JPH06104239A - Method and apparatus for drying substrate - Google Patents

Abstract

PURPOSE:To dry a highly cleaned substrate effectively without being exposed to an organic-substance atmosphere and without generating static electricity. CONSTITUTION:A washed wafer 1 on a carrier 2 is transferred into a drying chamber 3. The atmosphere inside the drying chamber 3 is replaced by an inert gas such as nitrogen gas, argon gas or the like, the wafer 1 is irradiated with infrared rays come from an infrared lamp 5 in the atmosphere of the inert gas. Moisture on the surface of the wafer 1 is heated and evaporated. The wafer 1, after washed with water, is not exposed to an organic-substance atmosphere and does not require any mechanical motion. As a result, static electricity is not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for cleaning and drying a substrate such as a wafer in a semiconductor integrated circuit manufacturing process.

[0002]

2. Description of the Related Art As is well known, in the manufacture of semiconductor integrated circuits, a substrate such as a wafer is washed with various chemicals as a pretreatment and a posttreatment for each step, and further the substrate is washed with pure water or an aqueous solution. After the organic substances are completely removed from the surface of the substrate, the substrate is completely dried. Conventionally, for drying the substrate after washing with water,
An IPA vapor drying method of evaporating water in an IPA (isopropyl alcohol) vapor atmosphere, or a spin dry method of removing water by centrifugal force by rotating a carrier having a substrate mounted thereon at high speed has been used.

[0003]

However, in the conventional IPA vapor drying method, since a highly clean substrate surface from which organic substances are completely removed by cleaning is exposed again to the organic substance atmosphere,
There is a problem that the cleanliness at the atomic level is easily impaired. Further, the conventional spin dry method has a problem that static electricity is easily generated by mechanical rotation, and an element formed on the substrate is broken or foreign matter is adsorbed to the cleaned substrate.

Therefore, the present invention provides a substrate drying method and apparatus capable of effectively drying a substrate highly cleaned by washing without exposing it to an organic atmosphere and without generating static electricity. With the goal.

[0005]

In order to achieve the above object, the present invention provides a method of drying a substrate after washing with water or an aqueous solution, in which the substrate is irradiated with infrared rays in an inert gas atmosphere. Is. Note that nitrogen gas or argon gas may be used as the inert gas. Further, it is preferable that the inert gas atmosphere is depressurized.

Further, the substrate drying apparatus according to the present invention comprises a drying chamber for containing the substrate after being washed with water or an aqueous solution, an intake / exhaust means for replacing the atmosphere in the drying chamber with an inert gas, Infrared radiation means for irradiating the substrate in the drying chamber with infrared radiation. Note that nitrogen gas or argon gas may be used as the inert gas. Further, it is preferable to provide a decompression adjusting unit for decompressing the inert gas atmosphere on the exhaust side of the intake and exhaust means.

[0007]

According to the present invention configured as described above, the moisture removal energy is applied by infrared radiation which is not in contact with the substrate under an inert gas atmosphere, not by IPA vapor or mechanical means. The infrared rays heat and evaporate the moisture on the substrate surface. Therefore, the substrate highly cleaned by cleaning is not exposed to the atmosphere of organic substances and does not require mechanical movement so that static electricity is not generated.
Furthermore, when the inert gas atmosphere is depressurized, the partial pressure of water vapor is reduced and the driving force for evaporation of water is increased, so that the drying speed can be increased.

[0008]

Embodiments of the present invention will be described below with reference to FIGS.

First, as shown in FIG. 1, a silicon wafer 1 which is a substrate is mounted on a wafer carrier 2 and is washed in a water washing tank (not shown) as a pretreatment. The wafer 1 after the water cleaning is housed in the drying chamber 3. The atmosphere in the drying chamber 3 is replaced with an inert gas such as nitrogen gas or argon gas through the intake nozzle 4a and the exhaust nozzle 4b. Furthermore, the drying chamber 3
An infrared lamp 5 for irradiating the wafer 1 with infrared rays is installed therein. In addition, 6 is an operation switch.

