JP3824835B2 - Method of operating dummy substrate in semiconductor manufacturing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dummy substrate operating method in a semiconductor manufacturing apparatus that processes a plurality of substrates simultaneously.
[0002]
[Prior art]
Semiconductor manufacturing devices used in manufacturing processes such as semiconductor devices and liquid crystal display devices include CVD (Chemical Vapor Deposition) devices, etching devices, which perform predetermined processing on semiconductor wafers and glass substrates using heat and plasma, There are various semiconductor manufacturing apparatuses such as an ashing apparatus.
[0003]
FIG. 5 is a top cross-sectional view of an example of a cluster type single wafer type apparatus among semiconductor manufacturing apparatuses.
[0004]
Reference numeral 6 denotes a wafer to be processed, 3A and 3B denote reaction processing chambers for processing the wafer to be processed 6, 2 denotes a transfer chamber for transferring the wafer to be processed 6 to the reaction processing chambers 3A and 3B, and 5 denotes a transfer chamber. A transfer robot for the wafer 6 to be processed, 4A and 4B are cooling chambers for the wafer 6 to be processed, 1A and 1B are load lock chambers for transferring the wafer 6 to the transfer chamber 2, and 17 is a cassette for storing the wafer 6 to be processed. is there.
[0005]
In a conventional semiconductor manufacturing apparatus, a dummy wafer is used during test film formation (seasoning) immediately after in-situ cleaning using the gases in the reaction processing chambers 3A and 3B.
[0006]
In recent years, for the purpose of further improving the throughput of a single-wafer semiconductor manufacturing apparatus that processes wafers one by one, a multi-sheet semiconductor manufacturing apparatus has attracted attention.
[0007]
[Problems to be solved by the invention]
In a multi-wafer type semiconductor manufacturing apparatus, when a defective product is generated on a wafer to be processed during the semiconductor manufacturing process and the wafer to be processed is pulled out, a reaction process is performed without charging a prescribed plurality of wafers in the reaction processing chamber. Then, unnecessary film formation, etching, and the like are performed on the wafer stage, which is not preferable. In particular, in the case of plasma processing, there is a problem that the electrical characteristics of the plasma electrode are changed due to unnecessary processing, and the film forming state is changed accordingly, resulting in deterioration of the film forming characteristics.
[0008]
Therefore, the insufficient number of wafers to be processed is replenished with dummy wafers prepared in advance, and the reaction processing chamber is always charged with a prescribed number.
[0009]
The load lock chamber is provided with an elevating mechanism (elevator) for transporting a wafer to be processed or a dummy wafer to a wafer take-out port of the load lock chamber.
[0010]
Conventionally, the elevating time and distance of the elevating mechanism of the load lock chamber is long, and the efficient operation of the dummy wafer has not been established yet, and the efficient operation of the dummy wafer is required.
[0011]
An object of the present invention is to provide a dummy substrate operation method in a semiconductor manufacturing apparatus that realizes efficient operation of a dummy wafer.
[0012]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides at least one reaction processing chamber for simultaneously processing a plurality of substrates, a transfer chamber for transferring the substrate to the reaction processing chamber, and the substrate in the transfer chamber. In a method for operating a dummy substrate in a semiconductor manufacturing apparatus having a load lock chamber to be delivered, a set of substrates to be processed and a set of dummy substrates are stored adjacent to each other in at least one load lock chamber, and the dummy When processing is started from the substrate to be processed on the side adjacent to the substrate, and the substrate to be processed is missing , the number of substrates in the reaction processing chamber at the time of reaction processing is determined based on the removal information of the substrate to be processed. The number of the dummy substrates is selected so as to always be the plural number, and the dummy substrates are used only for the first group to be processed .
[0013]
Further, the number of the dummy substrates stored in the load lock chamber is one less than the plurality of sheets.
[0014]
In the present invention, with such a configuration, the lifting time and the lifting distance by the lifting mechanism of the substrate to be processed and the dummy substrate can be reduced. Thereby, productivity (throughput) can be improved, production cost can be reduced, durability reliability can be improved, and efficient operation of the dummy substrate can be realized.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings described below, components having the same function are denoted by the same reference numerals, and repeated description thereof is omitted.
[0016]
FIG. 1A is a top cross-sectional view of a cluster type multi-wafer type semiconductor manufacturing apparatus according to an embodiment of the present invention, and FIG. 1B is a loading side (atmosphere side, transfer chamber and load chamber) of FIG. FIG. 2 is an enlarged view of a cassette for storing a wafer to be processed and a shelf for storing dummy wafers in the load lock chamber of FIG. This apparatus is a three-sheet type that processes three sheets simultaneously.
[0017]
Reference numeral 6 denotes a wafer to be processed, 3A and 3B denote reaction processing chambers for processing the wafer to be processed 6, 2 denotes a transfer chamber for transferring the wafer to be processed 6 to the reaction processing chambers 3A and 3B, and 5 denotes a transfer chamber. A transfer robot for the wafer 6 to be processed, 4A and 4B are cooling chambers for the wafer 6 to be processed, 1A and 1B are load lock chambers for transferring the wafer 6 to the transfer chamber 2, and 7 is a cassette for storing the wafer 6 to be processed. is there.
