JPH10175734A - Substrate carrier mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To instantaneously confirm presence or absence of a wafer at an arbitrary location and always monitor the attitude of the wafer while the wafer is transported by arranging a reflection type photosensor provided with a light emitting part and a light receiving part and a mirror reflecting laser light emitted from the reflection type photosensor on a blade on which a substrate is mounted. SOLUTION: A blade 2 on which a semiconductor wafer 1 is mounted is fitted on an arm tip of a wafer carrier robot and a mirror 4 having an arbitrary angle with a reflection type photosensor 3 is arranged on the blade 2. The reflection type photosensor 3 is adjusted so that laser light emitted from the reflection type photosensor 3 may reflect on the mirror 4 and reach the light receiving part of an air supply path 31 and is arranged. The mirror 4 arranged on the blade 2 is the one in which a recess is worked on the blade 2 and a surface opposed to a reflection type photosensor 3 mounting location is worked on a mirror surface by using an electropolishing. Thus, presence or absence of the semiconductor wafer on the blade 2 can be always detected at an arbitrary location.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a substrate transfer mechanism.

[0002]

2. Description of the Related Art In an LSI manufacturing process, a plurality of processes such as film formation and etching are performed. Most of these processes are performed in a reduced-pressure atmosphere, and an RΘ-type transfer robot is used to transfer a semiconductor wafer from a load lock chamber to a processing chamber, or from a processing chamber to a processing chamber, etc., which performs a preliminary evacuation from an air atmosphere. And a multi-joint type wafer transfer robot. In these wafer transports, it is important to transport the wafers at high speed and reliably. However, there are few known methods and systems for detecting whether a semiconductor wafer is securely mounted on a wafer mounting plate provided on the wafer transfer robot called a blade and maintaining its posture during transfer. Known methods and systems are described in JP-A-61-278149, JP-A-61-99345, and JP-A-6-224284.

[0003]

In each of the above-mentioned known methods and systems, the presence / absence and attitude of the semiconductor wafer on the blade are detected using a detection mechanism provided outside. Therefore, it is impossible to detect the displacement of the wafer on the blade during transfer or the presence or absence of the semiconductor wafer on the blade at an arbitrary position. On the other hand, in a semiconductor manufacturing process, high-speed conveyance and improvement in the reliability of conveyance are required to improve throughput. Therefore, the presence / absence of a wafer can be instantaneously confirmed at an arbitrary position, and constantly monitoring the posture of the wafer being transferred reduces defective transfer of the semiconductor wafer and improves the reliability of the process. In addition, in the above-mentioned known method and system, separately,
The provision of the detection mechanism is disadvantageous in reducing the space and cost. An object of the present invention is to provide a means for solving the above problems.

[0004]

According to the present invention, there is provided a reflection type optical sensor having a light emitting portion and a light receiving portion on a blade for mounting a substrate mounted on a substrate transfer robot, and a laser emitted from the reflection type optical sensor. It is constituted by a mirror having an arbitrary angle for reflecting light. By arranging one or a plurality of pairs of the reflection type optical sensor and the mirror on the blade as a pair, the presence or absence of the substrate and the posture thereof are detected.

[0005]

FIG. 1 is a perspective view of an essential part of a substrate transfer mechanism showing an example of the present invention. In the figure, reference numeral 2 denotes a blade on which the semiconductor wafer 1 is mounted, which is attached to the tip of the arm of the wafer transfer robot. A mirror 4 having an arbitrary angle with respect to the reflection type optical sensor 3 is arranged on the blade 2. The reflection type optical sensor is adjusted and arranged so that laser light emitted from the reflection type optical sensor is reflected by a mirror and reaches a light receiving portion of the reflection type optical sensor. Reference numeral 5 in the figure denotes a signal line for sending a signal of the reflection type optical sensor to an external control device.

In this embodiment, as shown in FIG. 1, the mirror 4 arranged on the blade 2 is formed with a depression on the blade, and the surface facing the mounting position of the reflection type optical sensor 3 is subjected to a method such as electric field polishing. Although it is used to form a mirror surface, it may be manufactured by a method of depositing a metal such as aluminum on this surface or a method of fixing an existing glass mirror or the like.

Here, in order to accurately obtain a signal, the laser light emitted from the reflection type optical sensor 3 is reflected by the mirror 4 formed on the blade 2 and reaches the light receiving portion of the reflection type optical sensor 3. The optical axis needs to be adjusted.

FIG. 2 shows details of the optical axis adjusting mechanism used in this embodiment. In the figure, reference numeral 3a denotes a light emitting unit of the reflection type optical sensor, and 3b denotes a light receiving unit. The reflection-type optical sensor is fixed on a base 6, and the base 6 is fixed to the blade 2 by screws 7 provided at four corners of the base 6 via an elastic body 8 having appropriate softness. The reflection type optical sensor 3 can be delicately adjusted to an arbitrary angle because the elastic body 8 is deformed by tightening the screws 7 provided at the four corners of the base 6.

In this embodiment, an O-ring made of silicon rubber is used as the elastic body having a suitable degree of softness. However, if an appropriate degree of softness can be obtained, the material and shape need not be limited. However, when used in a vacuum atmosphere, it is preferable to use a material with less degassing. The optical axis adjustment mechanism of the reflection type optical sensor 3 uses a sensor in which the dimensional accuracy of the mounting portion of the reflection type optical sensor 3 processed on the blade 2 is obtained, or a sensor that does not require the optical axis adjustment. It is not always necessary if you can.

