JPH0810676B2 - Processing methods such as vapor phase growth - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applicable to the inside of a processing chamber such as vapor phase growth for epitaxial growth on a semiconductor substrate (hereinafter referred to as a wafer) and diffusion for adding an impurity. The present invention relates to a processing method that requires a processing process including a large number of steps (sequences).

[Prior art]

Conventionally, as a device used for so-called epitaxial growth for growing a crystal thin film having the same crystal orientation as that of a wafer such as silicon on the surface of the wafer, three typical systems called horizontal type, vertical type and cylinder type have been put into practical use. . Although each of these devices has excellent features, it is desired to improve productivity, and the wafer diameter is being increased (5 inches and 6 inches). Increasing the size of the susceptor on which the wafer is placed (and thus increasing the size of the reaction chamber) is in progress. But,
Increasing the size of the susceptor is not only expensive, but there are also problems in manufacturing technology, and there is a limit. Further, quartz parts such as a quartz bell jar constituting the reaction chamber also have to be upsized, and upsizing of the quartz parts is a serious problem because it is fragile and expensive.

Furthermore, as the characteristics required for the epitaxial layer,
Although the uniformity of the film thickness and the film resistance is an important point, it becomes difficult to reduce the variation within the batch with the increase in size.

Further, if the number of processed sheets for each batch is increased, if a trouble occurs during the processing, all the products in the batch become defective products and the damage is large. Furthermore, since explosive gas corrosive or toxic gas is used for epitaxial growth, it can be said that increasing the size is not preferable. Moreover, since the volume of the reaction chamber is large, it takes a long time to make the inside of the reaction chamber, for example, an N ₂ gas atmosphere, so that the total time required for one process is considerably long. Such a problem is not limited to the vapor phase growth apparatus, but is almost the same also in the diffusion apparatus, the vapor deposition apparatus, the etching apparatus, and the like.

As an alternative to batch processing, various processing methods have been proposed in which processing units are formed into a line according to a series of processing processes, and wafers are flowed along this line to perform continuous processing. In the continuous treatment, when an explosive gas or a toxic gas is used, there are various problems in practical application such as reliable sealing of the gas.

On the other hand, the inventor of the present application uses a plurality of processing chambers that individually execute a series of processing process sequences in each processing chamber, and executes the processes by sequentially shifting the sequences in the plurality of processing chambers for a predetermined time. In this way, a processing apparatus has been proposed in which the processed articles are sequentially obtained from each processing chamber every predetermined time.

[Problems to be solved by the invention]

In the processing apparatus by the inventor of the present application, when the processing conditions of the processing process are repeatedly performed, the processing in each processing chamber is smoothly performed with a predetermined time difference, but the film thickness of the vapor phase growth layer The processing conditions of the processing process are not always constant because they vary depending on the type of semiconductor device that is the final product, and may change depending on the lot.In this case, the time lag of the sequence between processing chambers is disturbed. In some cases, two or more processing chambers may perform processing in the same time zone divided by the predetermined time of the same sequence as a unit at the same time. When duplication occurs in two or more processing chambers in this way, the processing may become impossible depending on the capability of the apparatus. That is,
For example, in a device in which a single loading / unloading device is used to load / unload wafers into / from each processing chamber, if the loading / unloading processes occur simultaneously in two or more processing chambers, some processing chambers cannot be loaded / unloaded. Is disturbed and becomes out of control.

[Means for solving problems]

According to the present invention, when the processes of the processes having different processing conditions are inserted as described above, the processes of the same time zone divided by the predetermined time unit of the same sequence at the same time are not performed in two or more processing chambers. The start time of the treatment process under the new condition is controlled.

[Action]

The start timing of the treatment process under the new condition is determined by comparing the sequence of the treatment process that precedes (including the time factor) with the sequence of the treatment process under the new condition, and Processing process that is inserted after the existing processing process is not preceded by a process with a new condition that is processed in the same time zone divided by a predetermined time unit of the same sequence at the same time. To When the process under the new condition is continuously performed, the next process is started at the same time as the preceding process process or with a predetermined time difference according to the new process process. . In this way, the sequences are executed in all the processing chambers with a certain time lag, and the sequence is not disturbed due to duplication in a predetermined time unit.

〔Example〕

Hereinafter, description will be given with reference to an embodiment in which the present invention is applied to vapor phase growth. In FIG. 1, 1 ₁ is a processing chamber, that is, a reaction chamber for vapor phase growth, and this reaction chamber ₁₁ is a base plate 2 and
Is constituted by the lift to the base plate 2 (open) capable placed on the quartz bell jar 3 _1. The aforementioned reaction chamber 1 _1, the susceptor 4 is provided on the susceptor 4 is placed a wafer 5 which is an object to be treated. The susceptor 4 is supported by the rotating shaft 6, the rotary shaft 6 is adapted to be given a rotation by the motor 9 ₁ via a gear 7 and 8.

