JP2000216149A - Substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent metal contamination inside a reaction tube to improve wafer-processing quality by not exposing metal surface inside the reaction tube. SOLUTION: A substrate processing apparatus is provided with a load-lock chamber 1 and a reaction tube 3 hermetrically connected to the load-lock chamber 1, wherein the load-lock chamber 1 and the reaction tube 3 are connected through a furnace port formed in the load-lock chamber 1, and wafers are loaded to inside the reaction tube 3 by being held on a boat 8, and processed. The boat 8 is fixed to a quartz cap base 21 made of quartz. In inserting the boat, the quartz cap base 21 contacts a flange of the reaction tube 3 to close the reaction tube 3, and in taking out the boat, a shutter of the furnace port contacts the load-lock chamber 1 to close the furnace port. This makes metal part not exposed in the reaction tube 3 in the course of wafer processing to prevent metal contamination of wafers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus for performing a film forming process such as diffusion of an oxide film, a metal film, and impurities on a wafer surface, and more particularly to a substrate processing apparatus having a vertical reactor and a load lock chamber. It is.

[0002]

2. Description of the Related Art A conventional substrate processing apparatus having a load lock chamber will be described with reference to FIG.

A furnace port 2 is provided on the upper surface of the airtight load lock chamber 1.
An upper end is bored, and a reaction tube 3 made of quartz is provided in a hermetically sealed manner in a concentric manner with the furnace port hole 2, and a heater unit 4 is provided around the reaction tube 3.

A boat elevator 5 is provided in the load lock chamber 1, and the boat elevator 5 supports a quartz cap seat 6 so as to be able to move up and down, and a quartz boat cap 7 is mounted on the cap seat 6. The boat 8 is erected through the boat. Wafers are stored in multiple stages in a horizontal posture in the boat 8, and the wafers are loaded into the reaction tubes 3 by the boat elevator 5 while being stored in the boat 8.

When the boat elevator 5 loads the boat 8 into the reaction tube 3, the cap seat 6 closes the furnace opening 2 hermetically and the boat 8 is completely lowered. The furnace port 2 is hermetically closed by a furnace port shutter (not shown).

First, the substrate processing will be described.

When the boat 8 is lowered, the furnace opening 2 is airtightly closed by the furnace shutter.
A gate valve (not shown) provided in the load lock chamber 1 is opened, and the wafer is transferred to the boat 8 by a substrate transfer machine (not shown). When the transfer to the boat 8 is completed, the gate valve is closed and the load lock chamber 1 is closed.
The inside is evacuated.

[0008] When the evacuation of the load lock chamber 1 is completed, a furnace port shutter (not shown) is opened, and the boat elevator 5 raises the boat 8 and mounts it in the reaction tube 3 heated to a predetermined temperature. Enter. A reaction gas is introduced into the reaction tube 3 in a state where the cap receiving hole 6 hermetically closes the furnace port hole 2, and required processing is performed on the wafer surface.

When the processing is completed, a furnace port shutter (not shown) is opened, the boat 8 is pulled out of the reaction tube 3 by the boat elevator 5, and the wafer is loaded into the load lock chamber 1.
Cooled within. When the boat 8 is pulled out, the furnace hole 2
Is closed again by the furnace port shutter. When the wafer cools to a required temperature, the inside of the load lock chamber 1 is returned to the atmospheric pressure, a gate valve (not shown) is opened, and the wafer is unloaded by a substrate transfer device (not shown).

As described above, during the wafer processing, the furnace opening 2 is closed air-tightly by the cap seat 6, and when the boat is lowered, the furnace opening 2 is closed by a furnace opening shutter (not shown) for heat shielding and airtightness. Has become.

Referring to FIGS. 4 and 5, the structure of a conventional furnace port will be described.

A metal ring-shaped base flange 10 is fitted into the furnace opening 2 of the load lock chamber 1 from above,
A metal ring-shaped furnace port flange 11 is provided on the base flange 10 in an overlapping manner. The reaction tube 3 is erected on the furnace port flange 11, and a reaction tube flange 12 is held between the furnace port flange 11 and a flange retainer 13.

A seal ring 1 is provided between the base flange 10 and the furnace opening flange 11 and between the periphery of the furnace opening 2 of the load lock chamber 1 and the base flange 10.
4. The seal ring 15 is sandwiched between the furnace port flanges 1
A seal ring 16 is sandwiched between the reaction tube 1 and the reaction tube flange 12. Further, a seal ring 17 is provided on the lower surface of the base flange 10, and the cap seat 6 can abut on the seal ring 17.

