Cleaning and liquid contact with solids – Apparatus – With plural means for supplying or applying different fluids...
Reexamination Certificate
2000-04-10
2001-11-20
Coe, Philip R. (Department: 1746)
Cleaning and liquid contact with solids
Apparatus
With plural means for supplying or applying different fluids...
C134S902000
Reexamination Certificate
active
06318386
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a treatment apparatus for cleaning or drying semiconductor wafers, LCD glass substrates, or other objects to be treated, for example.
2. Description of the Prior Art
In the field of semiconductors, in general, there are widely employed various treatment apparatuses, such as cleaning apparatuses for cleaning semiconductor wafers, LCD glass substrates, or other objects to be processed (hereinafter called wafers, etc.) by sequentially immersing them in a cleaning vessel or other treatment portion storing a chemical liquid, such as ammonia water (NH
4
OH) or hydrofluoric acid (HF), cleaning liquid, such as rinsing liquid (pure water), and drying apparatuses for drying wafers, etc. which have been cleaned.
A widely used conventional cleaning apparatus of this type includes a cleaning vessel or other treatment means which store a cleaning liquid to immerse wafers, etc. into the cleaning agent to clean their surfaces; a cleaning liquid supply pipe connecting the cleaning vessel to a pure water supply source; and a chemical liquid reservoir storing a chemical liquid and connected to the cleaning liquid supply pipe, so as to infuse the chemical liquid to the pure water flowing through the cleaning liquid supply pipe with the aid of a compressed carrier gas, such as nitrogen (N
2
) gas, into the chemical liquid in the chemical liquid reservoir so that the chemical liquid of a predetermined concentration be supplied into the cleaning vessel and used for cleaning objects to be processed.
A widely used conventional drying apparatus includes a drying chamber or other treatment portion for applying a drying gas onto wafers, etc. to dry them; a N
2
gas supply pipe connecting the drying chamber to a supply source of a drying gas carrier gas, such as N
2
gas,; a chemical liquid container storing a chemical liquid such as IPA (isopropyl alcohol) or other organic solvent; and a drying gas generator interposed in the N2 gas supply pipe, so as to compress IPA in the chemical liquid container with the N
2
gas or other carrier gas and to infuse it to the drying gas generator, such that the drying gas of a predetermined concentration be supplied into the drying chamber and used to dry objects to be processed.
However, since these conventional treatment apparatuses were configured to compress a chemical liquid stored in the chemical liquid container by using a pressurized inert gas such as N
2
gas, and to inject the chemical liquid into a pure water line or the dryer gas generator, the supplied amount of the chemical liquid was liable to vary with changes in flow rate of pure water or dryer gas or with changes in pressure. It inevitably caused fluctuation in concentration of the chemical liquid in the pure water or in the drying gas, a decrease in cleaning efficiency or drying efficiency, and a decrease in manufacturing yield.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a treatment apparatus in which an accurate quantity of a chemical liquid is infused into pure water or a drying gas generator irrespectively of changes in flow amount or pressure of a treatment medium such as pure water, drying gas carrier gas, etc., such that the chemical liquid or drying gas of a predetermined concentration be available for cleaning or drying treatment.
According to the invention, there is provided a treatment apparatus comprising: a treatment section storing a cleaning liquid, for cleaning a surface of an object to be treated immersed into the cleaning liquid; a pure water supply pipe; a supply pipe connecting the treatment section and the pure water supply source; a chemical liquid container storing a chemical liquid; a chemical liquid supply pipe connecting the supply pipe to the chemical liquid container via open/close switching means; and chemical liquid feed means provided in the chemical liquid supply pipe, the chemical liquid feed means being a positive displacement pump.
By using the positive displacement pump, an accurate quantity of the chemical liquid can be infused into pure water independently from changes in flow amount or pressure of the pure water flowing through the supply pipe to ensure that the chemical liquid of a predetermined concentration can be supplied to the treatment section. Therefore, the cleaning efficiency is improved, and the production yield can be improved.
The positive displacement pump may be a reciprocally driven pump, and a circulating conduit may be connected between a portion of the chemical liquid supply pipe near a chemical liquid outlet of the chemical liquid supply means and the chemical liquid container. An open/close means and a filter may be interposed in the circulating conduit.
In this manner, the chemical liquid, currently out of use, can be always circulated and filtered to smoothly supply the chemical liquid and to stabilize the supplied quantity of the chemical liquid.
According to the invention, there is further provided a treatment apparatus comprising: a treatment section for drying an object to be treated by supplying a drying gas into contact therewith; a supply source of a drying gas carrier gas; a supply pipe connecting the treatment section and the supply source of a drying gas carrier gas; a chemical liquid container storing a chemical liquid; a drying gas generator provided in the supply pipe; a chemical liquid supply pipe connecting the drying gas generator and the chemical liquid container; and chemical liquid feed means provided in the chemical liquid feed pipe, the chemical liquid feed means being a positive displacement pump.
In this manner, an accurate quantity of the chemical liquid can be infused (mixed) into the carrier gas independently from changes in flow rate or pressure of the carrier gas supplied to the drying gas generator to ensure that the chemical liquid of a predetermined concentration can be supplied to the treatment portion. Therefore, the drying efficiency is improved, and the production yield can be improved.
A filter may be provided in the chemical liquid supply pipe in a location near a chemical liquid outlet of the chemical liquid supply means.
In this manner, the chemical liquid can be filtered just before infusion to remove particles or other impurities from the chemical liquid.
The positive displacement pump may be a reciprocally driven pump in the form of an air-pressurized diaphragm pump having one diaphragm or a plurality of interlinked diaphragms, and the treatment apparatus may further comprise air pressure adjusting means and channel open/close switching means interposed in an air supply pipe connecting a driving portion of the diaphragm pump to a driving air supply source. The channel open/ close switching means is controllable in switching speed.
In this manner, an accurate quantity of the chemical liquid can be infused reliably into the pure water or to the drying gas generator to facilitate adjustment of the concentration of the chemical liquid.
The reciprocally driven pump may be one electrically driven bellows pump or a plurality of electrically driven bellows pumps communicating with each other. In this case a ball screw may be used as means for driving the bellows pump.
In this manner, an accurate quantity of the chemical liquid can be infused reliably into the pure water or to the drying gas generator, and the chemical liquid can be infused continuously by elongating the strokes of the bellows pumps.
The reciprocally driven pump may be a plurality of electrically driven bellows pumps communicating with each other and driven in different phases from each other.
In this manner, the chemical liquid can be infused continuously by diving one of the bellows pumps for the suction stroke and the other for the discharge stroke.
Pressure detecting means may be provided near an outlet of the reciprocally driven pump to issue a detection signal used to control a driving portion of the reciprocally driven pump so as to regulate the quantity of the chemical liquid to be discharged.
In this manner, the infus
Kamikawa Yuji
Kitahara Shigenori
Shindo Naoki
Coe Philip R.
Morrison & Foerster / LLP
Tokyo Electron Limited
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