JP3250843B2 - Semiconductor manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical diffusion / CVD apparatus.
Throat portion temperature system etc. semiconductor manufacturing apparatus in which your to concerns.

[0002]

2. Description of the Related Art As one of semiconductor manufacturing apparatuses, there is a vertical diffusion apparatus. As shown in FIG. 3, a heater 2 surrounds a standing reaction tube 1 made of quartz, and the inside of the reaction tube 1 is heated and maintained at a predetermined temperature. And reactant gas is passed therethrough to perform wafer surface treatment.

[0003] In FIG. 3, reference numeral 4 denotes a heat equalizing tube for making the temperature distribution inside the reaction tube 1 uniform, and a reaction gas supply tube 5 communicating with an upper portion of the reaction tube 1 is provided to the reaction tube 1. Is supplied and discharged from a discharge pipe 6 communicating with a lower part of the reaction tube 1.

The wafer 3 is loaded into the reaction tube 1 in a state of being held in multiple stages by a boat 7, and the boat 7 is loaded with a cap 8 placed in a furnace port of the reaction tube 1.
And a flange 9 formed at a lower end of the cap 8 abuts a furnace port flange 10 formed at a lower end of the reaction tube 1 in a gas-tight manner to block the reaction tube 1 in a gas-tight manner. .

Referring to FIG. 4, details of the furnace port will be described.

The reaction tube 1 is supported by a casing 11 of the apparatus, and the furnace port flange 10 is fixed to the casing 11 by a flange retainer 12. The cap 8 is placed on a boat cradle 13 of a lifting device of a boat loading device (not shown), and is fixed to the boat cradle 13 by a fixing ring 14. A seal ring 15 is provided between the flange 9 and the furnace opening flange 10.

Conventionally, in order to prevent the seal ring 15 from burning and deterioration, the flange retainer 12 and the boat pedestal 1
3, cooling water passages 16 and 17 are formed.
The cooling water is constantly circulated through the cooling water 7 to cool the seal ring 15.

[0008]

As a method for forming an oxide film on the surface of a silicon wafer in a vertical diffusion device, pyrogenic oxidation is performed. In the pyrogenic oxidation, a hydrogen gas and an oxygen gas are flowed and burned before a vertical furnace, high-purity steam is supplied into the furnace, and the silicon wafer surface is oxidized with the high-purity steam. Since a clean oxidizing atmosphere can be easily obtained, it is widely used as a method for manufacturing an ultra-high integrated circuit.

As described above, steam is used in the pyrogenic oxidation. However, in recent years, a low-temperature process has been promoted, and since the above-described furnace port has been cooled, a dew condensation phenomenon occurs at the furnace port, and the flange 9 is formed on the flange 9. Water 27 accumulates. Further, during the wafer processing, there is a problem that a halogen gas supplied for the purpose of removing and inactivating impurities such as heavy metals is melted in the pool water and evaporated after the sequence is completed, thereby corroding the metal surface in the apparatus. .

The present invention has been made in view of such circumstances, and aims to prevent the dew condensation phenomenon at the furnace port while cooling the furnace port.

[0011]

According to the present invention, there is provided a reaction chamber into which a boat loaded with wafers is loaded from below.
A semiconductor which has a furnace port flange formed at the lower end of the reaction chamber , places the boat on a boat support, and hermetically closes the reaction chamber via at least a sealing material between the furnace port flange and the boat support. In the manufacturing equipment, the vicinity of the sealing material
Forming a cooling passage for cooling the sealing material near, yet the cooling
A heater for heating the furnace port of the reaction chamber is provided near the road,
The flow of the coolant based on the temperature of the coolant flowing through the cooling path
The cooling state of the sealing material is controlled by controlling the flow rate and the energization state of the heater .

[0012]

According to the present invention, the cooling state of the coolant is controlled based on the temperature of the coolant, and when the furnace port is lower than the target temperature, the heater is controlled by controlling the energized state of the heater. This also prevents condensation of water vapor and the like at a temperature that does not damage the sealing material.

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, those having the same functions as those shown in FIGS. 3 and 4 are denoted by the same reference numerals.

The lower surface of the boat cradle 13, the cooling water passage 17
Is provided at a position corresponding to, and the heater is covered with a heater cover. The heater 28 is driven by a controller 30, which is controlled by a main controller 24, so that the flange 9 can be heated by the heater 28.

The cooling water passage 16 of the flange holder 12 is connected to a cooling water source 20 via an electromagnetic valve 19, and the cooling water passage 17 of the boat pedestal 13 is connected to a cooling water source 2 via an electromagnetic valve 21.
Connect to 0.

The solenoid valves 19 and 21 are driven by a controller 22 and a controller 23, respectively.
2. The controller 23 is controlled by the main controller 24. The cooling water passage 16 and the cooling water passage 17 are respectively provided with a cooling water temperature detector 25 and a cooling water temperature detector 26.
The detection signals from the cooling water temperature detector 25 and the cooling water temperature detector 26 are input to the main controller 24. Also, set values A and B for setting the cooling temperature are input to the main controller 24.

The set value A of the cooling water temperature of the cooling water passage 16 of the flange retainer 12 is 50 ° C., and the set value B of the cooling water temperature of the cooling water passage 17 of the boat pedestal 13 is 70 ° C.

The operation will be described below.

The main controller 24 receives the temperature detection signals from the cooling water temperature detector 25 and the cooling water temperature detector 26.
Continuously monitors the cooling state, and the monitored temperature is the set value A,
B, the corresponding solenoid valves 19, 2
1 is closed to reduce the amount of heat removed by the cooling water. When the monitored temperature is higher than the set values A and B, the corresponding solenoid valves 19 and 21 are opened to allow cooling water to flow, thereby enhancing the cooling of the flange holder 12 and the boat pedestal 13.