In this embodiment, the optical axis of the reflection type optical sensor 3 is adjusted using this mechanism, and the laser light emitted from the reflection type optical sensor is adjusted so as to accurately enter the light receiving portion of the reflection type optical sensor. Was done. This makes it possible for the transfer robot to always detect the presence or absence of the semiconductor wafer on the blade at an arbitrary position.

FIG. 3 is a perspective view showing another embodiment of the present invention. In the figure, 3c is a probe of a reflection type optical sensor using an optical fiber, 9c is a probe and a light emitting portion of a laser,
It is an optical fiber that connects the light receiving unit. The reflection type optical sensor using an optical fiber has a small weight at the tip of the probe, and the laser light emitting unit, light receiving unit, and amplifiers for controlling signals can be installed on the transfer robot main body. This is advantageous for miniaturization. Also,
The optical fiber has an excellent mechanical strength such as a repeated bending load, so that it is optimal to be installed on a transfer robot that moves at high speed.

In this embodiment, the optical axis of the reflection type optical sensor using the optical fiber is adjusted using the optical axis adjusting mechanism used in the first embodiment. This makes it possible for the transfer robot to always detect the presence or absence of the semiconductor wafer on the blade at an arbitrary position, as in the first embodiment.

FIG. 4 is a perspective view showing another embodiment of the present invention. In the figure, reference numerals 3d, 3e, and 3f denote probes of a reflection type optical sensor using optical fibers, and reference numerals 9d, 9e, and 9f denote optical fibers that connect the probes corresponding to the respective alphabets to the light emitting portion and the light receiving portion of the laser. In addition, mirrors 4d, 4e and 4f in the figure are used to reflect laser light emitted from a reflection type optical sensor using optical fibers corresponding to the respective alphabets.

These mirrors are manufactured by the method shown in the first embodiment, and are each paired with a reflection type optical sensor using an optical fiber adjusted by using the optical axis adjusting mechanism shown in the first embodiment. Thus, the attitude of the semiconductor wafer on the blade 2 is detected. For example, when the semiconductor wafer which should originally be in the state 1a is in the state 1b, the reflection type optical sensor 3d using the optical sensor and the blade 2 are used.
The upper mirror 4d immediately detects that the semiconductor wafer is not in the state 1a.

When the semiconductor wafer is in the state 1c, the reflection type optical sensor 3f using an optical fiber and the mirror 4f on the blade 2 immediately detect that the semiconductor wafer is not in the state 1a. This makes it possible to immediately detect, for example, when the semiconductor wafer is displaced from the blade during transfer, when the semiconductor wafer is removed from the wafer cassette, or when the semiconductor wafer is transferred from the processing chamber to the processing chamber. In addition, it is possible to minimize the damage in the event of a transport failure. Further, if a mechanism for returning the posture of the semiconductor wafer to a normal position is provided in the processing apparatus provided with the transfer robot, the transfer can be performed again.

In this embodiment, an example is shown in which three systems are used for a reflection type optical sensor using an optical fiber and a detection system using a mirror arranged on a blade. However, the present invention is limited to the number of detection systems. Instead, it is desirable to use a plurality of detection systems as needed. Also, when a plurality of detection systems are used, it is possible to detect whether or not the orientation flat position of the semiconductor wafer is at a specific location. The conveyance can be performed while detecting the orientation flat position, and the process can be performed with the orientation of the orientation flat reliably.

[0017]

As described above, some of the embodiments of the present invention have been described with reference to the drawings. However, the present invention is not limited to the transfer of semiconductor wafers, but can be applied to any substrate transfer.
A transparent substrate such as a glass substrate can be detected by using a reflection-type optical sensor capable of detecting a change in the amount of light in the reflection-type optical sensor, and thus is within the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a substrate transfer mechanism according to an embodiment of the present invention.

FIG. 2 is a perspective view of an optical axis adjusting mechanism according to one embodiment of the present invention.

FIG. 3 is a perspective view of a main part of the substrate transfer mechanism according to the embodiment of the present invention.

FIG. 4 is a perspective view of a main part of the substrate transfer mechanism according to one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor wafer, 2 ... Blade, 3 ... Reflection type optical sensor, 4 ... Mirror, 5 ... Signal line.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yasuhide Matsumura 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Kunio Harada 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Central Research Laboratory (72) Inventor Hideo Kashima 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside Central Research Laboratory, Hitachi, Ltd.

Claims (5)

[Claims] 1. A substrate transfer robot for transferring a substrate, wherein a reflection type optical sensor and light emitted from the reflection type optical sensor are reflected on a portion where a substrate mounted on a tip of the substrate transfer robot is mounted. A substrate transport mechanism, comprising a mirror for reflecting light on a light receiving portion of the optical sensor. 2. The reflection type optical sensor according to claim 1, wherein the reflection type optical sensor and the light emitted from the reflection type optical sensor are received by the reflection type optical sensor at a portion where a substrate attached to a tip of the substrate transfer robot is mounted. A substrate transport mechanism that detects the presence / absence and attitude of mounting a substrate by mounting a plurality of mirrors for reflecting light on a unit. 3. The substrate transport mechanism according to claim 1, wherein the light emitting unit and the light receiving unit of the reflection type optical sensor use optical fibers. 4. The method according to claim 1, wherein the reflection type optical sensor is fixed to a portion for mounting a substrate attached to a tip of the substrate transfer robot via an elastic body having appropriate softness. A substrate transport mechanism having a mechanism for adjusting the optical axis of the reflection type optical sensor. 5. The semiconductor device according to claim 2, wherein a target of the substrate to be transferred is a semiconductor wafer, and at least a presence / absence, a posture, and an orientation flat position of the semiconductor wafer are provided on a portion for mounting the semiconductor wafer attached to a tip of the substrate transfer robot. A substrate transfer device that detects one.