JPH07142418A - Vertical furnace for semiconductor production system - Google Patents

Abstract

PURPOSE:To provide a vertical furnace in which an object to be processed is protected against metallic contamination while enhancing the durability. CONSTITUTION:A boat cap 44 is mounted on a furnace cover 45 provided for a boat elevator such that the boat cap can abut, at the flange thereof, on the lower face of the flange of a reaction tube. A bank part is provided along the periphery of the furnace cover and a seal ring 48 is fitted to the upper face of the bank part. Another seal ring 50 is fitted concentrically to the seal ring 48 onto the upper face of the flange of the boat cap. Furthermore, a hole communicating the seal rings 48, 50 is made through the flange of reaction pipe and a suction port 58 communicating with the hole 59 is provided for a reaction pipe fixing ring. Since suction is effected through the suction port, silicon surface is employed entirely at the part exposed to the interior of the reaction pipe and thereby metallic contamination is prevented. Furthermore, a double seal is employed for the flange 52 of reaction pipe so that the gap between the seal rings can be sucked thus enhancing the sealing performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical furnace of a semiconductor manufacturing apparatus for performing diffusion and chemical vapor deposition, which belongs to a pretreatment step of a semiconductor manufacturing process, and more particularly to a furnace opening portion of a high temperature vertical furnace. is there.

[0002]

2. Description of the Related Art There is a diffusion and chemical vapor deposition process as one of the pretreatment processes of a semiconductor manufacturing process, and there is a vertical furnace as an apparatus for performing such pretreatment process. There are high-temperature vertical furnaces such as a vertical diffusion furnace and an annealing furnace that heat an object to a high temperature for processing.

The high-temperature vertical furnace performs treatments such as damage and deterioration recovery of an object to be treated by an ion implantation device, reflow of a phosphorus diffusion film, and hydrogen annealing.

An outline of a vertical semiconductor manufacturing apparatus equipped with a high temperature vertical furnace will be described with reference to FIG.

A high temperature vertical furnace 2 is provided above the inside of the housing 1, and a boat elevator 3 is provided below the high temperature vertical furnace 2. The elevator slider 4 of the boat elevator 3 is provided with a lower furnace port 5 forming a part of the high-temperature vertical furnace 2, and a quartz boat 6 is provided in the lower furnace port 5 via a quartz boat cap 32. Is placed. Wafers 7, which are objects to be processed, are horizontally inserted into and held in the boat 6 in multiple stages.

A wafer transfer machine 8 is provided on the side of the boat elevator 3, and a cassette shelf 10 is provided further on the side of the wafer transfer machine 8 with a heat shield shutter 9 interposed.

The cassette shelf 10 is a wafer cassette 11
The required number of wafers are stored, and the wafer 7 is loaded into and unloaded from the semiconductor manufacturing apparatus while being loaded in the wafer cassette 11.

In the boat elevator 3, the boat 6 having the wafers 7 inserted therein is loaded into the high temperature vertical furnace 2, and by loading the boat 6, the furnace lower part 5 is a furnace of the high temperature vertical furnace 2. Block the mouth. The wafer 7 is subjected to required processing in the high temperature vertical furnace 2, and when the processing is completed, the boat 6 is pulled out by the boat elevator 3.

Immediately after the boat 6 is pulled out, the temperature of the boat 6 and the wafer 7 is high, and the heat shield shutter 9 prevents the wafer 7 of the cassette shelf 10 from being affected by heat. or,
The wafer transfer machine 8 stores the unprocessed wafers in the cassette shelf 1
The wafers are transferred from 0 to the boat 6, and the processed wafers are transferred from the boat 6 to the cassette shelf 10.

Next, the furnace opening of a conventional high temperature vertical furnace will be described with reference to FIG.

In the high temperature vertical furnace 2, a heat unit 12, a soaking tube 13 made of quartz, and a reaction tube 14 made of quartz are concentrically arranged.

The heat unit 12 is a furnace base 15
The soaking tube 13 is fixed to the furnace body base 15 via a ring seat 16. A flange 17 is formed at the lower end of the reaction tube 14, and the flange 17 is held by a flange retainer 18 and a furnace opening adapter 19 made of metal. The furnace opening adapter 19 is held by a holding means (not shown) on the furnace body base 15 side. It is fixed to.

A seal 2 is provided on the upper surface of the flange retainer 18.
0 is provided, and the seal 20 is in airtight contact with the ring seat 16. Further, a flange 21 and a flange 22 are formed at the upper and lower ends of the furnace port adapter 19, the flange 21 abuts the flange 17, and the O-ring 2 is provided between the flange 17 and the flange 22.
3. The O-ring 24 is concentrically provided.

A furnace port lid 25 is in contact with the flange 22, a double O-ring 26 and an O-ring 27 are embedded in the upper surface of the furnace port lid 25, and the furnace port lid 25 is attached to the flange 22.
The inside of the reaction tube 14 is hermetically closed by abutting against.

