JPH05295549A - Heat treatment device - Google Patents

Abstract

PURPOSE:To stabilize a treatment and to improve throughput by previously heat-treating gases of a slow reaction or bringing the gases into reaction before sending the gases to a treatment chamber. CONSTITUTION:This heat treatment device is constituted to treat wafers 8 by using the treating gases introduced into the treatment chamber formed by inner tubes 26, etc. Only the treating gases of the slow reactivity supplied to the above-mentioned pretreatment chamber through a piping 30 side are passed into a prereaction chamber 32 where the gases are irradiated with UV light, by which the reactivity is enhanced. These gases are supplied to the treatment chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment technique using a treatment gas, and more particularly to a technique effective for reacting and decomposing the treatment gas by heat.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing an example of a conventional heat treatment apparatus. Here, an example of an oxidizer is shown.

A cylindrical processing chamber 1 made of quartz or the like.
Has one end open and the other end closed. A partition plate 2 is provided in a cone shape on the closed side, the tip of the partition plate is opened in a circular shape, and a pipe 4 for introducing a processing gas is attached to the preheating chamber 3 formed thereby. .. Further, a pipe 5 is provided for penetrating the preheating chamber 3 and the partition plate 2 to introduce a reaction gas.
A heater 7 for heating the inside of the main processing chamber 6 is attached to the outer periphery of the processing chamber 1. A large number of wafers 8 to be processed are loaded upright in the main processing chamber 6 at regular intervals, and a holder 9 is provided to hold and fix the wafers 8. The holder 9 holds the open end of the processing chamber 1. It is attached to a lid 10 adapted to be closed. The lid 10 may be attached via an O-ring 11 having chemical resistance and heat resistance in order to complete the sealing with the processing chamber 1.

When the wafer is processed by the heat treatment apparatus having such a structure, the processing chamber 1 is heated by the heater 7. Then, the lid 10 having the wafer 8 attached to the holder 9 is attached to the processing chamber 1, and the wafer 8 is set in the processing chamber 1.
Further, the processing gas is introduced from the pipe 4, and at the same time, the reaction gas is introduced from the pipe 5.

Here, the processing gas (for example, nitrogen [or phosphine]) at the time of supply is used in a large amount and the gas temperature rises slowly (or the temperature is low and the thermal reaction rate is slow), whereas the reaction gas ( For example, oxygen gas [or monosilane gas] is generally used in a small amount and the temperature rises quickly (or the reaction is fast even without heating). In the configuration shown in FIG. 3, the process gas enters the preheating chamber 3 and the speed thereof decreases, and further, the process gas is warmed in the process of stirring while passing through the preheating chamber 3 and the reaction is promoted. Therefore, the processing gas that has left the partition plate 2 can react with the reaction gas from the pipe 5 that reacts quickly with an optimum thermal reactivity.

FIG. 4 is a sectional view showing a second example of a conventional heat treatment apparatus (here, an example of a horizontal low pressure CVD apparatus is shown).

A process tube 13 (outer tube) is provided on the outer side of a cylindrical process tube 12 (inner tube: provided to facilitate cleaning of foreign substances generated during processing) in which the wafer 8 is loaded. The cartridge heater 14 is arranged coaxially and surrounds the process tube 13.
(The heater and an insulator that protects the heater and protects the heat and prevents the heat from escaping to the outside are integrated), and the heat of the cartridge heater 14 is transferred to the process tube 13 between the cartridge heater 14 and the process tube 13. A soaking tube 15 is arranged so that the heat is evenly transmitted. Sleeves 16 and 17 are attached to both ends of the process tube 12, and a lid 18 for loading and unloading the wafer 8 is attached to the sleeve 17 via an O-ring 19 so as to be openable and closable. The sleeve 16 is connected to a vacuum exhaust system (not shown) (for making the inside of the process tube 12 a vacuum and exhausting the processed gas, and including a pump, a valve, etc.). ..

