JP2000114345A - Positioning equipment of substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of particles caused by a sliding robot hand on a substrate, by calculating the position of a substrate center by measuring the distance between the outer peripheral part of the substrate and a sensor while horizontally rotating once a rotary table. SOLUTION: After a substrate W held by a robot hand 10 is mounted on a mounting table 24 in a positioning chamber 18, the hand 10 is drawn out from the positioning chamber 18. In this state, a rotary table 26 and the substrate W are made to ascend, a distance as far as the outer peripheral part of the substrate W is continuously measured with a sensor 28 rotating 360 degrees. Next the substrate W is delivered to the hand 10 in the state that the position of the substrate W is adjusted to the hand 10. The position of the center of the substrate W is calculated with an operation processing unit and inputted in a control unit of the hand 10. The hand 10 is inserted in a gap to the rotary table 26. After the position is so adjusted in a plane that the center of the hand 10 coincides with the center of the wafer W, the substrate W is made to ascend and held. The substrate W is carried in a substrate treatment chamber 20 and positioned on the mounting table 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for positioning a substrate, for example, in an apparatus for performing various processes on a substrate such as a semiconductor wafer.

[0002]

2. Description of the Related Art FIG. 9 is a diagram showing an entire configuration of a film forming apparatus for forming a high dielectric or ferroelectric thin film such as barium / strontium titanate. Raw material gas pipe 11 downstream of the vessel 110
2, a chamber (reaction chamber) 114 is provided, and a vacuum pump 116 is further arranged in an exhaust path on the downstream side thereof to form an exhaust pipe 118. An oxidizing gas pipe 120 for supplying an oxidizing gas such as oxygen is connected to the chamber 114.

[0003] The substrate W
Is placed on a heating plate provided on the substrate holding table 124, and the substrate W
While maintaining the temperature at a predetermined temperature, a mixed gas (reactive gas) of a source gas and an oxidizing gas is jetted from the nozzle hole 126 of the gas supply head 128 toward the substrate W to grow a thin film on the surface of the substrate W.

When processing a substrate W in such an apparatus, it may be necessary to position the substrate W at a predetermined position in the processing apparatus by a robot hand from a cassette.
As means for this purpose, there is a robot hand itself having a function of centering the substrate W when the robot hand grips the substrate W.

[0005] Fig. 10 shows a pair of semicircular robot hands 132 provided at the end of an arm 130 so as to be openable and closable, and a plurality of rollers 134 arranged inside the robot hand 132. , The peripheral portion of the substrate W is sandwiched and gripped from the left and right. FIG. 11 shows the tapered surface 13 that gradually opens upward on the robot hand 138.
6, a substrate holding portion 139 is formed thereon. The substrate W is dropped into the substrate holding portion 139 from above, and the substrate W is slid along the tapered surface 136.

Further, the semiconductor wafer is provided with an orientation flat and a notch for facilitating the discrimination and alignment of the crystal direction, and the orientation flat and the notch may be used for positioning. FIG. 12 shows a light receiving element 142 and a light source 144 at the end of the substrate W held by the chuck 140.
Are provided with an optical sensor 146 that is disposed to face up and down. While rotating the chuck 140, the light receiving element 142
When the amount of light incident on the chuck 140 is measured, the substrate W
If the substrate W is decentered, the eccentric amount and the eccentric direction of the substrate W can be obtained from the change in the amount of light incident on the light receiving element 142.

[0007]

However, in the method of performing centering by holding the substrate or sliding along the tapered surface, there is sliding between the substrate and the hand, and particles are generated. Also, if there is an orientation flat or a notch, an error is likely to occur. Further, in the method of sliding the substrate along the tapered surface, there is a problem that the substrate is difficult to smoothly slide along the tapered surface, and particles are generated from the sliding surface.

On the other hand, in the prior art in which the light amount is measured by an optical sensor to align the orientation flat, the optical sensor is generally installed outside the chamber and measures the light amount through glass. Therefore, not only the sensitivity may be degraded due to the fogging of the glass, but also if the optical sensor has hysteresis, the optical sensor may be turned ON / OFF (recognition of light transmission / shielding) at a target position centered on the orientation flat. However, there is a problem that the adjustment of the optical sensor is considerably troublesome.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to easily and reliably position a substrate while preventing generation of particles due to sliding of the substrate with a robot hand. It is an object of the present invention to provide a positioning device for a substrate.

