Drying and gas or vapor contact with solids – Apparatus – With automatic control
Reexamination Certificate
2001-04-20
2004-02-10
Wilson, Pamela (Department: 3749)
Drying and gas or vapor contact with solids
Apparatus
With automatic control
C034S558000, C034S567000, C034S572000
Reexamination Certificate
active
06688020
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a substrate processing method and substrate processing apparatus for processing substrates.
2. Related Background Art
In photolithography processing for, e.g., a semiconductor wafer (hereinafter called “a wafer”), a resist is applied to the wafer, and a pattern is exposed and developed. Then, the resist is removed from the wafer.
A cleaning equipment is used in such removal of the resist. In the conventional cleaning equipment, a wafer is immersed in a cleaning tank loaded with a chemical liquid which is called SMP (a mixed liquid of H
2
SO
4
/H
2
O
2
) to release the resist. On the other hand, recently it is required from the ecological viewpoint that the resist is removed by using a solution with ozone (O
3
) solved in, which is easy to waste. In such cleaning, the so-called dip-type, in which a wafer is immersed in a cleaning tank loaded with a solution with ozone solved in, is used to oxidize the resist with oxygen radicals in the solution to decompose the resist to carbon dioxide, water, etc.
The solution is produced by bubbling a high concentration of ozone gas into pure water to solve the ozone in the pure water, and the thus produced solution is loaded in a cleaning tank. Meanwhile the ozone in the solution is decomposed to decrease the ozone concentration of the solution, which often makes it impossible to sufficiently remove the resist. Furthermore, with a wafer immersed in the solution, while the ozone is reacting with the resist and is continuously being decomposed, ozone supply to the resist surface is insufficient, which makes a reaction rate low.
Then, a cleaning equipment in which ozone gas and steam are used to utilize ozone for the processing for removing a resist from a wafer is anew proposed in place of the cleaning equipment of the dip-type, in which a wafer is immersed in the solution. In such cleaning equipment, ozone gas is applied to wafers loaded in a tightly closed processing vessel. For processing using ozone, which is a harmful substance to the human body, etc., it is required that various accident preventive means and safety means are used.
Thus, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus which can prevent accidents in advance, specifically, can ensure safety even if the apparatus should be instantaneously stopped due to power failures or others, or processing gas leakage should take place.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a substrate processing method and a substrate processing apparatus which can prevent accidents in advance, specifically, can ensure safety even if the apparatus should be instantaneously stopped due to power failures or others, or processing gas leakage should take place.
To solve the above-described problems, a first invention of the present application provides a substrate processing method in which a substrate is processed by feeding a processing gas to the substrate loaded in a processing vessel while an interior atmosphere in the processing vessel is being exhausted to be subjected to a post-treatment, the processing gas being fed under a condition that the processing vessel is tightly closed, and the post-treatment of the exhausted interior atmosphere is normally carried out.
In a first substrate processing method according to the present invention, ozone gas, for example, is suitably used as the processing gas. According to the first substrate processing method of the present invention, the processing gas is fed to substrates loaded in the tightly closed vessel, and the substrates are suitably processed in the processing vessel by using the processing gas. On the other hand, an interior atmosphere in the processing vessel is exhausted to thereby exhaust the processing gas out of the processing vessel. The exhausted processing gas is post-treated. In the post-treatment, when a processing gas, e.g., ozone gas, contains a substance (ozone) which is harmful to the human body, the harmful substance is removed, making the processing gas harmless to be exhausted for safety to, e.g., an exhaust system of a plant. A processing gas can be, other than ozone gas, e.g., chlorine gas, fluoride gas, hydrogen gas, chlorine gas, fluoride gas, hydrogen gas, etc. containing various radicals in advance.
Here, when a processing gas is fed before the processing vessel is tightly closed, the processing gas disperses around. When the post-treatment is abnormal, there is a risk that the processing gas may be discharged as it is to an exhaust system of a plant. However, according to the present invention, the processing gas is fed under conditions that the processing vessel is tightly closed, and that the exhausted interior atmosphere is normally post-treated, and unless both conditions are satisfied, the processing gas is not fed, whereby the dispersion and the untreated drain of the processing gas can be prevented. Especially in a case that the processing gas contains ozone gas, which is harmful, accidents to the human body due to, e.g., the harmful substance can be precluded.
In a second substrate processing method according to the present invention, it is possible that when the processing of the substrate is interrupted, the interior atmosphere of the processing vessel is forcedly exhausted. When the processing is interrupted by, e.g., a power failure, an earthquake or others, the interior atmosphere in the processing vessel is forcedly exhausted to expel the processing gas from the interior of the processing vessel. Then, when the processing is resumed, often operators of the plant, for example, open the processing vessel to check interior states of the processing vessel. If the processing vessel is opened with the processing gas remaining therein, the processing gas may disperse. However, the thus forced-exhaust of the processing gas can prevent such dispersion of the processing gas. Especially when the processing gas is ozone gas, the forced exhaust of the processing gas can prevent such accident for safety.
In a third substrate processing method according to the present invention, it is possible that when the processing gas leaks around the processing vessel, the interior atmosphere of the processing vessel is forcedly exhausted while the feed of the processing gas is paused. According to the third substrate processing method, when the gas leakage has occurred, immediately the interior atmosphere is forcedly exhausted while the feed of the processing gas is stopped, whereby no more gas leakage can occur, and the damage can be minimized.
A fourth substrate processing method according to the present invention which a substrate is processed by feeding a processing gas to the substrate loaded in a processing vessel while an interior atmosphere in the processing vessel is being exhausted to be post-treated, when the processing gas leaks around the processing vessel, the interior atmosphere of the processing vessel is forcedly exhausted while the feed of the processing gas is paused.
According to the fourth substrate processing method of the present invention, as in the first substrate processing method, ozone gas, for example, can be suitably used as the processing gas. In the fourth substrate processing method according to the present invention, as in the first substrate processing method, the processing gas is fed into the processing vessel, and the substrates are suitably processed. On the other hand, the processing gas is exhausted out of the processing vessel, then is post-treated to be made harmless to be exhausted for safety to, e.g., an exhaust system of a plant. Here, when the processing gas leaks through, e.g., a gap of the processing vessel, at the time of the gas leakage, immediately the interior atmosphere is forcedly exhausted while the feed of the processing gas is paused. Then, the processing gas is prevented from leaking from the processing vessel. Thus, the leakage of the processing gas can be minimized for safety.
According to
Iino Tadashi
Toshima Takayuki
Morrison & Foerster / LLP
Tokyo Electron Limited
Wilson Pamela
LandOfFree
Substrate processing apparatus 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, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Substrate processing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3331073