Drying and gas or vapor contact with solids – Process – Gas or vapor contact with treated material
Reexamination Certificate
2001-12-28
2004-05-04
Bennett, Henry (Department: 3749)
Drying and gas or vapor contact with solids
Process
Gas or vapor contact with treated material
C034S074000, C034S218000, C034S558000, C034S568000, C034S570000
Reexamination Certificate
active
06729041
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
This invention relates to a substrate processing apparatus and a substrate processing method. More in detail, the invention relates to substrate processing apparatus and method for processing substrates, for example, semiconductor wafers, glass substrates for LCD, etc. with a processing gas, such as ozone gas, the substrates being accommodated in a processing container capable of establishing a closed atmosphere therein.
2. Description of the Related Art
Generally, the manufacturing process for semiconductor devices comprises the following steps of: applying photo-resist on substrates, for example, semiconductor wafers and LCD baseplates; transferring a circuit pattern, which has been scaled down by the photo-lithography technique, to the above photo-resist; developing this pattern; and thereafter removing the photo-resist from the wafers etc. Note, the semiconductor wafers will be simply referred as “wafers”, hereinafter.
As means for removing the photo-resist, there exists a substrate cleaning apparatus. In the prior art cleaning apparatus, the operation to remove the photo-resist from the substrates is accomplished by dipping the wafers etc. into a cleaning bath filled up with a chemical liquid generally called “SPM” (mixture of H
2
SO
4
and H
2
O
2
). To the contrary, there has been a general demand to use a solution of ozone (O
3
) for the removal operation since its effluent process from a factory is preferable in view of the protection of the environment. In using the solution of ozone (O
3
) for the removal operation, there is generally employed a cleaning method that the wafers etc. are dipped into a cleaning bath filled up with a solution having ozone melted thereinto, which is so-called “dip” type cleaning method. In this method, the photo-resist on the wafers is oxidized and dissolved into carbon dioxide and water etc. by oxygen atomic radicals in the solution.
Incidentally, according to the above-mentioned method, the ozone gas of high concentration is firstly dissolved into pure water in the form of bubbles thereby to produce the “ozone” solution and thereafter, the resultant solution is supplied into the cleaning bath. Therefore, there sometimes arises a situation that ozone(s) in the solution gradually disappear during the transportation, so that the concentration of ozone is reduced to cause an insufficient removal of the photo-resist. Additionally, the removal operation by dipping the wafers etc. into the ozone solution cannot afford the reaction (oxidation of resist) at high speed. Because, the removal operation is apt to make the quantity of ozone(s) for the resist insufficient although ozone(s) successively disappears as the result of the reaction with the resist.
In place of such a cleaning method for cleaning the wafers etc. by dipping them into the ozone solution, there is newly proposed a cleaning (etching) method for removing the resist from the wafers etc. while using a processing gas, for example, mixture of ozone gas and vapor of solvent, for example, steam. Note, in this specification, the above vapor of solvent will be referred “solvent vapor”, hereinafter. According to this cleaning (etching) method, the processing gas, for example, ozone gas is supplied to the wafers accommodated in a closed processing container where the resist is removed from the wafers.
However, the substrate processing apparatus employing the above-mentioned cleaning method has problems to be solved. First, dewdrops of the solvent vapor are produced in a solvent-vapor nozzle disposed in the processing container, thereby causing sources of bacteria and particles. Second, the dewdrops are scattered to stick to the wafers at the time of ejecting the solvent vapor, thereby causing the wafers to be cleaned with unevenness. Additionally, the solvent vapor is condensed into dewdrops of water that sticks to an upside inner wall of the processing container. Then, the waterdrops fall onto the wafers to cause the sources of particles. Further, the dewdrops of water are scattered into the processing container, causing the wafers to be cleaned with unevenness.
Since the above-mentioned substrate processing apparatus includes a steam generator whose inside pressure is constant (almost atmospheric pressure), there exists a limit in producing the steam. Therefore, under a situation that an interior of the processing container is pressurized more than the atmospheric pressure, then a problem arises in that the quantity of solvent vapor to be supplied into the processing container decreases, so that the processing capability of the apparatus itself is lowered.
SUMMARY OF THE INVENTION
Under such a circumference as mentioned above, an object of the present invention is to provide a substrate processing apparatus that restricts the formation of dewdrops of the solvent vapor which may produce sources of particles etc. or cause cleaning (etching) unevenness etc. in the processing container thereby to improve the processing efficiency of the apparatus. Additionally, another object of the present invention is to provide substrate processing method and apparatus by which an amount of solvent vapor generated is so adjusted as to supply the processing container with an appropriate amount of solvent vapor thereby to improve the processing efficiency of the apparatus.
In order to attain the above objects, according to the first aspect of the present invention, there is provided a substrate processing apparatus for supplying a substrate to be processed with processing gas and solvent vapor, comprising:
a processing container for accommodating the substrate therein;
a processing-gas supplier for supplying the processing gas into the processing container;
a solvent-vapor generator for generating the solvent vapor to be supplied into the processing container; and
a solvent-vapor nozzle arranged in the processing container and also connected to the solvent-vapor generator,
wherein the solvent-vapor nozzle includes a nozzle body having a plurality of nozzle orifices formed at appropriate intervals and a condensation-proof mechanism for preventing dewdrops from being formed in an inside space of the nozzle body.
According to the second feature of the invention, the condensation-proof mechanism comprises a heater for heating the inside space of the nozzle body. Accordingly, it is possible to prevent the solvent-vapor from being condensed into dewdrops in the nozzle body. Also, there is no possibility that the dewdrops of water are scattered onto the substrates at the ejection of the solvent-vapor. Thus it is possible to restrict an outbreak of bacteria due to the formation of dewdrops in the nozzle body and an occurrence of particles due to the scattering of dewdrops.
According to the third feature of the invention, the condensation-proof mechanism comprises a drain port formed on the bottom of the nozzle body to communicate the inside space of the nozzle body with an outside thereof. Accordingly, the drain port can drain the dewdrops from the nozzle body to the outside, preventing the dewdrops of water from being scattered around at the ejection of the solvent-vapor. In connection, the nozzle body may be modified to have an inner pipe inserted thereinto through a clearance and also connected to the solvent-vapor generator, the inner pipe having communication holes formed on the opposite side of the nozzle orifices in the nozzle body. In such a case, the supplied solvent-vapor is ejected from the nozzle orifices after the vapor has entered into a clearance between the nozzle body and the inner pipe through the communication hole. Thus it is possible to eject the solvent-vapor from the nozzle orifices uniformly.
According to the fourth feature of the invention, the drain port is arranged on the side of one end of the nozzle body. The dewdrops collected on respective bottoms of the nozzle body and the inner pipe move toward the end of the nozzle body due to an ejection power of the solvent-vapor. Therefore, owing to the formation of the drain port
Iino Tadashi
Shindo Naoki
Morrison & Foerster / LLP
Nguyen Camtu
Tokyo Electron Limited
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