[0010]

According to a first aspect of the present invention, there is provided a rotary table for holding and rotating a circular substrate in a horizontal plane, a driving device for rotating the rotary table, and a periphery of the rotary table. A sensor that continuously measures a distance or a displacement amount in a horizontal direction with respect to an outer peripheral portion of the rotating substrate, and a position of the substrate that is rotating based on the distance or distance displacement amount measurement information of the sensor. Alternatively, the present invention is a substrate positioning device, comprising: a calculation control unit that calculates a displacement of the substrate position.

If the substrate is held eccentrically on the turntable, the distance between the outer peripheral portion of the substrate and the sensor fluctuates in accordance with the amount of eccentricity when the turntable is rotated once by one turn, and the maximum value or the minimum value is obtained. From the value and the angle at which the maximum or minimum value is taken, the position of the center of the substrate can be determined. The number of sensors may be one or two or more. The calculation in the calculation control unit may be performed in a polar coordinate system or a rectangular coordinate system. By arranging the sensors obliquely and simultaneously detecting the upper surface of the substrate, the amount of warpage of the substrate can also be obtained.

According to a second aspect of the present invention, the positioning notch is formed in the substrate, and the arithmetic control unit calculates the angle of the notch position. Device. If there is a notch such as an orientation flat or a notch in the outer peripheral portion of the substrate, the distance from the outer peripheral portion of the substrate to the sensor changes specifically at this notched portion, so that the position of the notch can be obtained from the angle at this time. .

According to a third aspect of the present invention, the arithmetic and control unit controls the driving device so as to correct the position of the substrate based on the calculated position or the displacement of the position or the angle of the position. The substrate positioning device according to claim 1 or 2, wherein As a result, the substrate can be taken out with the robot hand or the like performing at least the centering positioning, the orientation flat, the notch positioning, and the like.

Further, when the robot hand takes out the substrate without controlling and moving the substrate mounting surface, the center of the substrate and the center of the robot hand are matched even if the substrate is located at a position other than the center of the substrate mounting table. Can be taken out. Alternatively, when placing the substrate in the next process chamber, the center of the next process chamber and the center of the substrate can be matched and placed.

It is to be noted that a sensor that measures the distance to the outer peripheral portion of the substrate using light or ultrasonic waves may be used as the sensor.

According to a fourth aspect of the present invention, in accordance with the calculated position information of the substrate, the center of the substrate mounting surface on which the robot for transporting the substrate is to be mounted on the substrate mounting surface, and the robot actually mounted thereon The substrate positioning apparatus according to claim 1, wherein the substrate is transported while controlling the robot so that the center position of the substrate on the band is matched.

According to a fifth aspect of the present invention, there is provided a positioning apparatus according to any one of the first to fourth aspects, a processing apparatus for processing the substrate, a robot hand for transferring the substrate from the turntable to the processing apparatus, And a robot hand control unit for controlling a position at which the robot hand unloads or unloads the substrate based on the calculated position.

[0018]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 shows an embodiment of a semiconductor manufacturing apparatus provided with a substrate positioning apparatus according to the present invention. This semiconductor manufacturing apparatus has a robot hand 10 in a substrate transfer chamber 14 having a polygonal cross section. A substrate transfer robot 12 is provided, and the substrate transfer chamber 14
, A load lock chamber 16, a positioning chamber 18, a substrate processing chamber 20, and the like are arranged. Robot hand 10
Is formed with a projection which forms a recess for receiving the substrate W in the peripheral portion of the flat member, but does not have a centering function.

In the positioning chamber 18, FIG.
A positioning device 21 as shown in FIG. The positioning device 21 includes a mounting table 24 having a recess in the center, a rotary table 26 disposed in the recess, and a sensor 28 disposed at one corner in the positioning chamber 18. A gap 23 for the robot hand 10 to enter is formed in the mounting table 24.
The substrate W can be transferred to the mounting table 24 through the gap 23. A drive unit (not shown) for rotating and raising / lowering the turntable 26 via a shaft 27 is provided below the positioning chamber 18.

The sensor 28 is connected to the turntable 2 by a driving device.
The turntable 26 is disposed at a height position when the turntable 6 is raised so as to substantially face the center of rotation of the turntable 26. This sensor 28
For example, a light emitting element and a light receiving element, or an ultrasonic oscillation element and a receiving element are provided, and the distance in the horizontal direction between the sensor 28 and the outer peripheral portion of the substrate W can be continuously measured. Although not shown, there is provided an arithmetic processing unit which receives and stores the output data of the sensor 28 and performs processing described later based on the data.