[0018]
Two reaction processing chambers 3A and 3B are provided, and two cooling chambers 4A and 4B are also provided correspondingly. Gate valves (not shown) are provided between the load lock chambers 1A and 1B and the transfer chamber 2 and between the transfer chamber 2 and the reaction processing chambers 3A and 3B, respectively, so that airtightness is maintained. .
[0019]
The wafer 6 to be processed after the reaction processing is once charged as necessary in the cooling chambers 4A and 4B adjacent to the reaction processing chambers 3A and 3B by the transfer robot 5 in the transfer chamber 2, and after the necessary time has elapsed, the load lock is performed. Returned to chambers 1A, 1B.
[0020]
The cooling chambers 4A and 4B can be provided with a wafer alignment function, and once transferred to the cooling chambers 4A and 4B before being transferred to the reaction processing chambers 3A and 3B, the reaction processing chambers are provided. Wafer charging to 3A and 3B can be performed accurately.
[0021]
In this apparatus, as shown in FIG. 1B and FIG. 2, a dummy is placed in each of the two load lock chambers 1 </ b> A and 1 </ b> B under a cassette 7 that can carry in / out the wafer 6 to be processed. A shelf 11 for storing the wafer 10 is provided. The dummy wafer 10 can be taken in and out directly from the atmosphere side of the load lock chambers 1 </ b> A and 1 </ b> B, similarly to the processing target wafer 6. The dummy wafer 10 may also be stored in a cassette that can be loaded and unloaded instead of being stored in the shelf 11.
[0022]
For example, the dummy wafer 10 is used at the time of test film formation immediately after in-situ cleaning using the gas in the reaction processing chambers 3A and 3B. In particular, when an insulating film is formed, if the test film is formed without placing the wafer on the wafer stage (susceptor) in the reaction processing chambers 3A and 3B, the plasma electrode is covered with the insulating film. A wafer 10 is used. The dummy wafer 10 is normally used a plurality of times, and film formation is performed on the dummy wafer 10 a plurality of times.
[0023]
Excessive use of one dummy wafer 10 increases the accumulated film thickness on the dummy wafer 10, generates particles, or warps the dummy wafer 10 due to excessive film stress or thermal history due to repeated use. Since the deformation occurs, a conveyance error is likely to occur. For this reason, the operator predicts the film thickness to be deposited by a single film formation process of the dummy wafer 10, calculates the cumulative film thickness according to the number of times the dummy wafer 10 is used, and defines the threshold film thickness. . When the actual accumulated film thickness on the dummy wafer 10 exceeds the threshold film thickness, the operator is notified by appropriate means, and the operator replaces the dummy wafer 10 with a new one. It is effective to do.
[0024]
Further, since the dummy wafer 10 is formed a plurality of times as described above, particles are likely to be generated. Therefore, the shelf 11 for storing the dummy wafer 10 is processed as shown in FIGS. It is desirable to arrange the wafer 6 below the cassette 7 for storing the wafer 6.
[0025]
In addition, in this multi-wafer type apparatus, when a defective product is generated on the wafer 6 to be processed and the wafer 6 to be processed is detached, the reaction processing chambers 3A and 3B are not charged with the prescribed number of reaction processing. If it is performed, unnecessary film formation, etching, and the like are performed on the wafer stage, which is not desirable. In particular, in the case of plasma treatment, the film formation characteristics are deteriorated due to a change in electrical characteristics of the plasma electrode due to unnecessary treatment and a change in the film formation state associated therewith. Accordingly, the shortage of the wafer 6 to be processed is supplemented with the dummy wafer 10 prepared in advance, so that the reaction processing chambers 3A and 3B are always charged with a prescribed number.
[0026]
In addition, in the load lock chambers 1A and 1B, the cassette 7 storing the wafer 6 to be processed and the shelf 11 storing the dummy wafers 10 are moved up and down to the wafer take-out ports (not shown) of the load lock chambers 1A and 1B. A lifting mechanism (elevator, not shown) is provided.
[0027]
As necessary, the dummy wafer 10 is lifted up and down to the wafer take-out port of the load lock chambers 1A and 1B by the elevating mechanism similarly to the wafer 6 to be processed, and taken out to the reaction processing chambers 3A and 3B by the transfer robot 5. And used. After use, it is returned to the shelf 11 by the transfer robot 5.
[0028]
Next, details of a case where a deficient amount of the wafer 6 to be processed is supplemented with a dummy wafer 10 prepared in advance and the reaction processing chambers 3A and 3B are always charged with a prescribed number will be described. In this case, the dummy wafer 10 is not used for the test film formation immediately after the in-situ cleaning, and the two load lock chambers 1A and 1B are not used continuously. The 1B cassette 7 is used as one lot.
[0029]
As shown in FIGS. 1B and 2, the set of dummy wafers 10 is disposed adjacent to the lower side of the set of wafers 6 to be processed. The processed wafer 6 starts processing from the lower side adjacent to the dummy wafer 10.
