JPH09306857A - Vertical heat treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability by preventing a lid and a turn table from corrosion with a treating gas. SOLUTION: An apparatus comprises a vertical reaction tube 1 for heat treating wafers W mounted on a boat 2 inserted into the tube from below with a specified treating gas at a high temp., a lid 12 for closing the opening of the tube 1, and a turn table 14 disposed at the lid 12 for rotating the boat 2. The lid 12 and the turn table 14 are made of another heat- and corrosion- resistive material and a seal member 17 is settled in a lower part of an axial hole 16 of the lid 12 which a rotary shaft 15 of the turn table 14 pierces.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vertical heat treatment apparatus.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, oxidation, diffusion, CV
Various heat treatment apparatuses are used to perform treatments such as D and annealing. A vertical heat treatment apparatus, which is a typical heat treatment apparatus thereof, has a vertical reaction tube into which a boat loaded with the above-mentioned wafer is loaded from below, and the above reaction is performed by raising a lid on which the boat is placed. The boat is loaded into the tube, the lower end opening of the reaction tube is closed with a lid, and the surface to be processed of the wafer is subjected to heat treatment such as film formation under a predetermined process gas atmosphere and high temperature. .

Further, in order to make the heat treatment on the surface to be processed of the wafer uniform within the surface, the lid is provided with a rotary table for mounting and rotating the boat. In general, the lid and the turntable are formed of a metal material having heat resistance and corrosion resistance, such as stainless steel.

[0004]

However, in the above-mentioned vertical heat treatment apparatus, when a corrosive gas such as chlorine gas is used as the processing gas, the lid and the rotary table are made of stainless steel. Even if it is formed, there is a possibility that the portion that comes into direct contact with the processing gas may be corroded. In addition, since the lid and the rotary table are made of metal and have high thermal conductivity, a cooling water passage is provided around the bearing and the like in order to prevent thermal influence on the seal portion and the bearing of the rotary table, for example. However, if the above processing gas becomes highly corrosive due to dew condensation due to overcooling, bearings will corrode and rotation of the rotary table will become difficult, resulting in reduced durability. To be forced.

The present invention has been made to solve the above problems, and an object thereof is to provide a vertical heat treatment apparatus capable of improving the durability by preventing corrosion of a lid, a rotary table and the like due to a processing gas. is there.

[0006]

In order to achieve the above object, in the vertical heat treatment apparatus according to the first aspect of the present invention, a boat loaded with a substrate to be processed is loaded from below and a predetermined process gas is supplied. And a vertical reaction tube that heat-treats the substrate to be processed at high temperature, a lid that opens and closes the open end of the reaction tube, and a rotary table that is provided on the lid and that rotates the boat. The body and the rotary table are formed of a heat-resistant and corrosion-resistant material other than metal, and a seal member is provided below the shaft hole of the lid body through which the rotary shaft portion of the rotary table penetrates.

According to the second aspect of the present invention, there is provided a vertical heat treatment apparatus in which a boat loaded with a substrate to be processed is loaded from below and a vertical reaction tube for heat-treating the substrate to be processed under a predetermined processing gas and high temperature is provided. A lid for opening and closing the open end of the reaction tube, and a rotary table provided on the lid for rotating the boat, the lid and the rotary table being formed of a heat-resistant and corrosion-resistant material other than metal, and A seal member is provided below the shaft hole of the lid body through which the rotary shaft portion of the rotary table penetrates, and a support having a bearing and a rotation mechanism of the rotary shaft portion is provided below the lid body.

A vertical heat treatment apparatus according to a third aspect of the present invention is characterized in that it has an inert gas supply section for supplying an inert gas to the gap between the rotary table and the lid.

A vertical heat treatment apparatus according to a fourth aspect is characterized in that a heat shield plate is provided below the lid body.

A vertical heat treatment apparatus according to a fifth aspect of the present invention is characterized in that a radiation fin is provided around the seal member in the lid.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the present invention is applied to a vertical heat treatment apparatus suitable for oxidation diffusion treatment will be described in detail below with reference to the accompanying drawings.