An exhaust pipe 33 is provided so as to extend between the flange 21 and the flange 22, and an upper end of the exhaust pipe 33 communicates with a gap between the O-ring 23 and the O-ring 24, and the exhaust pipe 33 is provided. The lower end of the O-ring 26 and O-ring 2
7, an exhaust port 34 is provided in the middle of the exhaust pipe 33, and the exhaust port 34 is connected to an air supply pump (not shown).

The furnace lid 25 is attached to a boat pedestal 29 via a spring 28, and the boat pedestal 29 is fixed to an elevator arm (not shown) extending from the elevator slider 4 of the boat elevator 3. . A pedestal 30 is erected at the center of the boat pedestal 29, the pedestal 30 penetrates the furnace port lid 25 and projects upward, and a bellows 31 is provided at a position where the pedestal 30 penetrates the furnace port lid 25. It is airtightly sealed. The boat cap 32 is mounted on the pedestal 30 via a metal cap receiver 35,
Further, the boat 6 is erected on the boat cap 32.

When the elevating slider 4 is moved up and down by the boat elevator 3, the boat 6 is loaded into and unloaded from the reaction tube 14, and when the furnace port lid 25 closes the furnace port, the repulsive force of the spring 28 causes the boat 6 to move. Furnace lid 25
And an adhesion force between the flange 22 and the flange 22 is obtained.

When the wafer 7 is subjected to the hydrogen annealing treatment, hydrogen is introduced into the reaction tube 14 through an introduction pipe (not shown), and the inside of the reaction tube 14 is heated to a high temperature by the heating unit 12 to treat the wafer 7. . Since it is dangerous that hydrogen leaks from the furnace opening, the flange 17 and the flange 21 are doubly sealed by the O-ring 23 and the O-ring 24 as described above, and the flange 22 and the furnace opening lid 25 are connected to each other. O-ring 26 and O-ring 2 between
7 are doubly provided and sealed.

Further, from the exhaust port 34 through the exhaust pipe 33, between the O ring 23 and the O ring 24, the O ring 26,
The space between the O-rings 27 is sucked so that hydrogen gas does not leak.

[0020]

In the above-mentioned conventional furnace opening structure, the metal furnace opening adapter 19, the furnace opening lid 25,
Since the inner surface of the cap receiver 35 is exposed in the reaction chamber, it causes metal diffusion and metal contamination of the wafer, and there is a problem in terms of thermal durability, and the processing temperature cannot be raised.

In view of the above situation, the present invention aims to provide a vertical furnace for a semiconductor manufacturing apparatus which is free from metal contamination and whose durability is not deteriorated.

[0022]

According to the present invention, a reaction tube is supported at a peripheral edge portion of a reaction tube flange, a boat cap is mounted on a furnace port lid provided in a boat elevator, and the flange of the boat cap is set as described above. The reaction tube can be brought into contact with the lower surface of the reaction tube flange, or the reaction tube is erected on the base plate at the peripheral edge of the reaction tube flange, and the reaction tube flange is attached from the upper surface side of the reaction tube flange. The boat cap is fixed to the base plate by a fixing ring, and the boat cap is placed on the furnace lid that can be raised and lowered, and the flange of the boat cap can be brought into contact with the lower surface of the reaction tube flange, and the reaction is performed along the periphery of the furnace lid. A bank portion that can contact the lower surface of the pipe is provided, a seal ring is provided on the upper surface of the bank portion, and the seal ring is provided on the upper surface of the flange of the boat cap. Is provided with another seal ring, the reaction tube flange is provided with a communication hole that opens between the seal ring and the other seal ring, and the reaction tube fixing ring is provided with an intake port that communicates with the communication hole. It is characterized in that suction is possible through the suction port.

[0023]

[Function] All exposed surfaces inside the reaction tube are quartz surfaces,
Metal contamination is prevented, and the seal of the reaction tube flange becomes a double seal. Further, by sucking between the seal rings, the sealing performance is improved.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

A soaking tube 41 is erected on the furnace body base 43, and a reaction tube 42 is concentrically provided inside the soaking tube 41.
A boat (not shown) is housed inside the boat 2 via a boat cap 44. The furnace port lid 45 is provided on a boat elevator (not shown) via a boat pedestal 46, and a boat cap 44 is mounted on the furnace port lid 45. A seal 62 is provided between the furnace port lid 45 and the boat cap 44, and a cooling water passage 63 is connected to a cooling water source via a cooling water port 64 near the seal 62 inside the furnace port lid 45. ing.

The furnace port lid 45 has a flat concave shape in which a ring-shaped bank portion 47 is formed along the circumference, and a seal ring 48 is fitted on the upper surface of the bank portion 47. ing. A flange 49 of the boat cap 44 is placed concentrically with the furnace port lid 45, a peripheral edge of the flange 49 is formed with two steps, and a seal ring 50 is fitted on the upper step.

