JPH04280420A - Heat treatment device - Google Patents

Abstract

PURPOSE:To provide for a heat-treatment device which allows an extended part within a reaction pipe of a gas-introducing pipe feeding gas into the reaction pipe to be washed easily and achieves replacement to those with other configurations freely. CONSTITUTION:A gas-introducing pipe 12 is in a double-body configuration of a penetration part 12a which is mounting part to a reaction pipe 10 and an extended part 12b which is extended upward within the reaction pipe 10 and both can be mounted and removed. Further, the penetration part 12a in a complex shape is formed by a crystal (SiO2) which can be machined easily and the extended part 12b is formed by SiC with an improved heat resistance.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in heat treatment equipment.

0002

[Background Art] Conventionally, in the manufacturing process of semiconductor wafers, in order to perform various treatments such as CVD, oxidation, and diffusion on the semiconductor wafer, the object to be processed, such as the semiconductor wafer, is housed in a reaction tube and subjected to heat treatment. Heat treatment equipment is used.

FIG. 6 is a schematic diagram of an example of such a conventional vertical heat treatment apparatus.

In the figure, a reaction tube 10 is made of quartz SiO2
A gas introduction pipe 12 and a gas discharge pipe 14 are formed at the lower part of the gas introduction pipe 12, respectively. The gas introduction tube 12 is integrally formed in a substantially L-shape so as to communicate between the outside and the inside of the reaction tube 10, and is inserted through the gas introduction port 10a of the reaction tube 10 and fitted with, for example, an O-ring with a screw. , it is fixed airtight by tightening. The distal end of the gas introduction tube 12 extends to an upper position within the reaction tube 10 . On the other hand, the gas exhaust pipe 14 is connected to the reaction tube 10.
It is formed with a tube protruding from the lower part of the tube. Inside the reaction tube 10, semiconductor wafers 18 stacked on a boat 16 at predetermined intervals are housed. The boat 16 on which the semiconductor wafers 18 are installed is placed on a heat insulating cylinder 20. Further, the heat insulating tube 20 is moved up and down by an elevating mechanism 22 disposed below the heat insulating tube 20, and the semiconductor wafer can be stored in or taken out from the reaction tube 10 by this vertical movement. The reaction tube 10 is completely sealed when the heat insulating cylinder 20 is raised by the elevating mechanism 22 and the semiconductor wafer 18 is completely accommodated in the reaction tube 10.

[0005] Furthermore, a heating means 27 consisting of a heating element 24 and a heat insulating material 26 is arranged in an external region of the reaction tube 10. The heating element 24 is attached to the inner circumferential wall of the heat insulating material 26.

With this configuration, a process gas is introduced into the reaction tube 10 from the gas introduction tube 12, and the temperature inside the reaction tube 10 is raised to a predetermined temperature (
For example, it is heated to 1200°C). The semiconductor wafer 18 is subjected to heat treatment by reaction of process gas under heating.

FIGS. 7 and 8 show other configuration examples of the gas introduction tube 12, and each shows a longitudinal cross-sectional view of the reaction tube 10 at a portion where the gas introduction tube 12 is attached.

The gas introduction tube 12 shown in FIG. 7 is formed integrally with the reaction tube 10, and is configured such that a part of the outer circumferential wall of the reaction tube 10 serves as the gas introduction tube portion. On the other hand, the gas introduction tube shown in FIG. 8 is also formed integrally with the side wall of the reaction tube 10. A characteristic feature of the gas introduction pipe of this example is that a plurality of gas delivery openings 13 are formed in the side wall of the gas introduction pipe 12 in the vertical direction. That is, the gas introduction tube 12 in FIG. 7 delivers gas from approximately the top of the reaction tube 10, and fills the reaction tube 10 with gas from above to below. In the gas introduction tube 12 in FIG. 8, gas is delivered from a plurality of gas delivery openings 13 formed in the vertical direction, and the gas is delivered almost evenly at vertical positions of the reaction tube 10. It has characteristics.

Furthermore, with the gas introduction tube 12 integrally formed with these two reaction tubes 10, there is no need for a separate assembly process of attaching the gas introduction tube 12 to the reaction tube 10.

0010

[Problems to be Solved by the Invention] In an apparatus that performs a heat treatment process by introducing a process gas into the reaction tube 10, there is a risk that various reaction products may adhere to and become dirty on each component part of the apparatus due to reactions during the heat treatment. be. In particular, reaction products tend to adhere to the gas introduction pipe, and cleaning must be performed to remove this adherent in order to always perform a good heat treatment.

