JP2002222844A - Semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance throughput by efficiently loading dummy wafers and preventing reduction of the number of wafers to be processed in a semiconductor manufacturing apparatus. SOLUTION: This semiconductor manufacturing apparatus is provided with a transfer chamber 1, a reaction chamber directly connected to the transfer chamber, and a cassette chamber 2. A storage shelf 32 that stores dummy wafers is provided in the cassette chamber, and a cassette 38 is loaded on the storage shelf.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a single-wafer semiconductor manufacturing apparatus capable of simultaneously processing a plurality of substrates to be processed, for example, a plurality of wafers.

[0002]

2. Description of the Related Art First, an outline of a single-wafer type semiconductor manufacturing apparatus will be described with reference to FIG.

A first cassette chamber 2 and a second cassette chamber 3 are hermetically provided in front of an air-tight transfer chamber 1 having a pentagonal plan shape. The first chamber communicates with the chamber 1 through gate valves 6 and 7.
Cassette doors 4 and 5 are provided on the surfaces of the cassette chamber 2 and the second cassette chamber 3 on the side opposite to the transfer chamber 1.

Air-tight cooling chambers 8 and 9 are provided on two surfaces adjacent to the front surface of the transfer chamber 1 so as to face each other, and the cooling chambers 8 and 9 are provided via the gate valves 11 and 12 respectively. It communicates with room 1. A first reaction chamber 13 and a second reaction chamber 14 are provided on two surfaces facing the front surface of the transfer chamber 1, respectively.
The first reaction chamber 13 and the second reaction chamber 14 communicate with the transfer chamber 1 via gate valves 15 and 16.

A transfer robot 17 having a three-joint arm 18 is provided in the transfer chamber 1.
Is rotatable about a vertical axis and is expandable and contractible in the radial direction.

[0006] A cassette (not shown) is carried into the first cassette chamber 2 and the second cassette chamber 3 from the external transfer device (not shown) through the cassette doors 4 and 5. The cassette is loaded with a predetermined number (usually 25) of product wafers.

The transfer robot 17 is provided with the three-node arm 1.
8, the cooperation of rotation and expansion and contraction and opening and closing of the gate valves 6 and 7 and gate valves 15 and 16 transfer the product wafer from the cassettes of the first cassette chamber 2 and the second cassette chamber 3 to the first reaction. It is carried into the chamber 13 and the second reaction chamber 14.

In the first and second reaction chambers 13, a film is formed on the loaded wafer. When the film forming process is completed, the transfer robot 17 transfers the processed wafer to the cooling chambers 8 and 9 by the three-node arm 18 and circulates nitrogen gas through the cooling chambers 8 and 9 to cool the wafer to a predetermined temperature. After that, the cassettes in the first cassette chamber 2 and the second cassette chamber 3 are refunded. When the processing for all the product wafers in the cassette is completed, the cassette loaded with the processed wafers is unloaded through the cassette doors 4 and 5, and the cassette loaded with the product wafers is loaded.

In the wafer processing step, a plurality of wafers are simultaneously processed in the first reaction chamber 13 and the second reaction chamber 14.
When processing with a fraction less than the specified number of storages in the reaction chamber 14,
Dummy wafers are supplemented and the processing is always performed with the specified number of sheets stored. This is to keep the processing conditions constant and the film formation quality constant.

Conventionally, in a single-wafer type semiconductor manufacturing apparatus, when a fraction processing is scheduled and dummy wafers are required, a necessary number of dummy wafers are loaded in a cassette in advance, and the dummy wafers are filled in the first cassette chamber 2. The transfer robot 17 performs the transfer from the cassette in the second cassette chamber 3.

[0011]

In a single-wafer type semiconductor manufacturing apparatus, one of the cassettes accommodated in the first cassette chamber 2 and the second cassette chamber 3 is used exclusively for dummy wafers. I do. Alternatively, it is conceivable to load dummy wafers together with product wafers into one cassette, but if one cassette is dedicated to dummy wafers, the number of product wafers that can be processed is reduced, and throughput is reduced. In addition, when the product wafer and the dummy wafer are mixed, the loading of the wafer into the cassette is performed manually, which lowers the working efficiency and causes a problem of contamination of the product wafer by particles.

The present invention has been made in view of the above circumstances, and aims to improve the throughput by efficiently filling the dummy wafer, preventing the number of processed wafers from being reduced.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a semiconductor manufacturing apparatus having a transfer chamber, a reaction chamber connected to the transfer chamber, and a cassette chamber, wherein the cassette chamber is a storage shelf for storing dummy wafers. And the cassette relates to a semiconductor manufacturing apparatus mounted on the storage shelf.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

According to the present invention, a storage shelf capable of storing a required number of dummy wafers is provided in at least one of the transfer chamber, the cassette chamber, the cooling chamber, and the reaction chamber, and the dummy wafers are stored in the storage shelf. The semiconductor wafer is repeatedly used a predetermined number of times, and the throughput of the semiconductor manufacturing apparatus is improved by reducing the number of times of loading and unloading of the dummy wafer without reducing the number of processed product wafers.

