KR20040011997A - Apparatus for detecting protrusion of wafers from carrier - Google Patents

Abstract

PURPOSE: An apparatus for detecting the protrusion of a wafer from a carrier is provided to effectively detect the protrusion of the wafer in the carrier in real time by using a non-contact detection method, and to be adapted to all kinds of wafer carriers and semiconductor equipment by simplifying the structure of a wafer protrusion detecting apparatus. CONSTITUTION: A plurality of reflection surfaces(411,413,415,417) form a light path that vertically cuts the inlet of a carrier door(150), installed inside the inlet of the carrier door. The light that will proceed to the light path is supplied to any one of the reflection surfaces by a light detection unit. The light detection unit receives the light having passed through the light path from any one of the reflection surfaces and detects whether the wafer(200) protrudes from the carrier.

Description

Apparatus for detecting protrusion of wafers from carrier}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus used for semiconductor manufacturing, and more particularly, to detect undesired protrusion of a wafer contained in a carrier used for the transfer of wafers when the carrier door is opened. Relates to a device.

Wafer carrier refers to a container that houses or contains a wafer when transferring a semiconductor wafer. FOUPs used in the case of 300 mm wafers can also be regarded as one of these carriers. After the wafers are placed in a slot installed inside the carrier, the wafers are transferred by closing the carrier door and transferring the carrier.

In order to take out wafers from a carrier moved to a load port or the like of a semiconductor manufacturing facility and transfer the wafers to a semiconductor manufacturing facility, an operation of opening a carrier door is first performed. The wafer carrier door is opened by a load port door, which may occur when the wafers slide out of the slot and protrude away from the open carrier door. When the carrier door is opened by the load port door, the wafer may be separated from the normal position toward the wafer carrier door and protrude due to static electricity, friction, vibration, or the like. This protrusion of the wafer may cause problems during subsequent mapping or operation of a mapping arm or wafer transfer robot arm for wafer transfer.

Specifically, after the wafer carrier door is opened, mapping is performed to determine which slot is located in the carrier. Thereafter, the robot arm is operated to take the wafer out of the carrier and transfer the wafer to the facility. Recently, a through-beam type mapping sensor with higher accuracy and higher productivity than a reflective type mapping sensor has been used.

The transmissive mapping sensor has a light emitting part at one end of the two mapping arms at a certain distance, and a light receiving part at the end of the other arm, and allows the wafer to enter between the two mapping arms to determine the presence of the wafer by blocking light. Therefore, the closer the mapping arm is to the wafer, the more accurate mapping is possible. On the other hand, some installations are provided with a mapping sensor in the wafer transfer robot arm.

The mapping arm or wafer transfer robot arm for mapping is moved very close to the wafer in the wafer carrier. At this time, if some of the wafers protrude more than the normal position, the mapping arms or robot arms that map in close proximity and the protruding wafers collide with each other and the wafers are broken by such collisions, and the wafer carriers and equipment are destroyed by the destruction of the wafers. The interior is contaminated. When such an accident occurs, problems such as cost increase due to productivity or wafer damage occur, such as the need to stop the operation of the facility for cleaning the facility.

Therefore, it is very important to check whether the wafer has protruded out of the normal position inside the wafer carrier. In other words, it is very important to detect whether the wafer protrudes in advance and set an interlock to notify the operator to take action.

However, up to now, most semiconductor manufacturing facilities do not detect whether the wafer protrudes from such a carrier. However, in some semiconductor manufacturing facilities, the contact wafer protrusion detection sensor is installed under the mapping sensor, and the contact wafer protrusion detection sensor collides with the wafer when the mapping sensor moves up and down. It sends a signal to stop the mapping. Alternatively, some mapping devices start mapping from a long distance in consideration of collision with the protruding wafer during mapping, and repeat the mapping two or three times while gradually approaching the wafer.

However, the above-described contact sensing method also needs to be in contact with the wafer, so it is necessary to use a non-contact method because it may damage the wafer. In addition, the method of repeating the mapping several times while approaching the wafer at a long distance consumes a lot of time, and thus a faster sensing method is required.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a wafer sensing device capable of detecting a wafer protruding from a carrier at a faster time, without removing contact with the wafer.

1 is a view schematically illustrating an apparatus for detecting protrusion of a wafer in a carrier according to an embodiment of the present invention.

