JPH08148547A - Wafer transfer method in semiconductor manufacture device - Google Patents

Abstract

PURPOSE: To precisely transfer a wafer even if misregistration is generated in a groove of a cassette and a boat by modifying only independent address numbers requiring modification separately and by transferring a wafer on the basin of position data of more accurate supporting part. CONSTITUTION: Position data of a groove at a cassette side of a carrier stage and the side of a boat 7 obtained by a palletizing method is substituted separately for each independent address number wherein data obtained by a palletizing method is stored. In this example, a groove P7 is out of position below by ΔL (0.2mm); therefore, a setting position of the groove P7 is modified to place a wafer in a position 0.2mm below from a value of a groove position obtained by a palletizing method. Furthermore, since a groove P5 at the side of the boat 7 is missing, an operation is performed to place a wafer in the next P6 by skipping the groove P5 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a wafer transfer method by a robot in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, a semiconductor manufacturing apparatus for forming a semiconductor single crystal on a material wafer has a structure as shown in FIG. In the figure, reference numeral 1 is a semiconductor manufacturing apparatus which forms a dust-free chamber. A robot 2 is a transfer device, and a pencil 4 provided at the tip of an arm 3 of the robot 2 stores a wafer 5 as a material in a groove provided in a column in a cassette 6 of a carrier stage. The wafer is taken out, transferred and loaded into a groove 8 as a support portion for storing a wafer provided on a column in the boat 7, and the boat 7 having the wafer 5 loaded therein is lifted by a lifting means (not shown), The wafer 5 is housed in the reactor 9 and the required heat treatment is performed. Further, 10 is a control device of this semiconductor manufacturing apparatus, 1
The operation panel 1 is placed outside the dust-free room. By the way, usually 100 to 150 grooves 8 for storing wafers, which are provided on the support columns in the boat 7, are provided. As described above, when the wafer 5 is transferred and there are a large number of grooves in which the wafers are stored and grooves on the transfer side, it is difficult to teach the robot 2 all the positions of these individual grooves. It is difficult to work. Therefore, the robot 2 is taught less points (the positions of the grooves), and the positions of the other grooves are calculated.
The so-called palletizing method is used. here,
The palletizing method is a method in which two or more reference arbitrary positions are input and the distance between the two points is divided by a certain value (the number of grooves) to obtain all the groove positions between the two points by calculation.
In the conventional case, as shown in FIG. 4, the position of the groove in the cassette 6 of the carrier stage in transferring the wafer,
The position of the groove on the lower surface of the groove 8 of the boat 7 (hereinafter, the position of the lower surface of each groove is simply referred to as the groove position) is calculated by using the palletizing method as follows. For example, assuming that the number of wafers stored in the boat is 125, five cassettes are provided on the carrier stage, and each cassette 6 has 25 cassettes.
It is assumed that the wafers are stored one by one and a total of 125 wafers are stored in the cassette on the carrier stage. In this case, if the position c of the uppermost groove and the position d of the lowermost groove of the groove 8 of the boat 7 are input as the reference position and divided by the total number of grooves 125 to calculate each groove, an average value is obtained. All the positions of the groove will be found. If the same calculation is performed at the uppermost groove position a and the lowermost groove position b of each cassette 6 of the carrier stage, all the groove positions in the cassette 6 can be calculated. Therefore, when the wafer is transferred by the robot 2 from the groove of the cassette 6 on the carrier stage to the groove of the boat 7,
The wafers are sequentially picked up at the determined groove positions in each cassette 6 of the carrier stage, and the wafers are sequentially placed at the required positions in the groove 8 on the boat 7 side to be transferred. There is. The operation of such a robot 2 is shown by the flowchart of FIG. In the figure, each step is displayed in ST11 to ST18, and
n indicates the address number of the groove. Starting from ST11, in ST12, the positions of the uppermost groove and the lowermost groove of the groove in the cassette 6 of the carrier stage and the groove 8 of the boat 7 are input. The position of each groove is calculated in ST13, and the calculated value is 125 in total on the cassette side of the carrier stage.
Depending on the address number of the boat, the boat 7 side also has a total of 125
Write with the address number of. And ST14-ST
Up to 18, 125 wafers are sequentially transferred from the cassette 6 on the carrier stage to the boat 7. Conventionally, wafers are transferred in a semiconductor manufacturing apparatus using the method described above.

[0003]

In the conventional wafer transfer method in the semiconductor manufacturing apparatus, the position of the groove of the cassette of the carrier stage and the position of the groove in the boat are calculated by using the palletizing method as described above. It was However, the wafer transfer method relying only on the palletizing method has the following problems. Since the position of the groove of the wafer is calculated by calculation, the position of each wafer cannot be set freely. In addition, when inputting the position of the uppermost groove and the position of the lowermost groove of the boat, if there is an error in the input value, the groove of the carrier stage cassette or the boat due to manufacturing error or damage during use, If there is a deviation in the position, or if one groove is missing, it becomes impossible to calculate the appropriate groove position. Incidentally, such a problem similarly occurs even when the supporting portion for accommodating the wafer is not the groove but the shelf is provided in place of the groove on the supporting column, and therefore, a countermeasure for this has been required. It is an object of the present invention to provide a wafer transfer method in a semiconductor manufacturing apparatus, which solves the above-mentioned problems (problems) of conventional ones.

[0004]

According to a method of transferring a wafer by a robot in a semiconductor manufacturing apparatus of the present invention, a supporting unit such as a cassette of a carrier stage in a semiconductor manufacturing apparatus and a groove for storing a wafer in a boat,
Replacing the address number of the position of each support part in the middle part obtained by using the palletizing method based on two predetermined coordinates of the reference position in each of these support parts with another independent address number. Independent address numbers are set according to the above, and only the ones that need to be corrected are added to the individual address numbers to obtain more accurate position data of the support part, and wafers are transferred based on this data. .

