JPS63161610A - Wafer boat - Google Patents

Abstract

PURPOSE:To lighten and miniaturize a wafer boat, and to set wafers easily in conformity with the desired number of setting by combining and constituting a plurality of split wafer boats in the direction of furnace length of a vertical furnace. CONSTITUTION:A wafer boat 5 has a plurality of split wafer boats 30. These split wafer boats 30 are combined in the direction of furnace length (the vertical direction) of a vertical furnace (a vertical type diffusion furnace 1), thus organizing the wafer boat 5. The split wafer boats 30 as required are combined in conformity with the number of semiconductor wafers (such as silicon wafers 31) to be treated. A plurality of piled up split wafer boats 30 are set into the vertical type diffusion furnace 1.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a wafer boat for supporting semiconductor wafers or the like.

凭”hiku”L A vertical furnace, for example a vertical diffusion furnace, will be explained as an example.

A semiconductor wafer, e.g. a silicon wafer, may be placed in a vertical diffusion furnace to diffuse an impurity, e.g. phosphorus, into the silicon wafer.

A plurality of silicon wafers are held on a wafer boat at predetermined intervals. This wafer boat is inserted from the bottom of the vertical diffusion furnace, and the 1° wafer boat is housed in the vertical diffusion furnace along the furnace length direction, and the phosphorus is fed into the vertical diffusion furnace at 1200°C along with N2 gas and 02 gas. . In this way, phosphorus glass is formed on the surface of the silicon wafer, and a certain amount of phosphorus is diffused into the silicon wafer.

However, this type of wafer board is an integrated type,
It has a length that is almost comparable to the furnace length of a vertical diffusion furnace. This length is the direction in which a plurality of silicon wafers are arranged.

In particular, wafer boats for accommodating large-diameter wafers (e.g., 8-inch silicon wafers) have become large, making it difficult to move them. In addition, cleaning the wafer boat was troublesome. Furthermore, even if the number of wafers to be processed is smaller than the number of wafers that can be set in wafer boats 1 to 1, a large wafer boat must be used, resulting in poor usage efficiency.

1- Since wafer boats are used at high temperatures (1000°C or higher), large wafer boats are severely deformed and have a short lifespan.

If a defective part appears in a part of the wafer boat, the wafer boat must be completely replaced with a new wafer boat, which is uneconomical.

1111 This invention was made to solve the above nC problem, and it is lightweight and compact, easy to move and clean,
It is an object of the present invention to provide a wafer boat that can be used economically and allows easy setting of wafers to a desired number of wafers.

31st and Summer - In order to achieve the above object, the present invention combines a plurality of divided wafer boats in the longitudinal direction of the vertical furnace in a wafer boat that holds semiconductor wafers and is set in a vertical furnace. The gist is a wafer boat characterized by the following configuration.

, see Figure 1. The wafer boat 5 includes a plurality of divided wafer boats 30.

The wafer boat 5 is constructed by combining these divided wafer boats 30 in the furnace length direction (vertical direction) of a vertical furnace (vertical diffusion furnace 1 in the embodiment).

1 to 30 are combined as needed according to the number of semiconductor wafers to be processed (silicon wafers 31 in the example).

And stacked multiple pieces ^ 11 wafer bow, To 3
0 is set in the vertical diffusion furnace 1.

See-1-9 Please refer to FIGS. 1 and 2.

The vertical diffusion furnace 1 includes a main body 2, a furnace body 3, a radiator 4, a wafer boat 50, and a loading device 6.

A radiator 4 is provided at the top of the furnace body 3. A rod 20 of a loading device 6 is located below the furnace body 3. The furnace body 3 includes a heat insulator 7, a coil 8, and a process tube 9.

As shown in FIG.
a and a support layer 7G that supports the fiber layer 7b.

The felt layer 7a, the fiber layer 7b and the support layer 7C are surrounded by a skin 10. The coil 8 is arranged inside the heat insulator 7.

Process tube 9 is made of quartz. This process tube 9 is surrounded by a coil 8. As shown in FIG. 1, the process tube 9 has a center zone CZ and an end zone EZ.