FIG. 2 is a view schematically illustrating an inlet shape of a carrier to describe an apparatus for detecting protrusion of a wafer from a carrier according to an embodiment of the present invention.

FIG. 3 is a view schematically illustrating an inner shape of a carrier along the 3 ′ 3 ′ cutting line of FIG. 2 to describe an apparatus for detecting protrusion of a wafer from a carrier according to an embodiment of the present invention.

4 is a view schematically illustrating a shape of a load port door side in order to describe an apparatus for detecting protrusion of a wafer from a carrier according to an exemplary embodiment of the present invention.

FIG. 5 is a view schematically illustrating an operation in which a carrier door is opened by a load port door to explain an operation of an apparatus for detecting protrusion of a wafer from a carrier according to an embodiment of the present invention.

FIG. 6 is a view schematically illustrating an operation in which a load port door descends to explain an operation of an apparatus for detecting protrusion of a wafer from a carrier according to an embodiment of the present invention.

FIG. 7 is a diagram schematically illustrating an operation of an apparatus for detecting protrusion of a wafer from a carrier according to an exemplary embodiment of the present invention.

One aspect of the present invention for achieving the above technical problem is that a carrier used to receive and transport wafers is mounted to a load port of a semiconductor facility so that the carrier door is opened by a load port door. Provided is an apparatus for detecting the protrusion of a wafer from a carrier after the carrier door is opened.

The sensing device includes a plurality of reflective surfaces installed inside a door entrance of the carrier to form an optical path terminating the entrance, and light to travel to the optical path to any one of the reflective surfaces. And a light sensing unit configured to receive light passing through the light path from one of the reflective surfaces and detect whether the wafer protrudes from the carrier.

Here, the optical path may be formed at a position aligned with the centerline of the carrier.

The light detector determines that the protrusion of the wafer from the carrier occurs when the light that passes through the optical path cannot be received.

The light detector provides light to be incident on the reflective surface after the door of the carrier is opened by a load port door of the semiconductor device.

The light detector may be installed at an upper end of the load port door.

The light detector provides light to be incident on the reflective surface when the load port door descends.

The light detecting unit may include a light emitting unit for emitting the light, and a light receiving unit for receiving the light.

The reflective surfaces are provided above the inlet of the carrier and are provided from the light sensing unit to reflect the incident light to the lower side of the inlet of the carrier and to the lower side of the inlet of the carrier to face the first reflective surface. A second reflecting surface which is installed in the second reflecting surface and is spaced apart from the second reflecting surface, and reflects the light reflected from the first reflecting surface in a lateral direction, and reflects the light reflected from the second reflecting surface above the entrance of the carrier A third reflecting surface reflecting the light and a fourth reflecting surface installed above the inlet of the carrier so as to face the third reflecting surface and reflecting the light reflected from the third reflecting surface to the light sensing unit to receive the light sensing unit. It includes a reflective surface.

The reflecting surface is a mirror surface formed by attaching a reflecting film or reflecting surface deposition. Alternatively, the reflective surface may be provided by a prism.

Alternatively, the sensing device may be provided in pairs opposed to each other above and below a door inlet of a carrier to form a plurality of reflective surfaces forming an optical path terminating the inlet, and to open the door of the carrier. Protruding of the wafer from the carrier by being provided at an upper end of the actuated load port door to provide light to the optical path to any one of the reflective surfaces and to receive light passing through the optical path from either of the reflective surfaces. It is configured to include a light sensing unit for detecting the presence.

According to the present invention, it is possible to effectively detect the presence or absence of wafer protruding from the carrier in real time by a non-contact sensing method using the presence of light propagation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Therefore, it is preferable to understand that the shape of an element etc. in the drawing are exaggerated in order to emphasize clearer description. Elements denoted by the same reference numerals in the drawings means the same element.

Embodiments of the present invention provide a wafer sensing device that detects the protrusion of a wafer to an abnormal position in a carrier used to receive and transport the wafer. The apparatus for detecting the protrusion of the wafer of the present invention provides a plurality of reflective surfaces inside the wafer carrier so that the detection light can be continuously reflected between the reflective surfaces. The light passing between the reflective surfaces may be sensed to detect whether the wafer protrudes in a non-contact state. That is, if the light passing between the reflective surfaces is obscured by the protruding wafer, the light to pass between the reflective surfaces will not be detected, thereby detecting that the wafer has protruded.