However, the gas introduction pipe 12 in the heat treatment apparatus shown in FIG. 6 is formed entirely in one piece.
In addition, the portion penetrating the reaction tube 10 is fixedly attached to ensure airtightness. Further, the gas introduction tube 12 shown in FIGS. 7 and 8 is also formed completely integrally with the reaction tube 10. Therefore, when cleaning these reaction tubes 12, it is not possible to remove and clean only the gas introduction tube 12, but it is necessary to remove the entire reaction tube 10 and clean the gas introduction tube 12. Therefore, there is a problem in that the work is not easy and it is difficult to completely remove the deposits.

Furthermore, with conventional gas introduction tubes, it is difficult to make various changes to the piping inside the reaction tube 10 to correspond to various processes. In the case of a gas introduction pipe 12 having 13 openings 13, it was not possible to change the number or diameter of the openings 13. This kind of problem occurs not only in vertical heat treatment apparatuses but also in horizontal heat treatment apparatuses.

The present invention was made to solve the above problem, and its purpose is to facilitate cleaning of deposits on a gas introduction tube for introducing gas into a reaction tube of a heat treatment apparatus. , and respond appropriately to various processes,
It is an object of the present invention to provide a heat treatment apparatus in which piping within a reaction tube can be changed in various ways.

[0014]

[Means for Solving the Problems] In order to achieve the above object, the invention of claim 1 provides a reaction tube for heat-treating an object to be treated;
In the heat treatment apparatus, the gas introduction tube includes a gas introduction tube that penetrates into the reaction tube from outside the reaction tube and sends a process gas into the reaction tube, and the gas introduction tube includes a penetration part that penetrates a lower side wall of the reaction tube. and a reaction tube internal extension part that is detachably attached to the tip of the penetration part that protrudes a predetermined length into the reaction tube, and extends to an upper position of the reaction tube in the attached state.

[0015] Further, in the invention according to claim 2, the penetrating portion of the gas introduction tube is formed of quartz, and the inner extension portion of the reaction tube is made of Si.
It is characterized by being formed of C.

[0016]

[Operation] According to the heat treatment apparatus having the above structure, the gas introduction pipe for feeding gas into the reaction tube is composed of two parts: a through part and an extension part inside the reactor. The in-reactor extension part is removably attached to the tip of the penetrating part in the reactor,
It is possible to remove only the reaction tube inner extension from the reaction tube 10.

Therefore, other members such as objects to be processed can be taken out from inside the reaction tube 10, and furthermore, the extension portion of the gas introduction tube inside the reaction tube can be easily removed. Thereby, it is possible to easily remove reaction products that adhered to the gas introduction pipe during the reaction, and complete cleaning can be achieved.

[0018] Furthermore, since the reaction tube inner extension portion can be easily replaced, it is also possible to variously change the configuration of the portion extending into the reaction tube. For example, when a gas delivery opening is formed in the side wall of an extension of a gas introduction pipe, the configuration of the opening can be changed in various ways depending on the process.

Furthermore, by configuring the gas introduction tube as two pieces, the penetrating portion and the inner extension portion of the reaction tube can be made of different materials, as in the second aspect of the invention. That is, by configuring the penetrating portion with quartz and the reaction tube inner extension portion with SiC, it is possible to improve the heat treatment function.

[0020] That is, by forming the extension part inside the reaction tube located near the object to be processed from SiC, SiC has superior heat resistance compared to quartz (SiO2),
Quartz (SiO2
), there is no risk of deformation or the like compared to the case where the reaction tube internal extension section is configured, and the reliability of the apparatus is improved.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a vertical heat treatment apparatus for performing a diffusion process on a semiconductor wafer is used as an example.

FIG. 1 is a schematic sectional view showing the overall structure of a heat treatment apparatus according to an embodiment, and the same elements as those of the conventional apparatus shown in FIG. 6 are given the same reference numerals.

In this embodiment, the gas introduction tube 12 has a penetration portion 12a that is a portion that penetrates the lower side wall of the reaction tube 10, and an extension portion 12 that extends upward inside the reaction tube 10.
It is said to have a two-body structure of b. These parts 12a and 12
The connection b is made by simply placing the extension portion 12b over the tip of the penetrating portion 12a by rubbing. That is, even if there is some leakage at the joint between the two, since the joint is inside the reaction tube 10, there will be no trouble at all due to impaired sealing.

