Coating apparatus – Gas or vapor deposition
Reexamination Certificate
2000-02-11
2001-06-26
Lund, Jeffrie R. (Department: 1763)
Coating apparatus
Gas or vapor deposition
C118S724000, C156S345420, C204S298150, C427S248100
Reexamination Certificate
active
06251189
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a substrate processing apparatus and substrate processing method, comprising a furnace constituting a quartz gas supply portion, which is connected to a reaction tube, and more particularly to an apparatus and method for eliminating the transmission to the reaction tube by way of the gas supply portion of a shock impacting on the furnace.
2. Description of the Related Art
For some time now, in accordance with the relationship between temperature and a process gas in a diffusion furnace, quartz has been utilized in a gas supply pipe leading to a reaction tube. As shown in
FIG. 9
, a reaction tube-side gas supply pipe
42
is integrally mounted to a quartz reaction tube
41
. A quartz source-side gas supply pipe
43
, which is linked to a reactant gas source, is connected to this reaction tube-side gas supply pipe
42
by a pipe clamp
44
to secure the respective flanges.
However, in general, quartz is a brittle material, and is disadvantageous in that it is easily damaged when impacted by a shock, such as that of an earthquake. The constitution of a diffusion furnace reaction chamber is such that the quartz reaction tube is manufactured in a practically integrated fashion, so that when a shock impacts this reaction tube, it is damaged easily, resulting in considerable losses when the reaction tube must be remanufactured. More specifically, as shown in
FIG. 10
, gas supply pipe
43
is affixed to the reaction tube
41
by being securely connected to gas supply pipe
42
via a pipe clamp
44
. Thus, when an earthquake occurs, the shock directly impacts the reaction tube
41
via the gas supply pipes
42
,
43
, causing damage to the weld portion
45
of the base of gas supply pipe
42
, which is the most brittle. For this reason, improvement of the gas supply portion is desirable in a furnace in which the reaction tube and gas pipes are constituted of quartz.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a substrate processing apparatus and substrate processing method, which make it possible to improve the gas supply portion of a furnace by eliminating the above-mentioned problems of the prior art by absorbing a shock before it reaches the reaction tube.
A first invention is a substrate processing apparatus, having a furnace, in which a reaction tube for processing substrates, and gas piping, which is connected to the reaction tube, and which supplies a gas required for processing the above-mentioned substrates, are constituted of quartz, this substrate processing apparatus being characterized in that a stress concentration portion is disposed on the above-mentioned gas piping. Here, a stress concentration portion refers to an element on which stress is preferentially concentrated, and which breaks more readily than another element, when an outside force impacts on gas piping. This stress concentration portion can be constituted using a depression, a groove or a thin-skinned portion.
When an earthquake or the like occurs, and an outside force impacts on a substrate processing apparatus, stress is concentrated in the stress concentration portion of a gas pipe so that the stress concentration portion breaks preferentially to another element before a shock impacts the reaction tube. Because a stress concentration portion of a gas pipe breaks before a shock impacts the reaction tube, the reaction tube can be effectively protected from damage. Therefore, only a pipe needs to be replaced, replacement work is easy, and losses can be greatly reduced.
A second invention is a substrate processing apparatus according to the first invention, which comprises a scavenger for preventing the dissipation of gas from the end of the above-mentioned furnace, and which disposes the above-mentioned stress concentration portion on a gas pipe of inside the above-mentioned scavenger. Here, a scavenger refers to a reaction tube connecting element, which is located at the end of a furnace body in a thermal oxidation apparatus, thermal diffusion apparatus, CVD apparatus or the like, and which is designed to prevent the dissipation of a process gas and heat toward the clean bench side. A stress concentration portion is desirably located on the inside of a scavenger. This is so that when a gas pipe breaks, the leakage of gas to the outside of the apparatus can be reduced. Since the leakage of gas to the outside of the apparatus can be reduced, gas countermeasures at gas pipe rupture can be improved.
A third invention is a substrate processing apparatus according to either the first or second invention, in which gas piping is connected to the reaction tube by way of a pipe connector, and the above-mentioned stress concentration portion is disposed on a gas pipe of the opposite side of the reaction tube having the above-mentioned pipe connector therebetween. When a stress concentration portion is disposed on a gas pipe of the side opposite the reaction tube, it is the gas pipe of the side opposite the reaction tube which breaks, and because the gas pipe leading to the reaction tube side need not be replaced, replacement is easier and more economical.
A fourth invention is a substrate processing apparatus according to either the first or second invention, in which a stress concentration portion is formed by a groove cut radially in a gas pipe. The orientation of the groove is optional, and can be either the radial direction, or the axial direction, and groove depth is in the radial direction. Further, as for the number of grooves, there can either be a single groove, or a plurality of grooves, and a groove can either be a ring shape that is continuous around the entire circumference, or a groove that is partially formed around the circumference of a gas pipe. The shape of a groove can be a V-groove, a U-groove, or the like. By cutting a groove in a gas pipe, stress concentration readily occurs in the portion thereof, making same easily breakable.
A fifth invention is a substrate processing apparatus according to either the first or second invention, in which the above-mentioned stress concentration portion is disposed on a gas supply pipe of the gas piping, without being so disposed on a gas exhaust pipe. In this invention, it is better to dispose a stress concentration portion on a gas supply pipe. This is because the temperature of a gas supply pipe is higher than that of a gas exhaust pipe, and a bellows cannot be used in the connection between the reaction tube and the gas piping.
A sixth invention is a substrate processing apparatus according to either the first or second invention, in which the above-mentioned furnace is a normal pressure furnace of either a diffusion furnace or an oxidation furnace. The present invention is particularly effective for a normal pressure furnace, which utilizes a quartz tube diffusion furnace or oxidation furnace, because a quartz bellows cannot be produced.
A seventh invention is a substrate processing method for processing substrates in a reaction tube, wherein a furnace having gas piping connected to the reaction tube and constituted of quartz is provided, and stress for negating an outside force is made to occur in a concentrated fashion part way along the above-mentioned gas piping so that the outside force which impacts the furnace travels down the gas piping and is absorbed before reaching the above-mentioned reaction tube. Because the outside force is absorbed by stress before reaching the reaction tube, the outside force does not impact the reaction tube, making it possible to effectively prevent the breaking of the reaction tube by the outside force.
An eighth invention is a substrate processing method according to the seventh invention, wherein a scavenger is provided at from an end of the above-mentioned furnace for preventing the dissipation of a gas, the stress is made to occur in a concentrated fashion part way along a gas pipe inside the scavenger.
A ninth invention is a substrate processing method according to either the seventh or eighth in
Matsumoto Naoki
Morita Shinya
Odake Shigeru
Tometsuka Kouji
Kokusai Electric Co. Ltd.
Lund Jeffrie R.
Oliff & Berridg,e PLC
LandOfFree
Substrate processing apparatus and substrate processing method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Substrate processing apparatus and substrate processing method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Substrate processing apparatus and substrate processing method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2459828