Further, a radiator 20 is arranged above the cartridge heater 14 so as to secure a predetermined space,
An exhaust fan 21 is arranged on the radiator 20. Cooling water is supplied to the radiator 20 from the outside,
The heat from the CVD device is radiated to the surroundings to prevent the work environment from being deteriorated. Further, the entire CVD apparatus is covered with an outer casing 22, and inside thereof,
Air blown through a HEPA filter (not shown) or the like can be taken out while cooling the outside of the cartridge heater 14. Further, pipes 23 and 24 are connected to the process tube 12 to supply a processing gas and a reaction gas.

In the above structure, the process tube 1
The inside of the wafer 2 is heated by the cartridge heater 14, and the wafer 8 is loaded into the process tube 12 by opening the lid 18.

After this loading, the lid 18 is closed and the inside of the process tube 12 is evacuated by using a vacuum exhaust system.
The processing gas and the reaction gas are supplied from the pipes 23 and 24, and the CVD processing is performed on the wafer. The treated gas is discharged from the sleeve 16 side. Further, the heat generated from the outer peripheral portion of the cartridge heater 14 during use is not affected by the outer casing 22.
It is cooled by the air introduced to the exhaust fan 21
And the exhaust fan 21 cools.

FIG. 5 is a sectional view showing a third example of a conventional heat treatment apparatus (here, an example of a vertical CVD apparatus is shown).

A plurality of wafers 8 stacked horizontally and vertically at regular intervals are fixed to a holder 25. A cylindrical inner tube 26 is arranged on the outer periphery of the wafer 8, and the lower portion thereof is fixed to the holder 17. An outer tube 27 is coaxially arranged on the outer side of the inner tube 26, and a lower end of the outer tube 27 is similarly fixed to the holder 17, but a part of the outer tube 27 is opened and connected to a vacuum exhaust system. Further, the outer tube 27 is closed at the upper part, and a space is provided between the outer tube 27 and the upper end of the inner tube 26. Therefore, the gas in the inner tube 26 can flow into the outer tube 27 as shown by the arrow in the figure, and can be further discharged from the opening at the lower end of the outer tube 27.

A cartridge heater 29 having a cylindrical shape (the lower end is open in this example) and having a heater 28 attached to the inner peripheral portion is provided so as to cover the outer tube 27. Further, pipes 30 and 31 for introducing two kinds of processing gases (for example, monosilane gas and phosphine gas) are arranged below the inner tube 26.

In this apparatus, when the wafer 8 is processed, the heater 28 is energized to heat the inside of the process tube 12. Then, the holder 2 is driven by a driving means (not shown).
5 is lowered, a predetermined number of wafers 8 are set on it, and then the holder 25 is raised to a fixed position. Further, the vacuum exhaust system is operated to evacuate the inside of the inner tube 26 (corresponding to the processing chamber), and then the two types of processing gases are introduced. The introduced gas undergoes necessary processing on the wafer 8 in the process of rising in the inner tube 26, and the processed gas is sent into the outer tube 27 and sent to the vacuum exhaust system.

Regarding this type of technology, for example,
There are JP-A-64-2324 and JP-A-61-195314.

[0016]

According to the study by the present inventor, in the conventional configuration shown in FIG. 3, the heat delay time is increased with respect to the processing gas having a large amount of gas and slow thermal reactivity. However, since the preheating chamber is controlled according to the temperature conditions of the main processing chamber, the preheating chamber is not heated at the required temperature.If the conditions of the main processing chamber are changed, the reaction conditions will be different. There is a problem in that the processing chamber needs to be rebuilt, the flexibility is poor, and the processing chamber is reduced by the space of the preheating chamber, so that the throughput is also reduced. Furthermore, the gas with fast reactivity undergoes a thermal reaction when passing through a part of the preheating chamber for a short time, but if the gas with slow reaction is monosilane, the reaction product is the inner wall of the pipe. On the wafer, or as a foreign substance on the wafer, or as a resistance to gas flow. Although foreign matter is generated in the main processing chamber, it is difficult to sufficiently clean the inside due to its structure, and the foreign matter is likely to adhere to the wafer.

