JPH0236548A - Wafer transfer - Google Patents

Abstract

PURPOSE:To make it possible to improve the reliability of the transfer of a water by a method wherein the pressing amount of the wafer to a static chuck is adjusted automatically to the most effective distance. CONSTITUTION:A static chuck 1 is moved (T2) to the position (M1) of a cassette 3 by a control signal 13, which is outputted by a pulse generator 7, on the basis of the command of a controller 10. A control part 6 makes the cassette 3 operate in the axial direction through a driving mechanism 4 by this control signal 14 and a wafer (a) is pressed (T3) to the chuck 1. A power supply 12 applies a high voltage to the chuck 1 by a control signal 15 and the wafer (a) is sucked to the chuck 1 and is rotational driven to a transfer position M3, but at this time, the wafer is stopped temporarily at a position M2 and whether the wafer is sucked on the chuck 1 or not is detected by a detecting means 17. In case the wafer is not sucked, the cassette 3 is returned to a position T1 and the chuck 1 is again sent (T6) to the position M1 on the side of the cassette.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to wafer transport for semiconductor-related devices.

[Summary of the invention]

The present invention provides a method for transporting a wafer using an electrostatic chuck, by automatically adjusting the amount of pressure of the wafer against the electrostatic chuck to the most effective distance.
Improved reliability of wafer transfer.

[Conventional technology]

Conventionally, in a wafer transport method using an electrostatic chuck, as shown in FIG. By applying a high voltage using the power source 12, the wafer is attracted to the electrostatic chuck 1 and transported.

[Problem to be solved by the invention 1] However, in the conventional method, there was a problem in that the reliability of wafer transportation deteriorated due to warping of the wafer itself and variations in the degree of adhesion between the wafer and the electrostatic chuck. Means for Solving] In order to solve the above problems, in the present invention, the amount of pressing of the wafer against the electrostatic chuck is controlled by a detection means for detecting the wafer on the electrostatic chuck and a drive mechanism for driving the cassette. It automatically controls, detects the optimal adsorption conditions, and achieves highly reliable wafer transfer.

[Function] If the above method is used, using an electrostatic chuck,
The reliability of wafer transport can be improved, and further, the reliability and operating rate of semiconductor manufacturing equipment using the above method can be improved.

[Example] Hereinafter, an example will be described based on the drawings. FIG. 1 shows a block diagram according to the present invention. First, the configuration will be explained.

The electrostatic chuck 1 is supported by a drive mechanism 2, and the electrostatic chuck 1 is supported by a drive mechanism 2.
is connected to the control unit 5, and further includes a pulse generator 7.8
, power supply control unit 9, input circuit 16, and controller 1
0 is connected to the control means 11 consisting of 0. Cassette 3
is supported by a drive mechanism 4, and accommodates a predetermined number of wafers at a predetermined pitch.The drive mechanism 4 is connected to a control section 6 and further connected to a control means 11. The electrostatic chuck 1 is connected to a power source 12 and is also connected to a control means 11 .

Next, the operation will be explained with reference to FIG.

TI indicates that the wafer is in the groove in the cassette 3. Here, in the electrostatic chuck 1, the control section 5 is operated by the control signal 13 outputted from the pulse generator 7 based on a command from the controller 10 in the control means 11, and the drive mechanism 2 is further rotated to move the cassette 3. Move to position (Ml) (T2).

Next, the control means 11 outputs the set number of pulses as a control signal 14 via the pulse generator 8 according to the controller lOa command. In response to this control signal 14, the control unit 6 operates the cassette 3 in the axial direction via the drive mechanism 4, so that the wafer is pressed against the electrostatic chuck l (
T3), the control means 11 outputs a control signal 15 to turn on the power through the power supply control unit 9 in response to a command from the controller 10. The power supply 12 applies a high voltage to the electrostatic chuck 1 according to the control signal 15, and the wafer is transferred to the electrostatic chuck l.
is adsorbed to.

The control means 11 drives the cassette 3 in the direction opposite to T3, and controls the wafer to come to the middle position of the cassette groove (
T4). Next, the electrostatic chuck 1 is rotationally driven to the transfer position M3, but at this time, it is temporarily stopped at the M2 position, and the detection means 17 detects whether the wafer is attracted to the electrostatic chuck 1. . At this time, if the wafer is attracted, there is no problem and the wafer is sent to the next transfer position M3. A feature of the invention is when the wafer is not suctioned, which is indicated by T5.