[0030]
FIG. 3 is an operation explanatory diagram of the dummy wafer.
[0031]
The missing information (mapping data) of the wafer 6 to be processed in the cassette 7 is obtained in advance, and based on this, the dummy wafer 10 is operated as shown below.
[0032]
As shown in FIG. 3, when 25 defective wafers 6 in one lot have become defective and there are not enough 3 wafers, dummy wafers 10 are processed as a set of three wafers to be processed first based on the mapping data. use. In this case, it is desirable that the number of dummy wafers 10 be one less than the number (two in this case) that is simultaneously processed in the reaction processing chambers 3A and 3B (three in this case).
[0033]
That is, two dummy wafers 10 are added to 22 wafers 6 to be processed which are not enough for 3 of the 25 wafers 6 to be processed, and the number of processing times 4 in one of the reaction processing chambers 3A and 3B is 4. A total of 24 wafers are processed a total of 8 times.
[0034]
By using the dummy wafer 10 for the first processing for the first time, the lifting time and the lifting distance by the lifting mechanism of the cassette 7 and the shelf 11 can be reduced as compared with the case where the dummy wafer 10 is used at the last or halfway. Thereby, productivity can be improved, production cost can be reduced, and durability reliability can be improved, and efficient operation of the dummy wafer 10 can be realized.
[0035]
Preferably, the cassette 7 for storing the wafer 6 to be processed is made heat resistant. When a high temperature process is performed, it is necessary to secure a sufficient cooling time for the wafer 6 to be processed. However, in order to improve the throughput, when a sufficient cooling time cannot be ensured, a cassette 7 made of a heat resistant material is used. Good.
[0036]
Reference Example FIG. 4A is a top cross-sectional view of a cluster type single wafer type semiconductor manufacturing apparatus according to a reference example of the present invention, and FIG. 4B is a front view of the load side of the load lock chamber of FIG.
[0037]
In the apparatus of this reference example, three load lock chambers 1A, 1B and 1C are provided, the middle load lock chamber 1B accommodates only the dummy wafer 10, and the two load lock chambers 1A and 1C on both sides are the wafer 6 to be processed. Only store.
[0038]
That is, the load lock chamber 1B dedicated to the dummy wafer 10 stores only the dummy wafer 10 in the cassette, and accesses the load lock chamber 1B when the dummy wafer 10 is necessary, and uses the dummy wafer 10.
[0039]
Although the present invention has been specifically described above based on the embodiments, the present invention is not limited to the above-described embodiments, and it is needless to say that various changes can be made without departing from the scope of the invention.
[0040]
【The invention's effect】
As described above, according to the present invention, the raising / lowering time and the raising / lowering distance by the raising / lowering mechanism of the substrate to be processed and the dummy substrate can be reduced, so that productivity can be improved, production cost can be reduced, and durability reliability can be improved. And efficient operation of the dummy substrate can be realized.
[Brief description of the drawings]
FIG. 1A is a top cross-sectional view of a cluster type multi-wafer type semiconductor manufacturing apparatus according to an embodiment of the present invention, and FIG. 1B is a front view of a load lock chamber of FIG.
2 is an enlarged view of a wafer storage cassette and a dummy wafer storage shelf in the load lock chamber of FIG. 1. FIG.
FIG. 3 is an operation explanatory diagram of a dummy wafer according to the embodiment of the present invention.
4A is a top cross-sectional view of a cluster type single wafer semiconductor manufacturing apparatus according to a reference example of the present invention, and FIG. 4B is a front view of the loading side of the load lock chamber of FIG.
FIG. 5 is a top sectional view of an example of a cluster type single wafer type semiconductor manufacturing apparatus;
[Explanation of symbols]
1A, 1B, 1C ... load lock chamber, 2 ... transfer chamber, 3A, 3B ... reaction processing chamber, 4A, 4B ... cooling chamber, 5 ... transfer robot, 6 ... processed wafer, 7, 16, 17 ... processed wafer Storage cassette, 10 ... dummy wafer, 11 ... dummy wafer storage shelf.

Claims (2)

In a semiconductor manufacturing apparatus having at least one reaction processing chamber for simultaneously processing a plurality of substrates, a transfer chamber for transferring the substrate to the reaction processing chamber, and a load lock chamber for transferring the substrate to the transfer chamber In the method for operating a dummy substrate, a set of substrates to be processed and a set of dummy substrates are stored adjacent to each other in at least one load lock chamber and processed from the substrate to be processed on the side adjacent to the dummy substrate. When the substrate to be processed is missing , the dummy substrate is configured such that the number of substrates in the reaction processing chamber at the time of the reaction processing is always the plurality of substrates based on the information on the substrate to be processed. A method for operating a dummy substrate in a semiconductor manufacturing apparatus , wherein the dummy substrate is used only for the first group to be processed . 2. The method for operating a dummy substrate in a semiconductor manufacturing apparatus according to claim 1, wherein the number of the dummy substrates stored in the load lock chamber is one less than the plurality of the plurality of substrates.

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