleaning bath and a drying chamber for cleaning and drying a wafer chuck. CONSTITUTION:A wafer lifting mechanism 9 is arranged at the lower part of a carrier setting part 8 in a main body 1. A wafer-mounting-dish containing plate 11 is provided on a conveying stage 10 wherein a long hole 10a is provided so that the plate can be moved in the axial direction of X. A lifting device 12 is provided at the lower part of the conveying stage 10 so that the device can be moved in the axial direction of the X. The positions of the wafer- mounting-dish containing plate 11 and the lifting device 12 are detected with a detector and moved with chains 15 and 16, respectively. A cleaning bath 17 and a drying chamber 18 for cleaning and drying a chuck 3 are provided along an X-axis guide 4. The chuck 3 which is cleaned in the cleaning bath 17 is moved with a three-axis moving mechanism 2. Air (hot wind) is jetted through a jetting port 22a, and the chuck 3 is dried.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to the transfer of semiconductor wafers between a wafer carrier and a wafer port for advancing and retracting semiconductor wafers into a high heat treatment furnace in the manufacturing process of semiconductor devices. The present invention relates to a wafer transfer device that performs wafer transfer.

<Prior Art> In micropattern processing of semiconductor wafers when manufacturing highly integrated semiconductor devices, there are very strict requirements for the cleanliness of the surface of the semiconductor wafer. Therefore, the work of transferring semiconductor wafers between a wafer carrier and a wafer port for moving semiconductor wafers into and out of a high heat treatment furnace is automated by a wafer transfer device.

As a conventional wafer transfer device, for example, Japanese Patent Application Laid-Open No. 61-5
541 or Japanese Patent Application Laid-Open No. 61-1099, there is a device equipped with a wafer chuck that can be freely moved in three mutually orthogonal axes directions by an orthogonal three-axis moving mechanism. That is, the semiconductor wafer is gripped by the wafer chuck and transferred between a wafer carrier placed on the main body of the wafer transfer device and a wafer port.

(Problem to be solved by the invention) However, since the chemicals used when performing high heat treatment, chemical vapor phase generation treatment, etc. on semiconductor wafers vary depending on the processing process, the wafer transfer device with the above configuration is used. If the wafer is transferred to a semiconductor quencher, a problem arises in that products adhering to the wafer chuck from the semiconductor wafer during the previous operation of the wafer transfer device contaminate other semiconductor wafers during the next operation.

<Means for Solving the Problems> The present invention is a wafer transfer device proposed to solve the above problems.

That is, below the wafer carrier installation section of the main body, there are a plurality of wafer placement trays and an elevator for raising and lowering one of the plurality of wafer placement trays, and the semiconductor wafers can be taken in and out of the wafer carrier on the wafer carrier installation section. The main body is equipped with a wafer lifting mechanism for cleaning the wafer chuck,
This device is characterized by being provided with a washing tank and a drying tank for drying.

<Operation> In the wafer transfer apparatus having the above configuration, the wafer mounting plate to be used is selected and the wafer chuck is cleaned according to the processing process.

<Example> Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a partially cutaway perspective view of a wafer transfer device according to the present invention.

As shown in the figure, an orthogonal three-axis movement mechanism 2 (hereinafter simply referred to as the three-axis movement mechanism 2) is provided on the upper surface of the main body 1 forming a housing, and a wafer chuck 3 (hereinafter simply referred to as the chuck 3) is supported. The three-axis moving mechanism 2 includes a columnar X-axis slide part 5 that moves along an X-axis guide 4 in the longitudinal direction of the main body l (hereinafter referred to as the X-axis direction), and a main body that is supported by the X-axis slide part 5. 1 (hereinafter referred to as the Y-axis direction) and in a direction perpendicular to the upper surface of the main body l (hereinafter referred to as the Z-axis direction), and these X-axis slide portions 5 and arm 6 are driven. A drive mechanism (not shown) is provided. The chuck 3 is fixed to the tip of the arm 6 of the three-axis moving mechanism 2, and can be moved at high speed and with high precision in the X-axis, Y-axis, and Z-axis directions perpendicular to each other by the drive mechanism. Furthermore, the position of the chuck 3 is detected by a detection device such as a rotary encoder (not shown) provided on the three-axis moving mechanism 2, and the movement of the chuck 3 is controlled by a control device described later.

