JP2015015413A - Gas capturing body, and semiconductor manufacturing apparatus provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas capturing body capable of suppressing the occurrence of foreign matters without lowering an operation rate, and a semiconductor manufacturing apparatus provided with the same.SOLUTION: A decompression vapor-phase growth device 1 has a gas capturing body 16 for capturing a material gas flowing from the side of a front flange 4 arranged between a boat 14 and a rear flange 5 mounted on a semiconductor wafer. The gas capturing body 16 is formed of one cylindrical large-diameter quartz tube, and a plurality of cylindrical fine quartz tubes. The plurality of fine quartz tubes are arranged inside the large-diameter quartz tube. Each of the plurality of fine quartz tubes is not adhered to each other, and is arranged by being sequentially mounted on the inner wall of the horizontally arranged large-diameter quartz tube.

Description

  The present invention relates to a gas trap and a semiconductor manufacturing apparatus including the gas trap, and in particular, a gas trap that is disposed in a reaction tube and traps a flowing material gas, and a semiconductor manufacturing device including such a gas trap. Device.

  Semiconductor devices are manufactured through various semiconductor manufacturing apparatus processes. As one of semiconductor manufacturing apparatuses, there is a low pressure chemical vapor deposition (LPCVD) apparatus that vapor-deposits a predetermined film such as an insulating film on the surface of a semiconductor wafer under reduced pressure. In the reduced pressure vapor phase growth apparatus, a plurality of semiconductor wafers are arranged in a reaction tube, and a material gas that forms a film is supplied into the reaction tube under a predetermined temperature and pressure.

  A predetermined film is formed on the surface of the semiconductor wafer by the material gas supplied into the reaction tube. After the predetermined film is formed, the semiconductor wafer is taken out from the reaction tube, and the taken-out semiconductor wafer is sent to the next step. Patent documents 1 and 2 disclose patent documents disclosing such a semiconductor manufacturing apparatus for vapor phase growth of a film under reduced pressure.

Japanese Patent Application Laid-Open No. 07-201760 JP 05-112870 A

However, the conventional reduced pressure vapor phase growth apparatus has the following problems.
In the manufacturing process of a semiconductor device, it is important to prevent foreign matters from adhering to the surface of the semiconductor wafer in order to increase the yield and improve the reliability of the semiconductor device.

  In the reduced pressure vapor phase growth apparatus, the material gas that has not been consumed in the reaction tube is discharged from the exhaust pipe to the outside of the reduced pressure vapor phase growth apparatus via a vacuum pump. When the material gas flows through the exhaust pipe and the vacuum pump, a film is deposited as a foreign substance on the inner wall of the exhaust pipe and the vacuum pump. The film deposited on the inner wall of the exhaust pipe may be peeled off from the inner wall of the exhaust pipe due to pressure fluctuation, temperature fluctuation, vibration, or the like. The peeled film becomes a foreign substance and adheres to the surface of the semiconductor wafer, which can be one of the factors that reduce the yield of the semiconductor device.

  In addition, since a film is deposited as a foreign substance on the inner wall of the exhaust pipe, the exhaust pipe is likely to be clogged, and pressure control in the reaction pipe may not be performed satisfactorily. For this reason, it is necessary to wash | clean a reaction tube, exhaust piping, etc. regularly.

  However, although cleaning of the reaction tubes and exhaust pipes, etc. can be performed frequently, foreign substances adhering to the semiconductor wafer can be suppressed. However, from the viewpoint of mass production of semiconductor devices, the operating rate of semiconductor manufacturing equipment is reduced. There was a problem that.

  The present invention has been made in order to solve the above-mentioned problems, and one object is to provide a gas trap that can suppress foreign matter without lowering the operation rate, and the other object is An object of the present invention is to provide a semiconductor manufacturing apparatus provided with such a gas trap.

  A gas trap according to the present invention is a gas trap used in a semiconductor manufacturing apparatus including a reaction tube, and includes a first tube and a plurality of second tubes. The plurality of second tubular bodies are respectively disposed inside the first tubular body and are thinner than the first tubular body.

  A semiconductor manufacturing apparatus according to the present invention is a semiconductor manufacturing apparatus provided with the gas trapping body, and includes a reaction tube, a gas supply system, and a gas exhaust system. The reaction tube is disposed horizontally and accommodates an object to be processed. The gas supply system is connected to one end side of the reaction tube. The gas exhaust system is connected to the other end side of the reaction tube. The gas trap is disposed between the region in which the workpiece is accommodated and the other end side in the reaction tube.

  According to the gas trap according to the present invention, the material gas introduced into the semiconductor manufacturing apparatus is consumed, and foreign substances in the exhaust system can be reduced. Thereby, the maintenance frequency of a semiconductor manufacturing apparatus can be lowered | hung and an operation rate can be raised.