In FIG. 1 showing the main part of a vertical heat treatment apparatus, reference numeral 1 denotes a quartz reaction tube (process tube) which is a vertical processing container having an upper end closed and an open lower end. A quartz boat (also referred to as a substrate holder or a wafer boat) 2 in which a large number of, for example, about 150 substrates to be processed, for example, semiconductor wafers W, are loaded in a multi-stage manner at a predetermined pitch in the height direction, is a quartz heat insulating tube 3. Along with that, it is designed to be loaded from below. An outward flange portion 4 is formed at the open end of the reaction tube 1, and the flange portion 4
Are detachably held by the base plate 5 via the manifold 6.

Below the side wall of the reaction tube 1, a plurality of gas introduction tubes 7 for introducing a reaction gas, an inert gas or the like into the upper portion of the reaction tube are provided, and an exhaust tube 8 for exhausting the inside of the reaction tube 1 is provided. It is provided. Above the base plate 5, there is provided a heater 9 composed of, for example, a heating resistor formed in a spiral shape so as to surround the reaction tube 1, and the inside of the reaction tube 1 in the furnace is desired by the heater 9. It is designed to be heated to a temperature of, for example, 700 to 1200 ° C.

The outside of the heater 9 is covered with a heat insulating material 10, and the outside of the heat insulating material 10 is covered with a water cooling jacket (not shown). Between the reaction tube 1 and the heater 9, for example, alumina (Al ₂ O ₃ ) or silicon carbide (SiC) is used to prevent heavy metal contamination from the heater 9 to the wafer W and to make heating uniform. A soaking tube 11 is provided.

A lid 12 for opening and closing the open end of the reaction tube 1 is provided below the reaction tube 1 so as to be able to move up and down through an elevating arm 13 of an elevating mechanism which is a loading mechanism. A rotary table 14 is provided on which the boat 2 is placed and rotated via the heat retaining cylinder 3. Especially,
The lid 12 and the rotary table 14 are made of a heat-resistant and corrosion-resistant material other than metal, such as quartz.

A rotary shaft portion 15 is integrally formed at the center of the bottom of the rotary table 14, and a shaft hole 16 is formed in the lid body 12 through which the rotary shaft portion 15 loosely penetrates. A seal member 17 is provided below the shaft hole 16 to seal the space between the shaft hole 16 and the rotary shaft portion 15.
In this case, a cylindrical boss portion 18 surrounding the rotary shaft portion 15 is integrally formed on the bottom portion of the lid body 12, and the seal member 17 is provided below the shaft hole 16 in the boss portion 18. ing.

Since the lid 12 and the rotary table 14 are made of quartz and have a lower thermal conductivity than metal, and the seal member 17 is arranged at a position distant from the inside of the furnace, the seal member 17 is affected by heat. Making it difficult. The seal member 17 may be a heat-resistant and corrosion-resistant material having elasticity, for example, an O-ring made of Teflon, but preferably a heat-corrosion-resistant radial seal in which an annular spring having a U-shaped cross section is covered with a Teflon cover.

Between the flange 4 of the reaction tube 1 and the lid 12, an inert gas such as nitrogen having a predetermined temperature, for example, room temperature (about 20 ° C.) is introduced into the gap S between the lid 12 and the rotary table 14. An inert gas supply unit 19 that supplies and blows (N ₂ ) gas is provided, which cools the seal member 17 and allows the processing gas to flow from the gap S through the seal member 1.
It prevents it from going around to the 7 side. Further, by blowing the inert gas, the contact surface between the flange portion 4 of the reaction tube 1 and the lid 12 is sealed to prevent leakage of the processing gas, and dust generated from the seal member 17 is generated. Prevents entry into the furnace. The inert gas supply unit 19 communicates with the supply pipe 21 that supplies the inert gas to the supply hole 20 formed in the flange portion 4 of the reaction tube 1 and the supply hole 20 on the upper surface of the lid 12. Supply groove 22 formed in an annular shape along the peripheral edge of the rotary table 14.
It is mainly composed of

As shown in FIGS. 2 to 3, the lid 12 has a lower peripheral edge portion mounted on a stainless steel support ring 23, and is attached and detached by a clamp member 24 disposed at an appropriate interval on the peripheral edge portion. Installed as possible. The support ring 23 is a horizontal support 25 made of stainless steel.
Is elastically supported in a horizontal state via a plurality of springs 26 and guide rods 27, etc., which are arranged at three points above, and the bottom of the support 25 has the tip of the lifting mechanism bifurcated. An arm 13 is attached.