On the top surface of the main body 1, a wafer port installation section 7 (hereinafter simply referred to as the boat installation section 7) and a wafer carrier installation section 8 (hereinafter simply referred to as the carrier installation section 8) are long in the X-axis direction.
It is provided parallel to the X-axis guide 4 of the three-axis moving mechanism 2. The boat installation section 7 has one wafer port B (hereinafter simply referred to as boat B), and the carrier installation section 8 has a plurality of, for example, six wafer carriers C (hereinafter simply referred to as carrier C).
) are placed in their respective positions. Furthermore, the carrier installation portion 8 is provided with a through hole (not shown) corresponding to each carrier C through which a wafer mounting plate, which will be described later, is passed.

As shown in the partially cutaway perspective views of FIGS. 1 and 2, below the carrier installation portion 8 in the main body 1 is provided.

A wafer lifting mechanism 9 is provided. The wafer elevating mechanism 9 includes a wafer tray storage plate 11 provided movably in the X-axis direction on a carrier 10 having a long hole 10a, and an elevator 12 disposed below the carrier 10 in the X-axis direction. It is movably provided. Wafer tray storage plate 11
A predetermined number, for example, three wafer mounting plates 13 are housed in the wafer tray 13, each of which is fitted into the housing hole 11a. The number of wafer plates 13 is determined depending on the type of chemicals used in each processing step. Also, wafer mounting plate 13
A plurality of grooves 13a are formed in which semiconductor wafers W (hereinafter simply referred to as wafers W) housed in the carrier C are placed in an upright state.

The elevator 12 is equipped with a rod 14 that extends and contracts in the Z-axis direction.

The respective positions of the wafer tray storage plate 11 and the elevator 12 are detected by a detection device (not shown), and
Each of them is moved by a drive mechanism using a chain Is, 16, etc., and controlled by a control device to be described later.

Then, the elevator 12 is moved directly below the carrier C containing the wafer W to be transferred, and the wafer tray storage plate 11 is moved to place the wafer tray 13 selected according to the processing process as described later. to the position of the elevator 12. When the rod 14 is extended in this state, the rod 14
The tip of the wafer mounting plate 13 is inserted into a fitting hole (not shown) provided on the lower surface of the wafer mounting plate 13, and the wafer mounting plate 13 is pushed up, and the wafer mounting plate 13 passes through the inside of the carrier C. As a result, the wafer W in the carrier C is pushed up while being placed on the wafer tray 13. The pushed up wafer W is gripped by the chuck 3 and transferred to the boat B.

Conversely, when transferring from boat B to carrier C, by retracting the rod 14, the wafer W transferred from the chuck 3 to the wafer tray 13 is lowered together with the wafer tray 13 and stored in the carrier C. At the same time, the wafer tray 13 further descends and is stored in the storage hole 11a of the wafer tray storage plate 11.

Further, in the main body 1, a cleaning tank 17 and a drying tank 18 for cleaning and drying the chuck 3 are arranged in parallel along the X-axis guide 4.

As shown in the partially cutaway perspective view of FIG. 3, the cleaning tank 17 includes:
A cleaning liquid supply pipe 19 and a discharge port 20 are provided, and a cleaning liquid 21 is provided.
For example, if the product adhering to the chuck 3 is a phosphorus compound, a chemical organic solvent such as acetone is stored. When cleaning the chuck 3, the three-axis moving mechanism 2
The chuck 3 is moved and immersed in the cleaning liquid 21, and the chuck is opened and closed.

On the other hand, inside the drying tank 18, as shown in FIG.
A pipe 22 having a diameter of 2a is installed in the X-axis direction.

The chuck 3 that has been cleaned in the cleaning tank 17 is then moved by the three-axis moving mechanism 2 and positioned so as to cover the pipe 22, and in this state air (warm air) sent out by a pump (not shown) is ejected into the injection port. The chuck 3 can be dried by spraying it from 22a. This air injection is controlled by a control device described below.

FIG. 4 shows a block diagram of a control device that controls the wafer transfer device. This control device 23 includes a main control section 24
, a storage section 25 , an operation key display section 26 , and a drive mechanism control section 27 .

The main control section 24 consists of a microcomputer and its interface circuit, and the storage section 25
The air injection in the drying tank 18 is controlled according to the program stored in the drive mechanism control section 27.
Each drive mechanism 28 of the wafer transfer device is controlled via the wafer transfer device. Further, position signals from each position detection device 29 of the wafer transfer device are inputted to this main control section 24, and each drive mechanism 28 is controlled according to the position signal.

The operation key display section 26 is provided on the top surface of the main body 1 and is used to designate a control mode, which will be described later, or to display various data.

