JP2995479B2 - Substrate transfer method in vertical heat treatment equipment - Google Patents

Description

[Detailed Description of the Invention] (Object of the Invention) (Industrial application field) The present invention relates to a method of transferring a substrate.

(Prior Art) In general, in the semiconductor manufacturing process, when a substrate such as a semiconductor wafer is transferred, a transfer substrate holder called a wafer cassette or a wafer carrier is often used.
That is, the transfer substrate holder is made of a lightweight and inexpensive resin or the like, and is configured to be able to accommodate a plurality of semiconductor wafers, for example, 25 semiconductor wafers.

On the other hand, for example, when a large number of semiconductor wafers are batch-processed by a heat treatment apparatus or the like, since the above-described resin-made transfer substrate holder cannot be used as it is, quartz having excellent chemical stability and heat resistance is used. In many cases, a processing substrate holder, a so-called wafer boat, which is configured to be able to accommodate a plurality of, for example, a hundred or more semiconductor wafers, is used.

For this reason, it is necessary to transfer semiconductor wafers between the wafer cassette and the wafer boat described above. Conventionally, a transfer apparatus for performing such transfer has been disclosed in, for example, Japanese Unexamined Patent Publication No.
These are proposed in Japanese Patent Application Laid-Open No. 60-231337, Japanese Patent Application Laid-Open No. 61-54639, and the like. In such a transfer apparatus, a wafer boat is generally supported substantially horizontally, and a plurality of, for example, 25 semiconductor wafers accommodated in a wafer cassette are lifted from below and grasped, for example, by a plurality of arms at once, and are transferred. Perform the loading.

(Problems to be Solved by the Invention) As described above, in the method using the conventional transfer device, the wafer boat is supported substantially horizontally, and transfer is performed in this state.
On the other hand, in recent years, a vertical heat treatment apparatus having advantages such as an effective use of a clean room, a small installation area due to boat loading properties, and a capability of easily loading and unloading a wafer boat without contact with the inner wall of a reaction tube is frequently used. It has come to be. For this reason, when processing is performed by the vertical heat treatment apparatus, a device and space for converting the wafer boat from horizontal to vertical after the transfer of the semiconductor wafers are required, resulting in an increase in the size of the device. was there. In order to solve such a problem, a method of performing transfer while supporting the wafer boat substantially vertically may be considered. However, in this case, since the semiconductor wafer is substantially horizontal, dust is not deposited on the semiconductor wafer during transfer. However, there is a problem that the particles are easily dropped and adhered.

The present invention has been made in view of such a conventional situation, and can reduce the size of the vertical heat treatment apparatus as compared with the related art, and reduce the adhesion of dust to a substrate such as a semiconductor wafer during transfer. It is an object of the present invention to provide a method of transferring a substrate that can be performed.

[Structure of the Invention] (Means for Solving the Problems) That is, according to the present invention, when transferring the substrate between two substrate holders configured to be able to hold a plurality of substrates, The substrate is taken out from the lower side of the substrate holder by taking out the substrate by a transfer mechanism configured to support the substrate almost vertically and to simultaneously support and transfer up to five substrates. The loading of the substrate is performed in order from the upper side of the substrate holder.

(Operation) In the method of transferring a substrate of the present invention having the above-described configuration, the substrate is unloaded to the holder at the time of transfer, and the substrate is taken out from the bottom in order, and the loading is arranged in order from the top so that the loading and unloading operations are performed. It is characterized in that dust is prevented from dropping on the already placed semiconductor wafer.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 2 and 3, a control panel 2 is provided on an upper front surface of a housing 1 of the vertical heat treatment apparatus, and a reaction tube made of, for example, quartz or the like is provided behind the control panel 2. A heat treatment furnace 3 including a heat equalizing tube, a heater, a heat insulating material, and the like provided so as to surround the periphery of the tube is provided substantially vertically.

A boat elevator 4 is provided below the heat treatment furnace 3 so as to be vertically movable. The boat elevator 4 can be used to store a plurality of, for example, a hundred or more semiconductor wafers 5 made of quartz or the like. The processing substrate holder (wafer boat) 6, which can be held, is loaded and unloaded from below into the heat treatment furnace 3 in a state where the processing substrate holder (wafer boat) 6 is placed almost vertically on the heat retaining cylinder 7.

Further, a plurality of, for example, five transfer substrate holders (wafer cassettes) 8a to 8e each configured to accommodate a plurality of, for example, 25 semiconductor wafers 5, can be mounted on a lower front portion of the housing 1. A cassette accommodating portion 9 is provided;
A transfer device 10 for transferring the semiconductor wafer 5 between the wafer cassettes 8a to 8e and the wafer boat 6 is provided on a side of the wafer cassette accommodating portion 9.

In the vertical heat treatment apparatus having the above structure, the wafer cassettes 8a to 8e accommodated in the wafer cassette accommodation section 9 are rotated as shown by the arrows in FIG. The wafer boat 6 is moved in the direction of the transfer device 10 by the elevator 4, and in this state, the transfer of the semiconductor wafer 5 is performed by the transfer device 10 as follows.

That is, as shown in FIG. 1, the transfer device 10 includes one or more, for example, five wafer supporting arms 10a, and supports the semiconductor wafer 5 on these wafer supporting arms 10a. The semiconductor wafer 5 can be transferred five by five by moving in the r, θ, and z directions.

When the unprocessed semiconductor wafers 5 stored in the wafer cassettes 8a to 8e are transferred to the wafer boat 6, first, one of the wafer cassettes 8a to 8e, for example, The lowermost five semiconductor wafers 5a among the semiconductor wafers 5 accommodated in 8a are taken out, and these semiconductor wafers 5a are arranged on the uppermost portion of the empty portion of the wafer boat 6. For example, when performing a CVD process or the like, several dermy wafers (not shown) are often arranged above and below the wafer boat 6. In this case, the five semiconductor wafers 5a are arranged below the dermy wafer arranged above.