The electromagnetic valves 19 and 21 are controlled to open and close to intermittently carry out and stop the cooling water so that the temperatures of the flange holder 12 and the boat pedestal 13 are kept constant. Control the state.

Further, when the temperatures detected by the cooling water temperature detector 25 and the cooling water temperature detector 26 are low, a drive signal is issued from the main controller 24 to the controller 30.
The controller 30 energizes the heater 28 to heat the boat pedestal 13 and the flange 9 so that the temperatures detected by the cooling water temperature detector 25 and the cooling water temperature detector 26 become the set temperature. I do. Thus, when the detected temperature is lower than the set value, the temperature can be quickly raised. Accordingly, the seal ring 15 is not burned, and no dew condensation occurs at the lower part of the furnace port.

Further, the upper limit temperature set value C is inputted to the main controller 24, and when the cooling water in the cooling water passage 16 and the cooling water passage 17 exceeds the upper limit temperature set value C, the electromagnetic valve 19,
The ON / OFF control of the controller 22 is stopped, and the heater 28 is turned off.
Is turned off, and the cooling water is continuously circulated to prevent the seal ring 15 from burning.

Incidentally, the set value A is obtained by an experiment and is effective at 50 ° C. ± 10 ° C. The set value B is similarly effective within a range of 70 ° C. ± 10 ° C. The value C was suitably around 100 ° C.

Although water is used as the refrigerant in the above embodiment, it is needless to say that a refrigerant other than water may be used. Further, the temperature detection is performed based on the temperature of the cooling water. However, the temperature may be detected by directly providing a thermocouple to members such as the furnace port flange 10 and the flange 9.

Although the above embodiment has been described with reference to a vertical diffusion furnace, it goes without saying that the present invention can be similarly applied to a CVD apparatus.

In wafer processing in a CVD apparatus, S
NH4 Cl is generated during i3N4 film formation, and the NH4 Cl adheres to the furnace port to cause particles and contaminate the wafer. However, the adhesion of NH4 Cl to the furnace port occurs when the furnace port is cooled to 100 ° C. or lower. Therefore, when the CVD process is performed, the set values A and B are set to values near 150 ° C., and the temperature is controlled so that the temperature of the furnace port becomes close to 150 ° C.

[0028]

According to the present invention as described above, the following excellent effects are exhibited.

Since a cooling mechanism and a heating mechanism for the furnace opening are provided, quick temperature control is possible.

Since the furnace port is maintained at a predetermined temperature, that is, at a temperature below the temperature at which the sealing material is burned out, and moreover, at a temperature higher than the dew condensation temperature of steam, it is possible to solve the problem that water accumulates in the furnace port.

Since the water pool at the furnace mouth can be prevented,
Even if a corrosive gas is used, it is possible to prevent corrosion of the furnace opening.

[0032] It is possible to prevent NH4 Cl from adhering to the furnace port and suppress generation of particles.

Since the contamination of the furnace port can be prevented, the cleaning operation can be greatly reduced.

[0034] Since it is possible to prevent overcooling of the furnace port and to quickly raise the temperature when the temperature is equal to or lower than the target temperature, it is possible to prevent heat radiation from the furnace port and to stabilize the temperature distribution in the furnace. Can be.

[Brief description of the drawings]

FIG. 1 is a control block diagram showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a furnace port according to one embodiment of the same.

FIG. 3 is an elevation view schematically showing a vertical diffusion / CVD apparatus.

FIG. 4 is a sectional view of a conventional furnace opening.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction tube 3 Wafer 7 Boat 8 Cap 9 Flange 10 Furnace opening flange 12 Flange retainer 13 Boat pedestal 15 Seal ring 16 Cooling channel 17 Cooling channel 19 Solenoid valve 20 Cooling water source 21 Solenoid valve 28 Heater 30 Controller

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiya Shimada 2-3-13 Toranomon, Minato-ku, Tokyo Inside Kokusai Electric Co., Ltd. (72) Inventor Shoichiro Izumi 2-3-13 Toranomon, Minato-ku, Tokyo Kokusai Electric Inside (72) Inventor Shigeo Fukuda 2-3-13 Toranomon, Minato-ku, Tokyo International Electric Company (72) Inventor Taketoshi Sato 2-3-1-13 Toranomon, Minato-ku, Tokyo International Electric Company ( 72) Inventor Junichi Shimizu 2-3-1-13 Toranomon, Minato-ku, Tokyo International Electric Co., Ltd. (72) Inventor Kenichi Kamiya 2-3-1-13 Toranomon, Minato-ku, Tokyo International Electric Co., Ltd. (72) Inventor Hironobu Miya 3-3-1 Toranomon, Minato-ku, Tokyo Kokusai Denki Co., Ltd. (56) References JP-A-1-133728 (JP, A) JP-A-56-129329 (JP, A) Akira 64-31975 (JP, A) JP Akira 62-99473 (JP, A) JitsuHiraku Akira 61-142876 (JP, U) (58 ) investigated the field (Int.Cl. ^7, DB name) H01L 21 / twenty two

Claims (1)

(57) [Claims] A reaction chamber into which a boat loaded with wafers is loaded from below, a furnace port flange is formed at a lower end of the reaction chamber , and the boat is placed on a boat receiving table; in the semiconductor manufacturing apparatus for closing hermetically the reaction chamber via at least sealing material between the mouth flange and the boat cradles, to form a cooling path for cooling the sealing material in the vicinity of the sealing material, further A furnace port of the reaction chamber near the cooling passage
A heater for heating the section, and a flow rate of the coolant and an energized state of the heater based on a temperature of the coolant flowing through the cooling path.
Controlling the cooling state of the sealing material.