On the support 25, the rotary table 1 is attached.
The bearing 28 of the rotating shaft part 15 of No. 4 is provided, and the rotating mechanism 29 is provided. In particular,
A rotary shaft 3 made of stainless steel is attached to an end of the rotary shaft 15 of the rotary table 14 through a joint 30 made of stainless steel.
1 is detachably connected so that the rotary table 14 can be separated from the rotary shaft 31 and disassembled for cleaning or the like. The joint 30 has a fitting shaft 33 fitted in a central hole 32 formed downward in the rotary shaft portion 15, and an engaging convex portion 34 attached to the lower end of the rotary shaft portion 15,
It is mainly composed of an engaging concave portion 35 which is formed on the upper end of the rotary shaft 31 so as to engage with the engaging convex portion 34. The bearing 28 rotatably supports the rotary shaft 31, and a shaft hole 36 for heat radiation is formed in the rotary shaft 31 so as to open downward.

A support plate 37 is provided under the support body 25, and an electric motor 38 constituting a rotating mechanism 29 is attached to the support plate 37. Pulleys 39 and 40 are attached to the rotary shaft of the motor 38 and the rotary shaft 31 of the rotary table 14, and a belt 41 is wound around the pulleys 39 and 40. With the rotation mechanism 29 configured in this way, the rotary table 14 is rotated at a predetermined rotation speed, for example, 2 rotations per minute.

In order to prevent thermal influences on the bearing 28 and the rotating mechanism 29 due to light or heat rays from the inside of the furnace which penetrates the lid 12 and the rotary table 14, the lower portion of the lid 12 is made of stainless steel. A heat shield plate 42 is provided. The heat shield plate 42 is formed in an annular shape so as to be positioned in an annular space between the boss portion 18 of the lid 12 and the support ring 23, and an inward flange formed at the lower end of the support ring 23. It is horizontally attached above the portion 43 via a plurality of support pins 44. In addition, the motor 38
A stainless steel cover 45 is also attached to the periphery of the.

Further, the seal member 1 in the lid 12 is
Radiating fins 46 are provided around the periphery of 7, i.e., the boss portion 18 to cool the seal member 17. As shown in FIG. 4, this heat radiation fin 46 has a plurality of collar-shaped fins 48 formed around a mounting ring member 47 made of, for example, stainless steel, which is mounted on the outer periphery of the boss portion 18 by screwing. The fins 48 are provided with vertical grooves 49 for improving air permeability.

A scavenger (not shown) for exhausting the atmosphere around the furnace opening to the outside is provided below the reaction tube 1 to improve the flowability of the air flow to the heat radiation fins 46. To this end, the support ring 23 is provided with ventilation holes 50 penetrating in the radial direction at appropriate intervals in the circumferential direction, and the support plate 37 of the motor 38 is also provided.
Also, a ventilation hole 51 is provided.

Next, the operation of the vertical heat treatment apparatus configured as described above will be described. Lifting arm 13 of lifting mechanism
The lid 12 lowered downward from the open end of the reaction tube 1 by
When the boat 2 loaded with the wafers W is placed on the rotary table 14 via the heat insulation cylinder 3, the lid 12 is lifted and the boat 2 is moved downward together with the heat insulation cylinder 3 into the reaction tube 1. And the lid 12 abuts on the open end of the reaction tube 1 to close the open end. In this state, the wafer W in the reaction tube 1 is heated to a predetermined temperature by the heater 9, and the inside of the reaction tube 1 is exhausted through the exhaust pipe 8 while the reaction tube 1 is exhausted through the gas introduction pipe 7 to a predetermined temperature. By introducing the processing gas of, the target surface of the wafer W is subjected to a predetermined heat treatment.