The cooling water passage 1 is provided in the base flange 10.
The seal ring 14 and the seal ring 17 are cooled by flowing cooling water through the cooling water passage 18. A cooling water passage 19 is formed in the flange retainer 13, and cooling water flows through the cooling water passage 19 to cool the seal ring 16 via the reaction tube flange 12.

When the boat 8 is loaded in the furnace port 2, the cap seat 6 is in close contact with the base flange 10, and the inside of the reaction tube 3 and the inside of the load lock chamber 1 are sealed with the seal ring 17. Is hermetically sealed. The interior and exterior of the load lock chamber 1 are hermetically sealed by the seal ring 15, and the interior and exterior of the reaction tube 3 are hermetically sealed by the seal ring 14 and the seal ring 16.

When the boat 8 is pulled out, the furnace opening 2 is closed by a furnace shutter 20. The furnace port shutter 20 is in close contact with the base flange 10, and the space between the base flange 10 and the furnace port shutter 20 is hermetically sealed by the seal ring 17. Thus, the furnace port shutter 20 shuts off heat radiation from the reaction tube 3 and makes the load lock chamber 1 airtight.

[0017]

In the above-mentioned conventional furnace mouth structure, the cap seat 6 comes into contact with the lower surface of the base flange 10 and hermetically closes the inside of the reaction tube 3. The inner peripheral surfaces of the base flange 10 and the furnace port flange 11 are exposed inside the reaction tube 3. Since a corrosive gas is used as the reaction gas, the base flange 1
0, the inner peripheral surface of the furnace port flange 11 may be corroded, and the inside of the reaction tube 3 may be contaminated with metal.

In order to prevent metal contamination, a quartz ring may be provided inside the base flange 10 and the furnace opening flange 11, but the same problem cannot be avoided since the gap cannot be eliminated due to the structure.

An object of the present invention is to prevent a metal surface from being exposed in a reaction tube, prevent metal contamination in the reaction tube, and improve the processing quality of a wafer.

[0020]

The present invention comprises at least a load lock chamber and a reaction tube air-tightly connected to the load lock chamber, and the load lock chamber and the reaction tube are formed in the load lock chamber. In a substrate processing apparatus which is communicated through a provided furnace port hole and wafers are loaded and processed into the reaction tube in a state of being loaded in a boat, the boat is provided on a quartz cap base made of quartz, According to the substrate processing apparatus, the quartz cap base contacts the reaction tube flange to close the reaction tube when charging, and the furnace port shutter contacts the load lock chamber to close the furnace port hole when the boat is pulled out. Since the reaction tube is closed by the quartz cap base during wafer processing, the metal portion is not exposed in the reaction tube, and metal contamination of the wafer is prevented.

[0021]

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

FIG. 1 shows a state in which the boat 8 is inserted into the reaction tube 3, and FIG. 2 shows the state in which the boat 8 is pulled out from the reaction tube 3.
The state in which the furnace port hole 2 is closed by the furnace port shutter 20 is shown. 1 and 2, the same components as those shown in FIGS. 4 and 5 are denoted by the same reference numerals.

In FIG. 1, a base flange 10 having an inner diameter smaller than the outer diameter of the reaction tube flange 12 is fitted into the furnace opening 2 from above, and a seal ring is provided between the load lock chamber 1 and the base flange 10. 15 is inserted. A furnace port flange 11 having the same inner diameter as the base flange 10 is provided on the upper surface of the base flange 10 by being overlapped, and a seal ring 14 is sandwiched between the base flange 10 and the furnace port flange 11.

A reaction tube flange 12 is mounted on the upper surface of the furnace port flange 11, and the overlap between the reaction tube flange 12 and the furnace port flange 11 is set between the furnace port flange 11 and the reaction tube flange 12. Is sufficient to sandwich the seal ring 16 at the same time.

A quartz cap base 21 is provided on the upper surface of the cap seat 6 concentrically with the cap seat 6, and the boat 8 is erected on the quartz cap base 21 via the boat cap 7. The cap seat 6 is a boat elevator 5
(Refer to FIG. 3), which is supported so as to be able to ascend and descend, is smaller than the inner diameter of the base flange 10, and the quartz cap base 2
The outer diameter of 1 is smaller than the outer diameter of the cap seat 6.

The quartz cap base 21 can be brought into contact with the inner peripheral edge of the lower surface of the reaction tube flange 12, and an O-ring presser 22 is fitted over the quartz cap base 21. The O-ring presser 22 is made of fluororesin or the like. Made of synthetic resin
It is fixed to the cap seat 6.