In the substrate processing apparatus having such a configuration,
A process of taking out one substrate W from the cassette 22 accommodated in the load lock chamber 16 and placing it at a predetermined position in the substrate processing chamber 20 in a state where the substrate W is positioned will be described with reference to a flowchart shown in FIG. First, the cassette 22 is set in the load lock chamber 16 (step 1), and one substrate W is taken out of the cassette 22 by the robot hand 10 of the substrate transfer robot 12 (step 2).

The substrate W stored in the cassette 22 is
The position of the center is not accurate, and the position of the orientation flat F is also unknown. Therefore, the position of the center of the substrate W and the position of the orientation flat F when held by the robot hand 10 are also unknown. In addition, even if the position of the substrate W in the cassette 22 is shifted, the substrate receiving portion of the robot hand 10 is set wider so that the substrate W is held horizontally by the hand 10. Then, as shown in FIGS. 2A and 2B, the substrate W held by the robot hand 10 is carried into a position above the mounting table 24 in the positioning chamber 18 (Step 3).

Next, as shown in FIGS. 4A and 4B,
The robot hand 10 is lowered to place the substrate W on the mounting table 24 (step 4), and the robot hand 10 is pulled out of the positioning chamber 18. In this state, as shown in FIG.
The turntable 26 and the substrate W are raised by the driving device (step 5), and the turntable 26 and the substrate W are further moved by 360.
While rotating (step 6), the distance D to the outer peripheral portion of the substrate W is continuously measured by the sensor 28 (step 7).

Here, if the center Ow of the substrate W and the center (rotation center) O of the turntable 26 coincide, the measured value is constant within the range of the dimensional accuracy of the substrate W. As shown in FIG. 6A, when both are shifted by d, the sensor 28
Assuming that the angle between a line (base line) connecting the rotation center and the center Ow of the substrate W and the rotation center O is θ, when the turntable 26 rotates by θ, the state shown in FIG. The value is minimum (= Dmin). Assuming that the distance between the sensor 28 and the center of rotation is L and the radius of the substrate W is r, L = d + r +
Since it is Dmin, d is calculated from this, and Ow is obtained as a position separated by a distance d in the direction of the angle θ from the base line.

By rotating the substrate W once,
When Ow comes to the position farthest from the sensor 28 (angle = θ +
(π, D = Dmax) can also be measured, thereby improving the accuracy. Further, when the orientation flat F is present on the outer peripheral portion of the substrate W, at least one of Dmin and Dmax described above may not be measured, but there is no problem because one of them can always be measured.

Next, the positioning of the orientation flat F on the substrate W will be described with reference to FIG. When there is the orientation flat F, the measured value changes specifically, that is, discontinuously, at both ends of the orientation flat F. The coordinates of these end points are
From the angles (θ ₁ , θ ₂ ) of the points where the measured values change discontinuously and the measured values, the coordinates can be obtained as coordinate values in a polar coordinate system based on the rotation center and the base line.

The position of the center Ow of the substrate W can be calculated by geometrical calculation from the coordinate values and the radius r of the substrate W. Can be used.

After the relative position and posture of the turntable 26 and the substrate W are determined in this manner, the turntable 26 is rotated to adjust the position and the position of the substrate W, and the substrate W is moved to the robot hand 10. Robot hand 1 with the position adjusted
Hand over to 0. For example, the turntable 26 is rotated by a predetermined angle to adjust the orientation flat so as to be at a position orthogonal to the traveling direction of the robot hand 10 (step 9), and the turntable 26 is lowered to place the substrate W on the mounting table 24. It is set on (step 10).

Then, the position of the center of the substrate W after the rotation is calculated by the arithmetic processing unit and input to the control device of the robot hand 10, and the robot hand 10 of the substrate transfer robot 12 is inserted between the rotary table 26 and After adjusting the position within the plane so that the center of the robot hand 10 coincides with the center of the substrate W, the robot hand 10 is raised to hold the substrate W (step 11).

In this manner, the substrate W is carried into the substrate processing chamber 20 in a state where the centering and the orientation flat are performed, and the approach distance of the robot hand 10 is adjusted, so that the center of the substrate W and the substrate processing chamber 20 are adjusted. The substrate W can be positioned and installed on the mounting table 24 in the substrate processing chamber 20 by aligning the center with the mounting table inside.