In this heat treatment step, the rotary table 14 is rotated by the rotary mechanism 29, and the rotary table 14 and the lid body are fed from the inert gas supply section 19 between the flange portion 4 of the reaction tube 1 and the lid body 12. Inert gas, for example, nitrogen gas, is blown into the gap S between 12 and. Motor 3
8 through the ventilation holes 51 of the support plate 37, between the support 25 and the support ring 23, or through the ventilation holes 50 of the support ring 23, and the like. Cooling of various members is performed.

When the heat treatment is completed, the inside of the reaction tube 1 is once purged with an inert gas, and then the rotary table 14 is used.
And the supply of the inert gas from the inert gas supply unit 19 are stopped, the lid 12 is lowered, and the boat 2 is carried out from the reaction tube 1.

As described above, according to the vertical heat treatment apparatus,
Since the lid 12 and the rotary table 14 are made of a heat-resistant and corrosion-resistant material other than metal, such as quartz, it is possible to prevent the lid 12 and the rotary table 14 from being corroded by the processing gas. Further, since the seal member 17 is provided below the shaft hole 16 of the lid body 12 through which the rotary shaft portion 15 of the rotary table 14 penetrates, the lid body 12 on the fixed side and the rotary table 14 on the rotary side. It is possible to seal the space between them, prevent the processing gas from leaking out, and the lid 12 and the rotary table 14 are made of quartz to have a lower thermal conductivity than metal, and the sealing member 17 can be kept away from the furnace as much as possible. The influence of heat from the inside can be reduced and its durability can be improved.

A clearance S between the rotary table 14 and the lid 12 is provided between the flange 4 of the reaction tube 1 and the lid 12.
Since the inert gas supply unit 19 that supplies the inert gas to the space S is provided, the sealing member 17 can be cooled by blowing the inert gas into the space S, and the processing gas can be supplied from the space S. It is possible to prevent the seal member 17 from wrapping around. Moreover, by blowing the inert gas, the contact surface between the flange portion 4 of the reaction tube 1 and the lid 12 can be sealed to prevent the processing gas from leaking, and at the same time, it is possible to prevent the processing gas from being generated. It is also possible to prevent some refuse from entering the furnace.

Since the radiation fins 46 are provided around the seal member 17 in the lid 12, the seal member 17 can be appropriately cooled without providing a cooling water passage, and the processing gas due to overcooling can be removed. Condensation does not occur, and thus the durability of the seal member 17 can be further improved. Further, since the support 25 is provided below the lid 12, and the bearing 28 and the rotation mechanism 29 of the rotary shaft portion 15 are provided on the support 25, the bearing 28 is not directly exposed to the processing gas. Therefore, the durability of the bearing 28 can be improved.

A rotary shaft 31 is connected to the end of the rotary shaft portion 15 of the rotary table 14 through a joint 30, and the rotary shaft 31 is supported by the bearing 28. Therefore, the rotary table 14 can be easily separated from the lid 12 and the rotary shaft 31 for disassembly.
Further, since the heat shield plate 42 is provided in the lower portion of the lid body 12, it is possible to prevent the heat influence from the inside of the furnace on the bearing 28 and the rotating mechanism 29, and the durability of these is further improved. Can be improved.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the above embodiments, and various design changes and the like without departing from the gist of the present invention. Is possible. For example, the radiation fin 46
As a result, the fins 48 may be provided vertically instead of horizontally to improve air permeability. Further, instead of the heat radiation fin 46, the boss portion 18 may be water-cooled.
Further, as the vertical heat treatment apparatus to which the present invention is applied, it is possible to perform processing such as CVD and annealing in addition to oxidation diffusion. The substrate to be processed may be, for example, an LCD substrate or the like.

[0033]

In summary, according to the present invention, the following excellent effects can be obtained.

(1) According to the vertical heat treatment apparatus of the first aspect, the boat loaded with the substrate to be processed is loaded from below to perform heat treatment on the substrate to be processed under processing gas and high temperature. The reactor includes a reaction tube, a lid that opens and closes an open end of the reaction tube, and a rotary table that is provided on the lid and that rotates the boat. The lid and the rotary table are formed of a heat-resistant and corrosion-resistant material other than metal. At the same time, since the seal member is provided below the shaft hole of the lid body through which the rotary shaft portion of the rotary table penetrates, it is possible to prevent the lid body, the rotary table, and the like from being corroded by the processing gas, and the seal member furnace The influence of heat from the inside can be reduced, and the durability of the lid and its peripheral devices (including the rotary table and its rotating mechanism) can be improved.