1 is a view schematically showing an apparatus for detecting protrusion of a wafer in a carrier according to an embodiment of the present invention. 2 is a view schematically showing the inlet side shape of the carrier of the device for detecting the protrusion of the wafer in the carrier according to an embodiment of the present invention. FIG. 3 is a view schematically illustrating the cutting line of the wafer in the carrier according to an embodiment of the present invention along the 3-3 'cutting line of FIG. 4 is a view schematically illustrating a load port door side shape to describe an apparatus for detecting protrusion of a wafer from a carrier according to an exemplary embodiment of the present invention.

Referring to FIG. 1, an apparatus for detecting protrusion of a wafer from a carrier according to an exemplary embodiment of the present invention forms an optical path terminating the entrance inside the door inlet of the carrier 100 so that light is projected along the optical path. Detect wafers In order to implement such an optical path, a plurality of reflective surfaces 411, 413, 415, and 417 are installed inside the inlet of the carrier 100. In addition, the light emitting unit 431 and the light sensing unit 431, 435 of the light receiving unit 435 are provided to align and sense light in the optical path formed by the reflective surfaces 411, 413, 415, and 417. . The light emitting unit 431 and the light receiving unit 435 may be introduced integrally, but may be introduced in a separate form as shown in FIG. 1.

The wafers 200 to be transferred are accommodated in the carrier 100, and when the carrier 100 is transferred, the inlet of the carrier 100 is closed by the carrier door 150. When the carrier 100 is transported and mounted to a load port of a semiconductor device, the load port door 300 provided in the semiconductor device catches and opens the carrier door 150. The operation of the load port door 300 approaches the carrier door 150 to grasp the carrier door 150, and then moves backward to open the carrier door 150 and then descends to expose the entrance of the carrier 100 to expose the wafer. 200 may be drawn out by a robot arm (not shown) or the like.

However, when the wafer carrier door 150 is opened, the wafer may slide over the slot of the carrier 100 and protrude toward the wafer carrier door 150 due to various reasons such as static electricity, friction, and vibration. have. In general, when the wafer carrier door 150 is opened, mapping is performed to determine which slot in the carrier 100 is located. Recently, mapping using a transmissive mapping sensor has been introduced. At this time, if the wafer 200 protrudes from the normal position, the wafer 200 may be damaged by a collision with a mapping arm (not shown) that performs close mapping.

In an embodiment of the present invention, a sensing device including the reflective surfaces 411, 413, 415, and 417 and the light sensing units 431 and 435 may be introduced to detect a protruding state of the wafer 200. This prevents unwanted collisions and contacts with the wafer 200 as described above.

1 and 2 and 3 together, the reflective surfaces 411, 413, 415, 417 installed inside the wafer carrier 100 are installed to provide an optical path terminating the inlet of the carrier 100. do. For example, when the light detecting unit, that is, the light emitting unit 431 and the light receiving unit 435 is installed at the upper end of the load port door 300 as shown in Figs. 1 and 4, the load port door 300 is The first reflecting surface 411 is provided at a position where light generated by the light emitting unit 431 arrives downward.

The first reflective surface 411 may be installed above the inlet of the carrier 100 as shown in FIGS. 2 and 3. The first reflective surface 411 changes the path of the incident light to the lower end of the inlet of the carrier 100 to reflect the incident light. The second reflecting surface 413 is installed at a lower end of the inlet of the carrier 100 at a position where the light reflected from the first reflecting surface 411 arrives. As a result, an optical first path (510 of FIG. 1) is formed between the first reflection surface 411 and the second reflection surface 413 to terminate the inlet of the carrier 100. The longitudinal light path, such as the light first path 510, determines the permissible range for the wafer 200 to protrude. That is, the wafer 200 in contact with the optical first path 510 is detected as an abnormal protrusion. Therefore, the allowable range in which the wafer 200 protrudes is determined by the installation positions of the first reflective surface 411 and the second reflective surface 413 for implementing the optical first path 510.