  According to the semiconductor manufacturing apparatus according to the present invention, the material gas introduced into the semiconductor manufacturing apparatus is consumed by the gas capturing body, and foreign substances deposited in the gas exhaust system can be reduced. Thereby, the maintenance frequency of a semiconductor manufacturing apparatus can be lowered | hung and an operation rate can be raised.

1 is a side view including a partial cross section showing a reduced pressure vapor phase growth apparatus including a gas trap according to Embodiment 1 of the present invention. FIG. In the same embodiment, it is a perspective view which shows a gas capture body. In the same embodiment, it is a side view including a partial cross section for explaining the operation of the reduced pressure vapor phase growth apparatus. In the same embodiment, it is a perspective view which shows the gas capturing body which concerns on a modification. It is a perspective view which shows the gas trap which concerns on Embodiment 2 of this invention. It is a perspective view which shows the gas trap which concerns on Embodiment 3 of this invention. In the same embodiment, it is an exploded perspective view which shows a thermocouple mounting quartz thin tube and a holding member.

Embodiment 1
A gas trap according to the first embodiment and a horizontal vacuum vapor phase growth apparatus including the gas trap will be described. As shown in FIG. 1, in the reduced pressure vapor phase growth apparatus 1, a quartz reaction tube 2 into which a semiconductor wafer 15 is loaded is arranged substantially horizontally. A front flange 4 is attached to the front opening end of the reaction tube 2, and a rear flange 5 is attached to the rear opening end. Within the reaction tube 2, a plurality of semiconductor wafers 15 are placed on a boat 14 made of quartz.

  A heater 3 for heating the inside of the quartz tube 2 to a predetermined temperature is attached around the reaction tube 2. A gas supply system 6 is connected to the front flange 4, and a gas exhaust system 9 is connected to the rear flange 5. The gas supply system 6 includes a gas supply unit 7 and a supply pipe 8. The gas exhaust system 9 includes an exhaust pipe 10, an exhaust valve 11, a vacuum pump 13, and a pressure control mechanism 12.

  Between the boat 14 and the rear flange 5, a gas capturing body 16 that captures the material gas flowing from the front flange 4 side is disposed. As shown in FIG. 2, the gas trap 16 is formed by a single cylindrical large-diameter quartz tube 17 and a plurality of cylindrical quartz tubes 18 each having a cylindrical shape. The plurality of quartz thin tubes 18 are disposed in the large diameter quartz tube 17. Each of the plurality of quartz thin tubes 18 is not bonded to each other, and the plurality of quartz thin tubes 18 are disposed by sequentially placing the quartz thin tubes 18 on the inner wall of the large-diameter quartz tube 17 disposed horizontally. .

  Next, an example of processing by the above-described reduced pressure vapor phase growth apparatus 1 will be described. First, a front port (not shown) provided in the front flange 4 is opened, and a boat 14 loaded with a plurality of semiconductor wafers 15 is carried into the reaction tube 2 as shown in FIG. A gas capturing body 16 is disposed on the rear flange 5 side of the reaction tube 2, and the gas capturing body 16 is located on the downstream side of the flow of the material gas with respect to the semiconductor wafer 15 that has been loaded.

  Next, the front port is closed, and the inside of the reaction tube 2 is evacuated by the vacuum pump 13. The degree of vacuum in the reaction tube 2 is measured by the pressure control mechanism 12. Further, the reaction tube 2 is heated by the heater 3. The temperature of the reaction tube 2 is measured by a thermocouple 19. When the degree of vacuum in the reaction tube 2 reaches a predetermined degree of vacuum and the reaction tube 2 reaches a predetermined temperature, a material gas is supplied from the gas supply system 6 and introduced into the reaction tube 2.

  The material gas introduced into the reaction tube 2 is consumed on the surface of the semiconductor wafer 15 while flowing toward the rear flange 5 as shown by an arrow Y1, and an insulating film or a conductive material is formed on the surface of the semiconductor wafer 15. A predetermined film (not shown) such as a film is formed. The material gas remaining without being consumed is exhausted from the rear flange 5 through the gas exhaust system 9 (see arrow Y2) and out of the vacuum vapor phase growth apparatus 1 (see arrow Y3).