Also, the bell jar 3 ₁ is connected to a gas supply pipe 10 _1, so as to supply the various gases necessary for vapor phase growth process such as purge gas and the reaction gas from the gas unit 12 via an on-off valve 11 ₁ Has become. A gas exhaust pipe 13 ₁ is connected to the base 2 and communicates with an exhaust gas processing unit (not shown) via an opening / closing valve 14 ₁ .

On the upper surface portion of the bell jar 3 _1, it is provided an infrared lamp 15 ₁ for heating the wafer 5 and the susceptor 4,
Electric power is supplied from the heating unit 17 via the switch 16 ₁ . Note that this power is supplied to the wafer 5
Alternatively, it is controlled by the heating unit 17 according to the output from the temperature detector (not shown) of the susceptor 4.

On the base 2, similar to the bell jar and the bell jar 3 ₁
3 ₂ , 3 ₃ … 3 _n are arranged on a straight line or a circle by the number as described later. In each of the bell jar _{3 1, 3 2, 3 3} ... 3 n, the motor 9 ₁ similar motor 9 _2, and 9 ₃ ... 9 _n, closing valve 11 ₁ and the same on-off valve for the gas supply 11 ₂ , 11 ₃ … 11 _n , open / close valves 14 ₂ , 14 ₃ … 14 _n similar to the gas discharge open / close valve 14 ₁ and infrared lamps 15 ₂ , 15 ₃ … 15 _n and their switches 16 ₂ , 16
₃ ... 16 _n are provided respectively, and these are operated by the process control device 18.

Thus, when growing the vapor phase, together with the reaction gas is supplied from the gas supply pipe 10 ₁ into the reaction chamber 1 _1, it is heated by infrared lamps 15 _1, further susceptor 4 by the operation of the motor 9 ₁ Is rotated. The reaction gas supplied into the reaction chamber 1 ₁ is electronically excited to dissociated compound absorbs infrared rays, further, growing an epitaxial film on the wafer 5 by the heat energy of the wafer 5 which has been heated.

By the way, the number n of the reaction chambers 1 ₁ to 1 _n is determined by the selection of the sequence of the epitaxial growth process by the user, the number of wafers 5 that can be processed in _one reaction chamber 11 and the number of wafers to be produced per fixed time. Has been done. That is, if the total time required for the epitaxial growth process is 30 minutes and 60 wafers 5 are processed per hour, and one wafer 5 is processed in one reaction chamber, the predetermined time unit is 1 minute. And reaction room 1
The number n is 30.

Table 1 shows an example of a general epitaxial process, in which the sequence No., the sequence name, the sequence contents, and the time required for each sequence are displayed. In this Table 1, decides to 1 minute a predetermined time unit, because the total required time of 28 minutes, will be constituted by 28 of the reaction chamber 1 ₁ to 1 _28. In addition,
The 1 minute of the predetermined time unit does not have to match the time at which each sequence is divided, and the sequence Nos. 2, 3, and 8,
As shown in FIG. 9, switching may be performed halfway with respect to a predetermined time unit.

Figure 2 is an effort to provide a concise description of the present invention, the treatment process as shown in Table 1 was modeled simply, in 10 reaction chamber 1 ₁ to 1 ₁₀ of from No.1 No.10 It is a thing which shows the time chart of the processing process each performed. The example shown in FIG. 2 shows an example in which the total required time of the processing process is changed from 10 minutes to 8 minutes, and the predetermined time unit is 1 minute. Also, the treatment process consists of the sequence of 1 to 6 shown above the thick line and the outline arrow.

As shown in FIG. 2, the treatment process total time required indicated by a bold line of 10 minutes, the treatment with the start of the reaction chamber 1 ₁ in the reaction chamber or first view of No.1, the reaction chamber 1 ₂ 1 min delay is started, from the reaction chamber 1 ₃ likewise delayed by 1 minute or less 1
Sequential processing is executed up to ₁₀ . Thus, after a lapse of 10 minutes from the start of processing in the reaction chamber 1 _1, the reaction chamber 1 ₁ a series of sequence is finished processing process in the wafer 5 in the final sequence 6 is taken out by a not shown loading and unloading device . Then, the reaction chamber 1 _1, and 1 minute eyes of 11 min after Zoletile injection i.e. second, return to the sequence 1 again, the wafer 5 is loaded into the reaction chamber 1 _1, the second treatment process is performed. Further, in the second 1 min after Zoletile injection, out of the final sequence 6 i.e. the wafer 5 is performed in the reaction chamber 1 _2, is sequentially carried out a reaction chamber 1 _3, 1 ₄ ... wafer 5 that has been processed from every minute or less , The next wafer 5 is loaded.

