JPH07183359A - Substrate carrier - Google Patents

Abstract

PURPOSE:To retain a semiconductor wafer to the tip of a substrate fork and then prevent position deviation despite vibration on transfer by providing a cut-out part at a part colliding with the post of a wafer boat at the main part of the substrate fork. CONSTITUTION:Since a cut-out part 44 is provided at the tip part of a substrate fork 30, a semiconductor wafer 4 can be transferred from a substrate fork 30 to a wafer boat 3 or vice versa without causing the collision of the post 43 of the wafer boat 3 when transferring between the substrate fork 30 and the wafer boat 3. Further, even if vibration in horizontal direction or of rotary move by a transfer machine 21 during the placement or vibration in up/down movement by a raise/lower mechanism 22 is applied to the substrate fork 30, side deviation can be prevented by a protruding part 40 located at the substrate fork 30, thus preventing a falling accident. Also, the cut-out part 44 provided at the substrate fork 30 is matched to the shape of the wafer boat 3 and a protruding part 40 can be left in a state for supporting the semiconductor wafer 4 to cope with any shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer device.

[0002]

2. Description of the Related Art One of the main causes of reducing the yield in the semiconductor manufacturing process is that dust floating in the atmosphere adheres to a semiconductor wafer, which may damage a semiconductor element and thus reduce the yield. Are known. In order to improve the reduction in yield due to dust floating in the atmosphere, a method of manufacturing semiconductors in a clean room equipped with a facility for removing dust existing in the atmosphere has been adopted.

Generally, a vacuum chuck method and a soft landing method are used as a method for transferring a thin plate-shaped substrate, for example, a semiconductor wafer by a substrate fork in this clean room. The vacuum chuck method sucks a semiconductor wafer by suction from a suction hole provided in the substrate fork, and even if vibration is transmitted to the substrate fork during transfer, the substrate is sufficiently sucked by the suction action. The semiconductor wafer can be stably transported. However, in this method, a very small amount of dust remaining in the atmosphere in the clean room is collected on the substrate fork by the adsorption action of the semiconductor wafer, and this dust may adhere to the semiconductor wafer. Will result in serious defects. Therefore, the soft landing method has recently attracted attention. In this method, the convex portion provided on the substrate fork supports the periphery of the semiconductor wafer to prevent lateral displacement due to vibration during transportation of the semiconductor wafer. is doing.

[0004]

In other words, in the soft landing method, the lateral shift is prevented by the convex portion provided on the substrate fork and supporting the side surface of the semiconductor wafer. Supporting the semiconductor wafer by the convex portions becomes indispensable.

However, since the substrate fork collides with the support of the wafer boat depending on the position of the support of the wafer boat on which the semiconductor wafer is mounted, the semiconductor wafer cannot be completely supported and transferred. For example, when the wafer is transferred to a three-legged wafer boat as shown in FIG. 6, the semiconductor wafer can be mounted only in a state of protruding from the substrate fork.

With the vacuum chuck method, the semiconductor wafer can be sufficiently held by the suction action. But,
In the soft landing method, if there is no convex portion that surrounds the semiconductor wafer, the semiconductor wafer is simply placed on the substrate fork, and the semiconductor wafer may be displaced on the substrate fork due to vibration during transfer, There is a problem that it may be dropped and cannot be transferred onto the wafer boat properly.

The present invention has been made by paying attention to the problem of such a positional deviation, and its object is to ensure that a substrate transfer apparatus adopting a soft landing method is irrelevant to the position of the support of the wafer boat. A substrate transfer device capable of holding the substrate is provided.

[0008]

A substrate transfer apparatus for mounting and transferring a thin plate-shaped substrate used in a semiconductor manufacturing apparatus, and a substrate fork for mounting and transferring the thin plate-shaped substrate,
The substrate fork has a convex portion that supports the back surface of the thin plate-shaped substrate at multiple points, the convex portion that supports the side surface of the thin plate-shaped substrate at multiple points on the substrate fork, and the thin plate-shaped substrate at the substrate fork. A notch is provided at the tip of the substrate fork to avoid contact with the support of the wafer boat to be placed.