On the other hand, in the CVD apparatus, as shown in FIGS. 4 and 5, since the processing chamber needs to be evacuated, the wafer loading / unloading port and the processing gas supply unit are on the same side. Therefore, it is not possible to provide the preheating chamber as shown in FIG. 3, and when a gas with a slow reaction and a gas with a fast reaction are used as the processing gas, a difference in thermal reactivity occurs and the film thickness uniformity is increased. ,
There is a problem that the uniformity of the dope concentration is deteriorated.

Therefore, an object of the present invention is to provide a technique capable of reducing the difference in thermal reactivity without reducing the space of the processing chamber and improving the throughput.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0020]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, a heat treatment apparatus for heating or treating an object to be processed by using the treatment gas introduced into the treatment chamber, wherein a gas treatment section for preheating the treatment gas or enhancing its reactivity is provided in the treatment chamber. It is arranged independently in the previous stage.

[0022]

According to the above-mentioned means, the slow-reactive gas is sent to the gas processing section for preliminary heating or processing, and is sent to the processing chamber in a state sufficient for starting the processing. Therefore, even when a plurality of processing gases are used, the processing gas having a slow reaction can be matched with the processing gas having a fast reaction, and the processing (processing) can be performed under the condition that the processing chamber is not affected.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a heat treatment apparatus according to the present invention, and FIG. 2 is a perspective view showing details of the preliminary reaction chamber shown in FIG. In addition, in FIG. 1, C having the same structure as in FIG.
Since the VD device is taken as an example and the same reference numerals are used for the same members as those used in FIG. 5, duplicate description will be omitted here.

As shown in FIG. 1, the present invention is characterized in that a preliminary reaction chamber 32 as a gas processing section is provided in the middle of a supply system for a gas that thermally reacts slowly. This preliminary reaction chamber 3
2, a chamber 35 for pre-reaction is provided inside a casing 34 having a hermetically sealed structure, and a pipe 33 for introducing a processing gas from a gas source through a connector 36a is provided at one end thereof. It is connected. Similarly, a connector 36b is connected to the other end of the chamber 35, and a pipe 30 is connected to the connector 36b. The connectors 36a and 36b are made of a material that does not exert a thermal influence on the pipes 33 and 30.

Quartz glass, for example, is suitable as the material of the chamber 35. Then, in order to prevent the ozone generated by the irradiation of the ultraviolet light from diffusing into the working atmosphere, and further to cool the reaction source 37, the chamber 3
A purge gas is blown around 5 as described later.

Furthermore, a reaction source 37 (in this example, an ultraviolet lamp, which has a wavelength of 10) for preliminarily reacting the gas in the chamber 35 is provided above the chamber 35.
A monitor 38 for monitoring the life of the reaction source 37, or for monitoring the decrease of the emission intensity, the decomposition spectrum of the gas, etc. is provided above the reaction source 37. Is installed. Further, pipes 39 and 40 for introducing and discharging the purge gas are attached to the side wall of the preliminary reaction chamber 32. These pipes are provided at target positions, and their outlets and inlets communicate with the space inside the preliminary reaction chamber 32.

In the above structure, during the CVD process, the wafer 8 is loaded, the vacuum is drawn, and the gas is supplied as described with reference to FIG. 5, but the process gas having a slow reaction is subjected to the heat treatment. Preliminary reaction chamber 3 before feeding to the equipment
It is sent to the second chamber 35, and the processing gas is reacted by the light emitted from the reaction source 37. The processing gas that has undergone the preliminary reaction is fed into the inner tube 26 via the connector 36b and the pipe 30.

Therefore, the gas state necessary for the reaction can be maintained without being affected by the processing chamber side, and the film thickness and the doping concentration can be made uniform. In addition, since the preliminary reaction chamber 32 is provided independently of the main body side, the space of the processing chamber is not reduced, and the throughput can be improved. Furthermore, by monitoring the gas spectrum of the preliminary reaction chamber 32, the state of the gas can be monitored, so that stable processing can be expected.