An outer peripheral edge of the upper end of the quartz cap base 21 is cut off, and a groove is formed between the quartz cap base 21 and the O-ring presser 22. An O-ring 23 is fitted in the groove.

As shown in FIG.
The outer diameter of 0 is sufficiently larger than the outer diameter of the seal ring 17, and the seal ring 17 moves between the base flange 10 and the furnace port shutter 20 in a state where the furnace port shutter 20 is joined to the base flange 10. It is designed to be hermetically sealed.

The processing of the wafer in the present embodiment is the same as that of the above-described conventional example, and thus the description thereof will be omitted, and the operation of the furnace port will be described.

During processing of the wafer, the quartz cap base 21 contacts the inner peripheral edge of the lower surface of the reaction tube flange 12. The quartz cap base 21 and the reaction tube flange 1
The space between the two is hermetically sealed by the O-ring 23, and the inside of the reaction tube 3 is kept airtight.

The seal ring 15 is provided between the load lock chamber 1 and the base flange 10, and the seal ring 14 is provided between the base flange 10 and the furnace port flange 11. Since the space between the flanges 12 is sealed by the seal ring 16, the inside of the load lock chamber 1 is also kept airtight.

Further, by flowing cooling water through the cooling water passage 19, both the seal ring 16 and the O-ring 23 are cooled via the reaction tube flange 12. Although not particularly shown, a cooling water passage is formed in the base flange 10, and the seal rings 14 and 17 are cooled by flowing cooling water through the cooling water passage.

When the lower end of the reaction tube 3 is closed by the quartz cap base 21, the quartz cap base 21 made of quartz faces the inside of the reaction tube 3, and the base flange 10 and the furnace port flange 11 are inside the reaction tube 3. Not exposed to. Therefore,
There is no exposed portion of the metal in the reaction tube 3 and the reaction tube 3
There is no metal contamination inside or during processing.

When the boat 8 is pulled out and the reaction tube 3 is closed by the furnace port shutter 20, the furnace port shutter 20 contacts the base flange 10, and the base flange 10 and the furnace port shutter 20 Is hermetically sealed by the seal ring 17. Thus,
The inside of the reaction tube 3 and the inside of the load lock chamber 1 are independently evacuated and returned to the atmospheric pressure, and the above-described wafer transfer and transfer are performed. The base flange 10 and the furnace port flange 11 are exposed in the reaction tube 3 in a state where the boat is pulled out. However, the corrosive gas is not introduced into the reaction tube 3 in a non-treatment state. 1
0, The furnace port flange 11 is not corroded. Therefore, it is not necessary to use a corrosion-resistant material for the base flange 10 and the furnace port flange 11.

The base flange 10 is a member constituting the load lock chamber 1 and does not need to be made of a corrosion-resistant material. Therefore, the base flange 10 may be integrated with the load lock chamber 1. 11 may be integrated. Further, a quartz furnace port inner lid is attached to the furnace port shutter 20 via a spring or the like, and when the furnace port hole 2 is closed by the furnace port shutter 20, the lower end of the reaction tube 3 is hermetically sealed by the furnace port lid. It may be closed. In this way, the metal surface is not exposed in the reaction tube 3 even when the boat is pulled out.

[0036]

As described above, according to the present invention, since the metal portion is not exposed in the reaction chamber during wafer processing, it is possible to prevent the wafer from being metal-contaminated in the reaction chamber and to perform high-quality processing. In addition, since it is not necessary to use a corrosion-resistant material as a material forming the furnace port, various excellent effects such as reduction of material cost can be achieved.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is an elevational sectional view showing a main part of the embodiment of the present invention.

FIG. 3 is an overall schematic view of a substrate processing apparatus.

FIG. 4 is a vertical sectional view showing a main part of a conventional example.

FIG. 5 is a vertical sectional view showing a main part of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Load lock room 2 Furnace opening 3 Reaction tube 7 Heater unit 8 Boat 20 Furnace opening shutter 21 Quartz cap base

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/68 H01L 21/68 A

Claims (1)

[Claims] At least a load lock chamber and a reaction tube hermetically connected to the load lock chamber are provided, and the load lock chamber and the reaction tube communicate with each other through a furnace port hole formed in the load lock chamber. In a substrate processing apparatus in which a wafer is loaded and processed into the reaction tube in a state of being loaded in a boat, the boat is provided on a quartz cap base made of quartz. A substrate processing apparatus, wherein a reactor tube shutter is closed by contacting with a reaction tube flange, and a furnace port shutter is in contact with the load lock chamber when the boat is drawn out.