According to the present invention, since the semiconductor wafer can be held up to the tip of the substrate fork by providing a notch in a portion of the main body of the substrate fork which collides with the support of the wafer boat, the semiconductor wafer can be held even by vibration during transfer. The position shift can be prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a vertical heat treatment apparatus will be specifically described with reference to the drawings. As shown in FIG. 1, the vertical heat treatment apparatus 1 is configured as follows in order to heat-treat a thin plate-shaped substrate, for example, a semiconductor wafer, as an object to be processed. First, as a container for reacting a semiconductor wafer with a reaction gas, there is provided a reaction tube 2 in which a heat-resistant material, for example, quartz glass is formed into a cylindrical shape, the upper end is closed, and the lower end is opened. In this reaction tube 2, a heat-resistant material capable of stacking and mounting a large number of semiconductor wafers 4 at a predetermined pitch,
For example, a wafer boat 3 made of quartz glass is provided.

On the outer periphery of the reaction tube 2, a heating element for heating the semiconductor wafer 4, for example, a resistance heater 5 is provided. Furthermore, this resistance heater 5
An outer shell 7 made of stainless steel and having a cylindrical shape is provided on the outer periphery of the heat-insulating material 6 and constitutes a heating furnace as a whole. A gas introduction pipe 8 for supplying a processing gas is connected to one end of the reaction tube 2, and a discharge pipe 9 for discharging a processing gas is connected to the other end of the reaction tube 2, and this discharge pipe Reference numeral 9 is connected to an exhaust device (not shown) so that the inside of the reaction tube 2 can be exhausted.

The wafer boat 3 is made of a heat-resistant material,
For example, it is placed on a heat insulating cylinder 10 made of quartz, and the heat insulating cylinder 10 is placed on a lid 11 made of a heat resistant material, for example, quartz, and the lid 11 is held by an elevating mechanism, for example, a boat elevator 20. The wafer boat 3 can be loaded and unloaded in the soaking area in the reaction tube 2. A mechanism, for example, a wafer transfer machine 21, for transferring the semiconductor wafers 4 to the wafer boat 3 is provided below the reaction tube 2.

Next, FIG. 2 shows a semiconductor carrier device section. The wafer transfer machine 21 can vertically move five thin plate-like substrate forks 30 on which the semiconductor wafers 4 are placed by the elevating mechanism 22 and horizontally rotate by the rotating mechanism 23.
The horizontal movement mechanism 24 is configured to be capable of expanding and contracting in the horizontal direction. Further, a carrier 31 accommodating a plurality of semiconductor wafers 4 is placed on a carrier loading table 32.

Then, as shown in FIG. 3, the wafer transfer machine 21 is arranged such that five substrate forks 30 are overlapped with each other at a predetermined interval, for example, a 3/16 inch interval which is a semiconductor wafer accommodating pitch of the carrier 31. It is provided in. The wafer transfer machine 21 is connected to a belt 38 stretched around the shaft of a motor 37, and the rotation of the motor 37 can move the five substrate forks 30 horizontally at a time.

As shown in FIG. 4, the substrate fork 30 is provided.
Is made of silicon carbide or alumina, and has a thickness of 1.3 m
m, a length of 240 m, and a width of 40 mm are formed into a rectangular shape, and the surface of the substrate fork 30 has a convex portion 40, for example, so as to support the peripheral portion of the semiconductor wafer 4 so that the semiconductor wafer 4 does not laterally shift. Even if there is a warp of the semiconductor wafer 4 provided at four places and in contact with the back surface of the semiconductor wafer 4, the convex portion 41 is provided to surely hold the semiconductor wafer 4.
Is molded.

Further, four holes 42 for mounting the substrate fork 30 are provided at four positions at the base in the longitudinal direction.
On the other hand, at the tip of the substrate fork 30 in the longitudinal direction, for example, the column 43 at the center of the three-column wafer boat 3 is mounted on the substrate fork 30 even when it is transferred from the substrate fork 30 to the wafer boat. A notch 44 is provided so as not to collide with the column 43.

Next, the operation of the apparatus configured as described above will be described. The wafer transfer machine 21 includes the substrate fork 3
0 is moved to the front position of the carrier 31 by a predetermined motion of the elevator mechanism 22 and the rotation mechanism 23. Next, the substrate fork 30 is inserted into a predetermined position between the semiconductor wafers 4 by the forward horizontal movement of the wafer transfer machine 21. Then, the elevating mechanism 22 raises the substrate fork 30 by about 2 mm to move the semiconductor wafer 4 to the substrate fork 30.
It is placed so that it can be supported in the four convex portions 40 above.