[0024] The gas introduction pipe 12 constructed of these two bodies is made of materials such that the extension portion 12b is made of SiC, and the mounting portion 12a is made of quartz (SiO2).

The uppermost end of the extended portion 12b of the gas introduction pipe 12 passes through the buffer plate 30. This buffer board 30
is horizontally installed slightly below the ceiling of the reaction tube 10, and its planar shape is as shown in FIG. 3, with a plurality of openings 32 formed therein. That is, the process gas introduced from the gas introduction pipe 12 is introduced between the buffer plate 30 and the ceiling of the reaction tube 10. Here, the process gas enters downward through the opening 32 of the buffer plate 30, is dispersed, and fills the reaction tube 10.

Furthermore, in this embodiment, the reaction tube 10 is formed from two components: a first component 10a on the upper side and a second component 10b on the lower side. Similarly to the gas introduction pipe 12, the first component 10a is made of SiC,
The second constituent parts 10b are each made of quartz (SiO2). The first component is an outer region that surrounds the storage portion in which the semiconductor wafer 18 is stored.

Furthermore, the gas introduction pipe 12 and the gas discharge pipe 14
are attached to the second component 10b of the reaction tube 10, respectively, and FIG. 2 is an explanatory diagram showing their attachment positions. As shown in the figure, a gas exhaust pipe 14 is provided at an angle of approximately 90 degrees to the gas introduction pipe 12, and communicates the inside and outside of the reaction tube 10, respectively.

Note that the schematic cross-sectional view in FIG. 1 is for convenience of explanation.
The gas introduction pipe 12 is shown shifted by approximately 90 degrees.

Next, the first component 10a and the second component of the reaction tube are
The configuration of the joint portion of the component 10b will be explained.

As shown in FIG.
A groove 34 is formed at the joint between a and 10b. This groove 34 is formed by forming a continuous recess on the joint surface of the second component 10b with the first component 10a. Then, the seal exhaust pipe 3
6 is drawn out.

The installed state of this seal exhaust pipe 36 is shown in FIG.
is shown. FIG. 4 is a partially cutaway horizontal cross-sectional view showing the installed state of the seal exhaust pipe, in which the communication port 36a of the seal exhaust pipe 36 communicates with the groove 34.

Furthermore, in this embodiment, at the junction between the lid part 38 (see FIG. 1) on which the heat-insulating cylinder 20 is placed and the second component 10b of the reaction tube joined to this lid part, Seal exhaust means are formed. That is, a groove 40 is formed in the lower joint surface of the second component 10b, and the groove 40 is closed by joining with the lid part 38, and the seal exhaust pipe 42 is pulled out from this groove 40. It is connected to an exhaust device (not shown) and is constantly exhausted. Note that in FIG. 1, the seal exhaust pipe 42 is shown, and the seal exhaust pipe 36 is not shown because it is located behind the seal exhaust pipe 42.

As described above, in this embodiment, the grooves 34 and 40 are formed at both the upper and lower joints of the second component 10b of the reaction tube, and from each groove 34 and 40, as shown in FIG. Seal exhaust pipes 36 and 42 have been withdrawn as shown. In the figure, a communication port 42a of the seal exhaust pipe 42 communicates with the groove 40.

One of the actions to ensure airtightness by seal exhaust is to eliminate gaps by suctioning the upper and lower members.
Another method is to exhaust the wet gas from the joint together to prevent it from leaking to the outside.

According to the heat treatment apparatus having the above structure, since the gas introduction tube 12 is constructed in two pieces, the extension portion 12b inside the reaction tube can be easily removed during cleaning or the like. This removal and cleaning makes it possible to easily remove stains caused by reaction products adhering to the gas introduction pipe. Furthermore, it is also possible to remove the extension part 12b and replace it with an extension part of another configuration. Therefore, unlike the current structure shown in FIG. 1 in which no opening is provided in the middle part and the upper end thereof passes through the buffer plate, a plurality of gas delivery openings as shown in FIG. It is possible to replace the gas introduction pipe 12 with a configuration in which a plurality of gas introduction pipes 13 are provided. In the case of such a gas introduction tube, the buffer plate 30 for uniformly dispersing the process gas from above is unnecessary, and the tip of the gas introduction tube 12 is held by a holding part 31. Note that this extension part 12b can be replaced by using extension parts 12b of various configurations to suit each process by configuring its lower end so that it is attached to the tip of the penetrating part 12a by rubbing. It is possible.