Referring to FIGS. 2 and 3 again, the second reflection surface 413 has a reflection angle adjusted to reflect incident light in the lateral direction. The third reflecting surface 415 is provided on the side of the second reflecting surface 413, the light reflected by the second reflecting surface 413, the third reflecting surface 415 is a carrier ( 100) Change to the upper direction of the inlet. The fourth reflecting surface 417 is positioned at the upper end of the carrier 100 inlet of the light reflected by the third reflecting surface 415, and the fourth reflecting surface 417 is reflected by the third reflecting surface 415. The path of the light is changed to be aligned with the light receiving portion 435.

The fourth reflective surface 417 may be installed side by side in the lateral direction of the first reflective surface 411. This is to allow the light paths formed by the reflective surfaces 411, 413, 415, 417 to return appropriately to the light receiving portion 435 and the light emitting portion 431 which are installed side by side. Therefore, the distance between the first reflection surface 411 and the fourth reflection surface 417 is linked to the distance between the light receiving portion 435 and the light emitting portion 431. The distance between the first reflecting surface 411 and the fourth reflecting surface 417 is the same as the distance between the light receiving portion 435 and the light emitting portion 431 or the angle of reflection or the light emitting portion of the fourth reflecting surface 417. The light receiving unit 435 and the light emitting unit 431 may be smaller or larger than a distance separated by the incident angle of the light by 431. Accordingly, the distance between the first reflecting surface 411 and the fourth reflecting surface 417 or the distance between the light emitting part 431 and the light receiving part 435 is the same as when the two parts are composed of separate elements and the two optical elements are one. It can be changed accordingly if it is configured as a combined product.

When the wafer 200 accommodated in the carrier 100 comes into contact with the optical path terminating between the upper side and the lower side of the carrier 100 inlet, propagation of light through the optical path is disturbed. Accordingly, the light emitted from the light emitter 431 is not received by the light receiver 435. That is, it is effectively detected whether there is a wafer that protrudes with or without light propagation on the optical path.

In order to more effectively detect such protruding wafers, the optical path terminating at the inlet of the carrier 100 is positioned at the position (101 in FIG. 1) that is closest to the received wafer 200 as shown in FIG. 1, for example. , Is preferably implemented in the middle of the carrier 100. That is, when the first reflecting surface 411 and the second reflecting surface 413 are arranged along the center line 101 as shown in FIG. 1, even if the wafer 200 protrudes slightly, the reflecting surfaces 411, By changing the positions of 413, 415, and 417 in the front, rear, left, and right directions, it is possible to adjust the allowable range of wafer protruding so that even if the wafer protrudes.

The reflective surfaces 411, 413, 415, and 417 may be formed by mirror-processing a portion of the inside of the carrier 100 by a method such as attaching a reflective film or depositing a reflective film. Alternatively, the reflective surfaces 411, 413, 415, and 417 may be configured using a prism.

On the other hand, the light sensing unit provided at the upper end of the load port door 300 constitutes the light emitting unit 413 by using a laser-emitting diode (LED) or a light emitting device, and includes a photo detector or a photo transistor ( A light receiving unit 435 may be formed of a light receiving element such as a photo transistor to serve as a sensor.

Since the sensing device of the present invention is a non-contact sensing method using the presence or absence of light propagation, the sensing device does not substantially physically affect the wafer 200. In addition, since the load port door 300 can be detected while the wafer carrier door 150 is opened and lowered without setting a separate sensing step, the time for detecting the wafer protrusion is not consumed and thus does not affect the productivity of the facility. . Because of its very simple structure, it can be commonly applied to all wafer carriers and semiconductor equipments at a low investment cost, so it is advantageous to change and maintain the product, and the economic ripple effect is great when it becomes an international standard.

5 is a view schematically showing an operation in which the carrier door 150 is opened by the load port door 300. 6 is a view schematically showing the operation of the load port door 300 is lowered. FIG. 7 is a view schematically illustrating an operation of detecting the protruding wafer 201 by the apparatus for detecting the protrusion of the wafer in the carrier according to the embodiment of the present invention.

Referring to FIG. 5, after the wafer carrier 100 is mounted on a load port (not shown) of a semiconductor facility, the wafer carrier 100 is fixed to the load port door 300 and the front and rear of the load port door 300. The wafer carrier door 150 is opened by the movement. Referring to FIG. 6, after the wafer carrier door 150 is opened, the load port door 300 lowers the carrier door 150 opened in an up and down motion, that is, in a down motion, so that the inlet of the carrier 100 is exposed. do.