  In the above-described reduced pressure vapor phase growth apparatus 1, the gas trap 16 is disposed between the plurality of semiconductor wafers 15 placed on the boat 14 and the rear flange 5. The material gas that has not been consumed flows through the large-diameter quartz tube 17 of the gas capturing body 16 and the quartz thin tube 18 disposed inside thereof. While the material gas or the like flows through the large diameter quartz tube 17 and the quartz thin tube 18, it is consumed on the surface of the large diameter quartz tube 17 and the surface of the quartz thin tube 18, and a film is formed on these surfaces. Since the material gas is consumed in the gas capturing body 16, the amount (component) of the material gas flowing in the exhaust pipe 10 or the like per unit time is smaller than that in the case where the gas capturing body is not disposed.

  Thereby, the deposition rate of the film | membrane used as a foreign material can be suppressed, and the film | membrane as a foreign material deposited on the inner wall of the exhaust pipe 10 or the vacuum pump 13 can be reduced within a fixed time. As a result, the generation of foreign matter due to film peeling can be suppressed, the number of foreign matter attached to the surface of the semiconductor wafer 15 can be reduced, and the yield of the semiconductor device can be improved.

  Further, the gas exhaust system 9 such as the exhaust pipe 10 is not easily clogged, and the pressure control in the reaction tube 2 can be performed satisfactorily. Furthermore, since the film as a foreign substance deposited within a certain time is reduced, the cycle for periodically cleaning the reaction tube and the like can be lengthened, and the operating rate of the vacuum vapor phase growth apparatus 1 can be increased. it can.

  On the other hand, the gas capturing body 16 in which the material gas has been consumed and the film has grown is removed from the rear port (not shown) of the rear flange 5 without removing the exhaust pipe 10 and is subjected to maintenance processing such as being immersed in a predetermined cleaning liquid. After performing, maintenance work can be easily performed by inserting from the rear port. In addition, the maintenance time can be minimized by preparing a new gas trap in advance.

  Furthermore, by simply stacking and arranging the quartz capillaries 18 on the inner wall of the large-diameter quartz tube 17, compared to the case where a plurality of quartz capillaries are integrated, partial degradation of the quartz capillaries 18 is achieved. Operations such as repair and replacement of quartz tubes can be easily performed.

  As shown in FIG. 4, in the gas capturing body 16, the surface area of the quartz thin tube 18 can be changed by changing the diameter of the quartz thin tube 18 disposed in the large diameter quartz tube 17. It is possible to control the amount of consumption of material gas (gas adsorption amount). Furthermore, if necessary, a quartz capillary having a relatively large diameter and a quartz capillary having a small diameter may be mixed and arranged.

Embodiment 2
A gas trap according to the second embodiment and a vacuum vapor phase growth apparatus including the trap will be described.

  As shown in FIG. 5, in the gas trap 16, a pair of handles 20 are attached to the large-diameter quartz tube 17. The handle 20 is made of quartz, and is fixed to the end of the large diameter quartz tube 17 by welding. In addition, since it is the same as that of the gas capture body 16 shown in FIG. 2 about another structure, the same code | symbol is attached | subjected to the same member and the description is not repeated. Further, the horizontal reduced pressure vapor phase growth apparatus in which the gas trap 16 is disposed is the same as the reduced pressure vapor phase growth apparatus shown in FIG. 1, and therefore, the description thereof will not be repeated unless necessary.

  Next, processing by the reduced pressure vapor phase growth apparatus provided with the above-described gas capturing body 16 will be briefly described. This process is substantially the same as that of the above-described reduced-pressure weather growth apparatus. After the boat 14 loaded with a plurality of semiconductor wafers 15 is carried into the reaction tube 2, the reaction tube 2 reaches a predetermined degree of vacuum and the reaction tube 2 reaches a predetermined temperature. A material gas is introduced into 2. The introduced material gas is mainly consumed in the surface of the semiconductor wafer 15 and the gas trap 16 and then exhausted out of the vacuum vapor phase growth apparatus 1 through the gas exhaust system 9 (see FIG. 3). .

  In the reduced-pressure vapor phase growth apparatus provided with the gas trapping body 16 described above, in addition to the effects described in the first embodiment, such as the number of foreign matters adhering to the surface of the semiconductor wafer 15 can be reduced, the following Such effects can be obtained.

  That is, when performing a maintenance operation such as cleaning or exchanging the gas capturing body 16 on which the film has grown, the operation can be performed by grasping the handle 20 by hand. As a result, the maintenance work can be performed safely and reliably, the work efficiency can be increased, and the operation rate of the reduced pressure vapor phase growth apparatus can be further contributed.

Embodiment 3
A gas trap according to the third embodiment and a reduced pressure vapor phase growth apparatus including the trap will be described.