As shown in FIGS. 1 and 2, the process tube 9 has a closed upper end and an opening 11 at the lower end. A wafer boat 5, which will be described later, is inserted into this opening 11 from below.

1 and 2, a flange portion 12 is provided at the lower end of the process tube 9. As shown in FIGS. A gas introduction pipe 13 made of quartz passes near this flange portion 12 .

The outer end of the gas introduction pipe 13 is a connection port 13a, which is connected to a gas supply source (not shown). Gas introduction pipe 1
The inner end of 3 reaches close to the upper part 14 of the process tube 9.

A gas introduction port 15 is formed at the inner end of the gas introduction pipe 13 . On the other hand, a gas exhaust pipe 16 made of quartz is provided near the flange portion 12.

Not shown in Figure 2 J: Sea urchin, bottom of process tube 9 ff1
1 is closely attached to the outer skin 10 via a fiber seal 17. The process tube 9 is then held by the presser foot 18.
It is fixed to the support play i~19 by.

The loading device 6 shown in FIG. 1 is capable of vertically moving the rod 20 by a drive device (not shown).

At the lower end of this rod 20, a boat portion 21 is attached to a member 2.
-C is set via 2. , this member 22 and O:
:20 is omitted in FIG.

As shown in FIG. 2, the support portion 21 has an outer member 23 and an inner member 24. As shown in FIG. This external member 23 is made of metal such as 5US304. The one-way member 24 is made of SiC or quartz. The outer member 23 and the inner member 24 have circular shapes. The internal material 24 is
It is joined to the flange portion 12 of the process tube 9. An O-ring 25 is provided inside the internal member 24. The flange 12 and the internal member 24 are brought into close contact with each other via the O-ring 25. In addition, the external material 23 includes
An edge portion 23a is formed to cover the outer circumferential portion of the internal member 24 and the outer circumferential portion of the flange portion 12.

Next, in FIG. 2, a cooling part 26 is provided in the 5° flange part 12, which describes a cooling part for cooling the support part 21 and the flange part '12. This cooling section 26 is constructed by welding a quartz member 2B to the flange section 12 to provide an internal space. This cooling section 26
A cooling medium M, for example water, is circulated through the interior space of the cooling medium.

On the other hand, a cooling section 27 is formed in the outer member 23.

This cold fJI section 27 is formed by providing an internal space in the outer member 23, and a cooling medium M, for example, water, is circulated therein as well.

The cooling section 26 is for cooling the vicinity of the flange section 12. The cooling section 27 is for cooling the support section 21.

As shown in FIG.
9 is fixed. These sabots 1 to 2 are made of quartz.

As shown in FIG. 3, the wafer boat 5 is set on these two support stands.

The wafer boat 5 is a combination of multiple υ1 wafer boats 30 stacked one on top of the other, as shown in FIG. In the example, four minute υ1 wafer boats 30 are stacked.

Each divided wafer boat 30 is capable of arranging a plurality of silicon wafers 31 at predetermined intervals. For example, the divided wafer boat 30 is shaped like a J: in which 25 silicon wafers 31 having a diameter of 8 inches can be arranged. In the example shown in FIG. 4, four divided one-hub ports are combined along the furnace length direction (vertical direction), and 100 silicon wafers 31 can be set. As shown in FIG. 4, three protrusions 29b are formed on the base plate 29a of the support stand 29.

The structure of the divided wafer boat 30 will be explained with reference to FIG.

The split wafer boat 30 has sides 032.33. Between the side members 32, 33 there are support members 34 to 3.
9 is installed.

Each of the support members 34 to 39 is formed with a hole 40 into which the silicon wafer 31 is fitted. The groove 40 has a width of 4 mm, for example.

A protrusion 41 is provided on the side member 32.

The one side member 33 is provided with four parts 42 . This 3
The three protrusions 41 and the three recesses 42 are located at corresponding positions.

The three protrusions 29b of the base plate 29 shown in FIG. 4 fit into the recesses 42 of the side member 33 shown in FIG. 5, respectively.