6 and 7, as the load port door 300 descends, the light emitted from the light emitting unit 431 installed at the top of the load port door 300 reaches the first reflection surface 411. . As the light emitted from the light emitting unit 4310 reaches the first reflecting surface 411, the wafer protrusion detection according to the embodiment of the present invention starts.

Referring back to FIG. 1, when all the wafers 200 accommodated in the carrier 100 are in the normal position of the wafer carrier 100, the light emitted from the light emitting part 431 installed on the load port door 300 may be The reflection surfaces 411, 413, 415, and 417 of the wafer carrier 100 are sequentially reflected to enter the light receiving unit 435 on the load port door 300. That is, when light is normally detected by the light receiving unit 435, it is determined to be in a normal state and subsequent operations such as wafer mapping and movement of the wafer to the semiconductor facility are started.

Referring back to FIGS. 6 and 7, if even one wafer 201 is protruded, as shown in FIGS. 6 and 7, the light emitted from the light emitting unit 413 is protruded by the wafer 201. It is blocked and not transmitted to the light receiver 435. It is possible to effectively and immediately determine whether the wafer 201 is protruded by the presence or absence of light blocking.

As mentioned above, although this invention was demonstrated in detail through the specific Example, this invention is not limited to this, It is clear that the deformation | transformation and improvement are possible by the person of ordinary skill in the art within the technical idea of this invention.

According to the present invention described above, the non-contact detection method using the presence or absence of light propagation can effectively detect the presence or absence of wafer protruding from the carrier in real time. In addition, since the time for the wafer protrusion detection is hardly consumed, the negative influence on the productivity of the semiconductor facility can be prevented by introducing the wafer protrusion detection step. Since the structure of the wafer protrusion detection device is very simple, it can be commonly applied to all wafer carriers and semiconductor equipments at a low investment cost, so that the change and maintenance are advantageous, and the economic ripple effect is great when it becomes an international standard.

Claims (11)

A plurality of reflective surfaces provided inside a door inlet of a carrier to form an optical path terminating the inlet; And And a light sensing unit configured to provide light to travel to the optical path to any one of the reflective surfaces and to receive light passing through the optical path from any one of the reflective surfaces to detect whether the wafer protrudes from the carrier. Apparatus for detecting the protrusion of the wafer from the carrier to be made. The method of claim 1, And wherein the optical path is formed at a position aligned with the centerline of the carrier. The method of claim 1, And the light detector determines that the protrusion of the wafer from the carrier occurs when the light that passes through the optical path cannot be received. The method of claim 1, And the light detector provides light to be incident on the reflecting surface after the door of the carrier is opened by a load port door of a semiconductor device. The method of claim 4, wherein And the light detector is installed on an upper end of the load port door. The method of claim 5, And the light sensing unit provides light to be incident on the reflecting surface when the load port door descends. The method of claim 1, wherein the light detecting unit A light emitting unit for emitting the light; And And a light receiving unit for receiving the light. The method of claim 1, wherein the reflective surfaces A first reflection surface provided above the inlet of the carrier and reflecting the light incident from the light sensing unit to the lower side of the inlet of the carrier; A second reflection surface disposed below the inlet of the carrier to face the first reflection surface and reflecting light reflected from the first reflection surface in a lateral direction; A third reflecting surface spaced apart from the second reflecting surface and reflecting light reflected from the second reflecting surface above the inlet of the carrier; And And a fourth reflecting surface installed above the inlet of the carrier to face the third reflecting surface and reflecting light reflected from the third reflecting surface to the light sensing unit to receive the light sensing unit. Device for detecting wafer protrusion in the carrier. The method of claim 1, wherein the reflective surface And a mirror surface formed by a reflective film deposition or reflective surface deposition. The method of claim 1, wherein the reflective surface Apparatus for detecting wafer protrusion in a carrier, characterized in that provided by a prism. A plurality of reflective surfaces disposed in pairs opposed to each other above and below a door inlet of a carrier to form an optical path terminating the inlet; And It is installed on the top of the load port door for opening the door of the carrier to provide the light to travel to the optical path to any one of the reflective surfaces and to receive light passing through the optical path from any of the reflective surfaces Apparatus for detecting the protrusion of the wafer in the carrier, characterized in that it comprises a light sensing unit for detecting the presence or absence of the protrusion of the wafer in the carrier.