  As shown in FIGS. 6 and 7, in the gas trap 16, a thermocouple-mounted quartz capillary 21 in which a thermocouple (not shown) is mounted is disposed in a large-diameter quartz tube 17 together with a plurality of quartz tubes 18. Has been. The thermocouple-mounted quartz capillary 21 is held by a holding member 22 having a hollow portion. The holding member 22 is made of quartz and is welded to the large diameter quartz tube 17. The thermocouple-equipped quartz capillary 21 is held by being inserted into the hollow portion of the holding member 22.

  In addition, since it is the same as that of the gas capture body 16 shown in FIG. 2 about another structure, the same code | symbol is attached | subjected to the same member and the description is not repeated. Further, the horizontal reduced pressure vapor phase growth apparatus in which the gas trap 16 is disposed is substantially the same as the reduced pressure vapor phase growth apparatus shown in FIG. 1, and therefore, the description thereof will not be repeated unless necessary. .

  Next, processing by the reduced pressure vapor phase growth apparatus provided with the above-described gas capturing body 16 will be briefly described. This process is substantially the same as in the case of the reduced-pressure weather growth apparatus described above (Embodiment 1). After the boat 14 loaded with a plurality of semiconductor wafers 15 is carried into the reaction tube 2, the reaction tube 2 reaches a predetermined degree of vacuum and the reaction tube 2 reaches a predetermined temperature. A material gas is introduced into 2. The introduced material gas is mainly consumed in the surface of the semiconductor wafer 15 and the gas trap 16 and then exhausted out of the vacuum vapor phase growth apparatus 1 through the gas exhaust system 9 (see FIG. 3). .

  In the reduced-pressure vapor phase growth apparatus provided with the gas trapping body 16 described above, in addition to the effects described in the first embodiment, such as the number of foreign matters adhering to the surface of the semiconductor wafer 15 can be reduced, the following Such effects can be obtained.

  First, in general, in a low-pressure vapor phase growth apparatus, the temperature in the reaction tube is controlled based on the temperature measured by a thermocouple attached to a heater surrounding the reaction tube.

  In the above-described reduced-pressure vapor phase growth apparatus 1, the gas capturer 16 is provided with a plurality of quartz thin tubes 18 and a thermocouple-attached quartz thin tube 21 to which a thermocouple is attached. In a state in which the gas trap 16 is disposed in the reaction tube 2, a thermocouple (not shown) attached to the thermocouple-attached quartz thin tube 21 is, for example, a front side, a center portion, and a rear side in the reaction tube 2. It is arranged at a predetermined position.

  Thereby, the correlation between the temperature measured by the thermocouple 19 outside the reaction tube 2 and the temperature measured by the thermocouple inside the reaction tube 2 can be confirmed. As a result, more accurate temperature control can be performed, which can contribute to more stable film formation.

  The embodiment disclosed this time is an example, and the present invention is not limited to this. The present invention is defined by the terms of the claims, rather than the scope described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is particularly effectively used for a horizontal vacuum vapor phase growth apparatus.

  DESCRIPTION OF SYMBOLS 1 Low pressure vapor phase growth apparatus, 2 reaction tube, 3 heater, 4 front flange, 5 rear flange, 6 gas supply system, 7 gas supply part, 8 supply piping, 9 gas exhaust system, 10 exhaust piping, 11 exhaust valve, 12 Pressure control mechanism, 13 Vacuum pump, 14 Boat, 15 Semiconductor wafer, 16 Gas trap, 17 Large diameter quartz tube, 18 Quartz thin tube, 19 Thermocouple, 20 Handle, 21 Thermocouple mounted quartz thin tube, 22 Holding member, Y1, Y2, Y3 arrows.

Claims (6)

A gas trap used in a semiconductor manufacturing apparatus equipped with a reaction tube,
A first tube;
A gas capturing body comprising: a plurality of second tubular bodies which are respectively arranged inside the first tubular body and are thinner than the first tubular body.   The gas capturing body according to claim 1, wherein a handle is attached to one end side of the first tubular body. A third tubular body in which a thermocouple is disposed;
The gas capturing body according to claim 1, further comprising a support body that is disposed in the first tube body and supports the third tube body through the third tube body.   The gas capturing body according to any one of claims 1 to 3, wherein the plurality of second tubular bodies are arranged in a state where they are not adhered to each other.   The gas capturing body according to any one of claims 1 to 4, wherein the plurality of second pipe bodies include a large-diameter pipe body having a relatively large diameter and a small-diameter pipe body having a small diameter. A semiconductor manufacturing apparatus comprising the gas trap according to any one of claims 1 to 5,
A reaction tube in which a workpiece is accommodated and arranged horizontally;
A gas supply system connected to one end of the reaction tube;
A gas exhaust system connected to the other end of the reaction tube;
The gas capturing body is a semiconductor manufacturing apparatus, which is disposed in the reaction tube between a region in which the object to be processed is accommodated and the other end side.

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