Then, among the semiconductor wafers 5 accommodated in the wafer cassette 8a, the five semiconductor wafers 5b arranged above (at this time, at the bottom of) the parts where the five semiconductor wafers 5a are arranged And placed under the semiconductor wafer 5a of the wafer boat 6.

In this way, the semiconductor wafers 5 in the wafer cassette 8a are sequentially taken out five by five from the lower side, and these semiconductor wafers 5 are sequentially arranged from the upper part of the wafer boat 6. And
All the semiconductor wafers 5 in the wafer cassette 8a (for example, 25
), Similarly, for example, the wafer cassette 8b
The semiconductor wafers 5 accommodated in the wafers 8e are transferred to the wafer boat 6. At this time, for example, a test wafer may be stored in a wafer cassette 8c or the like, and may be appropriately arranged between the processing semiconductor wafers 5. In addition, the order of performing the transfer may be, for example, from the wafer cassette 8d provided at the lowermost position.

When the transfer is completed, the wafer boat 6 is moved to the heat treatment furnace 3.
, And loaded into the heat treatment furnace 3 to perform a predetermined process, for example, a CVD film. When the processing is completed, the wafer boat 6 is unloaded from the heat treatment furnace 3 and
The transfer of the semiconductor wafer 5 from the wafer boat 6 to the wafer cassettes 8a to 8e is performed in a procedure reverse to the above procedure.

That is, as shown in FIG. 2, first, when a dummy wafer is arranged at the lowermost portion or the lowermost portion of the wafer boat 6, the five semiconductor wafers 5t arranged above the dummy wafer are arranged.
Is taken out and placed at one of the wafer cassettes 8a to 8e, for example, at the uppermost part of the wafer cassette 8e arranged at the lowermost part.

Then, the semiconductor wafers 5 are sequentially taken out from the lower side of the wafer boat 6, and the semiconductor wafers 5 are sequentially arranged from the upper part of the wafer cassette 8e. When the transfer to the wafer cassette 8e is completed, the other wafer cassettes 8a to 8d are similarly operated.
Transfer to. Note that the wafer cassettes 8a to 8
The order of 8e is, for example, the wafer cassette placed at the top
It may be from 8a.

As described above, in this embodiment, the transfer is performed while the wafer boat 6 and the wafer cassettes 8a to 8e are supported almost vertically, so that the conventional apparatus for converting the wafer boat 6 from horizontal to vertical is used. In addition, no space is required, and the vertical heat treatment apparatus can be downsized. Further, the semiconductor wafers 5 are taken out from the lower side of the wafer boat 6 and the wafer cassettes 8a to 8e in this order.
Are arranged in order from the upper side of the wafer boat 6 and the wafer cassettes 8a to 8e. Therefore, when taking out and arranging the semiconductor wafers 5, these operations are always performed in a state where no other semiconductor wafers 5 are present below. Therefore, it is possible to prevent dust generated by these operations from falling and adhering to another semiconductor wafer 5.

In the above embodiment, the example in which the semiconductor wafers 5 are transferred five by five has been described. However, the semiconductor wafers 5 may be transferred one by one or in any number.

[Effects of the Invention] As described above, according to the method of transferring a substrate of the present invention, the vertical heat treatment apparatus can be downsized as compared with the conventional method, and at the time of transfer, dust is deposited on a substrate such as a semiconductor wafer. Adhesion can be reduced.

[Brief description of the drawings]

1 and 2 are views for explaining a method for transferring a substrate according to one embodiment of the present invention, and FIG. 3 is a vertical type for explaining a method for transferring a substrate according to one embodiment of the present invention. FIG. 4 is a front view of the heat treatment apparatus, FIG. 4 is a side view of the vertical heat treatment apparatus shown in FIG. 3, and FIG. 5 is a top view of the vertical heat treatment apparatus shown in FIG. DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Control panel, 3 ... Heat treatment furnace, 4 ... Boat elevator, 5 ... Semiconductor wafer, 6
... Wafer boat, 7 Heat insulation cylinder, 8a to 8e Wafer cassette 9, 9 Cassette storage section, 10 Transfer equipment.

Continuation of front page (72) Inventor Hirofumi Kitayama 3210-1, Hongo, Kawajiri-cho, Shiroyama-cho, Tsukui-gun, Kanagawa Prefecture Inside Tel Sagami Co., Ltd. (56) References JP-A-58-60553 (JP, A) JP-A-61-291335 (JP, A) JP-A-62-121111 (JP, A)

Claims (1)

(57) [Claims] The present invention relates to a vertical heat treatment apparatus configured to be capable of mounting a plurality of substrates in a vertical direction. One or more substrates are simultaneously transferred between a heat treatment substrate holder and a transfer substrate holder. In a method in which a plurality of substrates are horizontally supported by a transfer mechanism configured to be transferable, the mounted substrates before heat treatment are sequentially unloaded from the bottom of the transfer substrate holder, and unloaded. The substrate before the heat treatment is loaded and loaded in order from the top of the substrate holder for heat treatment, and the substrate holder for heat treatment mounting the substrate before the heat treatment is loaded into a heat treatment furnace to perform heat treatment. Thereafter, the substrate holder for heat treatment is unloaded from the heat treatment furnace, the substrates after heat treatment are sequentially carried out from the lowermost side of the substrate holder for heat treatment, and the carried-out substrate after heat treatment is held in the substrate for conveyance. Ingredient It mounted and carried from the outermost upper sequentially transferring method of a substrate in the vertical heat treatment apparatus, characterized in that.