When the divided wafer boats 30 are stacked in the state shown in FIG. 4, the lower divided wafer boats 3
One of the protrusions 41 of No. 0 fits into the recess 42 of the divided wafer boat 30 on the upper stage.

The operation of heat-treating silicon wafers 31 in wafer boat 5 in process tube 9 will be described with reference to FIGS. 1 and 2.

The O-rad 20 of the loading device 6 is raised upward, and the row boat stand 29 and the wafer boat 5 are inserted into the process tube 9. The leeboard portion 21 is joined to the flange portion 12. Water is not passed through the cooling parts 26 and 27.

Then, the process tube 9 is
A gas containing impurities is introduced into the chamber, and the coil 8 heats the tube at a predetermined temperature. Gases containing impurities such as phosphorus include, for example, 02 gas and N2 gas containing phosphorus. After the impurity is diffused into the silicon wafer 31, this gas is exhausted from the gas exhaust pipe 16. The rod 20 shown in FIG. 1 is lowered to take out the wafer boat 5 from the process tube 9.

In this process, the husks 1-1-5 are heated to a high temperature (for example, 1000° C.) or higher. However, each divided wafer boat 30 has a length ff in the direction in which the silicon wafers 31 are arranged, in other words, a length in the furnace length direction, so deformation of divided wafer boats 1 to 30 is difficult to occur. Therefore, the flea's lifespan becomes longer.

However, the present invention is not limited to the embodiments described above.

The wafer boat of this invention has a vertical diffusion furnace as well as a CVD
It can also be set in a furnace.

The number of combined stages of the divided wafer boats 30 can be changed according to the number of silicon wafers 31 to be processed. Further, even when the wafer boat 5 is used in another vertical diffusion furnace having a furnace length shorter than the furnace length of the vertical diffusion furnace of the embodiment, it can be used if the number of combined stages is reduced according to the furnace length.

Also, for the combination between 1st division and 30th division,
Although the protrusion 41 and the recess 42 are used so that they do not move relative to each other, the present invention is not limited thereto.

The shape of the divided wafer boat 30 is not limited to the illustrated embodiment.

As is clear from the above explanation, a wafer boat used at high temperatures can be constructed by combining a plurality of divided wafer boats. Therefore, each divided wafer boat can reduce deformation when used in a high-temperature atmosphere compared to conventional large integrated wafer boats, and has a longer lifespan. Even in this case, each divided wafer boat does not become large-sized, and its movement or conveyance work is easy.

Additionally, cleaning the split wafer boat is much easier than cleaning a conventional large integrated wafer boat.

Even if a defective part occurs in some of the divided wafer boats, only the divided wafer boats 1 to 1 need be replaced with new divided wafer boats, which is economical since there is no need to replace the entire wafer boat. By dividing the wafer boat into divided wafer boats, the wafer boat can be made smaller and lighter, making it easier to move the boat, making it easier to automate the movement.

The divided wafer boats can be combined according to the furnace length of the vertical furnace, and the number of combination stages can be adjusted according to the desired number of sets of semiconductor wafers to be processed, making it possible to use them efficiently for processing work.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a vertical diffusion furnace in which a wafer boat of the present invention is installed, Fig. 2 is an enlarged sectional view showing the vertical diffusion furnace, and Fig. 3 is a plan view showing the wafer boat and support stand. , FIG. 4 is a front view showing a wafer boat and lipo-1 to stand, and FIG. 5 is a partially omitted perspective view showing one divided wafer boat. 1... Vertical diffusion furnace 5... Wafer boat 9... Process tube 12... Flange portion 13... Gas introduction pipe 15... Gas inlet 16... Gas exhaust pipe 21...・Support department 29...Support stand 30...minutes! "1 Wafer boat 31...Silicon wafer 32.33...Side 81S material 34 to 39...Support member 4 Q...Groove 41...Protrusion 42...Concavity Agent Attorney- day 1 side
Toru 1st figure U2 2nd figure! No. 4 41 Figure 3 Figure 4

Claims (1)

[Scope of Claims] A wafer boat that holds semiconductor wafers and is set in a vertical furnace, characterized in that it is constructed by combining a plurality of divided wafer boats in the longitudinal direction of the vertical furnace.