A flange pressing ring 51 is provided which is fitted to the lower stage of the flange 49 and is fitted between the flange 49 and the bank portion 47, and the boat cap 44 is fixed to the furnace port lid 45 by the flange pressing ring 51. To do. The upper end edge of the inner surface of the flange pressing ring 51 is in the shape of an eave inclined toward the center side, and when the flange pressing ring 51 is fitted to the flange 49, the upper end edge of the flange pressing ring 51 presses the seal ring 50. It seems to be crowded.
Further, a step is formed on the edge side of the upper surface of the flange pressing ring 51, and the step forms a ring-shaped seal groove 60 with the reaction tube flange 52 described later.

The lower end of the reaction tube 42 is the furnace body base 4
3, a reaction tube flange 52 provided at the lower end of the reaction tube 42 extending further below 3 is placed on the base plate 53 at the peripheral edge thereof. A portion of the reaction tube 42 protruding from the soaking tube 41 is surrounded by a heat insulating material 54.

The reaction tube flange 52 is fixed to the base plate 53 by a reaction tube fixing ring 55. Two rows of cooling water passages 56 are provided inside the reaction tube flange pressing portion of the reaction tube fixing ring 55, and are connected to a cooling water source (not shown). Further, the suction hole 57 is provided with a sandwiching seal 61 at a position facing the cooling water passage 56 on the contact surface of the reaction tube fixing ring 55 with which the reaction tube fixing ring 55 abuts.

A required number of suction holes 57 are provided between the cooling water passages 56, and each suction hole 57 is provided with a suction port 58. The suction port 58 is provided with a vacuum pump (not shown). Connect to. Also, the reaction tube flange 5
2, a communication hole 59 is formed at a position facing the suction hole 57, and the communication hole 59 communicates with the seal groove 60.

In the figure, reference numerals 65 and 66 are heat resistant rubbers for preventing an excessive load from being applied to the reaction tube flange 52.
An elastic material such as heat-resistant resin.

The operation will be described below.

By raising and lowering the furnace port lid 45 by a boat elevator (not shown), a boat (not shown) can be loaded into and unloaded from the reaction tube 42.

In the state where the boat is completely loaded into the reaction tube, the flange 49 of the boat cap 44 and the bank portion 47 contact the reaction tube flange 52, and the seal ring 48 and the seal ring 50 move the reaction tube. Adheres closely to the flange 52. Thus, the inside and outside of the reaction tube 42 are sealed by the seal ring 48, the seal ring 50, the seal 62, and the seal 61. In addition, the suction port 58
By drawing more vacuum, communication hole 59 and seal groove 6
0, and a region having the seal ring 48, the seal ring 50, the seal 62, and the seal 61 as a boundary has a negative pressure, which prevents the gas in the reaction tube 42 from leaking to the outside and further improves the sealing performance. .

Further, since the metal surface is not exposed in the reaction tube 42, there is no fear of metal contamination and the heat resistance is improved.

[0036]

As described above, according to the present invention, since the metal surface exposed in the furnace is eliminated, metal diffusion and metal contamination are prevented, heat resistance is improved, and safety against gas leakage in the furnace is improved. Further, it is possible to improve the processing quality, improve the product yield, reduce the manufacturing cost of the device, improve the reliability of the device, etc.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing a main part of the embodiment.

FIG. 3 is a perspective view showing an outline of a semiconductor manufacturing apparatus having a vertical furnace.

FIG. 4 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 42 reaction tube 44 boat cap 45 furnace lid 48 seal ring 49 flange 50 seal ring 52 reaction tube flange 55 reaction tube fixing ring 58 suction port 59 communication hole

Claims (2)

[Claims] 1. A quartz reaction tube is supported at a peripheral portion of a reaction tube flange, a quartz boat cap is mounted on a furnace port cover provided in a boat elevator, and the flange of the boat cap is attached to the reaction tube flange. A vertical furnace for semiconductor manufacturing equipment, which is capable of contacting the lower surface. 2. A quartz reaction tube is erected on a base plate at the peripheral edge of the reaction tube flange, and the reaction tube flange is fixed to the base plate by a reaction tube fixing ring from the upper surface side of the reaction tube flange, and can be moved up and down. A quartz boat cap is mounted on the lid of the furnace, the flange of the boat cap can be brought into contact with the lower surface of the reaction tube flange, and the bank can be brought into contact with the lower surface of the reaction tube along the peripheral edge of the furnace opening lid. A seal ring is provided on the upper surface of the bank portion together with a portion, another seal ring is provided concentrically with the seal ring on the upper surface of the flange of the boat cap, and the seal ring and the other seal ring are provided on the reaction tube flange. A communication hole opening between the holes is provided, and a suction port communicating with the communication hole is provided in the reaction tube fixing ring so that suction can be performed through the suction port. A vertical furnace for semiconductor manufacturing equipment.