As is clear from FIG. 2, the sequences performed at the same time in the No. 1 to No. 10 reaction chambers are:
Each are shifted by one minute, the power supply from the 1 minute i.e. the gas supply and the heating unit 17 from the gas unit 12 with respect to 1 ₁₀ 1 ₁ each reaction chamber with respect to the predetermined time unit is controlled, the entire apparatus You can drive smoothly while maintaining order.

However, when it becomes necessary to insert a treatment process with a total required time of 8 minutes, as indicated by the white line in the column for the reaction chamber of No. 5 in Fig. 2, the first treatment process indicated by the thick line If the treatment process indicated by this white line is started immediately after the end of, the final sequence 6 of this treatment process overlaps with the final sequence 6 in the reaction chamber of No. 3 which precedes by two. Will end up. When the last sequence 6 is assumed to be out of the wafer 5, as described above, unloading point occurs two places simultaneously, if unloading the one loading and unloading apparatus by 1 ₁₀ leeks sequentially corresponding to 1 ₁ each reaction chamber Has
It is not possible to carry out the above two parts. Such a problem is that even in the case of supplying gas or energy for heating in a sequence in the middle, the capacity thereof is limited, and therefore, if the same time zone divided by a predetermined time unit exceeds the limitation, It can also occur.

Therefore, the present invention delays the start of the treatment process by a shortened time, that is, 2 minutes, as indicated by an outlined line in the column of the reaction chamber of No. 5 in FIG. In this case, it is possible to avoid overlapping the same time zones that are separated by a predetermined time unit of the same sequence at the same time, and carry out the wafer 5 after processing every minute after the preceding processing process. Done. Of course, the start of the treatment process of the white line in the No. 5 reaction chamber column is
It may be delayed by 3 minutes or more, but this is not preferable because it merely causes a time loss.

If the treatment process indicated by the outlined line is to be continued after that, as shown in the column of No. 6 to No. 10 in the reaction chamber in FIG. Good.

However, in this case, there is a blank time during which no processing is performed between the final sequence 6 and the start of the next processing process.
It occurs in each reaction chamber. This is because the performed by 1 ₁₀ to the total required time is 1 ₁ 10 reaction chamber 8 minutes of treatment processes.

FIG. 3 shows an example in which the number of reaction chambers that actually execute the treatment process is changed when the total required time of the treatment process changes.

That is, as shown by the white line in the column of No. 7 reaction chamber in FIG. 3, the process of the white line started from No. 5 reaction chamber in FIG. It is delayed by 2 minutes from the last sequence 6 of the preceding thick line in the column of No.
Jump over two of the reaction chambers of Nos. 5 and 6 and continue after the final sequence 6 of the preceding bold line of the reaction chamber of No. 7. No. 8 and subsequent reaction chambers can be started by deviating by 1 minute for the process of the white line, so as shown in FIG.
It is performed without a blank time after the last sequence 6 of the preceding bold line. If the treatment process of this outline line has been completed and the treatment has started in the No. 4 reaction chamber, the next treatment process can be performed again by removing the No. 5 and 6 reaction chambers.
Move to No.7 reaction chamber. That is, the treatment process is carried out by the eight reaction chambers excluding the reaction chambers Nos. 5 and 6. In this case, the eight reaction chambers that actually execute the treatment process operate without any blank time.

It should be noted that No. 5 and 6 do not participate in the execution of the above processing process
The reaction chamber of can be inspected and maintained.

When the condition of the treatment process changes in the direction of increasing the total required time, that is, when the outline line changes to the thick line, as is clear from the relationship between the outline line and the thick line in FIGS. 2 and 3. Even if it starts immediately after the end of the final sequence 6 of the preceding processing process, the same time zone divided by a predetermined time unit of the same sequence does not overlap at the same time.

Also, as is clear from FIG. 3, the total required time is 8
When the time returns from 10 minutes to 10 minutes, the reaction chambers of Nos. 5 and 6 are again involved in the execution of the treatment process.