(2) According to the vertical heat treatment apparatus of the second aspect, the boat in which the substrate to be processed is loaded is inserted from below to perform the heat treatment on the substrate to be processed under the processing gas and the high temperature. The reactor includes a reaction tube, a lid that opens and closes an open end of the reaction tube, and a rotary table that is provided on the lid and that rotates the boat. The lid and the rotary table are formed of a heat-resistant and corrosion-resistant material other than metal. Along with this, a seal member is provided below the shaft hole of the lid body through which the rotary shaft portion of the rotary table penetrates, and a support having a bearing and a rotation mechanism of the rotary shaft portion is provided below the lid body. It is possible to prevent corrosion of the lid and the rotary table, etc. due to gas, reduce the heat effect from the inside of the furnace of the sealing member, and further, to prevent the bearing from being directly exposed to the processing gas. Yo It is possible to improve the durability of the peripheral devices.

(3) According to the vertical heat treatment apparatus of the third aspect, since the inert gas supply unit for supplying the inert gas to the gap between the rotary table and the lid is provided, the vertical heat treatment apparatus is connected to the gap. It is possible to cool the seal member by blowing the inert gas and to prevent the processing gas from flowing into the seal member side from the gap.

(4) According to the vertical heat treatment apparatus of the fourth aspect, the heat shield plate is provided in the lower portion of the lid, so that the bearing and the rotating mechanism are prevented from being affected by heat from the inside of the furnace. Therefore, it is possible to further improve the durability.

(5) According to the vertical heat treatment apparatus of the fifth aspect, since the radiation fins are provided around the seal member in the lid, the seal member is appropriately cooled without providing a cooling water passage. This makes it possible to prevent dew condensation of the processing gas due to supercooling, thereby further improving the durability of the seal member.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts of a vertical heat treatment apparatus showing an embodiment of the present invention.

FIG. 2 is a bottom view of the lid body in FIG. 1 seen from below.

FIG. 3 is a side view of a lid body.

FIG. 4 is a plan view of a radiation fin.

[Explanation of symbols]

 1 Reaction Tube W Semiconductor Wafer (Substrate to be Processed) 2 Boat 12 Lid 14 Rotating Table 15 Rotating Shaft 16 Shaft Hole 17 Sealing Member 19 Inert Gas Supply 25 Support 28 Bearing 29 Rotating Mechanism 31 Rotating Shaft 42 Heat Shield 46 Radiating fin

Claims (5)

[Claims] 1. A vertical reaction tube in which a boat loaded with a substrate to be processed is loaded from below and heat-treats the substrate to be processed under a predetermined processing gas and high temperature, and an opening end of the reaction tube is opened and closed. And a rotary table provided on the lid for rotating the boat, and the lid and the rotary table are formed of a heat-resistant and corrosion-resistant material other than metal,
A vertical heat treatment apparatus characterized in that a seal member is provided below a shaft hole of a lid body through which a rotary shaft portion of the rotary table penetrates. 2. A vertical reaction tube in which a boat loaded with a substrate to be processed is loaded from below and heat-treats the substrate to be processed under a predetermined processing gas and high temperature, and an opening end of the reaction tube is opened and closed. And a rotary table provided on the lid for rotating the boat, and the lid and the rotary table are formed of a heat-resistant and corrosion-resistant material other than metal,
A vertical member characterized in that a seal member is provided below an inside of a shaft hole of a lid body through which a rotary shaft portion of the rotary table penetrates, and a support having a bearing and a rotation mechanism of the rotary shaft portion is provided below the lid body. Mold heat treatment equipment. 3. The vertical heat treatment apparatus according to claim 1, further comprising an inert gas supply section for supplying an inert gas to a gap between the rotary table and the lid. 4. The vertical heat treatment apparatus according to claim 1, further comprising a heat shield plate under the lid. 5. The heat dissipating fin is provided around the seal member of the lid,
The vertical heat treatment apparatus according to 3 or 4.