Next, the contents of the program stored in the storage unit 25,
The wafer transfer operation of the wafer transfer apparatus described above based on the program will now be described.

The control mode of the wafer transfer device includes a manual mode and an automatic mode. Manual mode is used when teaching work positions or performing maintenance. The automatic mode is a normally used mode in which the wafer transfer operation is automatically executed.

FIG. 5 shows the sequence flow of the automatic mode.

First, the transfer request is analyzed (step 5-1), and then the wafer mounting tray 13 corresponding to the transfer request is selected (S-
2). This selection of the wafer mounting plate 13 is made in order to prevent products that adhere to the wafer W during one type of processing from adhering to the wafer W undergoing other types of processing via the wafer mounting plate 13. This is done by referring to a process-wafer tray correspondence table as shown in FIG. 6, which associates each processing step performed in the high heat treatment furnace with the wafer tray number.

For example, if the processing step is rIJ, the wafer tray 13 with number "1" is selected. The process-wafer mounting plate correspondence table is stored in the storage section 25.

Next, the data of the previous operation is retrieved from the storage unit 25 and analyzed (S-3), and it is determined whether the chuck 3 needs to be cleaned (5-4), and if necessary, the cleaning tank 17 and the drying tank are cleaned. At step 18, the chucks 3 are washed and dried (S-S). This prevents products attached to the wafer W from one type of processing from adhering via the chuck 3 to the wafer W undergoing another type of processing.

The judgment as to whether or not it is necessary to clean the chuck 3 is made by comparing the processing steps and transfer mode of the previous operation with the processing steps and transfer mode of the next operation, as shown in FIG. This is done by referring to the next work correspondence table. This previous work-next work correspondence table is stored in the storage unit 25. The transfer mode includes load transfer, which is transfer from carrier C to boat B, and unload transfer UL, which is transfer from boat B to carrier C. For example, the processing step in the previous work is "Engineering", the transfer mode is rULJ, and the processing step in the next work is "■
", if the transfer mode is rLJ, the chuck 3 will be cleaned and dried. In this manner, in the case of transfer where there is a possibility of contamination of the wafer W via the chuck 3, the chuck 3 is cleaned before the next operation.

Next, the transfer mode is determined from the content of the analysis of the transfer request (S-6), and transfer processing is performed in accordance with each transfer mode (S-7, 8). Finally, the data of the current work is written into the storage section 25 (S-9), and the wafer transfer operation is completed.

<Effects of the Invention> As described above, according to the wafer transfer device of the present invention, the problem of contamination of semiconductor wafers due to transfer work is solved, and therefore, the problem of contamination of the semiconductor wafer surface, which is required in fine pattern processing of semiconductor wafers, is solved. High cleanliness can be ensured. Furthermore, since the wafer transfer apparatus and platform of the present invention can be used for a plurality of different types of processing steps, equipment costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a wafer transfer device according to the present invention, FIG. 2 is a partially cutaway perspective view of a wafer lifting mechanism, and FIG. 3 is a partially cutaway perspective view of a cleaning tank and a drying tank. FIG. 4 is a block diagram of the control device; FIG. 5 is a diagram showing the sequence flow of the wafer transfer operation; FIG. 6 is a diagram showing the process-wafer tray correspondence table; FIG. is a diagram showing a previous work-next work correspondence table. 1--Main body, 2--Orthogonal three-axis movement mechanism. 3...Wafer chuck. 7.--Wafer port installation section. 8... Wafer carrier installation section. 9... Wafer lifting mechanism, 12... Lifting machine. 13... Wafer mounting plate, 17... Cleaning tank. 18...Drying tank, B...Wafer port. C--Wafer carrier.

Claims (1)

[Claims] A wafer chuck supported movably in three axes by an orthogonal three-axis movement mechanism, a wafer carrier installation section, and a wafer port installation section are provided on the upper surface of the main body, and the wafer carrier installation section A wafer transfer device that transfers semiconductor wafers using the wafer chuck between a plurality of wafer carriers placed on the main body and a wafer port placed on the wafer port installation portion, the wafer carrier installation portion of the main body; A wafer lifting mechanism is provided below, comprising a plurality of wafer placement plates and an elevator for lifting and lowering one of the plurality of wafer placement plates, and for loading and unloading semiconductor wafers into and out of the wafer carrier on the wafer carrier installation section; A wafer transfer device characterized in that the main body is provided with a cleaning tank and a drying tank for cleaning and drying the wafer chuck.