Fig. 4 shows a treatment process in which the total required time becomes longer without increasing the number of reaction chambers when the treatment process having a total required time of 10 minutes is performed in 10 reaction chambers as shown by the bold line. It shows an example of insertion. That is,
This shows the case where the total required time for the treatment process is 12 minutes, as indicated by the second white line in the No. 5 reaction chamber column. In this case, the start time of the treatment process is No. 5 It may be immediately after the end of the final sequence 6 of the preceding treatment processes in the reaction chamber. However, in the example shown in Fig. 4, the number of reaction chambers does not increase even if the total required time increases, so the final sequence 6 in the bottom row in the No. 4 and No. 5 reaction chambers columns is respectively As you can see from the comparison,
The time lag of the final sequence 6 becomes longer as the total required time increases. This means that the interval of the end time of the treatment in each reaction chamber changes, but this does not make the treatment impossible. Similarly, if a processing process with a total required time of 12 minutes is executed also in the reaction chambers of No. 6 or less, the interval of the subsequent processing end time returns to 1 minute which is a predetermined time unit. However, when the treatment process with a total required time of 12 minutes continues, and when the cycle goes through the No. 4 reaction chamber to the No. 5 reaction chamber, the interval between the two treatment chambers at the end of the treatment becomes longer again. The same is repeated.

Although the above-described embodiment shows an example in which the synthesis required time of the processing process is increased / decreased by a predetermined time unit, this increase / decrease time does not necessarily have to be a predetermined time unit. For example, as described above, the predetermined time unit is 1 minute. In the case of, it may be increased or decreased by 10 seconds or 20 seconds. In this case, the start of a new processing process may be controlled according to this increase / decrease time, but even if it is 10 seconds, one unit of the predetermined time is required, and the control for each predetermined time unit is performed. May be The predetermined time unit is not always constant, and may be changed depending on the total time required for the treatment process, the number of reaction chambers, and the like.

Furthermore, although the above-described embodiments have been described by taking the vapor phase growth as an example, the present invention can be applied to various processes such as diffusion, vapor deposition, etching, etc., in which the process processes are performed in a single process chamber in multiple sequences. it can.

〔The invention's effect〕

As described above, according to the present invention, when a plurality of processing chambers that respectively execute a series of processing process sequences are executed in individual processing chambers, and the processing is executed by sequentially shifting the sequence in each processing chamber for a predetermined time. Even if the processing of the process having different processing conditions is inserted, the processing can be performed without the sequence in each processing chamber being complicated.

[Brief description of drawings]

FIG. 1 shows an example of a processing apparatus for carrying out the present invention, which is a partially omitted schematic view of partially cutaway, and FIGS. 2 to 4 show the progress of the sequence in each processing chamber when the processing conditions change. 3 is a time chart showing different examples of FIG. 1 ₁ to 1 _n ...... Processing chamber (reaction chamber), 5 ... Object to be processed (wafer), 12 ... Gas unit, 17 ... Heating unit, 18 ...
… Process control equipment.

Claims (4)

[Claims] 1. A large number of processing chambers capable of executing a series of processing processes in units of the processing chambers, and a processing body supply means such as gas and heat energy provided so as to be connectable to each processing chamber. And a means for controlling the supply from the processing body supply means to each of the processing chambers so that the execution of the sequence in each of the processing chambers is sequentially shifted with reference to a predetermined time unit. In the method of performing the treatment by using a treatment apparatus such as vapor phase growth, in which treated articles are sequentially obtained from each treatment chamber, when the treatments of different treatment conditions are inserted,
When the total processing time of the new processing condition to be inserted is shorter than the total processing time of the preceding processing process, the processing process of the new processing condition to be inserted is started. By delaying the time by the shortened time or more, processing in the same time zone divided by the predetermined time unit of the same sequence at the same time is prevented from being performed in two or more processing chambers. Treatment methods such as vapor phase growth. 2. When the total required time of the processing processes under the new conditions is shorter than the total required time of the preceding processing processes, it corresponds to the time when the number of processing chambers for actually performing the processing is shortened. The method for processing such as vapor phase growth according to claim 1, characterized in that the number is decreased by the number. 3. A plurality of processing chambers capable of executing a series of processing processes in units of the processing chambers, and a processing body supply means such as gas and heat energy provided so as to be connectable to each processing chamber. And a means for controlling the supply from the processing body supply means to each of the processing chambers so that the execution of the sequence in each of the processing chambers is sequentially shifted with reference to a predetermined time unit. In the method of performing the treatment by using a treatment apparatus such as vapor phase growth, in which treated articles are sequentially obtained from each treatment chamber, when the treatments of different treatment conditions are inserted,
If the total processing time of the new processing condition to be inserted is longer than the total processing time of the preceding processing process, the processing process of the new processing condition to be inserted is started. By performing the same timing as before, vapor phase growth characterized by preventing the processing in the same time zone divided by the predetermined time unit of the same sequence at the same time from being performed in two or more processing chambers. Processing method. 4. When the total required time of the processing processes under the new conditions is longer than the total required time of the preceding processing processes, it corresponds to the time when the number of processing chambers that actually perform the processing is increased. The method for processing such as vapor phase growth according to claim 3, characterized in that the number is increased by the number.