The first embodiment will be described with reference to FIG.

The arrangement of the cassette chamber, cooling chamber, reaction chamber and the like provided for the transfer chamber is the same as that of the semiconductor manufacturing apparatus shown in FIG. 4, and the same components are denoted by the same reference numerals. .

In the first embodiment, the case where the storage shelf 32 is provided in the first cassette chamber 2 is shown. The second cassette chamber 3 is provided in the same manner, but the first cassette chamber 2 will be described below.

A storage shelf elevating section 19 is provided below the first cassette chamber 2. The storage rack elevating unit 19 is stored in an elevating unit frame 20 that is provided below the first cassette chamber 2. An upper bearing plate 21 and a lower bearing plate 22 are provided on the elevating unit frame 20 at required vertical intervals, and a guide rod 23 and a screw rod 24 are provided in parallel with the upper bearing plate 21 and the lower bearing plate 22.

A slider 25 is slidably fitted on the guide rod 23, and a nut 2 is mounted on the screw rod 24.
The nut 26 and the slider 25 are connected so as to move up and down integrally. The screw rod 24
Has a lower end protruding downward, and a lower end connected to the elevating motor 28. The elevating motor 28 is capable of step driving, and the nut 26, that is, the slider 25 can be intermittently raised and lowered at a predetermined pitch by the step rotation of the screw rod 24.

A horizontal elevating substrate 27 is provided on the slider 25, and a column 29 is vertically erected on the elevating substrate 27. The column 29 extends upward through the bottom surface of the first cassette chamber 2, and a table 31 is fixed to an upper end of the column 29. The portion of the support 29 that penetrates the bottom surface is sealed by a bellows 30. The storage shelf 32 is provided on the upper surface of the table 31, and a wafer cassette 38 can be placed on the storage shelf 32. In addition, necessary positioning means such as wafer cassette positioning pins are provided on the upper surface of the storage shelf 32, and the wafer cassette 38 can be mounted at an optimum position by the positioning means.

The storage shelf 32 can store a required number of dummy wafers.

The storage shelf 32 and the wafer cassette 3
8 may be fixed and the three-bar arm 18 may be moved up and down. When the storage shelf 32 and the wafer cassette 38 are moved up and down, the first cassette chamber 2 is originally provided with a mechanism for moving up and down the wafer cassette 38. It is possible.

The operation will be described below.

As preparation for starting the processing, a wafer cassette 38 loaded with dummy wafers is loaded into the first cassette chamber 2 and placed on the table 31.

After the cassette door 4 is closed, the gate valve 6 is closed.
To release. The lifting motor 28 is driven, and the screw rod 24, the nut 26, the slider 25, the lifting board 27,
The table 31 is lowered via the support 29, and the wafer cassette 38 is opposed to the opening of the gate valve 6. Expansion and contraction of the three-bar arm 18, the lifting motor 28
The dummy wafer is received on the three-node arm 18 by the intermittent elevation of the table 31 by the
8 is driven, and the storage shelf 3 is inserted into the opening of the gate valve 6.
The table 31 is raised so that the two face each other.

The three-joint arm 18 of the transfer robot 17 expands and contracts, and the elevation
The dummy wafer on the joint arm 18 is transferred to a predetermined position on the storage shelf 32.

The operation of transferring the dummy wafers is repeated, and the required number of dummy wafers are stored in the storage shelf 3.
2

A wafer cassette loaded with product wafers is carried into the first cassette chamber 2 instead of the wafer cassette containing dummy wafers. The wafer for product is transferred to the first reaction chamber 13 and the second reaction chamber 13 by the forward and backward movement and rotation of the three-joint arm 18 by the transfer robot 17 and the intermittent elevation of the wafer cassette 38 by the storage shelf elevating unit 19.
Transfer to reaction chamber 14.

The processing of the wafer is the same as that of the conventional example, and the description is omitted below.

When fraction processing is performed in wafer processing,
The dummy wafer in the storage shelf 32 is transferred from the first cassette chamber 2 to the first reaction chamber 13 and the second reaction chamber 14 by the transfer robot 17, and the wafer is stored in the first reaction chamber 13 and the second reaction chamber 14 in the wafer storage section. Required processing such as film formation processing is performed such that there is no empty space.

When the processing is completed, the processed wafers for the product are returned to the wafer cassette 38, and the dummy wafers are returned to the storage shelf 32. The film thickness of the dummy wafer increases as the processing is repeated. As the film thickness increases, cracks will eventually form, causing particles,
The number of times the dummy wafer is used is counted, and when the number reaches the set number, the dummy wafer is replaced.

The method of using the dummy wafer is used not only for compensation during processing but also for the purpose of stabilizing processing conditions.