Next, the wafer transfer machine 21 performs a backward horizontal movement to take out the semiconductor wafer 4 from the carrier 31, and moves it to the front of the wafer boat 3 by a predetermined operation of the elevating mechanism 22 and the rotating mechanism 23. . Next, the wafer transfer device 21 advances the substrate fork toward the wafer boat 3 by the forward horizontal movement of the wafer transfer device 21. At this time, the support column 43 of the wafer boat 3 is attached to the substrate fork 3
When the semiconductor wafer 4 is fitted into a groove (not shown) provided in the wafer boat 3 and located in the notch 44 of 0, and the substrate fork 30 is lowered by 2 mm by the elevating mechanism 22, the semiconductor wafer 4 is mounted on the wafer boat 3. Can be placed. The above operation is repeated to transfer the desired number of semiconductor wafers 4 from the carrier 31 to the wafer boat 3.

Next, the wafer boat 3 accommodating the plurality of semiconductor wafers 4 is moved into the reaction tube 2 of the heat treatment furnace by the raising and lowering mechanism 22. The reaction tube 2 is preheated to, for example, 1000 ° C. by the resistance heater 5, and the processing gas is supplied from the gas supply tube 8 to heat-treat the semiconductor wafer 4. The high-temperature processed gas after processing the semiconductor wafer 4 is exhausted from the exhaust pipe 9 by an exhaust device (not shown).

After the heat treatment is completed, the boat elevator 20 is lowered to move the semiconductor wafer 4 below the heat treatment furnace. Then, the semiconductor wafer 4 has a predetermined temperature,
For example, when the semiconductor wafer 4 is transferred from the carrier 31 to the wafer boat 3 after being naturally cooled to 50 ° C.,
The semiconductor wafer 4, which has been heat-treated in the reverse order, is transferred from the wafer boat 3 to the carrier 31, and the predetermined heat treatment is completed.

As shown in the above-mentioned embodiment, since the notch 44 is provided at the tip of the substrate fork 30 in this embodiment, when the wafer is transferred between the substrate fork 30 and the wafer boat 3, the support of the wafer boat 3 is supported. The semiconductor wafer 4 can be placed on the wafer boat 3 from the substrate fork 30 or on the substrate fork 30 from the wafer boat 3 without the collision of 43. Further, the transfer machine 2 is mounted on the substrate fork 30 while being mounted.
Even if vibration is applied in the horizontal direction by 1 and rotational movement or vertical movement by the elevating mechanism 22, the lateral deviation can be prevented by the convex portion 40 on the substrate fork 30, and a fall accident can be prevented.

The present invention is not limited to the above-described embodiment, but any kind of shape can be obtained by matching the notch portion 44 provided on the substrate fork with the shape of the wafer boat and leaving the convex portion 40 in a state capable of supporting the semiconductor wafer 4. The shape of the wafer boat can also be accommodated. Further, not only a semiconductor wafer but also any device can be applied as long as it is a device for carrying a flat object such as a liquid crystal substrate or a glass substrate.

[0022]

As described above, according to the present invention,
The substrate can be transferred smoothly even when it is conveyed by the soft landing method in which the substrate is simply placed on the substrate fork.

[0023]

[Brief description of drawings]

FIG. 1 is an overall sectional view of the present invention suitable for a vertical heat treatment apparatus.

FIG. 2 is a perspective explanatory view of a semiconductor transfer device section.

FIG. 3 is an explanatory view of the wafer transfer machine of FIG.

FIG. 4 is a perspective view of a substrate fork.

FIG. 5 is a sectional view of a substrate fork.

FIG. 6 is a perspective view of a conventional substrate fork.

[0024]

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical heat treatment apparatus 2 Reaction tube 3 Wafer boat 4 Semiconductor wafer 20 Wafer transfer machine 30 Substrate fork 40 Convex portion 41 Recessed portion 43 Strut 44 Notched portion

Claims (1)

[Claims] In a substrate transfer device for mounting and transferring a thin plate-shaped substrate used in a semiconductor manufacturing apparatus, a substrate fork for mounting and transferring the thin plate-shaped substrate and a back surface of the thin plate-shaped substrate are often mounted on the substrate fork. Avoid contact between the convex portion that supports the point, the convex portion that supports the side surface of the thin plate substrate on the substrate fork at multiple points, and the support of the wafer boat on which the thin plate substrate is mounted on the substrate fork. A substrate transfer device, wherein a cutout portion is provided at the tip of the substrate fork.