[0005]

In the wafer transfer method in the semiconductor manufacturing apparatus of the present invention, the data of the positions of the carrier stage cassette and the supporting portions such as the grooves in the boat calculated by the palletizing method is used as the address containing the data calculated by the palletizing method. By substituting an address number that is independent of the number, the value obtained by the palletizing method can be easily modified according to the situation of each support part, and the position data of the support part can be corrected to a more correct value. Therefore, the transfer of the wafer can be performed more accurately.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in FIGS. FIG. 1 is a vertical sectional front view showing a robot and a boat according to an embodiment of the present invention. In the figure, P _{1 to} P ₁₂₅ represent grooves as a supporting portion for a total of 125 wafers, and these grooves are formed in each column of the boat. Although only one support is shown in FIG. 1 for the sake of simplicity, a plurality of support, such as three, is usually provided in the boat so as to face each other so that the wafers are accommodated and supported between the opposing grooves. I have to. T _{1 to} T ₁₂₅ are grooves P _{1 to} P
The position of the underside of ₁₂₅ is shown. Further, h indicates the height from the floor surface to the lower surface T ₁ of the groove P _{1 at} the bottom of the boat 7. In the present embodiment, for example, the groove P _{5 in the} fifth step from the bottom is
Is missing due to breakage, and the groove P _{7 in the} seventh step from the bottom is formed so as to be shifted downward by ΔL (0.2 mm) from the normal position. In such a case, in the conventional calculation of the groove position data by the palletizing method, an error occurs in the wafer positioning, so that the transfer and loading of the wafer cannot be performed accurately and the device itself may be damaged. It was Therefore, the present invention has been improved to provide a wafer transfer method capable of coping with the above case. Next, an example of a specific operation of the robot 2 of the present invention will be described with reference to the flowchart of FIG. Explained by. Note that n indicates the address number of the groove. In the figure, each step is indicated by ST21 to ST32. At ST22, the positions a, b, and c of the uppermost and lowermost grooves of the cassette 6 of the carrier stage and the groove 8 of the boat 7, respectively.
And d respectively. In ST23, the position of each groove is calculated, and the calculated value is written with a total of 125 address numbers on the cassette 6 side of the carrier stage and with a total of 125 address numbers on the boat side. ST24 is a characteristic step of the present invention, in which the position data of the groove on the cassette 6 side and the boat 7 side of the carrier stage obtained by the palletizing method is independent of each address number containing the data obtained by the palletizing method. The address numbers are replaced (for example, k1 → K1). ST2
Reference numeral 5 is a step for correcting the position data only for the groove for which the operator recognizes that the data thus replaced needs to be corrected. In this example, the groove P ₇ is ΔL (0.
2 mm), so the wafer is 0.2 mm away from the groove position value obtained by the palletizing method.
The setting position of the groove P ₇ is corrected so as to place it in the lowered position. Next, in ST26 to ST32, a procedure for sequentially transferring wafers from the cassettes 6 on the carrier stage to the boat 7 one by one is shown. In ST28 and ST29, since the grooves P ₅ of the boat 7 side is missing, by skipping a groove P ₅ is subjected to operations such as placing the wafers to the next groove P _6. The above example shows only the process of transferring a wafer from the carrier stage cassette 6 to the boat 7 when there is an abnormality in the groove 8 of the boat 7, but similar damage occurs in the groove of the carrier stage cassette. In this case, the present invention can be applied to the case where the processed wafer is returned from the boat 7 to the carrier stage cassette 6 by using a program for determining the groove as in the above example. . In the above embodiment, the case where the groove is formed on the support as the wafer supporting portion in the cassette and the boat is described, but instead of this,
It is also possible to form a shelf on the column and make the shelf serve as a support portion. In this case, the lower surface of the groove described in the above embodiment may be replaced with the upper surface of the shelf to obtain the reference shelf position and the correction shelf position.

[0007]

Since the wafer transfer method in the semiconductor manufacturing apparatus of the present invention is performed as described above, it has the following excellent effects. Since it is based on the palletizing method, the initial data input operation is small. Furthermore, the data of the position of the carrier stage cassette and the groove in the boat obtained by the palletizing method are temporarily replaced with the address numbers independent of the calculated address numbers obtained by the palletizing method. It became easy to correct the position data of the groove or the shelf to a more correct value according to the situation of the groove or the shelf as the wafer supporting part. In case of confusion caused by overcorrection, it is possible to easily return to the initial state and prevent confusion.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a main part of an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the robot of the present invention in FIG.

FIG. 3 is a front view showing a semiconductor manufacturing apparatus to which the present invention and a conventional one are applied.

FIG. 4 is a vertical sectional front view showing a main part of a conventional example.

FIG. 5 is a flowchart showing the operation of a conventional robot.

[Explanation of symbols]

2: Robot 3a, 3b: Arm 4: Pencil 5: Wafer P ₁ to P _125: groove in the boat T ₁ through T _125: the lower surface position of the groove in the boat

Claims (1)

[Claims] 1. A palletizing method based on two predetermined coordinates of a reference position in each of the supporting portions, such as a carrier stage cassette in a semiconductor manufacturing apparatus and a wafer storing groove in a boat. Independent address numbers are obtained by substituting the address numbers at the positions of the supporting parts in the middle part, which are obtained by using, with other independent address numbers. The method for transferring a wafer in a semiconductor manufacturing apparatus is characterized in that more accurate position data of the supporting portion is obtained by correcting the above, and the wafer is transferred based on this data.