That is, when the semiconductor manufacturing apparatus is started, the temperatures and temperature distributions of the first reaction chamber 13 and the second reaction chamber 14 have not reached a steady state, or the reaction gas concentration is different from that in the continuous processing. Subtly different. Therefore, the film quality of the first processed wafer may be different from that of the continuously processed wafer. Therefore, at the time of starting the semiconductor manufacturing apparatus or at the first processing step started after a pause, the film forming process is performed only on the dummy wafer, and thereafter, the film forming process is performed on the product wafer. As a result, the film forming process can be performed under the condition that all the product wafers are continuously processed, the processing conditions are stabilized, and the film forming quality is also stabilized.

Another method of using the dummy wafer for stabilizing the processing conditions will be described.

In a single-wafer type semiconductor manufacturing apparatus, particularly a hot wall type semiconductor manufacturing apparatus, the reaction chamber is heated.
The heat capacity of the reaction chamber differs between the case where there is a wafer in the reaction chamber and the case where the wafer is empty. Therefore, the temperature of the reaction chamber changes over time. If the resting state continues, such as after cleaning of the reaction chamber, the temperature of the reaction chamber rises above the processing temperature. In order to prevent a rise in the temperature of the reaction chamber in the idle state, a dummy wafer is loaded into the idle state reaction chamber,
The heat capacity is the same as the processing state. By making the heat capacity the same, a rise in temperature can be prevented, and at the start of processing, film formation processing of the wafer can be started immediately after removing the dummy wafer. Alternatively, the time required to stabilize the processing temperature can be reduced,
The time until the start of the film forming process can be reduced, and the throughput can be improved.

FIG. 2 shows a second embodiment, in which a storage shelf 32 is provided in at least one of the cooling chambers 8 and 9.

The case where the cooling chamber 8 is provided will be described below.

A storage rack elevating section 19 is provided below the cooling chamber 8 so that the table 31 can be moved up and down inside the cooling chamber 8. The storage shelf elevating unit 19 is the same as that in FIG.

A storage shelf 32 is placed on the table 31. A first function of the storage shelf 32 is to hold processed wafers for product for cooling, and a second function is to hold dummy wafers. Accordingly, the wafer storage capacity of the storage shelf 32 includes a shelf for holding the wafers after the film forming process, and a shelf for holding a required number of dummy wafers,
The shelf that holds the dummy wafer takes particles into account,
The lower position of the product wafer.

The transfer of wafers to and from the storage rack 32 is performed by the intermittent lifting of the table 31 by the storage rack lifting unit 19 and the rotation and expansion and contraction of the three-joint arm 18 by the transfer robot 17 (see FIG. 1). ).

FIG. 3 shows a third embodiment, in which a storage shelf 32 is provided in at least one of the cooling chambers 8 and 9.

The case where the cooling chamber 8 is provided will be described below.

The table 31 is fixedly provided at the bottom of the cooling chamber 8.

The transfer robot 17 is supported by a transfer robot elevating mechanism 33 so as to be able to move up and down intermittently. Since the transfer robot elevating mechanism 33 is the same as the storage shelf elevating section 19, the description is omitted.

The transfer robot elevating mechanism 33 has an elevating substrate 34, and a column 35 is erected vertically on the substrate 34, and the transfer robot 17 is provided on the column 35. Therefore, the three-bar arm 18 can be expanded, contracted, rotated, and moved up and down.

A storage shelf 32 is mounted on the table 31. The storage shelf 32 is the same as that shown in FIG.
It has a product wafer storage shelf and a dummy wafer storage shelf.

Transfer of wafers to the storage shelf 32,
Loading and unloading are performed by the expansion, contraction, rotation, and elevation of the three-joint arm 18.

[0049]

As described above, according to the present invention, in a semiconductor manufacturing apparatus having a transfer chamber, a reaction chamber connected to the transfer chamber, and a cassette chamber, the cassette chamber stores dummy wafers. A storage shelf is provided, and the cassette is placed on the storage shelf. If a fraction occurs in the processing, it can be compensated with dummy wafers, and the processing conditions can always be kept constant, thus stabilizing the processing quality. In addition, there is no need to carry in the dummy wafer from the outside each time, and an excellent effect such as an improvement in throughput can be achieved by shortening the transfer time of the dummy wafer.

[Brief description of the drawings]

FIG. 1 is a skeleton explanatory view showing a first embodiment of the present invention.

FIG. 2 is a skeleton explanatory view showing a second embodiment of the present invention.

FIG. 3 is a skeleton explanatory view showing a third embodiment of the present invention.

FIG. 4 is a plan view schematically showing a single-wafer semiconductor manufacturing apparatus.

[Explanation of symbols]

 Reference Signs List 1 transfer chamber 2 first cassette chamber 17 transfer robot 18 three-node arm 19 storage shelf elevating unit 27 elevating substrate 31 table 32 storage shelf 33 transfer robot elevating mechanism

Claims (1)

[Claims] A transfer chamber, a reaction chamber connected to the transfer chamber,
In a semiconductor manufacturing apparatus having a cassette chamber, the cassette chamber has a storage shelf for storing dummy wafers,
A semiconductor manufacturing apparatus, wherein a cassette is placed on the storage shelf.