In the above structure, the wafer 1 after being washed with water, which is mounted on the carrier 2, is transferred into the drying chamber 3. Then, when the operation switch 6 is pressed, the infrared lamp 5
As a result, infrared rays are generated and irradiated on the wafer 1. As a result, the water on the surface of the wafer 1 is heated and evaporated.

As described above, in this embodiment, by using infrared rays in an atmosphere of an inert gas such as nitrogen gas or argon gas, the wafer 1 after water cleaning is not exposed to an organic matter atmosphere and is free from static electricity. It is effectively dried without any generation. Therefore, the surface of the wafer 1 is maintained in a highly clean state immediately after cleaning, and no element destruction or foreign matter adsorption is observed on the surface of the dried wafer 1.

Next, FIG. 2 shows another embodiment. In addition to the structure of FIG. 1, a valve 7 is provided on the exhaust side from the exhaust nozzle 4b, one of which is connected to a vacuum pump 8. Has been done. In this embodiment, at the same time that the infrared lamp 5 emits infrared rays, the valve 7 switches the exhaust side to the depressurizing side by suction of the vacuum pump 8. As a result, the inert gas atmosphere in the drying chamber 3 is in a reduced pressure state, the partial pressure of water vapor is reduced, and the driving force for moisture evaporation is increased. Therefore, the drying speed is increased as compared with the case of FIG. Can be shortened.

Next, FIG. 3 shows still another embodiment. In addition to the configuration of FIG. 1, a valve 7 is provided on the exhaust side from the exhaust nozzle 4b, one of which is an orifice 9
It is connected to the. A high-speed nitrogen stream is supplied into this orifice 9. In this embodiment, the infrared lamp 5
As a result, infrared rays are generated, and at the same time, the valve 7 switches the exhaust side to the depressurized side generated by the high-speed nitrogen gas flow in the orifice 9. As a result, the inert gas atmosphere in the drying chamber 3 is in a reduced pressure state.
In addition to being able to shorten the drying time compared to
Since the decompressed state is obtained by the high-speed nitrogen gas flow in the orifice 9, it is possible to reduce the mixture of pollutants from the exhaust system as compared with the case of FIG.

The embodiments of the present invention have been described above.
The present invention is not limited to the above embodiments, and various effective modifications and applications are possible based on the technical idea of the present invention.

[0015]

As described above, according to the present invention,
By using infrared rays in an inert gas atmosphere, the substrate highly cleaned by cleaning is dried without being exposed to an organic atmosphere and without generating static electricity. Therefore, the cleanliness at the atomic level is not impaired by the organic atmosphere, and the static electricity does not damage the elements on the substrate or adsorb foreign matter to the substrate. Can be effectively dried. Further, the device can be manufactured at extremely low cost.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an apparatus according to another embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of an apparatus according to still another embodiment of the present invention.

[Explanation of symbols]

 1 Silicon Wafer 2 Wafer Carrier 3 Drying Chamber 4a Intake Nozzle 4b Exhaust Nozzle 5 Infrared Lamp 6 Operation Switch 7 Valve 8 Vacuum Pump 9 Orifice

Claims (6)

[Claims] 1. A method of drying a substrate after washing with water or an aqueous solution, wherein the substrate is irradiated with infrared rays under an inert gas atmosphere. 2. The method for drying a substrate according to claim 1, wherein nitrogen gas or argon gas is used as the inert gas. 3. The method for drying a substrate according to claim 1, wherein the inert gas atmosphere is depressurized. 4. A drying chamber for accommodating a substrate after cleaning with water or an aqueous solution, an intake / exhaust means for replacing an atmosphere in the drying chamber with an inert gas, and an infrared ray irradiating the substrate in the drying chamber. And an infrared radiation means for controlling the substrate. 5. The substrate drying apparatus according to claim 4, wherein nitrogen gas or argon gas is used as the inert gas. 6. The apparatus for drying a substrate according to claim 4, wherein a pressure reduction adjusting unit for reducing the pressure of the inert gas atmosphere is provided on the exhaust side of the intake / exhaust unit.