[0031] As described above, when taking out the substrate W from the cassette, the position of the substrate W in the cassette is indefinite, using the clearance L ₁ is large robot hand 10a of the outer peripheral portion and the step portion of the substrate W Is good.
On the other hand, when taking out the substrate W from the positioning chamber 18,
The robot hand and the substrate W because it is a state of being centered well clearance L ₂ is small, the better the substrate W after the positioning is less likely to move the robot hand. Therefore, as shown in FIG. 8, the outer peripheral portion and the step portion and the clearance L ₂ are two different types of robot hand 10a of the substrate W, by using a conveying robot comprising 10b, reliably performing the positioning of the substrate W Can be.

In the above-described embodiment, the sensors are arranged horizontally to detect the position of the side surface of the substrate W. However, the sensors may be installed in a state inclined with respect to the horizontal plane. Thereby, the position of the upper edge of the substrate W is detected,
The degree of warpage of the substrate W can also be detected.

[0033]

As described above, according to the present invention, the maximum value or the minimum value and the maximum value are measured by measuring the distance between the outer peripheral portion of the substrate and the sensor while rotating the turntable horizontally once. Alternatively, the position of the center of the substrate can be calculated from the angle at which the minimum value is obtained, and without performing the step of sliding the substrate with the robot hand, it is possible to easily and easily position the substrate while preventing generation of particles. It can be done reliably.

[Brief description of the drawings]

FIG. 1 is a plan layout view of a semiconductor manufacturing apparatus provided with a positioning device according to an embodiment of the present invention.

FIGS. 2A and 2B show a state when a substrate is carried into a positioning chamber; FIG. 2A is a sectional view taken along line AA in FIG. 1;

FIG. 3 is a flowchart showing an operation of the positioning device according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a main part in a state where the substrate is mounted on a mounting table.

FIG. 5 is a cross-sectional view showing a main part in a state where the turntable is raised.

FIG. 6 is a diagram showing a positional relationship between a sensor and centers before and after rotation of a substrate.

FIG. 7 is a diagram illustrating a positional relationship between a sensor and an orientation flat of a substrate.

FIG. 8 is a cross-sectional view showing another embodiment of the robot hand.

FIG. 9 is a diagram showing an overall configuration of a film forming apparatus.

FIG. 10 is a plan view showing a robot hand provided with a conventional centering mechanism.

FIG. 11 is a sectional view showing another conventional robot hand.

FIG. 12 is a side view showing a main part of a conventional positioning device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Robot hand 12 Substrate transfer robot 18 Positioning chamber 24 Mounting table 26 Rotating table 28 Sensor

Continuing from the front page (72) Inventor Hirogo Yamagishi 11-1 Haneda Asahimachi, Ota-ku, Tokyo F-term in Ebara Corporation (reference) 5F031 CA02 DA01 FA01 FA07 FA11 FA12 GA05 GA45 GA47 GA48 GA49 JA02 JA09 JA25 JA29 JA32 JA34 JA35 KA11 KA13 MA28 MA29 PA13

Claims (5)

[Claims] 1. A rotating table for holding and rotating a circular substrate in a horizontal plane, a driving device for rotating and driving the rotating table, and an outer peripheral portion of the rotating substrate disposed around the rotating table. A sensor for continuously measuring a distance or a displacement amount of a distance in a horizontal direction, and an arithmetic control unit for calculating a position of the substrate being rotated or a displacement of the substrate position from the distance or distance displacement amount measurement information of the sensor. A substrate positioning device, comprising: 2. The substrate positioning apparatus according to claim 1, wherein a positioning notch is formed in the substrate, and the arithmetic control unit calculates an angle of the notch position. 3. The apparatus according to claim 1, wherein the arithmetic control unit controls the driving device so as to correct the position of the substrate based on the calculated position or the displacement of the position or the angle of the position. A substrate positioning device as described in the above. 4. According to the calculated position information of the substrate,
Transferring a substrate while controlling the robot so that the robot that transports the substrate matches the center of the substrate mounting surface to be mounted on the substrate mounting surface with the center position of the substrate on the robot band that is actually mounted The substrate positioning apparatus according to claim 1, wherein: 5. The positioning device according to claim 1, wherein the processing device processes the substrate; a robot hand that transfers the substrate from the turntable to the processing device; A substrate processing apparatus comprising: a robot hand control unit that controls a position at which a substrate is unloaded or unloaded by a robot hand.