Further, according to this embodiment, the first component 10a of the reaction tube and the extension portion 1 of the gas introduction tube, which are the portions surrounding the area in which the semiconductor wafer 18 as the object to be processed is housed,
Since 0b is formed of SiC, when heating by the heating means 27 starts, the first component 10a and the extension part 10b quickly reach a high temperature due to their high thermal conductivity, and the whole is in a uniformly heated state. becomes. As a result, the heating effect on each semiconductor wafer 18 becomes substantially uniform, making it possible to perform uniform heat treatment.

Furthermore, since SiC has little deformability even under high temperature conditions, there is no risk of problems due to thermal deformation of the reaction tube 10 and the gas introduction tube.

Furthermore, the second component 10b is equipped with a gas introduction pipe penetration part 12a and a gas exhaust pipe 14, and in this embodiment seal exhaust pipes 36 and 42 are also installed. It has a complex structure. However, the penetrating portion 12a and the second component 10
Since b is made of quartz (SiO2), its workability is relatively good, and there is no fear that the machining work for both will be difficult.

Furthermore, the first component 10a and the second component 1
The state of connection with 0b is determined by the groove 34 formed at the joint between the two.
By evacuation using the sealed exhaust pipe 36, airtightness can be ensured. Furthermore, in this embodiment, a groove 40 and a seal exhaust pipe 42 are also provided at the joint between the second component 10b and the lid 38, which is the bottom thereof. Therefore, by performing evacuation using this seal exhaust pipe 42, complete airtightness is ensured on the lower side of the second component 10b. This not only makes it possible to prevent deterioration of airtightness due to the formation of two reaction tubes 10, but also makes it possible to ensure higher airtightness than before in the entire apparatus.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the gist of the present invention. For example, the present invention is not limited to a vertical heat treatment apparatus, but can also be applied to a horizontal heat treatment apparatus.

[0041]

[Effects of the Invention] As explained above, according to the heat treatment apparatus according to the present invention, the extension part of the gas introduction pipe extending inside the reaction tube can be easily attached and detached, so that the extension part can be cleaned more easily. Moreover, it is possible to completely carry out the reaction process, and the extension part can be replaced with one of various configurations, making it possible to perform piping of the gas introduction pipe that corresponds precisely to the reaction process.

Furthermore, by using SiC and quartz (SiO2) as the materials for the extended portion and the penetrating portion of the gas introduction pipe, it is possible to ensure thermal uniformity in the heated portion of the object to be processed.

[0043] Thereby, the reliability of the function of the heat treatment apparatus and the prevention of failure can be effectively achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing the overall configuration of an embodiment.

FIG. 2 is an explanatory diagram showing the installation state of a gas introduction pipe and a gas discharge pipe in the embodiment.

FIG. 3 is a plan view of the buffer plate of the embodiment.

FIG. 4 is a partially cutaway sectional view showing the installed state of the seal exhaust pipe of the embodiment.

FIG. 5 is a partial schematic sectional view showing another example of the configuration of the gas introduction pipe extension used in the example.

FIG. 6 is a schematic cross-sectional view showing an example of a conventional heat treatment apparatus.

FIG. 7 is an explanatory diagram showing another conventional configuration example of a reaction tube and a gas introduction tube.

FIG. 8 is an explanatory diagram showing another conventional configuration example of a reaction tube and a gas introduction tube.

[Explanation of symbols]

10 Reaction tube 10a First component 10b Second component 12 Gas introduction tube 12a Penetrating portion 12b Extension portion 13 Gas delivery opening 14 Gas discharge tube 16 Boat 18 Semiconductor wafer 20 Heat insulating tube 22 Lifting mechanism 24 Heating element 26 Heat insulating material 30 Buffer plate 34, 40 Groove 36, 42 Seal exhaust pipe
TE033101

Claims (2)

[Claims] 1. A heat treatment apparatus comprising a reaction tube for heat-treating an object to be treated, and a gas introduction tube provided to penetrate into the reaction tube from outside the reaction tube and feed a process gas into the reaction tube, wherein the gas introduction tube is removably attached to a penetrating portion penetrating the lower side wall of the reaction tube and a tip of the penetrating portion protruding a predetermined length into the reaction tube, and extends to an upper position of the reaction tube in the attached state. A heat treatment device comprising: an inner tube extension portion; 2. The heat treatment apparatus according to claim 1, wherein the penetrating portion of the gas introduction tube is made of quartz, and the inner extension portion of the reaction tube is made of SiC.