Further, since the frequency of contamination of the processing chamber can be reduced, the occurrence of defects due to foreign matter can be reduced, and higher quality processing can be performed. The piping from the preliminary reaction chamber 32 to the main processing chamber (the space inside the inner tube 26) does not need to be particularly considered.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above embodiment, the reaction source 3
Although an example using an ultraviolet lamp is shown as 7, other than this,
It can also be performed by a method of irradiating plasma, a method of irradiating laser light, or a heater (in the case of oxidation treatment, etc.). However, in the plasma system, it is necessary to provide a partition between the gas flow part and the electrode disposition part with a quartz tube or the like to provide a means for preventing foreign matter from entering from the electrode part.

Further, in the above embodiment, the vertical type CVD apparatus has been described as an example, but the horizontal type CVD apparatus as shown in FIG. 4 and further the oxidizing apparatus as shown in FIG. The present invention can be applied to a preheating chamber instead of the reaction chamber (however, in the example of FIG. 3, the partition plate 2 is removed from the drawing to make the space of the main processing chamber 6 larger). ). Also, although not shown, the present invention can be applied to lamp heating light intensity (processing one wafer), atmospheric pressure CVD equipment, and plasma CVD equipment.

Further, in the above embodiment, the processing gas is two kinds, but it is not limited to this and may be one kind or two or more kinds.

Further, in the above description, the case where the invention mainly made by the present inventor is applied to the processing of a wafer, which is the field of use of the invention, has been described, but the invention is not limited to this. The present invention can be applied to processing (processing) of elements, optical disks, disks (disks other than optical disks), and the like.

[0035]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

That is, a heat treatment apparatus for heating or treating a workpiece by using a treatment gas introduced into a treatment chamber, wherein a gas treatment section for preheating the treatment gas or enhancing its reactivity is provided in the treatment chamber. Since they are provided independently in the preceding stage, it is possible to make the film thickness uniform, the dope concentration uniform, the throughput improved, and the generation of foreign matter reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a heat treatment apparatus according to the present invention.

FIG. 2 is a perspective view showing details of a preliminary reaction chamber shown in FIG.

FIG. 3 is a sectional view showing an example of a conventional heat treatment apparatus.

FIG. 4 is a sectional view showing a second example of a conventional heat treatment apparatus.

FIG. 5 is a sectional view showing a third example of the conventional heat treatment apparatus.

[Explanation of symbols]

 1 Processing Room 2 Partition Plate 3 Preheating Room 4 Piping 5 Piping 6 Processing Room 7 Heater 8 Wafer 9 Holder 10 Lid 11, 19, O-ring 12, 13 Process Tube 14 Cartridge Heater 15 Soaking Tube 16, 17 Sleeve 18 Lid 20 Radiator 21 Exhaust fan 22 Outer casing 23, 24 Piping 25 Holder 26 Inner tube 27 Outer tube 28 Heater 29 Cartridge heater 30, 31 Piping 32 Preliminary reaction chamber 33, 39, 40 Piping 34 Housing 35 Chamber 36a, 36b Connector 37 Reaction source 38 monitors

Claims (7)

[Claims] 1. A heat treatment apparatus for heating or treating a workpiece by using a treatment gas introduced into a treatment chamber, wherein a gas treatment section for preheating the treatment gas or enhancing its reactivity is provided in the treatment chamber. A heat treatment device that is independently installed in the previous stage. 2. The heat treatment apparatus according to claim 1, wherein when there are a plurality of types of processing gas, only the gas having a slower thermal reaction is passed through the gas processing section. 3. The heat treatment apparatus according to claim 1, wherein the gas processing unit uses a heater as a heat source thereof. 4. The heat treatment apparatus according to claim 1, wherein the gas processing unit uses ultraviolet light, plasma, or laser light as a reaction source thereof. 5. The ultraviolet light has a wavelength of 100 to 40.
It is 0 nm, The heat processing apparatus of Claim 4 characterized by the above-mentioned. 6. The gas processing unit according to claim 4, wherein a monitor for monitoring the life of the reaction source, or for monitoring the decrease of light emission intensity, the decomposition spectrum of gas, and the like is installed in the gas processing unit. Heat treatment equipment. 7. The heat treatment apparatus according to claim 1, wherein the workpiece is a wafer.