In this case, the cassette 3 is returned to the position T1, the electrostatic chuck 1 is again sent to the cassette side position M1 (T6), and then the cassette 3 is moved as shown at T3.
The wafer is driven in the axial direction again and pressed against one surface of the electrostatic chuck, but at this time, the difference from T3 is that the wafer is fed an additional distance of 80 (T7).

In this state, the electrostatic chuck 1 is turned on again when the power supply 12 is turned ON.
Further, the cassette 3 is returned to the same position as T4, the electrostatic chuck 1 is transported to the M2 position, and after the detecting means 17 detects that the wafer is attracted, it is transported to M3, and the wafer is transferred. It will be done.

FIG. 4 shows the above contents in a flowchart, and FIG. 5 shows the movement of the cassette with arrows.

PL indicates that the number of repetitions of re-conveyance in the event of failure in wafer suction is set in advance. The electrostatic chuck 1 is rotated to the cassette side position M1 (P2),
The cassette 3 is driven by the 01 pulse to move to the N1 position (P3), and a high voltage is applied to the electrostatic chuck 1 by the power source 12 to attract the wafer (P4).

Next, the cassette 3 is driven by n2 pulses to the N2 position.
2 position (P5), and the drive mechanism 2 moves the electrostatic chuck l from the N1 position to the N2 position (P6). There, the detection means 17 checks whether the wafer is attracted onto the electrostatic chuck l. P7), if it is adsorbed,
The electrostatic chuck 1 is sent to the N3 position (P8), and the conveyance ends. Then, the cassette 3 moves by the wafer arrangement pitch (N3) and enters a state of waiting for the next wafer to be transported.

Also, if the wafer is not attracted, the cassette 3 is
The electrostatic chuck 1 is returned from the 2 position to the N0 position (PLO), the electrostatic chuck 1 is sent to M1 again (Pil), and the high voltage of the electrostatic chuck 1 is turned off (Pl2).

Next, the cassette 3 is moved from the N0 position to the N1+Δn position (Pl3), and after the high voltage is applied to the electrostatic chuck 1 again to attract the wafer (Pl4), the cassette 3 is moved from the N0 position to the N1+Δn position (Pl3).
It is returned to the 2nd position (Pl5).

P16 counts down the number of repetitions set in P1, and P17 indicates that if the result is greater than 0, the process returns to P6 and the following is repeated, and if the result is 0 or negative, a conveyance abnormality is displayed in P18.

In this flowchart, the re-transport operation is performed even if the value of K is 0, but when K=O, the re-transfer operation (P1
0 and later), Pl6, P
17 should be placed in the step before PIO, and in reality, a step for checking the upper limit of the K value was included, but this step is omitted in this flowchart.

[Effect 1 of the Invention] According to the above transfer method, the reliability of the wafer transfer device using an electrostatic chuck is improved, and furthermore, the operating rate of the semiconductor manufacturing device using this method is improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram according to the present invention, FIG. 2 is a sectional view of a conventional electrostatic chuck, FIG. 3 is a time chart showing the operation of the method of the present invention, and FIG. 4 is the operation of the method of the present invention. FIG. 5 is a cassette feeding diagram.・Electrostatic chuck ・Drive mechanism ・Cassette ・Drive mechanism ・Control unit ・Control unit ・Control means ・Power supply ・Detection unit 30th

Claims (1)

[Claims] An electrostatic chuck that attracts a wafer, a drive mechanism 2 that drives the electrostatic chuck, a control section 5 that controls the drive mechanism 2, a cassette that stores the wafer, and a drive mechanism 4 that drives the cassette. , a control unit 6 connected to and controlling the drive mechanism 4; a control unit 5, a control unit outputting a control signal to the control unit 6 and the electrostatic chuck; and a control unit connected to the electrostatic chuck. , comprising a power supply for controlling the voltage of the electrostatic chuck according to a control signal from the control means, and a detection means connected to the control means for detecting a wafer on the electrostatic chuck, the wafer being attracted to the electrostatic chuck. A wafer transport method comprising: correcting the moving distance of the cassette based on a signal from a detection means for detecting the presence or absence of a wafer, and correcting the amount of pressing of the wafer against an electrostatic chuck.